/* Low level interface to ptrace, for the remote server for GDB.
- Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1995-1996, 1998-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "server.h"
#include "linux-low.h"
+#include "linux-osdata.h"
+#include "agent.h"
#include <sys/wait.h>
#include <stdio.h>
#include <sys/param.h>
#include <sys/ptrace.h>
+#include "linux-ptrace.h"
+#include "linux-procfs.h"
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <pwd.h>
#include <sys/types.h>
#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <sys/uio.h>
+#ifndef ELFMAG0
+/* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
+ then ELFMAG0 will have been defined. If it didn't get included by
+ gdb_proc_service.h then including it will likely introduce a duplicate
+ definition of elf_fpregset_t. */
+#include <elf.h>
+#endif
+
+#ifndef SPUFS_MAGIC
+#define SPUFS_MAGIC 0x23c9b64e
+#endif
-#ifndef PTRACE_GETSIGINFO
-# define PTRACE_GETSIGINFO 0x4202
-# define PTRACE_SETSIGINFO 0x4203
+#ifdef HAVE_PERSONALITY
+# include <sys/personality.h>
+# if !HAVE_DECL_ADDR_NO_RANDOMIZE
+# define ADDR_NO_RANDOMIZE 0x0040000
+# endif
#endif
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
#endif
-/* If the system headers did not provide the constants, hard-code the normal
- values. */
-#ifndef PTRACE_EVENT_FORK
-
-#define PTRACE_SETOPTIONS 0x4200
-#define PTRACE_GETEVENTMSG 0x4201
-
-/* options set using PTRACE_SETOPTIONS */
-#define PTRACE_O_TRACESYSGOOD 0x00000001
-#define PTRACE_O_TRACEFORK 0x00000002
-#define PTRACE_O_TRACEVFORK 0x00000004
-#define PTRACE_O_TRACECLONE 0x00000008
-#define PTRACE_O_TRACEEXEC 0x00000010
-#define PTRACE_O_TRACEVFORKDONE 0x00000020
-#define PTRACE_O_TRACEEXIT 0x00000040
-
-/* Wait extended result codes for the above trace options. */
-#define PTRACE_EVENT_FORK 1
-#define PTRACE_EVENT_VFORK 2
-#define PTRACE_EVENT_CLONE 3
-#define PTRACE_EVENT_EXEC 4
-#define PTRACE_EVENT_VFORK_DONE 5
-#define PTRACE_EVENT_EXIT 6
-
-#endif /* PTRACE_EVENT_FORK */
-
-/* We can't always assume that this flag is available, but all systems
- with the ptrace event handlers also have __WALL, so it's safe to use
- in some contexts. */
-#ifndef __WALL
-#define __WALL 0x40000000 /* Wait for any child. */
+#ifndef W_STOPCODE
+#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
+#endif
+
+/* This is the kernel's hard limit. Not to be confused with
+ SIGRTMIN. */
+#ifndef __SIGRTMIN
+#define __SIGRTMIN 32
#endif
#ifdef __UCLIBC__
representation of the thread ID.
``all_lwps'' is keyed by the process ID - which on Linux is (presently)
- the same as the LWP ID. */
+ the same as the LWP ID.
+
+ ``all_processes'' is keyed by the "overall process ID", which
+ GNU/Linux calls tgid, "thread group ID". */
struct inferior_list all_lwps;
-/* A list of all unknown processes which receive stop signals. Some other
- process will presumably claim each of these as forked children
- momentarily. */
+/* A list of all unknown processes which receive stop signals. Some
+ other process will presumably claim each of these as forked
+ children momentarily. */
+
+struct simple_pid_list
+{
+ /* The process ID. */
+ int pid;
+
+ /* The status as reported by waitpid. */
+ int status;
+
+ /* Next in chain. */
+ struct simple_pid_list *next;
+};
+struct simple_pid_list *stopped_pids;
+
+/* Trivial list manipulation functions to keep track of a list of new
+ stopped processes. */
+
+static void
+add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
+{
+ struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
+
+ new_pid->pid = pid;
+ new_pid->status = status;
+ new_pid->next = *listp;
+ *listp = new_pid;
+}
+
+static int
+pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
+{
+ struct simple_pid_list **p;
+
+ for (p = listp; *p != NULL; p = &(*p)->next)
+ if ((*p)->pid == pid)
+ {
+ struct simple_pid_list *next = (*p)->next;
-struct inferior_list stopped_pids;
+ *statusp = (*p)->status;
+ xfree (*p);
+ *p = next;
+ return 1;
+ }
+ return 0;
+}
/* FIXME this is a bit of a hack, and could be removed. */
int stopping_threads;
/* FIXME make into a target method? */
int using_threads = 1;
-static int thread_db_active;
-static int must_set_ptrace_flags;
-
-/* This flag is true iff we've just created or attached to a new inferior
- but it has not stopped yet. As soon as it does, we need to call the
- low target's arch_setup callback. */
+/* True if we're presently stabilizing threads (moving them out of
+ jump pads). */
+static int stabilizing_threads;
+
+/* This flag is true iff we've just created or attached to our first
+ inferior but it has not stopped yet. As soon as it does, we need
+ to call the low target's arch_setup callback. Doing this only on
+ the first inferior avoids reinializing the architecture on every
+ inferior, and avoids messing with the register caches of the
+ already running inferiors. NOTE: this assumes all inferiors under
+ control of gdbserver have the same architecture. */
static int new_inferior;
-static void linux_resume_one_lwp (struct inferior_list_entry *entry,
+static void linux_resume_one_lwp (struct lwp_info *lwp,
int step, int signal, siginfo_t *info);
static void linux_resume (struct thread_resume *resume_info, size_t n);
-static void stop_all_lwps (void);
-static int linux_wait_for_event (int pid, int *wstat, int options);
-static int check_removed_breakpoint (struct lwp_info *event_child);
-static void *add_lwp (unsigned long pid);
-static int my_waitpid (int pid, int *status, int flags);
+static void stop_all_lwps (int suspend, struct lwp_info *except);
+static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
+static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
+static void *add_lwp (ptid_t ptid);
static int linux_stopped_by_watchpoint (void);
+static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
+static void proceed_all_lwps (void);
+static int finish_step_over (struct lwp_info *lwp);
+static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
+static int kill_lwp (unsigned long lwpid, int signo);
+static void linux_enable_event_reporting (int pid);
+
+/* True if the low target can hardware single-step. Such targets
+ don't need a BREAKPOINT_REINSERT_ADDR callback. */
+
+static int
+can_hardware_single_step (void)
+{
+ return (the_low_target.breakpoint_reinsert_addr == NULL);
+}
+
+/* True if the low target supports memory breakpoints. If so, we'll
+ have a GET_PC implementation. */
+
+static int
+supports_breakpoints (void)
+{
+ return (the_low_target.get_pc != NULL);
+}
+
+/* Returns true if this target can support fast tracepoints. This
+ does not mean that the in-process agent has been loaded in the
+ inferior. */
+
+static int
+supports_fast_tracepoints (void)
+{
+ return the_low_target.install_fast_tracepoint_jump_pad != NULL;
+}
struct pending_signals
{
struct pending_signals *prev;
};
-#define PTRACE_ARG3_TYPE long
+#define PTRACE_ARG3_TYPE void *
+#define PTRACE_ARG4_TYPE void *
#define PTRACE_XFER_TYPE long
#ifdef HAVE_LINUX_REGSETS
static int num_regsets;
#endif
-/* FIXME: Delete eventually. */
-#define inferior_pid (lwpid_of (get_thread_lwp (current_inferior)))
-
/* The read/write ends of the pipe registered as waitable file in the
event loop. */
static int linux_event_pipe[2] = { -1, -1 };
/* True if we're currently in async mode. */
#define target_is_async_p() (linux_event_pipe[0] != -1)
-static void send_sigstop (struct inferior_list_entry *entry);
+static void send_sigstop (struct lwp_info *lwp);
static void wait_for_sigstop (struct inferior_list_entry *entry);
+/* Return non-zero if HEADER is a 64-bit ELF file. */
+
+static int
+elf_64_header_p (const Elf64_Ehdr *header)
+{
+ return (header->e_ident[EI_MAG0] == ELFMAG0
+ && header->e_ident[EI_MAG1] == ELFMAG1
+ && header->e_ident[EI_MAG2] == ELFMAG2
+ && header->e_ident[EI_MAG3] == ELFMAG3
+ && header->e_ident[EI_CLASS] == ELFCLASS64);
+}
+
+/* Return non-zero if FILE is a 64-bit ELF file,
+ zero if the file is not a 64-bit ELF file,
+ and -1 if the file is not accessible or doesn't exist. */
+
+static int
+elf_64_file_p (const char *file)
+{
+ Elf64_Ehdr header;
+ int fd;
+
+ fd = open (file, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ if (read (fd, &header, sizeof (header)) != sizeof (header))
+ {
+ close (fd);
+ return 0;
+ }
+ close (fd);
+
+ return elf_64_header_p (&header);
+}
+
+/* Accepts an integer PID; Returns true if the executable PID is
+ running is a 64-bit ELF file.. */
+
+int
+linux_pid_exe_is_elf_64_file (int pid)
+{
+ char file[MAXPATHLEN];
+
+ sprintf (file, "/proc/%d/exe", pid);
+ return elf_64_file_p (file);
+}
+
static void
delete_lwp (struct lwp_info *lwp)
{
remove_thread (get_lwp_thread (lwp));
remove_inferior (&all_lwps, &lwp->head);
+ free (lwp->arch_private);
free (lwp);
}
+/* Add a process to the common process list, and set its private
+ data. */
+
+static struct process_info *
+linux_add_process (int pid, int attached)
+{
+ struct process_info *proc;
+
+ /* Is this the first process? If so, then set the arch. */
+ if (all_processes.head == NULL)
+ new_inferior = 1;
+
+ proc = add_process (pid, attached);
+ proc->private = xcalloc (1, sizeof (*proc->private));
+
+ if (the_low_target.new_process != NULL)
+ proc->private->arch_private = the_low_target.new_process ();
+
+ return proc;
+}
+
+/* Wrapper function for waitpid which handles EINTR, and emulates
+ __WALL for systems where that is not available. */
+
+static int
+my_waitpid (int pid, int *status, int flags)
+{
+ int ret, out_errno;
+
+ if (debug_threads)
+ fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
+
+ if (flags & __WALL)
+ {
+ sigset_t block_mask, org_mask, wake_mask;
+ int wnohang;
+
+ wnohang = (flags & WNOHANG) != 0;
+ flags &= ~(__WALL | __WCLONE);
+ flags |= WNOHANG;
+
+ /* Block all signals while here. This avoids knowing about
+ LinuxThread's signals. */
+ sigfillset (&block_mask);
+ sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
+
+ /* ... except during the sigsuspend below. */
+ sigemptyset (&wake_mask);
+
+ while (1)
+ {
+ /* Since all signals are blocked, there's no need to check
+ for EINTR here. */
+ ret = waitpid (pid, status, flags);
+ out_errno = errno;
+
+ if (ret == -1 && out_errno != ECHILD)
+ break;
+ else if (ret > 0)
+ break;
+
+ if (flags & __WCLONE)
+ {
+ /* We've tried both flavors now. If WNOHANG is set,
+ there's nothing else to do, just bail out. */
+ if (wnohang)
+ break;
+
+ if (debug_threads)
+ fprintf (stderr, "blocking\n");
+
+ /* Block waiting for signals. */
+ sigsuspend (&wake_mask);
+ }
+
+ flags ^= __WCLONE;
+ }
+
+ sigprocmask (SIG_SETMASK, &org_mask, NULL);
+ }
+ else
+ {
+ do
+ ret = waitpid (pid, status, flags);
+ while (ret == -1 && errno == EINTR);
+ out_errno = errno;
+ }
+
+ if (debug_threads)
+ fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
+ pid, flags, status ? *status : -1, ret);
+
+ errno = out_errno;
+ return ret;
+}
+
/* Handle a GNU/Linux extended wait response. If we see a clone
event, we need to add the new LWP to our list (and not report the
trap to higher layers). */
if (event == PTRACE_EVENT_CLONE)
{
+ ptid_t ptid;
unsigned long new_pid;
- int ret, status = W_STOPCODE (SIGSTOP);
+ int ret, status;
ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
/* If we haven't already seen the new PID stop, wait for it now. */
- if (! pull_pid_from_list (&stopped_pids, new_pid))
+ if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
{
/* The new child has a pending SIGSTOP. We can't affect it until it
hits the SIGSTOP, but we're already attached. */
warning ("wait returned unexpected status 0x%x", status);
}
- ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
+ linux_enable_event_reporting (new_pid);
+
+ ptid = ptid_build (pid_of (event_child), new_pid, 0);
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, new_lwp);
- new_lwp = (struct lwp_info *) add_lwp (new_pid);
- add_thread (new_pid, new_lwp, new_pid);
- new_thread_notify (thread_id_to_gdb_id (lwpid_of (new_lwp)));
+ /* Either we're going to immediately resume the new thread
+ or leave it stopped. linux_resume_one_lwp is a nop if it
+ thinks the thread is currently running, so set this first
+ before calling linux_resume_one_lwp. */
+ new_lwp->stopped = 1;
/* Normally we will get the pending SIGSTOP. But in some cases
we might get another signal delivered to the group first.
if (WSTOPSIG (status) == SIGSTOP)
{
if (stopping_threads)
- new_lwp->stopped = 1;
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
else
- ptrace (PTRACE_CONT, new_pid, 0, 0);
+ linux_resume_one_lwp (new_lwp, 0, 0, NULL);
}
else
{
new_lwp->stop_expected = 1;
+
if (stopping_threads)
{
- new_lwp->stopped = 1;
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
else
/* Pass the signal on. This is what GDB does - except
shouldn't we really report it instead? */
- ptrace (PTRACE_CONT, new_pid, 0, WSTOPSIG (status));
+ linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
}
/* Always resume the current thread. If we are stopping
threads, it will have a pending SIGSTOP; we may as well
collect it now. */
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping, 0, NULL);
+ linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
}
}
-/* This function should only be called if the process got a SIGTRAP.
+/* Return the PC as read from the regcache of LWP, without any
+ adjustment. */
+
+static CORE_ADDR
+get_pc (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ struct regcache *regcache;
+ CORE_ADDR pc;
+
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
+
+ if (debug_threads)
+ fprintf (stderr, "pc is 0x%lx\n", (long) pc);
+
+ current_inferior = saved_inferior;
+ return pc;
+}
+
+/* This function should only be called if LWP got a SIGTRAP.
The SIGTRAP could mean several things.
On i386, where decr_pc_after_break is non-zero:
instruction. */
static CORE_ADDR
-get_stop_pc (void)
+get_stop_pc (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
+ CORE_ADDR stop_pc;
- if (get_thread_lwp (current_inferior)->stepping)
- return stop_pc;
- else
- return stop_pc - the_low_target.decr_pc_after_break;
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ stop_pc = get_pc (lwp);
+
+ if (WSTOPSIG (lwp->last_status) == SIGTRAP
+ && !lwp->stepping
+ && !lwp->stopped_by_watchpoint
+ && lwp->last_status >> 16 == 0)
+ stop_pc -= the_low_target.decr_pc_after_break;
+
+ if (debug_threads)
+ fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
+
+ return stop_pc;
}
static void *
-add_lwp (unsigned long pid)
+add_lwp (ptid_t ptid)
{
struct lwp_info *lwp;
lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
memset (lwp, 0, sizeof (*lwp));
- lwp->head.id = pid;
+ lwp->head.id = ptid;
+
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread ();
add_inferior_to_list (&all_lwps, &lwp->head);
static int
linux_create_inferior (char *program, char **allargs)
{
- void *new_lwp;
+#ifdef HAVE_PERSONALITY
+ int personality_orig = 0, personality_set = 0;
+#endif
+ struct lwp_info *new_lwp;
int pid;
+ ptid_t ptid;
+
+#ifdef HAVE_PERSONALITY
+ if (disable_randomization)
+ {
+ errno = 0;
+ personality_orig = personality (0xffffffff);
+ if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+ {
+ personality_set = 1;
+ personality (personality_orig | ADDR_NO_RANDOMIZE);
+ }
+ if (errno != 0 || (personality_set
+ && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
+ warning ("Error disabling address space randomization: %s",
+ strerror (errno));
+ }
+#endif
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
pid = vfork ();
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
+#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN + 1, SIG_DFL);
+#endif
setpgid (0, 0);
+ /* If gdbserver is connected to gdb via stdio, redirect the inferior's
+ stdout to stderr so that inferior i/o doesn't corrupt the connection.
+ Also, redirect stdin to /dev/null. */
+ if (remote_connection_is_stdio ())
+ {
+ close (0);
+ open ("/dev/null", O_RDONLY);
+ dup2 (2, 1);
+ if (write (2, "stdin/stdout redirected\n",
+ sizeof ("stdin/stdout redirected\n") - 1) < 0)
+ /* Errors ignored. */;
+ }
+
execv (program, allargs);
if (errno == ENOENT)
execvp (program, allargs);
_exit (0177);
}
- new_lwp = add_lwp (pid);
- add_thread (pid, new_lwp, pid);
- must_set_ptrace_flags = 1;
- new_inferior = 1;
+#ifdef HAVE_PERSONALITY
+ if (personality_set)
+ {
+ errno = 0;
+ personality (personality_orig);
+ if (errno != 0)
+ warning ("Error restoring address space randomization: %s",
+ strerror (errno));
+ }
+#endif
+
+ linux_add_process (pid, 0);
+
+ ptid = ptid_build (pid, pid, 0);
+ new_lwp = add_lwp (ptid);
+ add_thread (ptid, new_lwp);
+ new_lwp->must_set_ptrace_flags = 1;
return pid;
}
/* Attach to an inferior process. */
-void
-linux_attach_lwp (unsigned long pid)
+static void
+linux_attach_lwp_1 (unsigned long lwpid, int initial)
{
+ ptid_t ptid;
struct lwp_info *new_lwp;
- if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
+ if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
{
- if (all_threads.head != NULL)
+ if (!initial)
{
/* If we fail to attach to an LWP, just warn. */
- fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", pid,
+ fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
strerror (errno), errno);
fflush (stderr);
return;
}
- else
- /* If we fail to attach to a process, report an error. */
- error ("Cannot attach to lwp %ld: %s (%d)\n", pid,
- strerror (errno), errno);
+
+ /* If we fail to attach to a process, report an error. */
+ error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
+ strerror (errno), errno);
+ }
+
+ if (initial)
+ /* If lwp is the tgid, we handle adding existing threads later.
+ Otherwise we just add lwp without bothering about any other
+ threads. */
+ ptid = ptid_build (lwpid, lwpid, 0);
+ else
+ {
+ /* Note that extracting the pid from the current inferior is
+ safe, since we're always called in the context of the same
+ process as this new thread. */
+ int pid = pid_of (get_thread_lwp (current_inferior));
+ ptid = ptid_build (pid, lwpid, 0);
}
- /* FIXME: This intermittently fails.
- We need to wait for SIGSTOP first. */
- ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, new_lwp);
- new_lwp = (struct lwp_info *) add_lwp (pid);
- add_thread (pid, new_lwp, pid);
- new_thread_notify (thread_id_to_gdb_id (lwpid_of (new_lwp)));
+ /* We need to wait for SIGSTOP before being able to make the next
+ ptrace call on this LWP. */
+ new_lwp->must_set_ptrace_flags = 1;
+
+ if (linux_proc_pid_is_stopped (lwpid))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Attached to a stopped process\n");
+
+ /* The process is definitely stopped. It is in a job control
+ stop, unless the kernel predates the TASK_STOPPED /
+ TASK_TRACED distinction, in which case it might be in a
+ ptrace stop. Make sure it is in a ptrace stop; from there we
+ can kill it, signal it, et cetera.
+
+ First make sure there is a pending SIGSTOP. Since we are
+ already attached, the process can not transition from stopped
+ to running without a PTRACE_CONT; so we know this signal will
+ go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
+ probably already in the queue (unless this kernel is old
+ enough to use TASK_STOPPED for ptrace stops); but since
+ SIGSTOP is not an RT signal, it can only be queued once. */
+ kill_lwp (lwpid, SIGSTOP);
+
+ /* Finally, resume the stopped process. This will deliver the
+ SIGSTOP (or a higher priority signal, just like normal
+ PTRACE_ATTACH), which we'll catch later on. */
+ ptrace (PTRACE_CONT, lwpid, 0, 0);
+ }
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
brings it to a halt.
1) gdbserver has already attached to the process and is being notified
of a new thread that is being created.
- In this case we should ignore that SIGSTOP and resume the process.
- This is handled below by setting stop_expected = 1.
+ In this case we should ignore that SIGSTOP and resume the
+ process. This is handled below by setting stop_expected = 1,
+ and the fact that add_thread sets last_resume_kind ==
+ resume_continue.
2) This is the first thread (the process thread), and we're attaching
to it via attach_inferior.
In this case we want the process thread to stop.
- This is handled by having linux_attach clear stop_expected after
- we return.
- ??? If the process already has several threads we leave the other
- threads running.
+ This is handled by having linux_attach set last_resume_kind ==
+ resume_stop after we return.
+
+ If the pid we are attaching to is also the tgid, we attach to and
+ stop all the existing threads. Otherwise, we attach to pid and
+ ignore any other threads in the same group as this pid.
3) GDB is connecting to gdbserver and is requesting an enumeration of all
existing threads.
because we are guaranteed that the add_lwp call above added us to the
end of the list, and so the new thread has not yet reached
wait_for_sigstop (but will). */
- if (! stopping_threads)
- new_lwp->stop_expected = 1;
+ new_lwp->stop_expected = 1;
+}
+
+void
+linux_attach_lwp (unsigned long lwpid)
+{
+ linux_attach_lwp_1 (lwpid, 0);
}
+/* Attach to PID. If PID is the tgid, attach to it and all
+ of its threads. */
+
int
linux_attach (unsigned long pid)
{
- struct lwp_info *lwp;
-
- linux_attach_lwp (pid);
+ /* Attach to PID. We will check for other threads
+ soon. */
+ linux_attach_lwp_1 (pid, 1);
+ linux_add_process (pid, 1);
if (!non_stop)
{
- /* Don't ignore the initial SIGSTOP if we just attached to this
- process. It will be collected by wait shortly. */
- lwp = (struct lwp_info *) find_inferior_id (&all_lwps, pid);
- lwp->stop_expected = 0;
+ struct thread_info *thread;
+
+ /* Don't ignore the initial SIGSTOP if we just attached to this
+ process. It will be collected by wait shortly. */
+ thread = find_thread_ptid (ptid_build (pid, pid, 0));
+ thread->last_resume_kind = resume_stop;
}
- new_inferior = 1;
+ if (linux_proc_get_tgid (pid) == pid)
+ {
+ DIR *dir;
+ char pathname[128];
+
+ sprintf (pathname, "/proc/%ld/task", pid);
+
+ dir = opendir (pathname);
+
+ if (!dir)
+ {
+ fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
+ fflush (stderr);
+ }
+ else
+ {
+ /* At this point we attached to the tgid. Scan the task for
+ existing threads. */
+ unsigned long lwp;
+ int new_threads_found;
+ int iterations = 0;
+ struct dirent *dp;
+
+ while (iterations < 2)
+ {
+ new_threads_found = 0;
+ /* Add all the other threads. While we go through the
+ threads, new threads may be spawned. Cycle through
+ the list of threads until we have done two iterations without
+ finding new threads. */
+ while ((dp = readdir (dir)) != NULL)
+ {
+ /* Fetch one lwp. */
+ lwp = strtoul (dp->d_name, NULL, 10);
+
+ /* Is this a new thread? */
+ if (lwp
+ && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL)
+ {
+ linux_attach_lwp_1 (lwp, 0);
+ new_threads_found++;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Found and attached to new lwp %ld\n", lwp);
+ }
+ }
+
+ if (!new_threads_found)
+ iterations++;
+ else
+ iterations = 0;
+
+ rewinddir (dir);
+ }
+ closedir (dir);
+ }
+ }
return 0;
}
-/* Kill the inferior process. Make us have no inferior. */
-
-static void
-linux_kill_one_lwp (struct inferior_list_entry *entry)
+struct counter
{
- struct thread_info *thread = (struct thread_info *) entry;
- struct lwp_info *lwp = get_thread_lwp (thread);
int pid;
- int wstat;
+ int count;
+};
- /* We avoid killing the first thread here, because of a Linux kernel (at
- least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
- the children get a chance to be reaped, it will remain a zombie
- forever. */
- if (entry == all_threads.head)
- return;
+static int
+second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
+{
+ struct counter *counter = args;
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (&lwp->head);
+ if (ptid_get_pid (entry->id) == counter->pid)
+ {
+ if (++counter->count > 1)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+last_thread_of_process_p (struct thread_info *thread)
+{
+ ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
+ int pid = ptid_get_pid (ptid);
+ struct counter counter = { pid , 0 };
+
+ return (find_inferior (&all_threads,
+ second_thread_of_pid_p, &counter) == NULL);
+}
+
+/* Kill LWP. */
+
+static void
+linux_kill_one_lwp (struct lwp_info *lwp)
+{
+ int pid = lwpid_of (lwp);
+
+ /* PTRACE_KILL is unreliable. After stepping into a signal handler,
+ there is no signal context, and ptrace(PTRACE_KILL) (or
+ ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
+ ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
+ alternative is to kill with SIGKILL. We only need one SIGKILL
+ per process, not one for each thread. But since we still support
+ linuxthreads, and we also support debugging programs using raw
+ clone without CLONE_THREAD, we send one for each thread. For
+ years, we used PTRACE_KILL only, so we're being a bit paranoid
+ about some old kernels where PTRACE_KILL might work better
+ (dubious if there are any such, but that's why it's paranoia), so
+ we try SIGKILL first, PTRACE_KILL second, and so we're fine
+ everywhere. */
+
+ errno = 0;
+ kill (pid, SIGKILL);
+ if (debug_threads)
+ fprintf (stderr,
+ "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n",
+ target_pid_to_str (ptid_of (lwp)),
+ errno ? strerror (errno) : "OK");
+
+ errno = 0;
+ ptrace (PTRACE_KILL, pid, 0, 0);
+ if (debug_threads)
+ fprintf (stderr,
+ "LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
+ target_pid_to_str (ptid_of (lwp)),
+ errno ? strerror (errno) : "OK");
+}
+
+/* Callback for `find_inferior'. Kills an lwp of a given process,
+ except the leader. */
+
+static int
+kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
+{
+ struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thread);
+ int wstat;
+ int pid = * (int *) args;
+
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
+
+ /* We avoid killing the first thread here, because of a Linux kernel (at
+ least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
+ the children get a chance to be reaped, it will remain a zombie
+ forever. */
+
+ if (lwpid_of (lwp) == pid)
+ {
+ if (debug_threads)
+ fprintf (stderr, "lkop: is last of process %s\n",
+ target_pid_to_str (entry->id));
+ return 0;
+ }
do
{
- ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
+ linux_kill_one_lwp (lwp);
/* Make sure it died. The loop is most likely unnecessary. */
- pid = linux_wait_for_event (lwpid_of (lwp), &wstat, __WALL);
+ pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
} while (pid > 0 && WIFSTOPPED (wstat));
+
+ return 0;
}
-static void
-linux_kill (void)
+static int
+linux_kill (int pid)
{
- struct thread_info *thread = (struct thread_info *) all_threads.head;
+ struct process_info *process;
struct lwp_info *lwp;
int wstat;
- int pid;
+ int lwpid;
- if (thread == NULL)
- return;
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
+
+ /* If we're killing a running inferior, make sure it is stopped
+ first, as PTRACE_KILL will not work otherwise. */
+ stop_all_lwps (0, NULL);
- for_each_inferior (&all_threads, linux_kill_one_lwp);
+ find_inferior (&all_threads, kill_one_lwp_callback , &pid);
/* See the comment in linux_kill_one_lwp. We did not kill the first
thread in the list, so do so now. */
- lwp = get_thread_lwp (thread);
+ lwp = find_lwp_pid (pid_to_ptid (pid));
- if (debug_threads)
- fprintf (stderr, "lk_1: killing lwp %ld\n", lwpid_of (lwp));
+ if (lwp == NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n",
+ lwpid_of (lwp), pid);
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
+ lwpid_of (lwp), pid);
- /* If we're killing a running inferior, make sure it is stopped
- first, as PTRACE_KILL will not work otherwise. */
- if (!lwp->stopped)
- send_sigstop (&lwp->head);
+ do
+ {
+ linux_kill_one_lwp (lwp);
- do
- {
- ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
+ /* Make sure it died. The loop is most likely unnecessary. */
+ lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ } while (lwpid > 0 && WIFSTOPPED (wstat));
+ }
- /* Make sure it died. The loop is most likely unnecessary. */
- pid = linux_wait_for_event (lwpid_of (lwp), &wstat, __WALL);
- } while (pid > 0 && WIFSTOPPED (wstat));
+ the_target->mourn (process);
- delete_lwp (lwp);
- clear_inferiors ();
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (0, NULL);
+ return 0;
}
-static void
-linux_detach_one_lwp (struct inferior_list_entry *entry)
+/* Get pending signal of THREAD, for detaching purposes. This is the
+ signal the thread last stopped for, which we need to deliver to the
+ thread when detaching, otherwise, it'd be suppressed/lost. */
+
+static int
+get_detach_signal (struct thread_info *thread)
{
- struct thread_info *thread = (struct thread_info *) entry;
- struct lwp_info *lwp = get_thread_lwp (thread);
+ enum target_signal signo = TARGET_SIGNAL_0;
+ int status;
+ struct lwp_info *lp = get_thread_lwp (thread);
- /* If we're detaching from a running inferior, make sure it is
- stopped first, as PTRACE_DETACH will not work otherwise. */
- if (!lwp->stopped)
+ if (lp->status_pending_p)
+ status = lp->status_pending;
+ else
+ {
+ /* If the thread had been suspended by gdbserver, and it stopped
+ cleanly, then it'll have stopped with SIGSTOP. But we don't
+ want to deliver that SIGSTOP. */
+ if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
+ || thread->last_status.value.sig == TARGET_SIGNAL_0)
+ return 0;
+
+ /* Otherwise, we may need to deliver the signal we
+ intercepted. */
+ status = lp->last_status;
+ }
+
+ if (!WIFSTOPPED (status))
{
- int pid = lwpid_of (lwp);
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s hasn't stopped: no pending signal\n",
+ target_pid_to_str (ptid_of (lp)));
+ return 0;
+ }
- stopping_threads = 1;
- send_sigstop (&lwp->head);
+ /* Extended wait statuses aren't real SIGTRAPs. */
+ if (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had stopped with extended "
+ "status: no pending signal\n",
+ target_pid_to_str (ptid_of (lp)));
+ return 0;
+ }
- /* If this detects a new thread through a clone event, the new
- thread is appended to the end of the lwp list, so we'll
- eventually detach from it. */
- wait_for_sigstop (&lwp->head);
- stopping_threads = 0;
+ signo = target_signal_from_host (WSTOPSIG (status));
- /* If LWP exits while we're trying to stop it, there's nothing
- left to do. */
- lwp = (struct lwp_info *) find_inferior_id (&all_lwps, pid);
- if (lwp == NULL)
- return;
+ if (program_signals_p && !program_signals[signo])
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had signal %s, but it is in nopass state\n",
+ target_pid_to_str (ptid_of (lp)),
+ target_signal_to_string (signo));
+ return 0;
+ }
+ else if (!program_signals_p
+ /* If we have no way to know which signals GDB does not
+ want to have passed to the program, assume
+ SIGTRAP/SIGINT, which is GDB's default. */
+ && (signo == TARGET_SIGNAL_TRAP || signo == TARGET_SIGNAL_INT))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s had signal %s, "
+ "but we don't know if we should pass it. Default to not.\n",
+ target_pid_to_str (ptid_of (lp)),
+ target_signal_to_string (signo));
+ return 0;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "GPS: lwp %s has pending signal %s: delivering it.\n",
+ target_pid_to_str (ptid_of (lp)),
+ target_signal_to_string (signo));
+
+ return WSTOPSIG (status);
}
+}
+
+static int
+linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
+{
+ struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thread);
+ int pid = * (int *) args;
+ int sig;
- /* Make sure the process isn't stopped at a breakpoint that's
- no longer there. */
- check_removed_breakpoint (lwp);
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
- /* If this process is stopped but is expecting a SIGSTOP, then make
- sure we take care of that now. This isn't absolutely guaranteed
- to collect the SIGSTOP, but is fairly likely to. */
+ /* If there is a pending SIGSTOP, get rid of it. */
if (lwp->stop_expected)
{
- int wstat;
- /* Clear stop_expected, so that the SIGSTOP will be reported. */
+ if (debug_threads)
+ fprintf (stderr,
+ "Sending SIGCONT to %s\n",
+ target_pid_to_str (ptid_of (lwp)));
+
+ kill_lwp (lwpid_of (lwp), SIGCONT);
lwp->stop_expected = 0;
- if (lwp->stopped)
- linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
- linux_wait_for_event (lwpid_of (lwp), &wstat, __WALL);
}
/* Flush any pending changes to the process's registers. */
regcache_invalidate_one ((struct inferior_list_entry *)
get_lwp_thread (lwp));
+ /* Pass on any pending signal for this thread. */
+ sig = get_detach_signal (thread);
+
/* Finally, let it resume. */
- ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+ if (ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, sig) < 0)
+ error (_("Can't detach %s: %s"),
+ target_pid_to_str (ptid_of (lwp)),
+ strerror (errno));
delete_lwp (lwp);
+ return 0;
+}
+
+static int
+linux_detach (int pid)
+{
+ struct process_info *process;
+
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
+
+ /* Stop all threads before detaching. First, ptrace requires that
+ the thread is stopped to sucessfully detach. Second, thread_db
+ may need to uninstall thread event breakpoints from memory, which
+ only works with a stopped process anyway. */
+ stop_all_lwps (0, NULL);
+
+#ifdef USE_THREAD_DB
+ thread_db_detach (process);
+#endif
+
+ /* Stabilize threads (move out of jump pads). */
+ stabilize_threads ();
+
+ find_inferior (&all_threads, linux_detach_one_lwp, &pid);
+
+ the_target->mourn (process);
+
+ /* Since we presently can only stop all lwps of all processes, we
+ need to unstop lwps of other processes. */
+ unstop_all_lwps (0, NULL);
+ return 0;
}
+/* Remove all LWPs that belong to process PROC from the lwp list. */
+
static int
-linux_detach (void)
+delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
{
- delete_all_breakpoints ();
- for_each_inferior (&all_threads, linux_detach_one_lwp);
- clear_inferiors ();
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct process_info *process = proc;
+
+ if (pid_of (lwp) == pid_of (process))
+ delete_lwp (lwp);
+
return 0;
}
static void
-linux_join (void)
+linux_mourn (struct process_info *process)
{
- int status, ret;
- struct thread_info *thread;
- struct lwp_info *lwp;
+ struct process_info_private *priv;
- thread = (struct thread_info *) all_threads.head;
- lwp = get_thread_lwp (thread);
+#ifdef USE_THREAD_DB
+ thread_db_mourn (process);
+#endif
+
+ find_inferior (&all_lwps, delete_lwp_callback, process);
+
+ /* Freeing all private data. */
+ priv = process->private;
+ free (priv->arch_private);
+ free (priv);
+ process->private = NULL;
+
+ remove_process (process);
+}
+
+static void
+linux_join (int pid)
+{
+ int status, ret;
do {
- ret = my_waitpid (lwpid_of (lwp), &status, 0);
+ ret = my_waitpid (pid, &status, 0);
if (WIFEXITED (status) || WIFSIGNALED (status))
break;
} while (ret != -1 || errno != ECHILD);
/* Return nonzero if the given thread is still alive. */
static int
-linux_thread_alive (unsigned long lwpid)
+linux_thread_alive (ptid_t ptid)
{
- if (find_inferior_id (&all_threads, lwpid) != NULL)
- return 1;
+ struct lwp_info *lwp = find_lwp_pid (ptid);
+
+ /* We assume we always know if a thread exits. If a whole process
+ exited but we still haven't been able to report it to GDB, we'll
+ hold on to the last lwp of the dead process. */
+ if (lwp != NULL)
+ return !lwp->dead;
else
return 0;
}
-/* Return nonzero if this process stopped at a breakpoint which
- no longer appears to be inserted. Also adjust the PC
- appropriately to resume where the breakpoint used to be. */
+/* Return 1 if this lwp has an interesting status pending. */
static int
-check_removed_breakpoint (struct lwp_info *event_child)
+status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
{
- CORE_ADDR stop_pc;
- struct thread_info *saved_inferior;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ ptid_t ptid = * (ptid_t *) arg;
+ struct thread_info *thread;
- if (event_child->pending_is_breakpoint == 0)
+ /* Check if we're only interested in events from a specific process
+ or its lwps. */
+ if (!ptid_equal (minus_one_ptid, ptid)
+ && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
return 0;
- if (debug_threads)
- fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
- lwpid_of (event_child));
-
- saved_inferior = current_inferior;
- current_inferior = get_lwp_thread (event_child);
-
- stop_pc = get_stop_pc ();
-
- /* If the PC has changed since we stopped, then we shouldn't do
- anything. This happens if, for instance, GDB handled the
- decr_pc_after_break subtraction itself. */
- if (stop_pc != event_child->pending_stop_pc)
- {
- if (debug_threads)
- fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
- event_child->pending_stop_pc);
+ thread = get_lwp_thread (lwp);
- event_child->pending_is_breakpoint = 0;
- current_inferior = saved_inferior;
- return 0;
- }
+ /* If we got a `vCont;t', but we haven't reported a stop yet, do
+ report any status pending the LWP may have. */
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
+ return 0;
- /* If the breakpoint is still there, we will report hitting it. */
- if ((*the_low_target.breakpoint_at) (stop_pc))
- {
- if (debug_threads)
- fprintf (stderr, "Ignoring, breakpoint is still present.\n");
- current_inferior = saved_inferior;
- return 0;
- }
+ return lwp->status_pending_p;
+}
- if (debug_threads)
- fprintf (stderr, "Removed breakpoint.\n");
+static int
+same_lwp (struct inferior_list_entry *entry, void *data)
+{
+ ptid_t ptid = *(ptid_t *) data;
+ int lwp;
- /* For decr_pc_after_break targets, here is where we perform the
- decrement. We go immediately from this function to resuming,
- and can not safely call get_stop_pc () again. */
- if (the_low_target.set_pc != NULL)
- (*the_low_target.set_pc) (stop_pc);
+ if (ptid_get_lwp (ptid) != 0)
+ lwp = ptid_get_lwp (ptid);
+ else
+ lwp = ptid_get_pid (ptid);
- /* We consumed the pending SIGTRAP. */
- event_child->pending_is_breakpoint = 0;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
+ if (ptid_get_lwp (entry->id) == lwp)
+ return 1;
- current_inferior = saved_inferior;
- return 1;
+ return 0;
}
-/* Return 1 if this lwp has an interesting status pending. This
- function may silently resume an inferior lwp. */
-static int
-status_pending_p (struct inferior_list_entry *entry, void *dummy)
+struct lwp_info *
+find_lwp_pid (ptid_t ptid)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
-
- if (lwp->status_pending_p && !lwp->suspended)
- if (check_removed_breakpoint (lwp))
- {
- /* This thread was stopped at a breakpoint, and the breakpoint
- is now gone. We were told to continue (or step...) all threads,
- so GDB isn't trying to single-step past this breakpoint.
- So instead of reporting the old SIGTRAP, pretend we got to
- the breakpoint just after it was removed instead of just
- before; resume the process. */
- linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
- return 0;
- }
-
- return (lwp->status_pending_p && !lwp->suspended);
+ return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
}
static struct lwp_info *
-linux_wait_for_lwp (int pid, int *wstatp, int options)
+linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
{
int ret;
- int to_wait_for = pid;
+ int to_wait_for = -1;
struct lwp_info *child = NULL;
if (debug_threads)
- fprintf (stderr, "linux_wait_for_lwp: %d\n", pid);
+ fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
+
+ if (ptid_equal (ptid, minus_one_ptid))
+ to_wait_for = -1; /* any child */
+ else
+ to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
options |= __WALL;
&& WSTOPSIG (*wstatp) != 33)))
fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
- child = (struct lwp_info *) find_inferior_id (&all_lwps, ret);
+ child = find_lwp_pid (pid_to_ptid (ret));
/* If we didn't find a process, one of two things presumably happened:
- A process we started and then detached from has exited. Ignore it.
was reported to us by the kernel. Save its PID. */
if (child == NULL && WIFSTOPPED (*wstatp))
{
- add_pid_to_list (&stopped_pids, ret);
+ add_to_pid_list (&stopped_pids, ret, *wstatp);
goto retry;
}
else if (child == NULL)
goto retry;
child->stopped = 1;
- child->pending_is_breakpoint = 0;
child->last_status = *wstatp;
new_inferior = 0;
}
+ /* Fetch the possibly triggered data watchpoint info and store it in
+ CHILD.
+
+ On some archs, like x86, that use debug registers to set
+ watchpoints, it's possible that the way to know which watched
+ address trapped, is to check the register that is used to select
+ which address to watch. Problem is, between setting the
+ watchpoint and reading back which data address trapped, the user
+ may change the set of watchpoints, and, as a consequence, GDB
+ changes the debug registers in the inferior. To avoid reading
+ back a stale stopped-data-address when that happens, we cache in
+ LP the fact that a watchpoint trapped, and the corresponding data
+ address, as soon as we see CHILD stop with a SIGTRAP. If GDB
+ changes the debug registers meanwhile, we have the cached data we
+ can rely on. */
+
+ if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
+ {
+ if (the_low_target.stopped_by_watchpoint == NULL)
+ {
+ child->stopped_by_watchpoint = 0;
+ }
+ else
+ {
+ struct thread_info *saved_inferior;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (child);
+
+ child->stopped_by_watchpoint
+ = the_low_target.stopped_by_watchpoint ();
+
+ if (child->stopped_by_watchpoint)
+ {
+ if (the_low_target.stopped_data_address != NULL)
+ child->stopped_data_address
+ = the_low_target.stopped_data_address ();
+ else
+ child->stopped_data_address = 0;
+ }
+
+ current_inferior = saved_inferior;
+ }
+ }
+
+ /* Store the STOP_PC, with adjustment applied. This depends on the
+ architecture being defined already (so that CHILD has a valid
+ regcache), and on LAST_STATUS being set (to check for SIGTRAP or
+ not). */
+ if (WIFSTOPPED (*wstatp))
+ child->stop_pc = get_stop_pc (child);
+
if (debug_threads
- && WIFSTOPPED (*wstatp))
+ && WIFSTOPPED (*wstatp)
+ && the_low_target.get_pc != NULL)
{
struct thread_info *saved_inferior = current_inferior;
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, lwpid_of (child));
- /* For testing only; i386_stop_pc prints out a diagnostic. */
- if (the_low_target.get_pc != NULL)
- get_stop_pc ();
+ struct regcache *regcache;
+ CORE_ADDR pc;
+
+ current_inferior = get_lwp_thread (child);
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
+ fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
current_inferior = saved_inferior;
}
return child;
}
-/* Wait for an event from child PID. If PID is -1, wait for any
- child. Store the stop status through the status pointer WSTAT.
- OPTIONS is passed to the waitpid call. Return 0 if no child stop
- event was found and OPTIONS contains WNOHANG. Return the PID of
- the stopped child otherwise. */
+/* This function should only be called if the LWP got a SIGTRAP.
+
+ Handle any tracepoint steps or hits. Return true if a tracepoint
+ event was handled, 0 otherwise. */
static int
-linux_wait_for_event (int pid, int *wstat, int options)
+handle_tracepoints (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc;
- struct lwp_info *event_child = NULL;
- int bp_status;
- struct lwp_info *requested_child = NULL;
+ struct thread_info *tinfo = get_lwp_thread (lwp);
+ int tpoint_related_event = 0;
- /* Check for a process with a pending status. */
- /* It is possible that the user changed the pending task's registers since
- it stopped. We correctly handle the change of PC if we hit a breakpoint
- (in check_removed_breakpoint); signals should be reported anyway. */
+ /* If this tracepoint hit causes a tracing stop, we'll immediately
+ uninsert tracepoints. To do this, we temporarily pause all
+ threads, unpatch away, and then unpause threads. We need to make
+ sure the unpausing doesn't resume LWP too. */
+ lwp->suspended++;
- if (pid == -1)
- {
- event_child = (struct lwp_info *)
- find_inferior (&all_lwps, status_pending_p, NULL);
- if (debug_threads && event_child)
- fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
- }
- else
- {
- requested_child = (struct lwp_info *)
- find_inferior_id (&all_lwps, pid);
- if (requested_child->status_pending_p
- && !check_removed_breakpoint (requested_child))
- event_child = requested_child;
- }
+ /* And we need to be sure that any all-threads-stopping doesn't try
+ to move threads out of the jump pads, as it could deadlock the
+ inferior (LWP could be in the jump pad, maybe even holding the
+ lock.) */
- if (event_child != NULL)
+ /* Do any necessary step collect actions. */
+ tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
+
+ tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
+
+ /* See if we just hit a tracepoint and do its main collect
+ actions. */
+ tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
+
+ lwp->suspended--;
+
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
+
+ if (tpoint_related_event)
{
if (debug_threads)
- fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
- lwpid_of (event_child), event_child->status_pending);
- *wstat = event_child->status_pending;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
- current_inferior = get_lwp_thread (event_child);
- return lwpid_of (event_child);
+ fprintf (stderr, "got a tracepoint event\n");
+ return 1;
}
- /* We only enter this loop if no process has a pending wait status. Thus
- any action taken in response to a wait status inside this loop is
- responding as soon as we detect the status, not after any pending
- events. */
- while (1)
- {
- event_child = linux_wait_for_lwp (pid, wstat, options);
+ return 0;
+}
- if ((options & WNOHANG) && event_child == NULL)
- return 0;
+/* Convenience wrapper. Returns true if LWP is presently collecting a
+ fast tracepoint. */
- if (event_child == NULL)
- error ("event from unknown child");
+static int
+linux_fast_tracepoint_collecting (struct lwp_info *lwp,
+ struct fast_tpoint_collect_status *status)
+{
+ CORE_ADDR thread_area;
- current_inferior = get_lwp_thread (event_child);
+ if (the_low_target.get_thread_area == NULL)
+ return 0;
- /* Check for thread exit. */
- if (! WIFSTOPPED (*wstat))
- {
- int lwpid = lwpid_of (event_child);
- if (debug_threads)
- fprintf (stderr, "LWP %d exiting\n", lwpid);
+ /* Get the thread area address. This is used to recognize which
+ thread is which when tracing with the in-process agent library.
+ We don't read anything from the address, and treat it as opaque;
+ it's the address itself that we assume is unique per-thread. */
+ if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
+ return 0;
- /* If the last thread is exiting, just return. */
- if (all_threads.head == all_threads.tail)
+ return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
+}
+
+/* The reason we resume in the caller, is because we want to be able
+ to pass lwp->status_pending as WSTAT, and we need to clear
+ status_pending_p before resuming, otherwise, linux_resume_one_lwp
+ refuses to resume. */
+
+static int
+maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
+{
+ struct thread_info *saved_inferior;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ if ((wstat == NULL
+ || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
+ && supports_fast_tracepoints ()
+ && agent_loaded_p ())
+ {
+ struct fast_tpoint_collect_status status;
+ int r;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad.\n",
+ lwpid_of (lwp));
+
+ r = linux_fast_tracepoint_collecting (lwp, &status);
+
+ if (wstat == NULL
+ || (WSTOPSIG (*wstat) != SIGILL
+ && WSTOPSIG (*wstat) != SIGFPE
+ && WSTOPSIG (*wstat) != SIGSEGV
+ && WSTOPSIG (*wstat) != SIGBUS))
+ {
+ lwp->collecting_fast_tracepoint = r;
+
+ if (r != 0)
{
+ if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
+ {
+ /* Haven't executed the original instruction yet.
+ Set breakpoint there, and wait till it's hit,
+ then single-step until exiting the jump pad. */
+ lwp->exit_jump_pad_bkpt
+ = set_breakpoint_at (status.adjusted_insn_addr, NULL);
+ }
+
if (debug_threads)
- fprintf (stderr, "LWP %d is last lwp of process\n", lwpid);
- return lwpid_of (event_child);
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad...it does\n",
+ lwpid_of (lwp));
+ current_inferior = saved_inferior;
+
+ return 1;
}
+ }
+ else
+ {
+ /* If we get a synchronous signal while collecting, *and*
+ while executing the (relocated) original instruction,
+ reset the PC to point at the tpoint address, before
+ reporting to GDB. Otherwise, it's an IPA lib bug: just
+ report the signal to GDB, and pray for the best. */
- dead_thread_notify (thread_id_to_gdb_id (lwpid_of (event_child)));
- delete_lwp (event_child);
+ lwp->collecting_fast_tracepoint = 0;
- if (!non_stop)
+ if (r != 0
+ && (status.adjusted_insn_addr <= lwp->stop_pc
+ && lwp->stop_pc < status.adjusted_insn_addr_end))
{
- current_inferior = (struct thread_info *) all_threads.head;
- if (debug_threads)
- fprintf (stderr, "Current inferior is now %ld\n",
- lwpid_of (get_thread_lwp (current_inferior)));
+ siginfo_t info;
+ struct regcache *regcache;
+
+ /* The si_addr on a few signals references the address
+ of the faulting instruction. Adjust that as
+ well. */
+ if ((WSTOPSIG (*wstat) == SIGILL
+ || WSTOPSIG (*wstat) == SIGFPE
+ || WSTOPSIG (*wstat) == SIGBUS
+ || WSTOPSIG (*wstat) == SIGSEGV)
+ && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
+ /* Final check just to make sure we don't clobber
+ the siginfo of non-kernel-sent signals. */
+ && (uintptr_t) info.si_addr == lwp->stop_pc)
+ {
+ info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
+ }
+
+ regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
+ (*the_low_target.set_pc) (regcache, status.tpoint_addr);
+ lwp->stop_pc = status.tpoint_addr;
+
+ /* Cancel any fast tracepoint lock this thread was
+ holding. */
+ force_unlock_trace_buffer ();
}
- else
+
+ if (lwp->exit_jump_pad_bkpt != NULL)
{
- current_inferior = NULL;
if (debug_threads)
- fprintf (stderr, "Current inferior is now <NULL>\n");
- }
+ fprintf (stderr,
+ "Cancelling fast exit-jump-pad: removing bkpt. "
+ "stopping all threads momentarily.\n");
- /* If we were waiting for this particular child to do something...
- well, it did something. */
- if (requested_child != NULL)
- return lwpid;
+ stop_all_lwps (1, lwp);
+ cancel_breakpoints ();
- /* Wait for a more interesting event. */
- continue;
- }
+ delete_breakpoint (lwp->exit_jump_pad_bkpt);
+ lwp->exit_jump_pad_bkpt = NULL;
- if (WIFSTOPPED (*wstat)
- && WSTOPSIG (*wstat) == SIGSTOP
- && event_child->stop_expected)
- {
- if (debug_threads)
- fprintf (stderr, "Expected stop.\n");
- event_child->stop_expected = 0;
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping, 0, NULL);
- continue;
+ unstop_all_lwps (1, lwp);
+
+ gdb_assert (lwp->suspended >= 0);
+ }
}
+ }
- if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
- && *wstat >> 16 != 0)
+ if (debug_threads)
+ fprintf (stderr, "\
+Checking whether LWP %ld needs to move out of the jump pad...no\n",
+ lwpid_of (lwp));
+
+ current_inferior = saved_inferior;
+ return 0;
+}
+
+/* Enqueue one signal in the "signals to report later when out of the
+ jump pad" list. */
+
+static void
+enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
+{
+ struct pending_signals *p_sig;
+
+ if (debug_threads)
+ fprintf (stderr, "\
+Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
+
+ if (debug_threads)
+ {
+ struct pending_signals *sig;
+
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
+ fprintf (stderr,
+ " Already queued %d\n",
+ sig->signal);
+
+ fprintf (stderr, " (no more currently queued signals)\n");
+ }
+
+ /* Don't enqueue non-RT signals if they are already in the deferred
+ queue. (SIGSTOP being the easiest signal to see ending up here
+ twice) */
+ if (WSTOPSIG (*wstat) < __SIGRTMIN)
+ {
+ struct pending_signals *sig;
+
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
{
- handle_extended_wait (event_child, *wstat);
- continue;
+ if (sig->signal == WSTOPSIG (*wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Not requeuing already queued non-RT signal %d"
+ " for LWP %ld\n",
+ sig->signal,
+ lwpid_of (lwp));
+ return;
+ }
}
+ }
- /* If GDB is not interested in this signal, don't stop other
- threads, and don't report it to GDB. Just resume the
- inferior right away. We do this for threading-related
- signals as well as any that GDB specifically requested we
- ignore. But never ignore SIGSTOP if we sent it ourselves,
- and do not ignore signals when stepping - they may require
- special handling to skip the signal handler. */
- /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
- thread library? */
- if (WIFSTOPPED (*wstat)
- && !event_child->stepping
- && (
-#ifdef USE_THREAD_DB
- (thread_db_active
- && (WSTOPSIG (*wstat) == __SIGRTMIN
- || WSTOPSIG (*wstat) == __SIGRTMIN + 1))
- ||
-#endif
- (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
- && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads))))
- {
- siginfo_t info, *info_p;
+ p_sig = xmalloc (sizeof (*p_sig));
+ p_sig->prev = lwp->pending_signals_to_report;
+ p_sig->signal = WSTOPSIG (*wstat);
+ memset (&p_sig->info, 0, sizeof (siginfo_t));
+ ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
- if (debug_threads)
- fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
- WSTOPSIG (*wstat), lwpid_of (event_child));
+ lwp->pending_signals_to_report = p_sig;
+}
- if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
- info_p = &info;
- else
- info_p = NULL;
- linux_resume_one_lwp (&event_child->head,
- event_child->stepping,
- WSTOPSIG (*wstat), info_p);
- continue;
- }
+/* Dequeue one signal from the "signals to report later when out of
+ the jump pad" list. */
+
+static int
+dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
+{
+ if (lwp->pending_signals_to_report != NULL)
+ {
+ struct pending_signals **p_sig;
- /* If this event was not handled above, and is not a SIGTRAP, report
- it. */
- if (!WIFSTOPPED (*wstat) || WSTOPSIG (*wstat) != SIGTRAP)
- return lwpid_of (event_child);
+ p_sig = &lwp->pending_signals_to_report;
+ while ((*p_sig)->prev != NULL)
+ p_sig = &(*p_sig)->prev;
- /* If this target does not support breakpoints, we simply report the
- SIGTRAP; it's of no concern to us. */
- if (the_low_target.get_pc == NULL)
- return lwpid_of (event_child);
+ *wstat = W_STOPCODE ((*p_sig)->signal);
+ if ((*p_sig)->info.si_signo != 0)
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
+ free (*p_sig);
+ *p_sig = NULL;
- stop_pc = get_stop_pc ();
+ if (debug_threads)
+ fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
+ WSTOPSIG (*wstat), lwpid_of (lwp));
- /* bp_reinsert will only be set if we were single-stepping.
- Notice that we will resume the process after hitting
- a gdbserver breakpoint; single-stepping to/over one
- is not supported (yet). */
- if (event_child->bp_reinsert != 0)
+ if (debug_threads)
{
- if (debug_threads)
- fprintf (stderr, "Reinserted breakpoint.\n");
- reinsert_breakpoint (event_child->bp_reinsert);
- event_child->bp_reinsert = 0;
+ struct pending_signals *sig;
- /* Clear the single-stepping flag and SIGTRAP as we resume. */
- linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
- continue;
+ for (sig = lwp->pending_signals_to_report;
+ sig != NULL;
+ sig = sig->prev)
+ fprintf (stderr,
+ " Still queued %d\n",
+ sig->signal);
+
+ fprintf (stderr, " (no more queued signals)\n");
}
- bp_status = check_breakpoints (stop_pc);
+ return 1;
+ }
- if (bp_status != 0)
- {
- if (debug_threads)
- fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ return 0;
+}
- /* We hit one of our own breakpoints. We mark it as a pending
- breakpoint, so that check_removed_breakpoint () will do the PC
- adjustment for us at the appropriate time. */
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
-
- /* We may need to put the breakpoint back. We continue in the event
- loop instead of simply replacing the breakpoint right away,
- in order to not lose signals sent to the thread that hit the
- breakpoint. Unfortunately this increases the window where another
- thread could sneak past the removed breakpoint. For the current
- use of server-side breakpoints (thread creation) this is
- acceptable; but it needs to be considered before this breakpoint
- mechanism can be used in more general ways. For some breakpoints
- it may be necessary to stop all other threads, but that should
- be avoided where possible.
-
- If breakpoint_reinsert_addr is NULL, that means that we can
- use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
- mark it for reinsertion, and single-step.
-
- Otherwise, call the target function to figure out where we need
- our temporary breakpoint, create it, and continue executing this
- process. */
+/* Arrange for a breakpoint to be hit again later. We don't keep the
+ SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
+ will handle the current event, eventually we will resume this LWP,
+ and this breakpoint will trap again. */
- /* NOTE: we're lifting breakpoints in non-stop mode. This
- is currently only used for thread event breakpoints, so
- it isn't that bad as long as we have PTRACE_EVENT_CLONE
- events. */
- if (bp_status == 2)
- /* No need to reinsert. */
- linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
- else if (the_low_target.breakpoint_reinsert_addr == NULL)
- {
- event_child->bp_reinsert = stop_pc;
- uninsert_breakpoint (stop_pc);
- linux_resume_one_lwp (&event_child->head, 1, 0, NULL);
- }
- else
- {
- reinsert_breakpoint_by_bp
- (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
- linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
- }
+static int
+cancel_breakpoint (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
- continue;
- }
+ /* There's nothing to do if we don't support breakpoints. */
+ if (!supports_breakpoints ())
+ return 0;
- if (debug_threads)
- fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
+ /* breakpoint_at reads from current inferior. */
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
- /* If we were single-stepping, we definitely want to report the
- SIGTRAP. Although the single-step operation has completed,
- do not clear clear the stepping flag yet; we need to check it
- in wait_for_sigstop. */
- if (event_child->stepping)
- return lwpid_of (event_child);
+ if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: Push back breakpoint for %s\n",
+ target_pid_to_str (ptid_of (lwp)));
- /* A SIGTRAP that we can't explain. It may have been a breakpoint.
- Check if it is a breakpoint, and if so mark the process information
- accordingly. This will handle both the necessary fiddling with the
- PC on decr_pc_after_break targets and suppressing extra threads
- hitting a breakpoint if two hit it at once and then GDB removes it
- after the first is reported. Arguably it would be better to report
- multiple threads hitting breakpoints simultaneously, but the current
- remote protocol does not allow this. */
- if ((*the_low_target.breakpoint_at) (stop_pc))
+ /* Back up the PC if necessary. */
+ if (the_low_target.decr_pc_after_break)
{
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
+ struct regcache *regcache
+ = get_thread_regcache (current_inferior, 1);
+ (*the_low_target.set_pc) (regcache, lwp->stop_pc);
}
- return lwpid_of (event_child);
+ current_inferior = saved_inferior;
+ return 1;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: No breakpoint found at %s for [%s]\n",
+ paddress (lwp->stop_pc),
+ target_pid_to_str (ptid_of (lwp)));
}
- /* NOTREACHED */
+ current_inferior = saved_inferior;
return 0;
}
-/* Wait for process, returns status. */
+/* When the event-loop is doing a step-over, this points at the thread
+ being stepped. */
+ptid_t step_over_bkpt;
+
+/* Wait for an event from child PID. If PID is -1, wait for any
+ child. Store the stop status through the status pointer WSTAT.
+ OPTIONS is passed to the waitpid call. Return 0 if no child stop
+ event was found and OPTIONS contains WNOHANG. Return the PID of
+ the stopped child otherwise. */
-static unsigned long
-linux_wait_1 (struct target_waitstatus *ourstatus, int target_options)
+static int
+linux_wait_for_event (ptid_t ptid, int *wstat, int options)
{
- int w;
- struct thread_info *thread = NULL;
- struct lwp_info *lwp = NULL;
- int options;
- int wait_pid = -1;
- int pid;
+ struct lwp_info *event_child, *requested_child;
+ ptid_t wait_ptid;
- /* Translate generic target options into linux options. */
- options = __WALL;
- if (target_options & TARGET_WNOHANG)
- options |= WNOHANG;
+ event_child = NULL;
+ requested_child = NULL;
-retry:
- ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ /* Check for a lwp with a pending status. */
- /* If we were only supposed to resume one thread, only wait for
- that thread - if it's still alive. If it died, however - which
- can happen if we're coming from the thread death case below -
- then we need to make sure we restart the other threads. We could
- pick a thread at random or restart all; restarting all is less
- arbitrary. */
- if (!non_stop && cont_thread != 0 && cont_thread != -1)
+ if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
{
- thread = (struct thread_info *) find_inferior_id (&all_threads,
- cont_thread);
+ event_child = (struct lwp_info *)
+ find_inferior (&all_lwps, status_pending_p_callback, &ptid);
+ if (debug_threads && event_child)
+ fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
+ }
+ else
+ {
+ requested_child = find_lwp_pid (ptid);
- /* No stepping, no signal - unless one is pending already, of course. */
- if (thread == NULL)
+ if (!stopping_threads
+ && requested_child->status_pending_p
+ && requested_child->collecting_fast_tracepoint)
{
- struct thread_resume resume_info;
- resume_info.thread = -1;
- resume_info.kind = resume_continue;
- resume_info.sig = 0;
- linux_resume (&resume_info, 1);
+ enqueue_one_deferred_signal (requested_child,
+ &requested_child->status_pending);
+ requested_child->status_pending_p = 0;
+ requested_child->status_pending = 0;
+ linux_resume_one_lwp (requested_child, 0, 0, NULL);
}
- else
- wait_pid = cont_thread;
- }
- pid = linux_wait_for_event (wait_pid, &w, options);
- if (pid == 0) /* only if TARGET_WNOHANG */
- return pid;
+ if (requested_child->suspended
+ && requested_child->status_pending_p)
+ fatal ("requesting an event out of a suspended child?");
- lwp = get_thread_lwp (current_inferior);
+ if (requested_child->status_pending_p)
+ event_child = requested_child;
+ }
- if (must_set_ptrace_flags)
+ if (event_child != NULL)
{
- ptrace (PTRACE_SETOPTIONS, lwpid_of (lwp), 0, PTRACE_O_TRACECLONE);
- must_set_ptrace_flags = 0;
+ if (debug_threads)
+ fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
+ lwpid_of (event_child), event_child->status_pending);
+ *wstat = event_child->status_pending;
+ event_child->status_pending_p = 0;
+ event_child->status_pending = 0;
+ current_inferior = get_lwp_thread (event_child);
+ return lwpid_of (event_child);
}
- /* If we are waiting for a particular child, and it exited,
- linux_wait_for_event will return its exit status. Similarly if
- the last child exited. If this is not the last child, however,
- do not report it as exited until there is a 'thread exited' response
- available in the remote protocol. Instead, just wait for another event.
- This should be safe, because if the thread crashed we will already
- have reported the termination signal to GDB; that should stop any
- in-progress stepping operations, etc.
- Report the exit status of the last thread to exit. This matches
- LinuxThreads' behavior. */
+ if (ptid_is_pid (ptid))
+ {
+ /* A request to wait for a specific tgid. This is not possible
+ with waitpid, so instead, we wait for any child, and leave
+ children we're not interested in right now with a pending
+ status to report later. */
+ wait_ptid = minus_one_ptid;
+ }
+ else
+ wait_ptid = ptid;
- if (all_threads.head == all_threads.tail)
+ /* We only enter this loop if no process has a pending wait status. Thus
+ any action taken in response to a wait status inside this loop is
+ responding as soon as we detect the status, not after any pending
+ events. */
+ while (1)
{
- if (WIFEXITED (w) || WIFSIGNALED (w))
+ event_child = linux_wait_for_lwp (wait_ptid, wstat, options);
+
+ if ((options & WNOHANG) && event_child == NULL)
{
- int pid;
+ if (debug_threads)
+ fprintf (stderr, "WNOHANG set, no event found\n");
+ return 0;
+ }
+
+ if (event_child == NULL)
+ error ("event from unknown child");
- pid = pid_of (lwp);
+ if (ptid_is_pid (ptid)
+ && ptid_get_pid (ptid) != ptid_get_pid (ptid_of (event_child)))
+ {
+ if (! WIFSTOPPED (*wstat))
+ mark_lwp_dead (event_child, *wstat);
+ else
+ {
+ event_child->status_pending_p = 1;
+ event_child->status_pending = *wstat;
+ }
+ continue;
+ }
- delete_lwp (lwp);
- clear_inferiors ();
+ current_inferior = get_lwp_thread (event_child);
- current_inferior = NULL;
+ /* Check for thread exit. */
+ if (! WIFSTOPPED (*wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
- if (WIFEXITED (w))
+ /* If the last thread is exiting, just return. */
+ if (last_thread_of_process_p (current_inferior))
{
- ourstatus->kind = TARGET_WAITKIND_EXITED;
- ourstatus->value.integer = WEXITSTATUS (w);
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld is last lwp of process\n",
+ lwpid_of (event_child));
+ return lwpid_of (event_child);
+ }
+ if (!non_stop)
+ {
+ current_inferior = (struct thread_info *) all_threads.head;
if (debug_threads)
- fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
+ fprintf (stderr, "Current inferior is now %ld\n",
+ lwpid_of (get_thread_lwp (current_inferior)));
}
else
{
- ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
- ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
-
+ current_inferior = NULL;
if (debug_threads)
- fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+ fprintf (stderr, "Current inferior is now <NULL>\n");
+ }
+ /* If we were waiting for this particular child to do something...
+ well, it did something. */
+ if (requested_child != NULL)
+ {
+ int lwpid = lwpid_of (event_child);
+
+ /* Cancel the step-over operation --- the thread that
+ started it is gone. */
+ if (finish_step_over (event_child))
+ unstop_all_lwps (1, event_child);
+ delete_lwp (event_child);
+ return lwpid;
}
- return pid;
- }
- }
- else
- {
- if (!WIFSTOPPED (w))
- goto retry;
- }
+ delete_lwp (event_child);
- /* In all-stop, stop all threads. Be careful to only do this if
- we're about to report an event to GDB. */
- if (!non_stop)
- stop_all_lwps ();
+ /* Wait for a more interesting event. */
+ continue;
+ }
- ourstatus->kind = TARGET_WAITKIND_STOPPED;
+ if (event_child->must_set_ptrace_flags)
+ {
+ linux_enable_event_reporting (lwpid_of (event_child));
+ event_child->must_set_ptrace_flags = 0;
+ }
- if (lwp->suspended && WSTOPSIG (w) == SIGSTOP)
- {
- /* A thread that has been requested to stop by GDB with vCont;t,
- and it stopped cleanly, so report as SIG0. The use of
- SIGSTOP is an implementation detail. */
- ourstatus->value.sig = TARGET_SIGNAL_0;
- }
- else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP)
- {
- /* A thread that has been requested to stop by GDB with vCont;t,
- but, it stopped for other reasons. Set stop_expected so the
- pending SIGSTOP is ignored and the LWP is resumed. */
- lwp->stop_expected = 1;
- ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
- }
- else
- {
- ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
- }
+ if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
+ && *wstat >> 16 != 0)
+ {
+ handle_extended_wait (event_child, *wstat);
+ continue;
+ }
- if (debug_threads)
- fprintf (stderr, "linux_wait ret = %ld, %d, %d\n",
- lwpid_of (lwp),
- ourstatus->kind,
- ourstatus->value.sig);
+ if (WIFSTOPPED (*wstat)
+ && WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected)
+ {
+ int should_stop;
- return lwpid_of (lwp);
-}
+ if (debug_threads)
+ fprintf (stderr, "Expected stop.\n");
+ event_child->stop_expected = 0;
-/* Get rid of any pending event in the pipe. */
-static void
-async_file_flush (void)
-{
- int ret;
- char buf;
+ should_stop = (current_inferior->last_resume_kind == resume_stop
+ || stopping_threads);
- do
- ret = read (linux_event_pipe[0], &buf, 1);
- while (ret >= 0 || (ret == -1 && errno == EINTR));
-}
+ if (!should_stop)
+ {
+ linux_resume_one_lwp (event_child,
+ event_child->stepping, 0, NULL);
+ continue;
+ }
+ }
-/* Put something in the pipe, so the event loop wakes up. */
-static void
-async_file_mark (void)
-{
- int ret;
+ return lwpid_of (event_child);
+ }
- async_file_flush ();
+ /* NOTREACHED */
+ return 0;
+}
- do
- ret = write (linux_event_pipe[1], "+", 1);
- while (ret == 0 || (ret == -1 && errno == EINTR));
+/* Count the LWP's that have had events. */
- /* Ignore EAGAIN. If the pipe is full, the event loop will already
- be awakened anyway. */
+static int
+count_events_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *count = data;
+
+ gdb_assert (count != NULL);
+
+ /* Count only resumed LWPs that have a SIGTRAP event pending that
+ should be reported to GDB. */
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind != resume_stop
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ (*count)++;
+
+ return 0;
}
-static unsigned long
-linux_wait (struct target_waitstatus *ourstatus, int target_options)
-{
- unsigned long event_ptid;
+/* Select the LWP (if any) that is currently being single-stepped. */
- if (debug_threads)
- fprintf (stderr, "linux_wait\n");
+static int
+select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
- /* Flush the async file first. */
- if (target_is_async_p ())
- async_file_flush ();
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind == resume_step
+ && lp->status_pending_p)
+ return 1;
+ else
+ return 0;
+}
- event_ptid = linux_wait_1 (ourstatus, target_options);
+/* Select the Nth LWP that has had a SIGTRAP event that should be
+ reported to GDB. */
- /* If at least one stop was reported, there may be more. A single
- SIGCHLD can signal more than one child stop. */
- if (target_is_async_p ()
- && (target_options & TARGET_WNOHANG) != 0
- && event_ptid != 0)
- async_file_mark ();
+static int
+select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *selector = data;
+
+ gdb_assert (selector != NULL);
+
+ /* Select only resumed LWPs that have a SIGTRAP event pending. */
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ if ((*selector)-- == 0)
+ return 1;
- return event_ptid;
+ return 0;
}
-/* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
- thread groups are in use, we need to use tkill. */
-
static int
-kill_lwp (unsigned long lwpid, int signo)
+cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
{
- static int tkill_failed;
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ struct lwp_info *event_lp = data;
- errno = 0;
+ /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
+ if (lp == event_lp)
+ return 0;
-#ifdef SYS_tkill
- if (!tkill_failed)
- {
- int ret = syscall (SYS_tkill, lwpid, signo);
- if (errno != ENOSYS)
- return ret;
- errno = 0;
- tkill_failed = 1;
- }
-#endif
+ /* If a LWP other than the LWP that we're reporting an event for has
+ hit a GDB breakpoint (as opposed to some random trap signal),
+ then just arrange for it to hit it again later. We don't keep
+ the SIGTRAP status and don't forward the SIGTRAP signal to the
+ LWP. We will handle the current event, eventually we will resume
+ all LWPs, and this one will get its breakpoint trap again.
+
+ If we do not do this, then we run the risk that the user will
+ delete or disable the breakpoint, but the LWP will have already
+ tripped on it. */
+
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !lp->stepping
+ && !lp->stopped_by_watchpoint
+ && cancel_breakpoint (lp))
+ /* Throw away the SIGTRAP. */
+ lp->status_pending_p = 0;
- return kill (lwpid, signo);
+ return 0;
}
static void
-send_sigstop (struct inferior_list_entry *entry)
+linux_cancel_breakpoints (void)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
- int pid;
-
- if (lwp->stopped)
- return;
+ find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
+}
- pid = lwpid_of (lwp);
+/* Select one LWP out of those that have events pending. */
- /* If we already have a pending stop signal for this process, don't
- send another. */
- if (lwp->stop_expected)
+static void
+select_event_lwp (struct lwp_info **orig_lp)
+{
+ int num_events = 0;
+ int random_selector;
+ struct lwp_info *event_lp;
+
+ /* Give preference to any LWP that is being single-stepped. */
+ event_lp
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ select_singlestep_lwp_callback, NULL);
+ if (event_lp != NULL)
{
if (debug_threads)
- fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
-
- /* We clear the stop_expected flag so that wait_for_sigstop
- will receive the SIGSTOP event (instead of silently resuming and
- waiting again). It'll be reset below. */
- lwp->stop_expected = 0;
- return;
+ fprintf (stderr,
+ "SEL: Select single-step %s\n",
+ target_pid_to_str (ptid_of (event_lp)));
}
+ else
+ {
+ /* No single-stepping LWP. Select one at random, out of those
+ which have had SIGTRAP events. */
- if (debug_threads)
- fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
+ /* First see how many SIGTRAP events we have. */
+ find_inferior (&all_lwps, count_events_callback, &num_events);
- kill_lwp (pid, SIGSTOP);
-}
+ /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
+ random_selector = (int)
+ ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
-static void
-wait_for_sigstop (struct inferior_list_entry *entry)
-{
- struct lwp_info *lwp = (struct lwp_info *) entry;
- struct thread_info *saved_inferior;
- int wstat;
- unsigned long saved_tid;
- unsigned long ptid;
+ if (debug_threads && num_events > 1)
+ fprintf (stderr,
+ "SEL: Found %d SIGTRAP events, selecting #%d\n",
+ num_events, random_selector);
- if (lwp->stopped)
- return;
+ event_lp = (struct lwp_info *) find_inferior (&all_lwps,
+ select_event_lwp_callback,
+ &random_selector);
+ }
- saved_inferior = current_inferior;
- if (saved_inferior != NULL)
- saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
- else
- saved_tid = 0; /* avoid bogus unused warning */
+ if (event_lp != NULL)
+ {
+ /* Switch the event LWP. */
+ *orig_lp = event_lp;
+ }
+}
- ptid = lwpid_of (lwp);
+/* Decrement the suspend count of an LWP. */
- linux_wait_for_event (ptid, &wstat, __WALL);
+static int
+unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
- /* If we stopped with a non-SIGSTOP signal, save it for later
- and record the pending SIGSTOP. If the process exited, just
- return. */
- if (WIFSTOPPED (wstat)
- && WSTOPSIG (wstat) != SIGSTOP)
- {
- if (debug_threads)
- fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
- lwpid_of (lwp), wstat);
-
- /* Do not leave a pending single-step finish to be reported to
- the client. The client will give us a new action for this
- thread, possibly a continue request --- otherwise, the client
- would consider this pending SIGTRAP reported later a spurious
- signal. */
- if (WSTOPSIG (wstat) == SIGTRAP
- && lwp->stepping
- && !linux_stopped_by_watchpoint ())
- {
- if (debug_threads)
- fprintf (stderr, " single-step SIGTRAP ignored\n");
- }
- else
- {
- lwp->status_pending_p = 1;
- lwp->status_pending = wstat;
- }
- lwp->stop_expected = 1;
- }
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
- if (saved_inferior == NULL || linux_thread_alive (saved_tid))
- current_inferior = saved_inferior;
- else
- {
- if (debug_threads)
- fprintf (stderr, "Previously current thread died.\n");
+ lwp->suspended--;
- if (non_stop)
- {
- /* We can't change the current inferior behind GDB's back,
- otherwise, a subsequent command may apply to the wrong
- process. */
- current_inferior = NULL;
- }
- else
- {
- /* Set a valid thread as current. */
- set_desired_inferior (0);
- }
- }
+ gdb_assert (lwp->suspended >= 0);
+ return 0;
}
+/* Decrement the suspend count of all LWPs, except EXCEPT, if non
+ NULL. */
+
static void
-stop_all_lwps (void)
+unsuspend_all_lwps (struct lwp_info *except)
{
- stopping_threads = 1;
- for_each_inferior (&all_lwps, send_sigstop);
- for_each_inferior (&all_lwps, wait_for_sigstop);
- stopping_threads = 0;
+ find_inferior (&all_lwps, unsuspend_one_lwp, except);
}
-/* Resume execution of the inferior process.
- If STEP is nonzero, single-step it.
- If SIGNAL is nonzero, give it that signal. */
+static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
+static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
+ void *data);
+static int lwp_running (struct inferior_list_entry *entry, void *data);
+static ptid_t linux_wait_1 (ptid_t ptid,
+ struct target_waitstatus *ourstatus,
+ int target_options);
+
+/* Stabilize threads (move out of jump pads).
+
+ If a thread is midway collecting a fast tracepoint, we need to
+ finish the collection and move it out of the jump pad before
+ reporting the signal.
+
+ This avoids recursion while collecting (when a signal arrives
+ midway, and the signal handler itself collects), which would trash
+ the trace buffer. In case the user set a breakpoint in a signal
+ handler, this avoids the backtrace showing the jump pad, etc..
+ Most importantly, there are certain things we can't do safely if
+ threads are stopped in a jump pad (or in its callee's). For
+ example:
+
+ - starting a new trace run. A thread still collecting the
+ previous run, could trash the trace buffer when resumed. The trace
+ buffer control structures would have been reset but the thread had
+ no way to tell. The thread could even midway memcpy'ing to the
+ buffer, which would mean that when resumed, it would clobber the
+ trace buffer that had been set for a new run.
+
+ - we can't rewrite/reuse the jump pads for new tracepoints
+ safely. Say you do tstart while a thread is stopped midway while
+ collecting. When the thread is later resumed, it finishes the
+ collection, and returns to the jump pad, to execute the original
+ instruction that was under the tracepoint jump at the time the
+ older run had been started. If the jump pad had been rewritten
+ since for something else in the new run, the thread would now
+ execute the wrong / random instructions. */
static void
-linux_resume_one_lwp (struct inferior_list_entry *entry,
- int step, int signal, siginfo_t *info)
+linux_stabilize_threads (void)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
- struct thread_info *saved_inferior;
+ struct thread_info *save_inferior;
+ struct lwp_info *lwp_stuck;
- if (lwp->stopped == 0)
- return;
-
- /* If we have pending signals or status, and a new signal, enqueue the
- signal. Also enqueue the signal if we are waiting to reinsert a
- breakpoint; it will be picked up again below. */
- if (signal != 0
- && (lwp->status_pending_p || lwp->pending_signals != NULL
- || lwp->bp_reinsert != 0))
+ lwp_stuck
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ stuck_in_jump_pad_callback, NULL);
+ if (lwp_stuck != NULL)
{
- struct pending_signals *p_sig;
- p_sig = xmalloc (sizeof (*p_sig));
- p_sig->prev = lwp->pending_signals;
- p_sig->signal = signal;
- if (info == NULL)
- memset (&p_sig->info, 0, sizeof (siginfo_t));
- else
- memcpy (&p_sig->info, info, sizeof (siginfo_t));
- lwp->pending_signals = p_sig;
+ if (debug_threads)
+ fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
+ lwpid_of (lwp_stuck));
+ return;
}
- if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
- return;
-
- saved_inferior = current_inferior;
- current_inferior = get_lwp_thread (lwp);
+ save_inferior = current_inferior;
- if (debug_threads)
- fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
- lwpid_of (lwp), step ? "step" : "continue", signal,
- lwp->stop_expected ? "expected" : "not expected");
+ stabilizing_threads = 1;
- /* This bit needs some thinking about. If we get a signal that
- we must report while a single-step reinsert is still pending,
- we often end up resuming the thread. It might be better to
- (ew) allow a stack of pending events; then we could be sure that
- the reinsert happened right away and not lose any signals.
+ /* Kick 'em all. */
+ for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
- Making this stack would also shrink the window in which breakpoints are
- uninserted (see comment in linux_wait_for_lwp) but not enough for
- complete correctness, so it won't solve that problem. It may be
- worthwhile just to solve this one, however. */
- if (lwp->bp_reinsert != 0)
+ /* Loop until all are stopped out of the jump pads. */
+ while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
{
- if (debug_threads)
- fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
- if (step == 0)
- fprintf (stderr, "BAD - reinserting but not stepping.\n");
- step = 1;
+ struct target_waitstatus ourstatus;
+ struct lwp_info *lwp;
+ int wstat;
- /* Postpone any pending signal. It was enqueued above. */
- signal = 0;
- }
+ /* Note that we go through the full wait even loop. While
+ moving threads out of jump pad, we need to be able to step
+ over internal breakpoints and such. */
+ linux_wait_1 (minus_one_ptid, &ourstatus, 0);
+
+ if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
+ {
+ lwp = get_thread_lwp (current_inferior);
- check_removed_breakpoint (lwp);
+ /* Lock it. */
+ lwp->suspended++;
- if (debug_threads && the_low_target.get_pc != NULL)
- {
- fprintf (stderr, " ");
- (*the_low_target.get_pc) ();
+ if (ourstatus.value.sig != TARGET_SIGNAL_0
+ || current_inferior->last_resume_kind == resume_stop)
+ {
+ wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig));
+ enqueue_one_deferred_signal (lwp, &wstat);
+ }
+ }
}
- /* If we have pending signals, consume one unless we are trying to reinsert
- a breakpoint. */
- if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
- {
- struct pending_signals **p_sig;
+ find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
- p_sig = &lwp->pending_signals;
- while ((*p_sig)->prev != NULL)
- p_sig = &(*p_sig)->prev;
+ stabilizing_threads = 0;
- signal = (*p_sig)->signal;
- if ((*p_sig)->info.si_signo != 0)
- ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
+ current_inferior = save_inferior;
- free (*p_sig);
- *p_sig = NULL;
- }
-
- regcache_invalidate_one ((struct inferior_list_entry *)
- get_lwp_thread (lwp));
- errno = 0;
- lwp->stopped = 0;
- lwp->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, signal);
-
- current_inferior = saved_inferior;
- if (errno)
+ if (debug_threads)
{
- /* ESRCH from ptrace either means that the thread was already
- running (an error) or that it is gone (a race condition). If
- it's gone, we will get a notification the next time we wait,
- so we can ignore the error. We could differentiate these
- two, but it's tricky without waiting; the thread still exists
- as a zombie, so sending it signal 0 would succeed. So just
- ignore ESRCH. */
- if (errno == ESRCH)
- return;
-
- perror_with_name ("ptrace");
+ lwp_stuck
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ stuck_in_jump_pad_callback, NULL);
+ if (lwp_stuck != NULL)
+ fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
+ lwpid_of (lwp_stuck));
}
}
-struct thread_resume_array
+/* Wait for process, returns status. */
+
+static ptid_t
+linux_wait_1 (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
{
- struct thread_resume *resume;
- size_t n;
-};
+ int w;
+ struct lwp_info *event_child;
+ int options;
+ int pid;
+ int step_over_finished;
+ int bp_explains_trap;
+ int maybe_internal_trap;
+ int report_to_gdb;
+ int trace_event;
-/* This function is called once per thread. We look up the thread
- in RESUME_PTR, and mark the thread with a pointer to the appropriate
- resume request.
+ /* Translate generic target options into linux options. */
+ options = __WALL;
+ if (target_options & TARGET_WNOHANG)
+ options |= WNOHANG;
- This algorithm is O(threads * resume elements), but resume elements
- is small (and will remain small at least until GDB supports thread
- suspension). */
-static int
-linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
-{
- struct lwp_info *lwp;
- struct thread_info *thread;
- int ndx;
- struct thread_resume_array *r;
+retry:
+ bp_explains_trap = 0;
+ trace_event = 0;
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
- thread = (struct thread_info *) entry;
- lwp = get_thread_lwp (thread);
- r = arg;
+ /* If we were only supposed to resume one thread, only wait for
+ that thread - if it's still alive. If it died, however - which
+ can happen if we're coming from the thread death case below -
+ then we need to make sure we restart the other threads. We could
+ pick a thread at random or restart all; restarting all is less
+ arbitrary. */
+ if (!non_stop
+ && !ptid_equal (cont_thread, null_ptid)
+ && !ptid_equal (cont_thread, minus_one_ptid))
+ {
+ struct thread_info *thread;
- for (ndx = 0; ndx < r->n; ndx++)
- if (r->resume[ndx].thread == -1 || r->resume[ndx].thread == entry->id)
- {
- lwp->resume = &r->resume[ndx];
- return 0;
- }
+ thread = (struct thread_info *) find_inferior_id (&all_threads,
+ cont_thread);
- /* No resume action for this thread. */
- lwp->resume = NULL;
+ /* No stepping, no signal - unless one is pending already, of course. */
+ if (thread == NULL)
+ {
+ struct thread_resume resume_info;
+ resume_info.thread = minus_one_ptid;
+ resume_info.kind = resume_continue;
+ resume_info.sig = 0;
+ linux_resume (&resume_info, 1);
+ }
+ else
+ ptid = cont_thread;
+ }
- return 0;
-}
+ if (ptid_equal (step_over_bkpt, null_ptid))
+ pid = linux_wait_for_event (ptid, &w, options);
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
+ target_pid_to_str (step_over_bkpt));
+ pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
+ }
+ if (pid == 0) /* only if TARGET_WNOHANG */
+ return null_ptid;
-/* Set *FLAG_P if this lwp has an interesting status pending. */
-static int
-resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
-{
- struct lwp_info *lwp = (struct lwp_info *) entry;
+ event_child = get_thread_lwp (current_inferior);
- /* LWPs which will not be resumed are not interesting, because
- we might not wait for them next time through linux_wait. */
- if (lwp->resume == NULL)
- return 0;
+ /* If we are waiting for a particular child, and it exited,
+ linux_wait_for_event will return its exit status. Similarly if
+ the last child exited. If this is not the last child, however,
+ do not report it as exited until there is a 'thread exited' response
+ available in the remote protocol. Instead, just wait for another event.
+ This should be safe, because if the thread crashed we will already
+ have reported the termination signal to GDB; that should stop any
+ in-progress stepping operations, etc.
- /* If this thread has a removed breakpoint, we won't have any
- events to report later, so check now. check_removed_breakpoint
- may clear status_pending_p. We avoid calling check_removed_breakpoint
- for any thread that we are not otherwise going to resume - this
- lets us preserve stopped status when two threads hit a breakpoint.
- GDB removes the breakpoint to single-step a particular thread
- past it, then re-inserts it and resumes all threads. We want
- to report the second thread without resuming it in the interim. */
- if (lwp->status_pending_p)
- check_removed_breakpoint (lwp);
+ Report the exit status of the last thread to exit. This matches
+ LinuxThreads' behavior. */
- if (lwp->status_pending_p)
- * (int *) flag_p = 1;
+ if (last_thread_of_process_p (current_inferior))
+ {
+ if (WIFEXITED (w) || WIFSIGNALED (w))
+ {
+ if (WIFEXITED (w))
+ {
+ ourstatus->kind = TARGET_WAITKIND_EXITED;
+ ourstatus->value.integer = WEXITSTATUS (w);
- return 0;
-}
+ if (debug_threads)
+ fprintf (stderr,
+ "\nChild exited with retcode = %x \n",
+ WEXITSTATUS (w));
+ }
+ else
+ {
+ ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
+ ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
-/* This function is called once per thread. We check the thread's resume
- request, which will tell us whether to resume, step, or leave the thread
- stopped; and what signal, if any, it should be sent.
+ if (debug_threads)
+ fprintf (stderr,
+ "\nChild terminated with signal = %x \n",
+ WTERMSIG (w));
- For threads which we aren't explicitly told otherwise, we preserve
- the stepping flag; this is used for stepping over gdbserver-placed
- breakpoints.
+ }
- If pending_flags was set in any thread, we queue any needed
- signals, since we won't actually resume. We already have a pending
- event to report, so we don't need to preserve any step requests;
- they should be re-issued if necessary. */
+ return ptid_of (event_child);
+ }
+ }
+ else
+ {
+ if (!WIFSTOPPED (w))
+ goto retry;
+ }
-static int
-linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
-{
- struct lwp_info *lwp;
- struct thread_info *thread;
- int step;
- int pending_flag = * (int *) arg;
+ /* If this event was not handled before, and is not a SIGTRAP, we
+ report it. SIGILL and SIGSEGV are also treated as traps in case
+ a breakpoint is inserted at the current PC. If this target does
+ not support internal breakpoints at all, we also report the
+ SIGTRAP without further processing; it's of no concern to us. */
+ maybe_internal_trap
+ = (supports_breakpoints ()
+ && (WSTOPSIG (w) == SIGTRAP
+ || ((WSTOPSIG (w) == SIGILL
+ || WSTOPSIG (w) == SIGSEGV)
+ && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
+
+ if (maybe_internal_trap)
+ {
+ /* Handle anything that requires bookkeeping before deciding to
+ report the event or continue waiting. */
+
+ /* First check if we can explain the SIGTRAP with an internal
+ breakpoint, or if we should possibly report the event to GDB.
+ Do this before anything that may remove or insert a
+ breakpoint. */
+ bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
+
+ /* We have a SIGTRAP, possibly a step-over dance has just
+ finished. If so, tweak the state machine accordingly,
+ reinsert breakpoints and delete any reinsert (software
+ single-step) breakpoints. */
+ step_over_finished = finish_step_over (event_child);
+
+ /* Now invoke the callbacks of any internal breakpoints there. */
+ check_breakpoints (event_child->stop_pc);
+
+ /* Handle tracepoint data collecting. This may overflow the
+ trace buffer, and cause a tracing stop, removing
+ breakpoints. */
+ trace_event = handle_tracepoints (event_child);
+
+ if (bp_explains_trap)
+ {
+ /* If we stepped or ran into an internal breakpoint, we've
+ already handled it. So next time we resume (from this
+ PC), we should step over it. */
+ if (debug_threads)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
- thread = (struct thread_info *) entry;
- lwp = get_thread_lwp (thread);
+ if (breakpoint_here (event_child->stop_pc))
+ event_child->need_step_over = 1;
+ }
+ }
+ else
+ {
+ /* We have some other signal, possibly a step-over dance was in
+ progress, and it should be cancelled too. */
+ step_over_finished = finish_step_over (event_child);
+ }
- if (lwp->resume == NULL)
- return 0;
+ /* We have all the data we need. Either report the event to GDB, or
+ resume threads and keep waiting for more. */
- if (lwp->resume->kind == resume_stop)
+ /* If we're collecting a fast tracepoint, finish the collection and
+ move out of the jump pad before delivering a signal. See
+ linux_stabilize_threads. */
+
+ if (WIFSTOPPED (w)
+ && WSTOPSIG (w) != SIGTRAP
+ && supports_fast_tracepoints ()
+ && agent_loaded_p ())
{
if (debug_threads)
- fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp));
-
- if (!lwp->stopped)
+ fprintf (stderr,
+ "Got signal %d for LWP %ld. Check if we need "
+ "to defer or adjust it.\n",
+ WSTOPSIG (w), lwpid_of (event_child));
+
+ /* Allow debugging the jump pad itself. */
+ if (current_inferior->last_resume_kind != resume_step
+ && maybe_move_out_of_jump_pad (event_child, &w))
{
+ enqueue_one_deferred_signal (event_child, &w);
+
if (debug_threads)
- fprintf (stderr, "running -> suspending %ld\n", lwpid_of (lwp));
+ fprintf (stderr,
+ "Signal %d for LWP %ld deferred (in jump pad)\n",
+ WSTOPSIG (w), lwpid_of (event_child));
- lwp->suspended = 1;
- send_sigstop (&lwp->head);
+ linux_resume_one_lwp (event_child, 0, 0, NULL);
+ goto retry;
}
- else
+ }
+
+ if (event_child->collecting_fast_tracepoint)
+ {
+ if (debug_threads)
+ fprintf (stderr, "\
+LWP %ld was trying to move out of the jump pad (%d). \
+Check if we're already there.\n",
+ lwpid_of (event_child),
+ event_child->collecting_fast_tracepoint);
+
+ trace_event = 1;
+
+ event_child->collecting_fast_tracepoint
+ = linux_fast_tracepoint_collecting (event_child, NULL);
+
+ if (event_child->collecting_fast_tracepoint != 1)
+ {
+ /* No longer need this breakpoint. */
+ if (event_child->exit_jump_pad_bkpt != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "No longer need exit-jump-pad bkpt; removing it."
+ "stopping all threads momentarily.\n");
+
+ /* Other running threads could hit this breakpoint.
+ We don't handle moribund locations like GDB does,
+ instead we always pause all threads when removing
+ breakpoints, so that any step-over or
+ decr_pc_after_break adjustment is always taken
+ care of while the breakpoint is still
+ inserted. */
+ stop_all_lwps (1, event_child);
+ cancel_breakpoints ();
+
+ delete_breakpoint (event_child->exit_jump_pad_bkpt);
+ event_child->exit_jump_pad_bkpt = NULL;
+
+ unstop_all_lwps (1, event_child);
+
+ gdb_assert (event_child->suspended >= 0);
+ }
+ }
+
+ if (event_child->collecting_fast_tracepoint == 0)
{
if (debug_threads)
+ fprintf (stderr,
+ "fast tracepoint finished "
+ "collecting successfully.\n");
+
+ /* We may have a deferred signal to report. */
+ if (dequeue_one_deferred_signal (event_child, &w))
{
- if (lwp->suspended)
- fprintf (stderr, "already stopped/suspended LWP %ld\n",
- lwpid_of (lwp));
- else
- fprintf (stderr, "already stopped/not suspended LWP %ld\n",
- lwpid_of (lwp));
+ if (debug_threads)
+ fprintf (stderr, "dequeued one signal.\n");
}
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "no deferred signals.\n");
- /* Make sure we leave the LWP suspended, so we don't try to
- resume it without GDB telling us to. FIXME: The LWP may
- have been stopped in an internal event that was not meant
- to be notified back to GDB (e.g., gdbserver breakpoint),
- so we should be reporting a stop event in that case
- too. */
- lwp->suspended = 1;
+ if (stabilizing_threads)
+ {
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
+ ourstatus->value.sig = TARGET_SIGNAL_0;
+ return ptid_of (event_child);
+ }
+ }
}
-
- /* For stop requests, we're done. */
- lwp->resume = NULL;
- return 0;
}
- else
- lwp->suspended = 0;
-
- /* If this thread which is about to be resumed has a pending status,
- then don't resume any threads - we can just report the pending
- status. Make sure to queue any signals that would otherwise be
- sent. In all-stop mode, we do this decision based on if *any*
- thread has a pending status. */
- if (non_stop)
- resume_status_pending_p (&lwp->head, &pending_flag);
- if (!pending_flag)
+ /* Check whether GDB would be interested in this event. */
+
+ /* If GDB is not interested in this signal, don't stop other
+ threads, and don't report it to GDB. Just resume the inferior
+ right away. We do this for threading-related signals as well as
+ any that GDB specifically requested we ignore. But never ignore
+ SIGSTOP if we sent it ourselves, and do not ignore signals when
+ stepping - they may require special handling to skip the signal
+ handler. */
+ /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
+ thread library? */
+ if (WIFSTOPPED (w)
+ && current_inferior->last_resume_kind != resume_step
+ && (
+#if defined (USE_THREAD_DB) && !defined (__ANDROID__)
+ (current_process ()->private->thread_db != NULL
+ && (WSTOPSIG (w) == __SIGRTMIN
+ || WSTOPSIG (w) == __SIGRTMIN + 1))
+ ||
+#endif
+ (pass_signals[target_signal_from_host (WSTOPSIG (w))]
+ && !(WSTOPSIG (w) == SIGSTOP
+ && current_inferior->last_resume_kind == resume_stop))))
{
+ siginfo_t info, *info_p;
+
if (debug_threads)
- fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
+ fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
+ WSTOPSIG (w), lwpid_of (event_child));
- if (lwp->resume->thread == -1
- && lwp->stepping
- && lwp->pending_is_breakpoint)
- step = 1;
+ if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
+ info_p = &info;
else
- step = (lwp->resume->kind == resume_step);
-
- linux_resume_one_lwp (&lwp->head, step, lwp->resume->sig, NULL);
+ info_p = NULL;
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ WSTOPSIG (w), info_p);
+ goto retry;
}
- else
+
+ /* If GDB wanted this thread to single step, we always want to
+ report the SIGTRAP, and let GDB handle it. Watchpoints should
+ always be reported. So should signals we can't explain. A
+ SIGTRAP we can't explain could be a GDB breakpoint --- we may or
+ not support Z0 breakpoints. If we do, we're be able to handle
+ GDB breakpoints on top of internal breakpoints, by handling the
+ internal breakpoint and still reporting the event to GDB. If we
+ don't, we're out of luck, GDB won't see the breakpoint hit. */
+ report_to_gdb = (!maybe_internal_trap
+ || current_inferior->last_resume_kind == resume_step
+ || event_child->stopped_by_watchpoint
+ || (!step_over_finished
+ && !bp_explains_trap && !trace_event)
+ || (gdb_breakpoint_here (event_child->stop_pc)
+ && gdb_condition_true_at_breakpoint (event_child->stop_pc)));
+
+ /* We found no reason GDB would want us to stop. We either hit one
+ of our own breakpoints, or finished an internal step GDB
+ shouldn't know about. */
+ if (!report_to_gdb)
{
if (debug_threads)
- fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
-
- /* If we have a new signal, enqueue the signal. */
- if (lwp->resume->sig != 0)
{
- struct pending_signals *p_sig;
- p_sig = xmalloc (sizeof (*p_sig));
- p_sig->prev = lwp->pending_signals;
- p_sig->signal = lwp->resume->sig;
- memset (&p_sig->info, 0, sizeof (siginfo_t));
+ if (bp_explains_trap)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ if (step_over_finished)
+ fprintf (stderr, "Step-over finished.\n");
+ if (trace_event)
+ fprintf (stderr, "Tracepoint event.\n");
+ }
- /* If this is the same signal we were previously stopped by,
- make sure to queue its siginfo. We can ignore the return
- value of ptrace; if it fails, we'll skip
- PTRACE_SETSIGINFO. */
- if (WIFSTOPPED (lwp->last_status)
- && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
- ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
+ /* We're not reporting this breakpoint to GDB, so apply the
+ decr_pc_after_break adjustment to the inferior's regcache
+ ourselves. */
- lwp->pending_signals = p_sig;
+ if (the_low_target.set_pc != NULL)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (get_lwp_thread (event_child), 1);
+ (*the_low_target.set_pc) (regcache, event_child->stop_pc);
}
- }
-
- lwp->resume = NULL;
- return 0;
-}
-static void
-linux_resume (struct thread_resume *resume_info, size_t n)
-{
- int pending_flag;
- struct thread_resume_array array = { resume_info, n };
+ /* We may have finished stepping over a breakpoint. If so,
+ we've stopped and suspended all LWPs momentarily except the
+ stepping one. This is where we resume them all again. We're
+ going to keep waiting, so use proceed, which handles stepping
+ over the next breakpoint. */
+ if (debug_threads)
+ fprintf (stderr, "proceeding all threads.\n");
- find_inferior (&all_threads, linux_set_resume_request, &array);
+ if (step_over_finished)
+ unsuspend_all_lwps (event_child);
- /* If there is a thread which would otherwise be resumed, which
- has a pending status, then don't resume any threads - we can just
- report the pending status. Make sure to queue any signals
- that would otherwise be sent. In non-stop mode, we'll apply this
- logic to each thread individually. */
- pending_flag = 0;
- if (!non_stop)
- find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
+ proceed_all_lwps ();
+ goto retry;
+ }
if (debug_threads)
{
- if (pending_flag)
- fprintf (stderr, "Not resuming, pending status\n");
- else
- fprintf (stderr, "Resuming, no pending status\n");
+ if (current_inferior->last_resume_kind == resume_step)
+ fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
+ if (event_child->stopped_by_watchpoint)
+ fprintf (stderr, "Stopped by watchpoint.\n");
+ if (gdb_breakpoint_here (event_child->stop_pc))
+ fprintf (stderr, "Stopped by GDB breakpoint.\n");
+ if (debug_threads)
+ fprintf (stderr, "Hit a non-gdbserver trap event.\n");
}
- find_inferior (&all_threads, linux_resume_one_thread, &pending_flag);
-}
+ /* Alright, we're going to report a stop. */
-#ifdef HAVE_LINUX_USRREGS
+ if (!non_stop && !stabilizing_threads)
+ {
+ /* In all-stop, stop all threads. */
+ stop_all_lwps (0, NULL);
+
+ /* If we're not waiting for a specific LWP, choose an event LWP
+ from among those that have had events. Giving equal priority
+ to all LWPs that have had events helps prevent
+ starvation. */
+ if (ptid_equal (ptid, minus_one_ptid))
+ {
+ event_child->status_pending_p = 1;
+ event_child->status_pending = w;
-int
-register_addr (int regnum)
-{
- int addr;
+ select_event_lwp (&event_child);
- if (regnum < 0 || regnum >= the_low_target.num_regs)
- error ("Invalid register number %d.", regnum);
-
- addr = the_low_target.regmap[regnum];
-
- return addr;
-}
+ event_child->status_pending_p = 0;
+ w = event_child->status_pending;
+ }
-/* Fetch one register. */
-static void
-fetch_register (int regno)
-{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
+ /* Now that we've selected our final event LWP, cancel any
+ breakpoints in other LWPs that have hit a GDB breakpoint.
+ See the comment in cancel_breakpoints_callback to find out
+ why. */
+ find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
+
+ /* If we were going a step-over, all other threads but the stepping one
+ had been paused in start_step_over, with their suspend counts
+ incremented. We don't want to do a full unstop/unpause, because we're
+ in all-stop mode (so we want threads stopped), but we still need to
+ unsuspend the other threads, to decrement their `suspended' count
+ back. */
+ if (step_over_finished)
+ unsuspend_all_lwps (event_child);
+
+ /* Stabilize threads (move out of jump pads). */
+ stabilize_threads ();
+ }
+ else
+ {
+ /* If we just finished a step-over, then all threads had been
+ momentarily paused. In all-stop, that's fine, we want
+ threads stopped by now anyway. In non-stop, we need to
+ re-resume threads that GDB wanted to be running. */
+ if (step_over_finished)
+ unstop_all_lwps (1, event_child);
+ }
- if (regno >= the_low_target.num_regs)
- return;
- if ((*the_low_target.cannot_fetch_register) (regno))
- return;
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
- regaddr = register_addr (regno);
- if (regaddr == -1)
- return;
- size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
- & - sizeof (PTRACE_XFER_TYPE));
- buf = alloca (size);
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) == SIGSTOP)
{
- errno = 0;
- *(PTRACE_XFER_TYPE *) (buf + i) =
- ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
- regaddr += sizeof (PTRACE_XFER_TYPE);
- if (errno != 0)
- {
- /* Warning, not error, in case we are attached; sometimes the
- kernel doesn't let us at the registers. */
- char *err = strerror (errno);
- char *msg = alloca (strlen (err) + 128);
- sprintf (msg, "reading register %d: %s", regno, err);
- error (msg);
- goto error_exit;
- }
+ /* A thread that has been requested to stop by GDB with vCont;t,
+ and it stopped cleanly, so report as SIG0. The use of
+ SIGSTOP is an implementation detail. */
+ ourstatus->value.sig = TARGET_SIGNAL_0;
+ }
+ else if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) != SIGSTOP)
+ {
+ /* A thread that has been requested to stop by GDB with vCont;t,
+ but, it stopped for other reasons. */
+ ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
}
-
- if (the_low_target.supply_ptrace_register)
- the_low_target.supply_ptrace_register (regno, buf);
else
- supply_register (regno, buf);
+ {
+ ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ }
+
+ gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
+
+ if (debug_threads)
+ fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
+ target_pid_to_str (ptid_of (event_child)),
+ ourstatus->kind,
+ ourstatus->value.sig);
-error_exit:;
+ return ptid_of (event_child);
}
-/* Fetch all registers, or just one, from the child process. */
+/* Get rid of any pending event in the pipe. */
static void
-usr_fetch_inferior_registers (int regno)
+async_file_flush (void)
{
- if (regno == -1 || regno == 0)
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- fetch_register (regno);
- else
- fetch_register (regno);
+ int ret;
+ char buf;
+
+ do
+ ret = read (linux_event_pipe[0], &buf, 1);
+ while (ret >= 0 || (ret == -1 && errno == EINTR));
}
-/* Store our register values back into the inferior.
- If REGNO is -1, do this for all registers.
- Otherwise, REGNO specifies which register (so we can save time). */
+/* Put something in the pipe, so the event loop wakes up. */
static void
-usr_store_inferior_registers (int regno)
+async_file_mark (void)
{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
+ int ret;
- if (regno >= 0)
- {
- if (regno >= the_low_target.num_regs)
- return;
+ async_file_flush ();
- if ((*the_low_target.cannot_store_register) (regno) == 1)
- return;
+ do
+ ret = write (linux_event_pipe[1], "+", 1);
+ while (ret == 0 || (ret == -1 && errno == EINTR));
- regaddr = register_addr (regno);
- if (regaddr == -1)
- return;
- errno = 0;
- size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
- & - sizeof (PTRACE_XFER_TYPE);
- buf = alloca (size);
- memset (buf, 0, size);
+ /* Ignore EAGAIN. If the pipe is full, the event loop will already
+ be awakened anyway. */
+}
- if (the_low_target.collect_ptrace_register)
- the_low_target.collect_ptrace_register (regno, buf);
- else
- collect_register (regno, buf);
+static ptid_t
+linux_wait (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
+{
+ ptid_t event_ptid;
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
- {
- errno = 0;
- ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
- *(PTRACE_XFER_TYPE *) (buf + i));
- if (errno != 0)
- {
- /* At this point, ESRCH should mean the process is
- already gone, in which case we simply ignore attempts
- to change its registers. See also the related
- comment in linux_resume_one_lwp. */
- if (errno == ESRCH)
- return;
+ if (debug_threads)
+ fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
- if ((*the_low_target.cannot_store_register) (regno) == 0)
- {
- char *err = strerror (errno);
- char *msg = alloca (strlen (err) + 128);
- sprintf (msg, "writing register %d: %s",
- regno, err);
- error (msg);
- return;
- }
- }
- regaddr += sizeof (PTRACE_XFER_TYPE);
- }
- }
- else
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- usr_store_inferior_registers (regno);
-}
-#endif /* HAVE_LINUX_USRREGS */
+ /* Flush the async file first. */
+ if (target_is_async_p ())
+ async_file_flush ();
+
+ event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
+ /* If at least one stop was reported, there may be more. A single
+ SIGCHLD can signal more than one child stop. */
+ if (target_is_async_p ()
+ && (target_options & TARGET_WNOHANG) != 0
+ && !ptid_equal (event_ptid, null_ptid))
+ async_file_mark ();
+ return event_ptid;
+}
-#ifdef HAVE_LINUX_REGSETS
+/* Send a signal to an LWP. */
static int
-regsets_fetch_inferior_registers ()
+kill_lwp (unsigned long lwpid, int signo)
{
- struct regset_info *regset;
- int saw_general_regs = 0;
-
- regset = target_regsets;
+ /* Use tkill, if possible, in case we are using nptl threads. If tkill
+ fails, then we are not using nptl threads and we should be using kill. */
- while (regset->size >= 0)
- {
- void *buf;
- int res;
+#ifdef __NR_tkill
+ {
+ static int tkill_failed;
- if (regset->size == 0 || disabled_regsets[regset - target_regsets])
- {
- regset ++;
- continue;
- }
+ if (!tkill_failed)
+ {
+ int ret;
- buf = xmalloc (regset->size);
-#ifndef __sparc__
- res = ptrace (regset->get_request, inferior_pid, 0, buf);
-#else
- res = ptrace (regset->get_request, inferior_pid, buf, 0);
+ errno = 0;
+ ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno != ENOSYS)
+ return ret;
+ tkill_failed = 1;
+ }
+ }
#endif
- if (res < 0)
- {
- if (errno == EIO)
- {
- /* If we get EIO on a regset, do not try it again for
- this process. */
- disabled_regsets[regset - target_regsets] = 1;
- continue;
- }
- else
- {
- char s[256];
- sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
- inferior_pid);
- perror (s);
- }
- }
- else if (regset->type == GENERAL_REGS)
- saw_general_regs = 1;
- regset->store_function (buf);
- regset ++;
- }
- if (saw_general_regs)
- return 0;
- else
- return 1;
+
+ return kill (lwpid, signo);
}
-static int
-regsets_store_inferior_registers ()
+void
+linux_stop_lwp (struct lwp_info *lwp)
{
- struct regset_info *regset;
- int saw_general_regs = 0;
+ send_sigstop (lwp);
+}
- regset = target_regsets;
+static void
+send_sigstop (struct lwp_info *lwp)
+{
+ int pid;
- while (regset->size >= 0)
+ pid = lwpid_of (lwp);
+
+ /* If we already have a pending stop signal for this process, don't
+ send another. */
+ if (lwp->stop_expected)
{
- void *buf;
- int res;
+ if (debug_threads)
+ fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
- if (regset->size == 0 || disabled_regsets[regset - target_regsets])
- {
- regset ++;
- continue;
- }
+ return;
+ }
- buf = xmalloc (regset->size);
+ if (debug_threads)
+ fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
- /* First fill the buffer with the current register set contents,
- in case there are any items in the kernel's regset that are
- not in gdbserver's regcache. */
-#ifndef __sparc__
- res = ptrace (regset->get_request, inferior_pid, 0, buf);
-#else
- res = ptrace (regset->get_request, inferior_pid, buf, 0);
-#endif
+ lwp->stop_expected = 1;
+ kill_lwp (pid, SIGSTOP);
+}
- if (res == 0)
- {
- /* Then overlay our cached registers on that. */
- regset->fill_function (buf);
+static int
+send_sigstop_callback (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
- /* Only now do we write the register set. */
-#ifndef __sparc__
- res = ptrace (regset->set_request, inferior_pid, 0, buf);
-#else
- res = ptrace (regset->set_request, inferior_pid, buf, 0);
-#endif
- }
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
- if (res < 0)
- {
- if (errno == EIO)
- {
- /* If we get EIO on a regset, do not try it again for
- this process. */
- disabled_regsets[regset - target_regsets] = 1;
- continue;
- }
- else if (errno == ESRCH)
- {
- /* At this point, ESRCH should mean the process is
- already gone, in which case we simply ignore attempts
- to change its registers. See also the related
- comment in linux_resume_one_lwp. */
- return 0;
- }
- else
- {
- perror ("Warning: ptrace(regsets_store_inferior_registers)");
- }
- }
- else if (regset->type == GENERAL_REGS)
- saw_general_regs = 1;
- regset ++;
- free (buf);
- }
- if (saw_general_regs)
+ if (lwp->stopped)
return 0;
- else
- return 1;
+
+ send_sigstop (lwp);
return 0;
}
-#endif /* HAVE_LINUX_REGSETS */
+/* Increment the suspend count of an LWP, and stop it, if not stopped
+ yet. */
+static int
+suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
+ void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ /* Ignore EXCEPT. */
+ if (lwp == except)
+ return 0;
-void
-linux_fetch_registers (int regno)
-{
-#ifdef HAVE_LINUX_REGSETS
- if (regsets_fetch_inferior_registers () == 0)
- return;
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_fetch_inferior_registers (regno);
-#endif
+ lwp->suspended++;
+
+ return send_sigstop_callback (entry, except);
}
-void
-linux_store_registers (int regno)
+static void
+mark_lwp_dead (struct lwp_info *lwp, int wstat)
{
-#ifdef HAVE_LINUX_REGSETS
- if (regsets_store_inferior_registers () == 0)
- return;
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_store_inferior_registers (regno);
-#endif
-}
+ /* It's dead, really. */
+ lwp->dead = 1;
+ /* Store the exit status for later. */
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
-/* Copy LEN bytes from inferior's memory starting at MEMADDR
- to debugger memory starting at MYADDR. */
+ /* Prevent trying to stop it. */
+ lwp->stopped = 1;
-static int
-linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
-{
- register int i;
- /* Round starting address down to longword boundary. */
- register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
- /* Round ending address up; get number of longwords that makes. */
- register int count
- = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
- / sizeof (PTRACE_XFER_TYPE);
- /* Allocate buffer of that many longwords. */
- register PTRACE_XFER_TYPE *buffer
- = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
- int fd;
- char filename[64];
+ /* No further stops are expected from a dead lwp. */
+ lwp->stop_expected = 0;
+}
- /* Try using /proc. Don't bother for one word. */
- if (len >= 3 * sizeof (long))
+static void
+wait_for_sigstop (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *saved_inferior;
+ int wstat;
+ ptid_t saved_tid;
+ ptid_t ptid;
+ int pid;
+
+ if (lwp->stopped)
{
- /* We could keep this file open and cache it - possibly one per
- thread. That requires some juggling, but is even faster. */
- sprintf (filename, "/proc/%ld/mem", inferior_pid);
- fd = open (filename, O_RDONLY | O_LARGEFILE);
- if (fd == -1)
- goto no_proc;
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
- /* If pread64 is available, use it. It's faster if the kernel
- supports it (only one syscall), and it's 64-bit safe even on
- 32-bit platforms (for instance, SPARC debugging a SPARC64
- application). */
-#ifdef HAVE_PREAD64
- if (pread64 (fd, myaddr, len, memaddr) != len)
-#else
- if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
-#endif
+ saved_inferior = current_inferior;
+ if (saved_inferior != NULL)
+ saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
+ else
+ saved_tid = null_ptid; /* avoid bogus unused warning */
+
+ ptid = lwp->head.id;
+
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: pulling one event\n");
+
+ pid = linux_wait_for_event (ptid, &wstat, __WALL);
+
+ /* If we stopped with a non-SIGSTOP signal, save it for later
+ and record the pending SIGSTOP. If the process exited, just
+ return. */
+ if (WIFSTOPPED (wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld stopped with signal %d\n",
+ lwpid_of (lwp), WSTOPSIG (wstat));
+
+ if (WSTOPSIG (wstat) != SIGSTOP)
{
- close (fd);
- goto no_proc;
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ lwpid_of (lwp), wstat);
+
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
}
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
- close (fd);
- return 0;
+ lwp = find_lwp_pid (pid_to_ptid (pid));
+ if (lwp)
+ {
+ /* Leave this status pending for the next time we're able to
+ report it. In the mean time, we'll report this lwp as
+ dead to GDB, so GDB doesn't try to read registers and
+ memory from it. This can only happen if this was the
+ last thread of the process; otherwise, PID is removed
+ from the thread tables before linux_wait_for_event
+ returns. */
+ mark_lwp_dead (lwp, wstat);
+ }
}
- no_proc:
- /* Read all the longwords */
- for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ if (saved_inferior == NULL || linux_thread_alive (saved_tid))
+ current_inferior = saved_inferior;
+ else
{
- errno = 0;
- buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) addr, 0);
- if (errno)
- return errno;
+ if (debug_threads)
+ fprintf (stderr, "Previously current thread died.\n");
+
+ if (non_stop)
+ {
+ /* We can't change the current inferior behind GDB's back,
+ otherwise, a subsequent command may apply to the wrong
+ process. */
+ current_inferior = NULL;
+ }
+ else
+ {
+ /* Set a valid thread as current. */
+ set_desired_inferior (0);
+ }
}
+}
- /* Copy appropriate bytes out of the buffer. */
- memcpy (myaddr,
- (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
- len);
+/* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
+ move it out, because we need to report the stop event to GDB. For
+ example, if the user puts a breakpoint in the jump pad, it's
+ because she wants to debug it. */
- return 0;
+static int
+stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (lwp->stopped);
+
+ /* Allow debugging the jump pad, gdb_collect, etc.. */
+ return (supports_fast_tracepoints ()
+ && agent_loaded_p ()
+ && (gdb_breakpoint_here (lwp->stop_pc)
+ || lwp->stopped_by_watchpoint
+ || thread->last_resume_kind == resume_step)
+ && linux_fast_tracepoint_collecting (lwp, NULL));
}
-/* Copy LEN bytes of data from debugger memory at MYADDR
- to inferior's memory at MEMADDR.
- On failure (cannot write the inferior)
- returns the value of errno. */
+static void
+move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+ int *wstat;
+
+ gdb_assert (lwp->suspended == 0);
+ gdb_assert (lwp->stopped);
+
+ wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
+
+ /* Allow debugging the jump pad, gdb_collect, etc. */
+ if (!gdb_breakpoint_here (lwp->stop_pc)
+ && !lwp->stopped_by_watchpoint
+ && thread->last_resume_kind != resume_step
+ && maybe_move_out_of_jump_pad (lwp, wstat))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "LWP %ld needs stabilizing (in jump pad)\n",
+ lwpid_of (lwp));
+
+ if (wstat)
+ {
+ lwp->status_pending_p = 0;
+ enqueue_one_deferred_signal (lwp, wstat);
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Signal %d for LWP %ld deferred "
+ "(in jump pad)\n",
+ WSTOPSIG (*wstat), lwpid_of (lwp));
+ }
+
+ linux_resume_one_lwp (lwp, 0, 0, NULL);
+ }
+ else
+ lwp->suspended++;
+}
static int
-linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
+lwp_running (struct inferior_list_entry *entry, void *data)
{
- register int i;
- /* Round starting address down to longword boundary. */
- register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
- /* Round ending address up; get number of longwords that makes. */
- register int count
- = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
- /* Allocate buffer of that many longwords. */
- register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ if (lwp->dead)
+ return 0;
+ if (lwp->stopped)
+ return 0;
+ return 1;
+}
+
+/* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
+ If SUSPEND, then also increase the suspend count of every LWP,
+ except EXCEPT. */
+
+static void
+stop_all_lwps (int suspend, struct lwp_info *except)
+{
+ stopping_threads = 1;
+
+ if (suspend)
+ find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
+ else
+ find_inferior (&all_lwps, send_sigstop_callback, except);
+ for_each_inferior (&all_lwps, wait_for_sigstop);
+ stopping_threads = 0;
+}
+
+/* Resume execution of the inferior process.
+ If STEP is nonzero, single-step it.
+ If SIGNAL is nonzero, give it that signal. */
+
+static void
+linux_resume_one_lwp (struct lwp_info *lwp,
+ int step, int signal, siginfo_t *info)
+{
+ struct thread_info *saved_inferior;
+ int fast_tp_collecting;
+
+ if (lwp->stopped == 0)
+ return;
+
+ fast_tp_collecting = lwp->collecting_fast_tracepoint;
+
+ gdb_assert (!stabilizing_threads || fast_tp_collecting);
+
+ /* Cancel actions that rely on GDB not changing the PC (e.g., the
+ user used the "jump" command, or "set $pc = foo"). */
+ if (lwp->stop_pc != get_pc (lwp))
+ {
+ /* Collecting 'while-stepping' actions doesn't make sense
+ anymore. */
+ release_while_stepping_state_list (get_lwp_thread (lwp));
+ }
+
+ /* If we have pending signals or status, and a new signal, enqueue the
+ signal. Also enqueue the signal if we are waiting to reinsert a
+ breakpoint; it will be picked up again below. */
+ if (signal != 0
+ && (lwp->status_pending_p
+ || lwp->pending_signals != NULL
+ || lwp->bp_reinsert != 0
+ || fast_tp_collecting))
+ {
+ struct pending_signals *p_sig;
+ p_sig = xmalloc (sizeof (*p_sig));
+ p_sig->prev = lwp->pending_signals;
+ p_sig->signal = signal;
+ if (info == NULL)
+ memset (&p_sig->info, 0, sizeof (siginfo_t));
+ else
+ memcpy (&p_sig->info, info, sizeof (siginfo_t));
+ lwp->pending_signals = p_sig;
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
+ " has pending status\n",
+ lwpid_of (lwp), step ? "step" : "continue", signal,
+ lwp->stop_expected ? "expected" : "not expected");
+ return;
+ }
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
if (debug_threads)
+ fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
+ lwpid_of (lwp), step ? "step" : "continue", signal,
+ lwp->stop_expected ? "expected" : "not expected");
+
+ /* This bit needs some thinking about. If we get a signal that
+ we must report while a single-step reinsert is still pending,
+ we often end up resuming the thread. It might be better to
+ (ew) allow a stack of pending events; then we could be sure that
+ the reinsert happened right away and not lose any signals.
+
+ Making this stack would also shrink the window in which breakpoints are
+ uninserted (see comment in linux_wait_for_lwp) but not enough for
+ complete correctness, so it won't solve that problem. It may be
+ worthwhile just to solve this one, however. */
+ if (lwp->bp_reinsert != 0)
+ {
+ if (debug_threads)
+ fprintf (stderr, " pending reinsert at 0x%s\n",
+ paddress (lwp->bp_reinsert));
+
+ if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
+ {
+ if (fast_tp_collecting == 0)
+ {
+ if (step == 0)
+ fprintf (stderr, "BAD - reinserting but not stepping.\n");
+ if (lwp->suspended)
+ fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
+ lwp->suspended);
+ }
+
+ step = 1;
+ }
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
+ }
+
+ if (fast_tp_collecting == 1)
{
- fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
+ if (debug_threads)
+ fprintf (stderr, "\
+lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
+ lwpid_of (lwp));
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
}
+ else if (fast_tp_collecting == 2)
+ {
+ if (debug_threads)
+ fprintf (stderr, "\
+lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
+ lwpid_of (lwp));
- /* Fill start and end extra bytes of buffer with existing memory data. */
+ if (can_hardware_single_step ())
+ step = 1;
+ else
+ fatal ("moving out of jump pad single-stepping"
+ " not implemented on this target");
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
+ }
+
+ /* If we have while-stepping actions in this thread set it stepping.
+ If we have a signal to deliver, it may or may not be set to
+ SIG_IGN, we don't know. Assume so, and allow collecting
+ while-stepping into a signal handler. A possible smart thing to
+ do would be to set an internal breakpoint at the signal return
+ address, continue, and carry on catching this while-stepping
+ action only when that breakpoint is hit. A future
+ enhancement. */
+ if (get_lwp_thread (lwp)->while_stepping != NULL
+ && can_hardware_single_step ())
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "lwp %ld has a while-stepping action -> forcing step.\n",
+ lwpid_of (lwp));
+ step = 1;
+ }
+
+ if (debug_threads && the_low_target.get_pc != NULL)
+ {
+ struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+ CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
+ fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
+ }
+
+ /* If we have pending signals, consume one unless we are trying to
+ reinsert a breakpoint or we're trying to finish a fast tracepoint
+ collect. */
+ if (lwp->pending_signals != NULL
+ && lwp->bp_reinsert == 0
+ && fast_tp_collecting == 0)
+ {
+ struct pending_signals **p_sig;
+
+ p_sig = &lwp->pending_signals;
+ while ((*p_sig)->prev != NULL)
+ p_sig = &(*p_sig)->prev;
+
+ signal = (*p_sig)->signal;
+ if ((*p_sig)->info.si_signo != 0)
+ ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
+
+ free (*p_sig);
+ *p_sig = NULL;
+ }
- buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) addr, 0);
+ if (the_low_target.prepare_to_resume != NULL)
+ the_low_target.prepare_to_resume (lwp);
+
+ regcache_invalidate_one ((struct inferior_list_entry *)
+ get_lwp_thread (lwp));
+ errno = 0;
+ lwp->stopped = 0;
+ lwp->stopped_by_watchpoint = 0;
+ lwp->stepping = step;
+ ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG4_TYPE) (uintptr_t) signal);
+
+ current_inferior = saved_inferior;
+ if (errno)
+ {
+ /* ESRCH from ptrace either means that the thread was already
+ running (an error) or that it is gone (a race condition). If
+ it's gone, we will get a notification the next time we wait,
+ so we can ignore the error. We could differentiate these
+ two, but it's tricky without waiting; the thread still exists
+ as a zombie, so sending it signal 0 would succeed. So just
+ ignore ESRCH. */
+ if (errno == ESRCH)
+ return;
+
+ perror_with_name ("ptrace");
+ }
+}
+
+struct thread_resume_array
+{
+ struct thread_resume *resume;
+ size_t n;
+};
+
+/* This function is called once per thread. We look up the thread
+ in RESUME_PTR, and mark the thread with a pointer to the appropriate
+ resume request.
+
+ This algorithm is O(threads * resume elements), but resume elements
+ is small (and will remain small at least until GDB supports thread
+ suspension). */
+static int
+linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
+{
+ struct lwp_info *lwp;
+ struct thread_info *thread;
+ int ndx;
+ struct thread_resume_array *r;
+
+ thread = (struct thread_info *) entry;
+ lwp = get_thread_lwp (thread);
+ r = arg;
+
+ for (ndx = 0; ndx < r->n; ndx++)
+ {
+ ptid_t ptid = r->resume[ndx].thread;
+ if (ptid_equal (ptid, minus_one_ptid)
+ || ptid_equal (ptid, entry->id)
+ || (ptid_is_pid (ptid)
+ && (ptid_get_pid (ptid) == pid_of (lwp)))
+ || (ptid_get_lwp (ptid) == -1
+ && (ptid_get_pid (ptid) == pid_of (lwp))))
+ {
+ if (r->resume[ndx].kind == resume_stop
+ && thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, "already %s LWP %ld at GDB's request\n",
+ thread->last_status.kind == TARGET_WAITKIND_STOPPED
+ ? "stopped"
+ : "stopping",
+ lwpid_of (lwp));
+
+ continue;
+ }
+
+ lwp->resume = &r->resume[ndx];
+ thread->last_resume_kind = lwp->resume->kind;
+
+ /* If we had a deferred signal to report, dequeue one now.
+ This can happen if LWP gets more than one signal while
+ trying to get out of a jump pad. */
+ if (lwp->stopped
+ && !lwp->status_pending_p
+ && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
+ {
+ lwp->status_pending_p = 1;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Dequeueing deferred signal %d for LWP %ld, "
+ "leaving status pending.\n",
+ WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
+ }
+
+ return 0;
+ }
+ }
+
+ /* No resume action for this thread. */
+ lwp->resume = NULL;
+
+ return 0;
+}
+
+
+/* Set *FLAG_P if this lwp has an interesting status pending. */
+static int
+resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* LWPs which will not be resumed are not interesting, because
+ we might not wait for them next time through linux_wait. */
+ if (lwp->resume == NULL)
+ return 0;
+
+ if (lwp->status_pending_p)
+ * (int *) flag_p = 1;
+
+ return 0;
+}
+
+/* Return 1 if this lwp that GDB wants running is stopped at an
+ internal breakpoint that we need to step over. It assumes that any
+ required STOP_PC adjustment has already been propagated to the
+ inferior's regcache. */
+
+static int
+need_step_over_p (struct inferior_list_entry *entry, void *dummy)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread;
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+
+ /* LWPs which will not be resumed are not interesting, because we
+ might not wait for them next time through linux_wait. */
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, not stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ gdb_assert (lwp->suspended >= 0);
+
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, suspended\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ if (!lwp->need_step_over)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, has pending status.\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
+ or we have. */
+ pc = get_pc (lwp);
+
+ /* If the PC has changed since we stopped, then don't do anything,
+ and let the breakpoint/tracepoint be hit. This happens if, for
+ instance, GDB handled the decr_pc_after_break subtraction itself,
+ GDB is OOL stepping this thread, or the user has issued a "jump"
+ command, or poked thread's registers herself. */
+ if (pc != lwp->stop_pc)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Cancelling, PC was changed. "
+ "Old stop_pc was 0x%s, PC is now 0x%s\n",
+ lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
+
+ lwp->need_step_over = 0;
+ return 0;
+ }
+
+ saved_inferior = current_inferior;
+ current_inferior = thread;
+
+ /* We can only step over breakpoints we know about. */
+ if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
+ {
+ /* Don't step over a breakpoint that GDB expects to hit
+ though. If the condition is being evaluated on the target's side
+ and it evaluate to false, step over this breakpoint as well. */
+ if (gdb_breakpoint_here (pc)
+ && gdb_condition_true_at_breakpoint (pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, but found"
+ " GDB breakpoint at 0x%s; skipping step over\n",
+ lwpid_of (lwp), paddress (pc));
+
+ current_inferior = saved_inferior;
+ return 0;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, "
+ "found breakpoint at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
+
+ /* We've found an lwp that needs stepping over --- return 1 so
+ that find_inferior stops looking. */
+ current_inferior = saved_inferior;
+
+ /* If the step over is cancelled, this is set again. */
+ lwp->need_step_over = 0;
+ return 1;
+ }
+ }
+
+ current_inferior = saved_inferior;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
+
+ return 0;
+}
+
+/* Start a step-over operation on LWP. When LWP stopped at a
+ breakpoint, to make progress, we need to remove the breakpoint out
+ of the way. If we let other threads run while we do that, they may
+ pass by the breakpoint location and miss hitting it. To avoid
+ that, a step-over momentarily stops all threads while LWP is
+ single-stepped while the breakpoint is temporarily uninserted from
+ the inferior. When the single-step finishes, we reinsert the
+ breakpoint, and let all threads that are supposed to be running,
+ run again.
+
+ On targets that don't support hardware single-step, we don't
+ currently support full software single-stepping. Instead, we only
+ support stepping over the thread event breakpoint, by asking the
+ low target where to place a reinsert breakpoint. Since this
+ routine assumes the breakpoint being stepped over is a thread event
+ breakpoint, it usually assumes the return address of the current
+ function is a good enough place to set the reinsert breakpoint. */
+
+static int
+start_step_over (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+ int step;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Starting step-over on LWP %ld. Stopping all threads\n",
+ lwpid_of (lwp));
+
+ stop_all_lwps (1, lwp);
+ gdb_assert (lwp->suspended == 0);
+
+ if (debug_threads)
+ fprintf (stderr, "Done stopping all threads for step-over.\n");
+
+ /* Note, we should always reach here with an already adjusted PC,
+ either by GDB (if we're resuming due to GDB's request), or by our
+ caller, if we just finished handling an internal breakpoint GDB
+ shouldn't care about. */
+ pc = get_pc (lwp);
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ lwp->bp_reinsert = pc;
+ uninsert_breakpoints_at (pc);
+ uninsert_fast_tracepoint_jumps_at (pc);
+
+ if (can_hardware_single_step ())
+ {
+ step = 1;
+ }
+ else
+ {
+ CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
+ set_reinsert_breakpoint (raddr);
+ step = 0;
+ }
+
+ current_inferior = saved_inferior;
+
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+
+ /* Require next event from this LWP. */
+ step_over_bkpt = lwp->head.id;
+ return 1;
+}
+
+/* Finish a step-over. Reinsert the breakpoint we had uninserted in
+ start_step_over, if still there, and delete any reinsert
+ breakpoints we've set, on non hardware single-step targets. */
+
+static int
+finish_step_over (struct lwp_info *lwp)
+{
+ if (lwp->bp_reinsert != 0)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Finished step over.\n");
+
+ /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
+ may be no breakpoint to reinsert there by now. */
+ reinsert_breakpoints_at (lwp->bp_reinsert);
+ reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
+
+ lwp->bp_reinsert = 0;
+
+ /* Delete any software-single-step reinsert breakpoints. No
+ longer needed. We don't have to worry about other threads
+ hitting this trap, and later not being able to explain it,
+ because we were stepping over a breakpoint, and we hold all
+ threads but LWP stopped while doing that. */
+ if (!can_hardware_single_step ())
+ delete_reinsert_breakpoints ();
+
+ step_over_bkpt = null_ptid;
+ return 1;
+ }
+ else
+ return 0;
+}
+
+/* This function is called once per thread. We check the thread's resume
+ request, which will tell us whether to resume, step, or leave the thread
+ stopped; and what signal, if any, it should be sent.
+
+ For threads which we aren't explicitly told otherwise, we preserve
+ the stepping flag; this is used for stepping over gdbserver-placed
+ breakpoints.
+
+ If pending_flags was set in any thread, we queue any needed
+ signals, since we won't actually resume. We already have a pending
+ event to report, so we don't need to preserve any step requests;
+ they should be re-issued if necessary. */
+
+static int
+linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
+{
+ struct lwp_info *lwp;
+ struct thread_info *thread;
+ int step;
+ int leave_all_stopped = * (int *) arg;
+ int leave_pending;
+
+ thread = (struct thread_info *) entry;
+ lwp = get_thread_lwp (thread);
+
+ if (lwp->resume == NULL)
+ return 0;
+
+ if (lwp->resume->kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
+
+ /* Stop the thread, and wait for the event asynchronously,
+ through the event loop. */
+ send_sigstop (lwp);
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "already stopped LWP %ld\n",
+ lwpid_of (lwp));
+
+ /* The LWP may have been stopped in an internal event that
+ was not meant to be notified back to GDB (e.g., gdbserver
+ breakpoint), so we should be reporting a stop event in
+ this case too. */
+
+ /* If the thread already has a pending SIGSTOP, this is a
+ no-op. Otherwise, something later will presumably resume
+ the thread and this will cause it to cancel any pending
+ operation, due to last_resume_kind == resume_stop. If
+ the thread already has a pending status to report, we
+ will still report it the next time we wait - see
+ status_pending_p_callback. */
+
+ /* If we already have a pending signal to report, then
+ there's no need to queue a SIGSTOP, as this means we're
+ midway through moving the LWP out of the jumppad, and we
+ will report the pending signal as soon as that is
+ finished. */
+ if (lwp->pending_signals_to_report == NULL)
+ send_sigstop (lwp);
+ }
+
+ /* For stop requests, we're done. */
+ lwp->resume = NULL;
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
+ return 0;
+ }
+
+ /* If this thread which is about to be resumed has a pending status,
+ then don't resume any threads - we can just report the pending
+ status. Make sure to queue any signals that would otherwise be
+ sent. In all-stop mode, we do this decision based on if *any*
+ thread has a pending status. If there's a thread that needs the
+ step-over-breakpoint dance, then don't resume any other thread
+ but that particular one. */
+ leave_pending = (lwp->status_pending_p || leave_all_stopped);
+
+ if (!leave_pending)
+ {
+ if (debug_threads)
+ fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
+
+ step = (lwp->resume->kind == resume_step);
+ linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
+
+ /* If we have a new signal, enqueue the signal. */
+ if (lwp->resume->sig != 0)
+ {
+ struct pending_signals *p_sig;
+ p_sig = xmalloc (sizeof (*p_sig));
+ p_sig->prev = lwp->pending_signals;
+ p_sig->signal = lwp->resume->sig;
+ memset (&p_sig->info, 0, sizeof (siginfo_t));
+
+ /* If this is the same signal we were previously stopped by,
+ make sure to queue its siginfo. We can ignore the return
+ value of ptrace; if it fails, we'll skip
+ PTRACE_SETSIGINFO. */
+ if (WIFSTOPPED (lwp->last_status)
+ && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
+ ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
+
+ lwp->pending_signals = p_sig;
+ }
+ }
+
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
+ lwp->resume = NULL;
+ return 0;
+}
+
+static void
+linux_resume (struct thread_resume *resume_info, size_t n)
+{
+ struct thread_resume_array array = { resume_info, n };
+ struct lwp_info *need_step_over = NULL;
+ int any_pending;
+ int leave_all_stopped;
+
+ find_inferior (&all_threads, linux_set_resume_request, &array);
+
+ /* If there is a thread which would otherwise be resumed, which has
+ a pending status, then don't resume any threads - we can just
+ report the pending status. Make sure to queue any signals that
+ would otherwise be sent. In non-stop mode, we'll apply this
+ logic to each thread individually. We consume all pending events
+ before considering to start a step-over (in all-stop). */
+ any_pending = 0;
+ if (!non_stop)
+ find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
+
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. Make sure
+ to queue any signals that would otherwise be delivered or
+ queued. */
+ if (!any_pending && supports_breakpoints ())
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ leave_all_stopped = (need_step_over != NULL || any_pending);
+
+ if (debug_threads)
+ {
+ if (need_step_over != NULL)
+ fprintf (stderr, "Not resuming all, need step over\n");
+ else if (any_pending)
+ fprintf (stderr,
+ "Not resuming, all-stop and found "
+ "an LWP with pending status\n");
+ else
+ fprintf (stderr, "Resuming, no pending status or step over needed\n");
+ }
+
+ /* Even if we're leaving threads stopped, queue all signals we'd
+ otherwise deliver. */
+ find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
+
+ if (need_step_over)
+ start_step_over (need_step_over);
+}
+
+/* This function is called once per thread. We check the thread's
+ last resume request, which will tell us whether to resume, step, or
+ leave the thread stopped. Any signal the client requested to be
+ delivered has already been enqueued at this point.
+
+ If any thread that GDB wants running is stopped at an internal
+ breakpoint that needs stepping over, we start a step-over operation
+ on that particular thread, and leave all others stopped. */
+
+static int
+proceed_one_lwp (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread;
+ int step;
+
+ if (lwp == except)
+ return 0;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
+ return 0;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
+ {
+ if (debug_threads)
+ fprintf (stderr, " client wants LWP to remain %ld stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ gdb_assert (lwp->suspended >= 0);
+
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
+ return 0;
+ }
+
+ if (thread->last_resume_kind == resume_stop
+ && lwp->pending_signals_to_report == NULL
+ && lwp->collecting_fast_tracepoint == 0)
+ {
+ /* We haven't reported this LWP as stopped yet (otherwise, the
+ last_status.kind check above would catch it, and we wouldn't
+ reach here. This LWP may have been momentarily paused by a
+ stop_all_lwps call while handling for example, another LWP's
+ step-over. In that case, the pending expected SIGSTOP signal
+ that was queued at vCont;t handling time will have already
+ been consumed by wait_for_sigstop, and so we need to requeue
+ another one here. Note that if the LWP already has a SIGSTOP
+ pending, this is a no-op. */
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Client wants LWP %ld to stop. "
+ "Making sure it has a SIGSTOP pending\n",
+ lwpid_of (lwp));
+
+ send_sigstop (lwp);
+ }
+
+ step = thread->last_resume_kind == resume_step;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+ return 0;
+}
+
+static int
+unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ if (lwp == except)
+ return 0;
+
+ lwp->suspended--;
+ gdb_assert (lwp->suspended >= 0);
+
+ return proceed_one_lwp (entry, except);
+}
+
+/* When we finish a step-over, set threads running again. If there's
+ another thread that may need a step-over, now's the time to start
+ it. Eventually, we'll move all threads past their breakpoints. */
+
+static void
+proceed_all_lwps (void)
+{
+ struct lwp_info *need_step_over;
+
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. */
+
+ if (supports_breakpoints ())
+ {
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ if (need_step_over != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "proceed_all_lwps: found "
+ "thread %ld needing a step-over\n",
+ lwpid_of (need_step_over));
+
+ start_step_over (need_step_over);
+ return;
+ }
+ }
+
+ if (debug_threads)
+ fprintf (stderr, "Proceeding, no step-over needed\n");
+
+ find_inferior (&all_lwps, proceed_one_lwp, NULL);
+}
+
+/* Stopped LWPs that the client wanted to be running, that don't have
+ pending statuses, are set to run again, except for EXCEPT, if not
+ NULL. This undoes a stop_all_lwps call. */
+
+static void
+unstop_all_lwps (int unsuspend, struct lwp_info *except)
+{
+ if (debug_threads)
+ {
+ if (except)
+ fprintf (stderr,
+ "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
+ else
+ fprintf (stderr,
+ "unstopping all lwps\n");
+ }
+
+ if (unsuspend)
+ find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
+ else
+ find_inferior (&all_lwps, proceed_one_lwp, except);
+}
+
+
+#ifdef HAVE_LINUX_REGSETS
+
+#define use_linux_regsets 1
+
+static int
+regsets_fetch_inferior_registers (struct regcache *regcache)
+{
+ struct regset_info *regset;
+ int saw_general_regs = 0;
+ int pid;
+ struct iovec iov;
+
+ regset = target_regsets;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ while (regset->size >= 0)
+ {
+ void *buf, *data;
+ int nt_type, res;
+
+ if (regset->size == 0 || disabled_regsets[regset - target_regsets])
+ {
+ regset ++;
+ continue;
+ }
+
+ buf = xmalloc (regset->size);
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
+#ifndef __sparc__
+ res = ptrace (regset->get_request, pid, nt_type, data);
+#else
+ res = ptrace (regset->get_request, pid, data, nt_type);
+#endif
+ if (res < 0)
+ {
+ if (errno == EIO)
+ {
+ /* If we get EIO on a regset, do not try it again for
+ this process. */
+ disabled_regsets[regset - target_regsets] = 1;
+ free (buf);
+ continue;
+ }
+ else
+ {
+ char s[256];
+ sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
+ pid);
+ perror (s);
+ }
+ }
+ else if (regset->type == GENERAL_REGS)
+ saw_general_regs = 1;
+ regset->store_function (regcache, buf);
+ regset ++;
+ free (buf);
+ }
+ if (saw_general_regs)
+ return 0;
+ else
+ return 1;
+}
+
+static int
+regsets_store_inferior_registers (struct regcache *regcache)
+{
+ struct regset_info *regset;
+ int saw_general_regs = 0;
+ int pid;
+ struct iovec iov;
+
+ regset = target_regsets;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ while (regset->size >= 0)
+ {
+ void *buf, *data;
+ int nt_type, res;
+
+ if (regset->size == 0 || disabled_regsets[regset - target_regsets])
+ {
+ regset ++;
+ continue;
+ }
+
+ buf = xmalloc (regset->size);
+
+ /* First fill the buffer with the current register set contents,
+ in case there are any items in the kernel's regset that are
+ not in gdbserver's regcache. */
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
+#ifndef __sparc__
+ res = ptrace (regset->get_request, pid, nt_type, data);
+#else
+ res = ptrace (regset->get_request, pid, &iov, data);
+#endif
+
+ if (res == 0)
+ {
+ /* Then overlay our cached registers on that. */
+ regset->fill_function (regcache, buf);
+
+ /* Only now do we write the register set. */
+#ifndef __sparc__
+ res = ptrace (regset->set_request, pid, nt_type, data);
+#else
+ res = ptrace (regset->set_request, pid, data, nt_type);
+#endif
+ }
+
+ if (res < 0)
+ {
+ if (errno == EIO)
+ {
+ /* If we get EIO on a regset, do not try it again for
+ this process. */
+ disabled_regsets[regset - target_regsets] = 1;
+ free (buf);
+ continue;
+ }
+ else if (errno == ESRCH)
+ {
+ /* At this point, ESRCH should mean the process is
+ already gone, in which case we simply ignore attempts
+ to change its registers. See also the related
+ comment in linux_resume_one_lwp. */
+ free (buf);
+ return 0;
+ }
+ else
+ {
+ perror ("Warning: ptrace(regsets_store_inferior_registers)");
+ }
+ }
+ else if (regset->type == GENERAL_REGS)
+ saw_general_regs = 1;
+ regset ++;
+ free (buf);
+ }
+ if (saw_general_regs)
+ return 0;
+ else
+ return 1;
+}
+
+#else /* !HAVE_LINUX_REGSETS */
+
+#define use_linux_regsets 0
+#define regsets_fetch_inferior_registers(regcache) 1
+#define regsets_store_inferior_registers(regcache) 1
+
+#endif
+
+/* Return 1 if register REGNO is supported by one of the regset ptrace
+ calls or 0 if it has to be transferred individually. */
+
+static int
+linux_register_in_regsets (int regno)
+{
+ unsigned char mask = 1 << (regno % 8);
+ size_t index = regno / 8;
+
+ return (use_linux_regsets
+ && (the_low_target.regset_bitmap == NULL
+ || (the_low_target.regset_bitmap[index] & mask) != 0));
+}
+
+#ifdef HAVE_LINUX_USRREGS
+
+int
+register_addr (int regnum)
+{
+ int addr;
+
+ if (regnum < 0 || regnum >= the_low_target.num_regs)
+ error ("Invalid register number %d.", regnum);
+
+ addr = the_low_target.regmap[regnum];
+
+ return addr;
+}
+
+/* Fetch one register. */
+static void
+fetch_register (struct regcache *regcache, int regno)
+{
+ CORE_ADDR regaddr;
+ int i, size;
+ char *buf;
+ int pid;
+
+ if (regno >= the_low_target.num_regs)
+ return;
+ if ((*the_low_target.cannot_fetch_register) (regno))
+ return;
+
+ regaddr = register_addr (regno);
+ if (regaddr == -1)
+ return;
+
+ size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
+ & -sizeof (PTRACE_XFER_TYPE));
+ buf = alloca (size);
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ *(PTRACE_XFER_TYPE *) (buf + i) =
+ ptrace (PTRACE_PEEKUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
+ regaddr += sizeof (PTRACE_XFER_TYPE);
+ if (errno != 0)
+ error ("reading register %d: %s", regno, strerror (errno));
+ }
+
+ if (the_low_target.supply_ptrace_register)
+ the_low_target.supply_ptrace_register (regcache, regno, buf);
+ else
+ supply_register (regcache, regno, buf);
+}
+
+/* Store one register. */
+static void
+store_register (struct regcache *regcache, int regno)
+{
+ CORE_ADDR regaddr;
+ int i, size;
+ char *buf;
+ int pid;
+
+ if (regno >= the_low_target.num_regs)
+ return;
+ if ((*the_low_target.cannot_store_register) (regno))
+ return;
+
+ regaddr = register_addr (regno);
+ if (regaddr == -1)
+ return;
+
+ size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
+ & -sizeof (PTRACE_XFER_TYPE));
+ buf = alloca (size);
+ memset (buf, 0, size);
+
+ if (the_low_target.collect_ptrace_register)
+ the_low_target.collect_ptrace_register (regcache, regno, buf);
+ else
+ collect_register (regcache, regno, buf);
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
+ (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
+ if (errno != 0)
+ {
+ /* At this point, ESRCH should mean the process is
+ already gone, in which case we simply ignore attempts
+ to change its registers. See also the related
+ comment in linux_resume_one_lwp. */
+ if (errno == ESRCH)
+ return;
+
+ if ((*the_low_target.cannot_store_register) (regno) == 0)
+ error ("writing register %d: %s", regno, strerror (errno));
+ }
+ regaddr += sizeof (PTRACE_XFER_TYPE);
+ }
+}
+
+/* Fetch all registers, or just one, from the child process.
+ If REGNO is -1, do this for all registers, skipping any that are
+ assumed to have been retrieved by regsets_fetch_inferior_registers,
+ unless ALL is non-zero.
+ Otherwise, REGNO specifies which register (so we can save time). */
+static void
+usr_fetch_inferior_registers (struct regcache *regcache, int regno, int all)
+{
+ if (regno == -1)
+ {
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ if (all || !linux_register_in_regsets (regno))
+ fetch_register (regcache, regno);
+ }
+ else
+ fetch_register (regcache, regno);
+}
+
+/* Store our register values back into the inferior.
+ If REGNO is -1, do this for all registers, skipping any that are
+ assumed to have been saved by regsets_store_inferior_registers,
+ unless ALL is non-zero.
+ Otherwise, REGNO specifies which register (so we can save time). */
+static void
+usr_store_inferior_registers (struct regcache *regcache, int regno, int all)
+{
+ if (regno == -1)
+ {
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ if (all || !linux_register_in_regsets (regno))
+ store_register (regcache, regno);
+ }
+ else
+ store_register (regcache, regno);
+}
+
+#else /* !HAVE_LINUX_USRREGS */
+
+#define usr_fetch_inferior_registers(regcache, regno, all) do {} while (0)
+#define usr_store_inferior_registers(regcache, regno, all) do {} while (0)
+
+#endif
+
+
+void
+linux_fetch_registers (struct regcache *regcache, int regno)
+{
+ int use_regsets;
+ int all = 0;
+
+ if (regno == -1)
+ {
+ all = regsets_fetch_inferior_registers (regcache);
+ usr_fetch_inferior_registers (regcache, regno, all);
+ }
+ else
+ {
+ use_regsets = linux_register_in_regsets (regno);
+ if (use_regsets)
+ all = regsets_fetch_inferior_registers (regcache);
+ if (!use_regsets || all)
+ usr_fetch_inferior_registers (regcache, regno, 1);
+ }
+}
+
+void
+linux_store_registers (struct regcache *regcache, int regno)
+{
+ int use_regsets;
+ int all = 0;
+
+ if (regno == -1)
+ {
+ all = regsets_store_inferior_registers (regcache);
+ usr_store_inferior_registers (regcache, regno, all);
+ }
+ else
+ {
+ use_regsets = linux_register_in_regsets (regno);
+ if (use_regsets)
+ all = regsets_store_inferior_registers (regcache);
+ if (!use_regsets || all)
+ usr_store_inferior_registers (regcache, regno, 1);
+ }
+}
+
+
+/* Copy LEN bytes from inferior's memory starting at MEMADDR
+ to debugger memory starting at MYADDR. */
+
+static int
+linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
+{
+ register int i;
+ /* Round starting address down to longword boundary. */
+ register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
+ /* Round ending address up; get number of longwords that makes. */
+ register int count
+ = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+ / sizeof (PTRACE_XFER_TYPE);
+ /* Allocate buffer of that many longwords. */
+ register PTRACE_XFER_TYPE *buffer
+ = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ int fd;
+ char filename[64];
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+
+ /* Try using /proc. Don't bother for one word. */
+ if (len >= 3 * sizeof (long))
+ {
+ /* We could keep this file open and cache it - possibly one per
+ thread. That requires some juggling, but is even faster. */
+ sprintf (filename, "/proc/%d/mem", pid);
+ fd = open (filename, O_RDONLY | O_LARGEFILE);
+ if (fd == -1)
+ goto no_proc;
+
+ /* If pread64 is available, use it. It's faster if the kernel
+ supports it (only one syscall), and it's 64-bit safe even on
+ 32-bit platforms (for instance, SPARC debugging a SPARC64
+ application). */
+#ifdef HAVE_PREAD64
+ if (pread64 (fd, myaddr, len, memaddr) != len)
+#else
+ if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
+#endif
+ {
+ close (fd);
+ goto no_proc;
+ }
+
+ close (fd);
+ return 0;
+ }
+
+ no_proc:
+ /* Read all the longwords */
+ for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
+ if (errno)
+ return errno;
+ }
+
+ /* Copy appropriate bytes out of the buffer. */
+ memcpy (myaddr,
+ (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+ len);
+
+ return 0;
+}
+
+/* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
+ memory at MEMADDR. On failure (cannot write to the inferior)
+ returns the value of errno. */
+
+static int
+linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
+{
+ register int i;
+ /* Round starting address down to longword boundary. */
+ register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
+ /* Round ending address up; get number of longwords that makes. */
+ register int count
+ = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+ / sizeof (PTRACE_XFER_TYPE);
+
+ /* Allocate buffer of that many longwords. */
+ register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
+ alloca (count * sizeof (PTRACE_XFER_TYPE));
+
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+
+ if (debug_threads)
+ {
+ /* Dump up to four bytes. */
+ unsigned int val = * (unsigned int *) myaddr;
+ if (len == 1)
+ val = val & 0xff;
+ else if (len == 2)
+ val = val & 0xffff;
+ else if (len == 3)
+ val = val & 0xffffff;
+ fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
+ val, (long)memaddr);
+ }
+
+ /* Fill start and end extra bytes of buffer with existing memory data. */
+
+ errno = 0;
+ /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
+ if (errno)
+ return errno;
+
+ if (count > 1)
+ {
+ errno = 0;
+ buffer[count - 1]
+ = ptrace (PTRACE_PEEKTEXT, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
+ * sizeof (PTRACE_XFER_TYPE)),
+ 0);
+ if (errno)
+ return errno;
+ }
+
+ /* Copy data to be written over corresponding part of buffer. */
+
+ memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+ myaddr, len);
+
+ /* Write the entire buffer. */
+
+ for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ ptrace (PTRACE_POKETEXT, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr,
+ (PTRACE_ARG4_TYPE) buffer[i]);
+ if (errno)
+ return errno;
+ }
+
+ return 0;
+}
+
+/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
+static int linux_supports_tracefork_flag;
+
+static void
+linux_enable_event_reporting (int pid)
+{
+ if (!linux_supports_tracefork_flag)
+ return;
+
+ ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+}
+
+/* Helper functions for linux_test_for_tracefork, called via clone (). */
+
+static int
+linux_tracefork_grandchild (void *arg)
+{
+ _exit (0);
+}
+
+#define STACK_SIZE 4096
+
+static int
+linux_tracefork_child (void *arg)
+{
+ ptrace (PTRACE_TRACEME, 0, 0, 0);
+ kill (getpid (), SIGSTOP);
+
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ if (fork () == 0)
+ linux_tracefork_grandchild (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
+#ifdef __ia64__
+ __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
+ CLONE_VM | SIGCHLD, NULL);
+#else
+ clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
+ CLONE_VM | SIGCHLD, NULL);
+#endif
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
+ _exit (0);
+}
+
+/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
+ sure that we can enable the option, and that it had the desired
+ effect. */
+
+static void
+linux_test_for_tracefork (void)
+{
+ int child_pid, ret, status;
+ long second_pid;
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+ char *stack = xmalloc (STACK_SIZE * 4);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
+ linux_supports_tracefork_flag = 0;
+
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ child_pid = fork ();
+ if (child_pid == 0)
+ linux_tracefork_child (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
+ /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
+#ifdef __ia64__
+ child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
+ CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
+#else /* !__ia64__ */
+ child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
+ CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
+#endif /* !__ia64__ */
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
+ if (child_pid == -1)
+ perror_with_name ("clone");
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret == -1)
+ perror_with_name ("waitpid");
+ else if (ret != child_pid)
+ error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
+ if (! WIFSTOPPED (status))
+ error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
+
+ ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
+ (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
+ if (ret != 0)
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ {
+ warning ("linux_test_for_tracefork: failed to kill child");
+ return;
+ }
+
+ ret = my_waitpid (child_pid, &status, 0);
+ if (ret != child_pid)
+ warning ("linux_test_for_tracefork: failed to wait for killed child");
+ else if (!WIFSIGNALED (status))
+ warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
+ "killed child", status);
+
+ return;
+ }
+
+ ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to resume child");
+
+ ret = my_waitpid (child_pid, &status, 0);
+
+ if (ret == child_pid && WIFSTOPPED (status)
+ && status >> 16 == PTRACE_EVENT_FORK)
+ {
+ second_pid = 0;
+ ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
+ if (ret == 0 && second_pid != 0)
+ {
+ int second_status;
+
+ linux_supports_tracefork_flag = 1;
+ my_waitpid (second_pid, &second_status, 0);
+ ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill second child");
+ my_waitpid (second_pid, &status, 0);
+ }
+ }
+ else
+ warning ("linux_test_for_tracefork: unexpected result from waitpid "
+ "(%d, status 0x%x)", ret, status);
+
+ do
+ {
+ ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
+ if (ret != 0)
+ warning ("linux_test_for_tracefork: failed to kill child");
+ my_waitpid (child_pid, &status, 0);
+ }
+ while (WIFSTOPPED (status));
+
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+ free (stack);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+}
+
+
+static void
+linux_look_up_symbols (void)
+{
+#ifdef USE_THREAD_DB
+ struct process_info *proc = current_process ();
+
+ if (proc->private->thread_db != NULL)
+ return;
+
+ /* If the kernel supports tracing forks then it also supports tracing
+ clones, and then we don't need to use the magic thread event breakpoint
+ to learn about threads. */
+ thread_db_init (!linux_supports_tracefork_flag);
+#endif
+}
+
+static void
+linux_request_interrupt (void)
+{
+ extern unsigned long signal_pid;
+
+ if (!ptid_equal (cont_thread, null_ptid)
+ && !ptid_equal (cont_thread, minus_one_ptid))
+ {
+ struct lwp_info *lwp;
+ int lwpid;
+
+ lwp = get_thread_lwp (current_inferior);
+ lwpid = lwpid_of (lwp);
+ kill_lwp (lwpid, SIGINT);
+ }
+ else
+ kill_lwp (signal_pid, SIGINT);
+}
+
+/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
+ to debugger memory starting at MYADDR. */
+
+static int
+linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
+{
+ char filename[PATH_MAX];
+ int fd, n;
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+
+ xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
+
+ fd = open (filename, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ if (offset != (CORE_ADDR) 0
+ && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
+ n = -1;
+ else
+ n = read (fd, myaddr, len);
+
+ close (fd);
+
+ return n;
+}
+
+/* These breakpoint and watchpoint related wrapper functions simply
+ pass on the function call if the target has registered a
+ corresponding function. */
+
+static int
+linux_insert_point (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.insert_point != NULL)
+ return the_low_target.insert_point (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+linux_remove_point (char type, CORE_ADDR addr, int len)
+{
+ if (the_low_target.remove_point != NULL)
+ return the_low_target.remove_point (type, addr, len);
+ else
+ /* Unsupported (see target.h). */
+ return 1;
+}
+
+static int
+linux_stopped_by_watchpoint (void)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_by_watchpoint;
+}
+
+static CORE_ADDR
+linux_stopped_data_address (void)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_data_address;
+}
+
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+#if defined(__mcoldfire__)
+/* These should really be defined in the kernel's ptrace.h header. */
+#define PT_TEXT_ADDR 49*4
+#define PT_DATA_ADDR 50*4
+#define PT_TEXT_END_ADDR 51*4
+#elif defined(BFIN)
+#define PT_TEXT_ADDR 220
+#define PT_TEXT_END_ADDR 224
+#define PT_DATA_ADDR 228
+#elif defined(__TMS320C6X__)
+#define PT_TEXT_ADDR (0x10000*4)
+#define PT_DATA_ADDR (0x10004*4)
+#define PT_TEXT_END_ADDR (0x10008*4)
+#endif
+
+/* Under uClinux, programs are loaded at non-zero offsets, which we need
+ to tell gdb about. */
+
+static int
+linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
+{
+#if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
+ unsigned long text, text_end, data;
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+
+ errno = 0;
+
+ text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
+ text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
+ data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
+
+ if (errno == 0)
+ {
+ /* Both text and data offsets produced at compile-time (and so
+ used by gdb) are relative to the beginning of the program,
+ with the data segment immediately following the text segment.
+ However, the actual runtime layout in memory may put the data
+ somewhere else, so when we send gdb a data base-address, we
+ use the real data base address and subtract the compile-time
+ data base-address from it (which is just the length of the
+ text segment). BSS immediately follows data in both
+ cases. */
+ *text_p = text;
+ *data_p = data - (text_end - text);
+
+ return 1;
+ }
+#endif
+ return 0;
+}
+#endif
+
+static int
+linux_qxfer_osdata (const char *annex,
+ unsigned char *readbuf, unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
+{
+ return linux_common_xfer_osdata (annex, readbuf, offset, len);
+}
+
+/* Convert a native/host siginfo object, into/from the siginfo in the
+ layout of the inferiors' architecture. */
+
+static void
+siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
+{
+ int done = 0;
+
+ if (the_low_target.siginfo_fixup != NULL)
+ done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
+
+ /* If there was no callback, or the callback didn't do anything,
+ then just do a straight memcpy. */
+ if (!done)
+ {
+ if (direction == 1)
+ memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
+ else
+ memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
+ }
+}
+
+static int
+linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf, CORE_ADDR offset, int len)
+{
+ int pid;
+ struct siginfo siginfo;
+ char inf_siginfo[sizeof (struct siginfo)];
+
+ if (current_inferior == NULL)
+ return -1;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+
+ if (debug_threads)
+ fprintf (stderr, "%s siginfo for lwp %d.\n",
+ readbuf != NULL ? "Reading" : "Writing",
+ pid);
+
+ if (offset >= sizeof (siginfo))
+ return -1;
+
+ if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
+ return -1;
+
+ /* When GDBSERVER is built as a 64-bit application, ptrace writes into
+ SIGINFO an object with 64-bit layout. Since debugging a 32-bit
+ inferior with a 64-bit GDBSERVER should look the same as debugging it
+ with a 32-bit GDBSERVER, we need to convert it. */
+ siginfo_fixup (&siginfo, inf_siginfo, 0);
+
+ if (offset + len > sizeof (siginfo))
+ len = sizeof (siginfo) - offset;
+
+ if (readbuf != NULL)
+ memcpy (readbuf, inf_siginfo + offset, len);
+ else
+ {
+ memcpy (inf_siginfo + offset, writebuf, len);
+
+ /* Convert back to ptrace layout before flushing it out. */
+ siginfo_fixup (&siginfo, inf_siginfo, 1);
+
+ if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
+ return -1;
+ }
+
+ return len;
+}
+
+/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
+ so we notice when children change state; as the handler for the
+ sigsuspend in my_waitpid. */
+
+static void
+sigchld_handler (int signo)
+{
+ int old_errno = errno;
+
+ if (debug_threads)
+ {
+ do
+ {
+ /* fprintf is not async-signal-safe, so call write
+ directly. */
+ if (write (2, "sigchld_handler\n",
+ sizeof ("sigchld_handler\n") - 1) < 0)
+ break; /* just ignore */
+ } while (0);
+ }
+
+ if (target_is_async_p ())
+ async_file_mark (); /* trigger a linux_wait */
+
+ errno = old_errno;
+}
+
+static int
+linux_supports_non_stop (void)
+{
+ return 1;
+}
+
+static int
+linux_async (int enable)
+{
+ int previous = (linux_event_pipe[0] != -1);
+
+ if (debug_threads)
+ fprintf (stderr, "linux_async (%d), previous=%d\n",
+ enable, previous);
+
+ if (previous != enable)
+ {
+ sigset_t mask;
+ sigemptyset (&mask);
+ sigaddset (&mask, SIGCHLD);
+
+ sigprocmask (SIG_BLOCK, &mask, NULL);
+
+ if (enable)
+ {
+ if (pipe (linux_event_pipe) == -1)
+ fatal ("creating event pipe failed.");
- if (count > 1)
- {
- buffer[count - 1]
- = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) (addr + (count - 1)
- * sizeof (PTRACE_XFER_TYPE)),
- 0);
- }
+ fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
+ fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
- /* Copy data to be written over corresponding part of buffer */
+ /* Register the event loop handler. */
+ add_file_handler (linux_event_pipe[0],
+ handle_target_event, NULL);
- memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
+ /* Always trigger a linux_wait. */
+ async_file_mark ();
+ }
+ else
+ {
+ delete_file_handler (linux_event_pipe[0]);
- /* Write the entire buffer. */
+ close (linux_event_pipe[0]);
+ close (linux_event_pipe[1]);
+ linux_event_pipe[0] = -1;
+ linux_event_pipe[1] = -1;
+ }
- for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
- {
- errno = 0;
- ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
- if (errno)
- return errno;
+ sigprocmask (SIG_UNBLOCK, &mask, NULL);
}
- return 0;
+ return previous;
}
-static int linux_supports_tracefork_flag;
-
-/* Helper functions for linux_test_for_tracefork, called via clone (). */
-
static int
-linux_tracefork_grandchild (void *arg)
+linux_start_non_stop (int nonstop)
{
- _exit (0);
+ /* Register or unregister from event-loop accordingly. */
+ linux_async (nonstop);
+ return 0;
}
-#define STACK_SIZE 4096
+static int
+linux_supports_multi_process (void)
+{
+ return 1;
+}
static int
-linux_tracefork_child (void *arg)
+linux_supports_disable_randomization (void)
{
- ptrace (PTRACE_TRACEME, 0, 0, 0);
- kill (getpid (), SIGSTOP);
-#ifdef __ia64__
- __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
- CLONE_VM | SIGCHLD, NULL);
+#ifdef HAVE_PERSONALITY
+ return 1;
#else
- clone (linux_tracefork_grandchild, arg + STACK_SIZE,
- CLONE_VM | SIGCHLD, NULL);
+ return 0;
#endif
- _exit (0);
}
-/* Wrapper function for waitpid which handles EINTR, and emulates
- __WALL for systems where that is not available. */
-
static int
-my_waitpid (int pid, int *status, int flags)
+linux_supports_agent (void)
{
- int ret, out_errno;
+ return 1;
+}
- if (debug_threads)
- fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
+/* Enumerate spufs IDs for process PID. */
+static int
+spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
+{
+ int pos = 0;
+ int written = 0;
+ char path[128];
+ DIR *dir;
+ struct dirent *entry;
+
+ sprintf (path, "/proc/%ld/fd", pid);
+ dir = opendir (path);
+ if (!dir)
+ return -1;
- if (flags & __WALL)
+ rewinddir (dir);
+ while ((entry = readdir (dir)) != NULL)
{
- sigset_t block_mask, org_mask, wake_mask;
- int wnohang;
-
- wnohang = (flags & WNOHANG) != 0;
- flags &= ~(__WALL | __WCLONE);
- flags |= WNOHANG;
-
- /* Block all signals while here. This avoids knowing about
- LinuxThread's signals. */
- sigfillset (&block_mask);
- sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
-
- /* ... except during the sigsuspend below. */
- sigemptyset (&wake_mask);
-
- while (1)
- {
- /* Since all signals are blocked, there's no need to check
- for EINTR here. */
- ret = waitpid (pid, status, flags);
- out_errno = errno;
+ struct stat st;
+ struct statfs stfs;
+ int fd;
+
+ fd = atoi (entry->d_name);
+ if (!fd)
+ continue;
+
+ sprintf (path, "/proc/%ld/fd/%d", pid, fd);
+ if (stat (path, &st) != 0)
+ continue;
+ if (!S_ISDIR (st.st_mode))
+ continue;
+
+ if (statfs (path, &stfs) != 0)
+ continue;
+ if (stfs.f_type != SPUFS_MAGIC)
+ continue;
+
+ if (pos >= offset && pos + 4 <= offset + len)
+ {
+ *(unsigned int *)(buf + pos - offset) = fd;
+ written += 4;
+ }
+ pos += 4;
+ }
- if (ret == -1 && out_errno != ECHILD)
- break;
- else if (ret > 0)
- break;
+ closedir (dir);
+ return written;
+}
- if (flags & __WCLONE)
- {
- /* We've tried both flavors now. If WNOHANG is set,
- there's nothing else to do, just bail out. */
- if (wnohang)
- break;
+/* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
+ object type, using the /proc file system. */
+static int
+linux_qxfer_spu (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
+{
+ long pid = lwpid_of (get_thread_lwp (current_inferior));
+ char buf[128];
+ int fd = 0;
+ int ret = 0;
- if (debug_threads)
- fprintf (stderr, "blocking\n");
+ if (!writebuf && !readbuf)
+ return -1;
- /* Block waiting for signals. */
- sigsuspend (&wake_mask);
- }
+ if (!*annex)
+ {
+ if (!readbuf)
+ return -1;
+ else
+ return spu_enumerate_spu_ids (pid, readbuf, offset, len);
+ }
- flags ^= __WCLONE;
- }
+ sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
+ fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
+ if (fd <= 0)
+ return -1;
- sigprocmask (SIG_SETMASK, &org_mask, NULL);
- }
- else
+ if (offset != 0
+ && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
{
- do
- ret = waitpid (pid, status, flags);
- while (ret == -1 && errno == EINTR);
- out_errno = errno;
+ close (fd);
+ return 0;
}
- if (debug_threads)
- fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
- pid, flags, status ? *status : -1, ret);
+ if (writebuf)
+ ret = write (fd, writebuf, (size_t) len);
+ else
+ ret = read (fd, readbuf, (size_t) len);
- errno = out_errno;
+ close (fd);
return ret;
}
-/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
- sure that we can enable the option, and that it had the desired
- effect. */
-
-static void
-linux_test_for_tracefork (void)
+#if defined PT_GETDSBT || defined PTRACE_GETFDPIC
+struct target_loadseg
{
- int child_pid, ret, status;
- long second_pid;
- char *stack = xmalloc (STACK_SIZE * 4);
-
- linux_supports_tracefork_flag = 0;
-
- /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
-#ifdef __ia64__
- child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
- CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#else
- child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
- CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#endif
- if (child_pid == -1)
- perror_with_name ("clone");
+ /* Core address to which the segment is mapped. */
+ Elf32_Addr addr;
+ /* VMA recorded in the program header. */
+ Elf32_Addr p_vaddr;
+ /* Size of this segment in memory. */
+ Elf32_Word p_memsz;
+};
- ret = my_waitpid (child_pid, &status, 0);
- if (ret == -1)
- perror_with_name ("waitpid");
- else if (ret != child_pid)
- error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
- if (! WIFSTOPPED (status))
- error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
+# if defined PT_GETDSBT
+struct target_loadmap
+{
+ /* Protocol version number, must be zero. */
+ Elf32_Word version;
+ /* Pointer to the DSBT table, its size, and the DSBT index. */
+ unsigned *dsbt_table;
+ unsigned dsbt_size, dsbt_index;
+ /* Number of segments in this map. */
+ Elf32_Word nsegs;
+ /* The actual memory map. */
+ struct target_loadseg segs[/*nsegs*/];
+};
+# define LINUX_LOADMAP PT_GETDSBT
+# define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
+# define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
+# else
+struct target_loadmap
+{
+ /* Protocol version number, must be zero. */
+ Elf32_Half version;
+ /* Number of segments in this map. */
+ Elf32_Half nsegs;
+ /* The actual memory map. */
+ struct target_loadseg segs[/*nsegs*/];
+};
+# define LINUX_LOADMAP PTRACE_GETFDPIC
+# define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
+# define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
+# endif
- ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
- if (ret != 0)
- {
- ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
- if (ret != 0)
- {
- warning ("linux_test_for_tracefork: failed to kill child");
- return;
- }
+static int
+linux_read_loadmap (const char *annex, CORE_ADDR offset,
+ unsigned char *myaddr, unsigned int len)
+{
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+ int addr = -1;
+ struct target_loadmap *data = NULL;
+ unsigned int actual_length, copy_length;
+
+ if (strcmp (annex, "exec") == 0)
+ addr = (int) LINUX_LOADMAP_EXEC;
+ else if (strcmp (annex, "interp") == 0)
+ addr = (int) LINUX_LOADMAP_INTERP;
+ else
+ return -1;
- ret = my_waitpid (child_pid, &status, 0);
- if (ret != child_pid)
- warning ("linux_test_for_tracefork: failed to wait for killed child");
- else if (!WIFSIGNALED (status))
- warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
- "killed child", status);
+ if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
+ return -1;
- return;
- }
+ if (data == NULL)
+ return -1;
- ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
- if (ret != 0)
- warning ("linux_test_for_tracefork: failed to resume child");
+ actual_length = sizeof (struct target_loadmap)
+ + sizeof (struct target_loadseg) * data->nsegs;
- ret = my_waitpid (child_pid, &status, 0);
+ if (offset < 0 || offset > actual_length)
+ return -1;
- if (ret == child_pid && WIFSTOPPED (status)
- && status >> 16 == PTRACE_EVENT_FORK)
- {
- second_pid = 0;
- ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
- if (ret == 0 && second_pid != 0)
- {
- int second_status;
+ copy_length = actual_length - offset < len ? actual_length - offset : len;
+ memcpy (myaddr, (char *) data + offset, copy_length);
+ return copy_length;
+}
+#else
+# define linux_read_loadmap NULL
+#endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
- linux_supports_tracefork_flag = 1;
- my_waitpid (second_pid, &second_status, 0);
- ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
- if (ret != 0)
- warning ("linux_test_for_tracefork: failed to kill second child");
- my_waitpid (second_pid, &status, 0);
- }
- }
- else
- warning ("linux_test_for_tracefork: unexpected result from waitpid "
- "(%d, status 0x%x)", ret, status);
+static void
+linux_process_qsupported (const char *query)
+{
+ if (the_low_target.process_qsupported != NULL)
+ the_low_target.process_qsupported (query);
+}
- do
- {
- ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
- if (ret != 0)
- warning ("linux_test_for_tracefork: failed to kill child");
- my_waitpid (child_pid, &status, 0);
- }
- while (WIFSTOPPED (status));
+static int
+linux_supports_tracepoints (void)
+{
+ if (*the_low_target.supports_tracepoints == NULL)
+ return 0;
- free (stack);
+ return (*the_low_target.supports_tracepoints) ();
}
-
-static void
-linux_look_up_symbols (void)
+static CORE_ADDR
+linux_read_pc (struct regcache *regcache)
{
-#ifdef USE_THREAD_DB
- if (thread_db_active)
- return;
+ if (the_low_target.get_pc == NULL)
+ return 0;
- thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
-#endif
+ return (*the_low_target.get_pc) (regcache);
}
static void
-linux_request_interrupt (void)
+linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
- extern unsigned long signal_pid;
-
- if (cont_thread != 0 && cont_thread != -1)
- {
- struct lwp_info *lwp;
- int lwpid;
-
- lwp = get_thread_lwp (current_inferior);
- lwpid = lwpid_of (lwp);
- kill_lwp (lwpid, SIGINT);
- }
- else
- kill_lwp (signal_pid, SIGINT);
-}
+ gdb_assert (the_low_target.set_pc != NULL);
-/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
- to debugger memory starting at MYADDR. */
+ (*the_low_target.set_pc) (regcache, pc);
+}
static int
-linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
+linux_thread_stopped (struct thread_info *thread)
{
- char filename[PATH_MAX];
- int fd, n;
-
- snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid);
+ return get_thread_lwp (thread)->stopped;
+}
- fd = open (filename, O_RDONLY);
- if (fd < 0)
- return -1;
+/* This exposes stop-all-threads functionality to other modules. */
- if (offset != (CORE_ADDR) 0
- && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
- n = -1;
- else
- n = read (fd, myaddr, len);
+static void
+linux_pause_all (int freeze)
+{
+ stop_all_lwps (freeze, NULL);
+}
- close (fd);
+/* This exposes unstop-all-threads functionality to other gdbserver
+ modules. */
- return n;
+static void
+linux_unpause_all (int unfreeze)
+{
+ unstop_all_lwps (unfreeze, NULL);
}
-/* These watchpoint related wrapper functions simply pass on the function call
- if the target has registered a corresponding function. */
-
static int
-linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
+linux_prepare_to_access_memory (void)
{
- if (the_low_target.insert_watchpoint != NULL)
- return the_low_target.insert_watchpoint (type, addr, len);
- else
- /* Unsupported (see target.h). */
- return 1;
+ /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
+ running LWP. */
+ if (non_stop)
+ linux_pause_all (1);
+ return 0;
}
-static int
-linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
+static void
+linux_done_accessing_memory (void)
{
- if (the_low_target.remove_watchpoint != NULL)
- return the_low_target.remove_watchpoint (type, addr, len);
- else
- /* Unsupported (see target.h). */
- return 1;
+ /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
+ running LWP. */
+ if (non_stop)
+ linux_unpause_all (1);
}
static int
-linux_stopped_by_watchpoint (void)
+linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
+ CORE_ADDR collector,
+ CORE_ADDR lockaddr,
+ ULONGEST orig_size,
+ CORE_ADDR *jump_entry,
+ CORE_ADDR *trampoline,
+ ULONGEST *trampoline_size,
+ unsigned char *jjump_pad_insn,
+ ULONGEST *jjump_pad_insn_size,
+ CORE_ADDR *adjusted_insn_addr,
+ CORE_ADDR *adjusted_insn_addr_end,
+ char *err)
{
- if (the_low_target.stopped_by_watchpoint != NULL)
- return the_low_target.stopped_by_watchpoint ();
- else
- return 0;
+ return (*the_low_target.install_fast_tracepoint_jump_pad)
+ (tpoint, tpaddr, collector, lockaddr, orig_size,
+ jump_entry, trampoline, trampoline_size,
+ jjump_pad_insn, jjump_pad_insn_size,
+ adjusted_insn_addr, adjusted_insn_addr_end,
+ err);
}
-static CORE_ADDR
-linux_stopped_data_address (void)
+static struct emit_ops *
+linux_emit_ops (void)
{
- if (the_low_target.stopped_data_address != NULL)
- return the_low_target.stopped_data_address ();
+ if (the_low_target.emit_ops != NULL)
+ return (*the_low_target.emit_ops) ();
else
- return 0;
+ return NULL;
}
-#if defined(__UCLIBC__) && defined(HAS_NOMMU)
-#if defined(__mcoldfire__)
-/* These should really be defined in the kernel's ptrace.h header. */
-#define PT_TEXT_ADDR 49*4
-#define PT_DATA_ADDR 50*4
-#define PT_TEXT_END_ADDR 51*4
-#endif
+static int
+linux_get_min_fast_tracepoint_insn_len (void)
+{
+ return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
+}
-/* Under uClinux, programs are loaded at non-zero offsets, which we need
- to tell gdb about. */
+/* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
static int
-linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
+get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
+ CORE_ADDR *phdr_memaddr, int *num_phdr)
{
-#if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
- unsigned long text, text_end, data;
- int pid = lwpid_of (get_thread_lwp (current_inferior));
+ char filename[PATH_MAX];
+ int fd;
+ const int auxv_size = is_elf64
+ ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
+ char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
- errno = 0;
+ xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
- text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
- text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
- data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
+ fd = open (filename, O_RDONLY);
+ if (fd < 0)
+ return 1;
- if (errno == 0)
+ *phdr_memaddr = 0;
+ *num_phdr = 0;
+ while (read (fd, buf, auxv_size) == auxv_size
+ && (*phdr_memaddr == 0 || *num_phdr == 0))
{
- /* Both text and data offsets produced at compile-time (and so
- used by gdb) are relative to the beginning of the program,
- with the data segment immediately following the text segment.
- However, the actual runtime layout in memory may put the data
- somewhere else, so when we send gdb a data base-address, we
- use the real data base address and subtract the compile-time
- data base-address from it (which is just the length of the
- text segment). BSS immediately follows data in both
- cases. */
- *text_p = text;
- *data_p = data - (text_end - text);
+ if (is_elf64)
+ {
+ Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
- return 1;
+ switch (aux->a_type)
+ {
+ case AT_PHDR:
+ *phdr_memaddr = aux->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ *num_phdr = aux->a_un.a_val;
+ break;
+ }
+ }
+ else
+ {
+ Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
+
+ switch (aux->a_type)
+ {
+ case AT_PHDR:
+ *phdr_memaddr = aux->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ *num_phdr = aux->a_un.a_val;
+ break;
+ }
+ }
}
-#endif
- return 0;
+
+ close (fd);
+
+ if (*phdr_memaddr == 0 || *num_phdr == 0)
+ {
+ warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
+ "phdr_memaddr = %ld, phdr_num = %d",
+ (long) *phdr_memaddr, *num_phdr);
+ return 2;
+ }
+
+ return 0;
}
-#endif
-static int
-linux_qxfer_osdata (const char *annex,
- unsigned char *readbuf, unsigned const char *writebuf,
- CORE_ADDR offset, int len)
-{
- /* We make the process list snapshot when the object starts to be
- read. */
- static const char *buf;
- static long len_avail = -1;
- static struct buffer buffer;
+/* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
- DIR *dirp;
+static CORE_ADDR
+get_dynamic (const int pid, const int is_elf64)
+{
+ CORE_ADDR phdr_memaddr, relocation;
+ int num_phdr, i;
+ unsigned char *phdr_buf;
+ const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
- if (strcmp (annex, "processes") != 0)
+ if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
return 0;
- if (!readbuf || writebuf)
+ gdb_assert (num_phdr < 100); /* Basic sanity check. */
+ phdr_buf = alloca (num_phdr * phdr_size);
+
+ if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
return 0;
- if (offset == 0)
- {
- if (len_avail != -1 && len_avail != 0)
- buffer_free (&buffer);
- len_avail = 0;
- buf = NULL;
- buffer_init (&buffer);
- buffer_grow_str (&buffer, "<osdata type=\"processes\">");
-
- dirp = opendir ("/proc");
- if (dirp)
- {
- struct dirent *dp;
- while ((dp = readdir (dirp)) != NULL)
- {
- struct stat statbuf;
- char procentry[sizeof ("/proc/4294967295")];
-
- if (!isdigit (dp->d_name[0])
- || strlen (dp->d_name) > sizeof ("4294967295") - 1)
- continue;
-
- sprintf (procentry, "/proc/%s", dp->d_name);
- if (stat (procentry, &statbuf) == 0
- && S_ISDIR (statbuf.st_mode))
- {
- char pathname[128];
- FILE *f;
- char cmd[MAXPATHLEN + 1];
- struct passwd *entry;
-
- sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
- entry = getpwuid (statbuf.st_uid);
-
- if ((f = fopen (pathname, "r")) != NULL)
- {
- size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
- if (len > 0)
- {
- int i;
- for (i = 0; i < len; i++)
- if (cmd[i] == '\0')
- cmd[i] = ' ';
- cmd[len] = '\0';
-
- buffer_xml_printf (
- &buffer,
- "<item>"
- "<column name=\"pid\">%s</column>"
- "<column name=\"user\">%s</column>"
- "<column name=\"command\">%s</column>"
- "</item>",
- dp->d_name,
- entry ? entry->pw_name : "?",
- cmd);
- }
- fclose (f);
- }
- }
- }
-
- closedir (dirp);
- }
- buffer_grow_str0 (&buffer, "</osdata>\n");
- buf = buffer_finish (&buffer);
- len_avail = strlen (buf);
- }
-
- if (offset >= len_avail)
- {
- /* Done. Get rid of the data. */
- buffer_free (&buffer);
- buf = NULL;
- len_avail = 0;
+ /* Compute relocation: it is expected to be 0 for "regular" executables,
+ non-zero for PIE ones. */
+ relocation = -1;
+ for (i = 0; relocation == -1 && i < num_phdr; i++)
+ if (is_elf64)
+ {
+ Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_PHDR)
+ relocation = phdr_memaddr - p->p_vaddr;
+ }
+ else
+ {
+ Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_PHDR)
+ relocation = phdr_memaddr - p->p_vaddr;
+ }
+
+ if (relocation == -1)
+ {
+ /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
+ any real world executables, including PIE executables, have always
+ PT_PHDR present. PT_PHDR is not present in some shared libraries or
+ in fpc (Free Pascal 2.4) binaries but neither of those have a need for
+ or present DT_DEBUG anyway (fpc binaries are statically linked).
+
+ Therefore if there exists DT_DEBUG there is always also PT_PHDR.
+
+ GDB could find RELOCATION also from AT_ENTRY - e_entry. */
+
return 0;
}
- if (len > len_avail - offset)
- len = len_avail - offset;
- memcpy (readbuf, buf + offset, len);
+ for (i = 0; i < num_phdr; i++)
+ {
+ if (is_elf64)
+ {
+ Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
- return len;
+ if (p->p_type == PT_DYNAMIC)
+ return p->p_vaddr + relocation;
+ }
+ else
+ {
+ Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
+
+ if (p->p_type == PT_DYNAMIC)
+ return p->p_vaddr + relocation;
+ }
+ }
+
+ return 0;
}
-static int
-linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
- unsigned const char *writebuf, CORE_ADDR offset, int len)
+/* Return &_r_debug in the inferior, or -1 if not present. Return value
+ can be 0 if the inferior does not yet have the library list initialized. */
+
+static CORE_ADDR
+get_r_debug (const int pid, const int is_elf64)
{
- struct siginfo siginfo;
- long pid = -1;
+ CORE_ADDR dynamic_memaddr;
+ const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
+ unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
- if (current_inferior == NULL)
- return -1;
+ dynamic_memaddr = get_dynamic (pid, is_elf64);
+ if (dynamic_memaddr == 0)
+ return (CORE_ADDR) -1;
- pid = lwpid_of (get_thread_lwp (current_inferior));
+ while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
+ {
+ if (is_elf64)
+ {
+ Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
- if (debug_threads)
- fprintf (stderr, "%s siginfo for lwp %ld.\n",
- readbuf != NULL ? "Reading" : "Writing",
- pid);
+ if (dyn->d_tag == DT_DEBUG)
+ return dyn->d_un.d_val;
- if (offset > sizeof (siginfo))
- return -1;
+ if (dyn->d_tag == DT_NULL)
+ break;
+ }
+ else
+ {
+ Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
- if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
- return -1;
+ if (dyn->d_tag == DT_DEBUG)
+ return dyn->d_un.d_val;
- if (offset + len > sizeof (siginfo))
- len = sizeof (siginfo) - offset;
+ if (dyn->d_tag == DT_NULL)
+ break;
+ }
- if (readbuf != NULL)
- memcpy (readbuf, (char *) &siginfo + offset, len);
- else
- {
- memcpy ((char *) &siginfo + offset, writebuf, len);
- if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
- return -1;
+ dynamic_memaddr += dyn_size;
}
- return len;
+ return (CORE_ADDR) -1;
}
-/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
- so we notice when children change state; as the handler for the
- sigsuspend in my_waitpid. */
+/* Read one pointer from MEMADDR in the inferior. */
-static void
-sigchld_handler (int signo)
+static int
+read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
{
- int old_errno = errno;
+ *ptr = 0;
+ return linux_read_memory (memaddr, (unsigned char *) ptr, ptr_size);
+}
- if (debug_threads)
- /* fprintf is not async-signal-safe, so call write directly. */
- write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
+struct link_map_offsets
+ {
+ /* Offset and size of r_debug.r_version. */
+ int r_version_offset;
- if (target_is_async_p ())
- async_file_mark (); /* trigger a linux_wait */
+ /* Offset and size of r_debug.r_map. */
+ int r_map_offset;
- errno = old_errno;
-}
+ /* Offset to l_addr field in struct link_map. */
+ int l_addr_offset;
-static int
-linux_supports_non_stop (void)
-{
- return 1;
-}
+ /* Offset to l_name field in struct link_map. */
+ int l_name_offset;
+
+ /* Offset to l_ld field in struct link_map. */
+ int l_ld_offset;
+
+ /* Offset to l_next field in struct link_map. */
+ int l_next_offset;
+
+ /* Offset to l_prev field in struct link_map. */
+ int l_prev_offset;
+ };
+
+/* Construct qXfer:libraries:read reply. */
static int
-linux_async (int enable)
+linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
{
- int previous = (linux_event_pipe[0] != -1);
+ char *document;
+ unsigned document_len;
+ struct process_info_private *const priv = current_process ()->private;
+ char filename[PATH_MAX];
+ int pid, is_elf64;
- if (previous != enable)
+ static const struct link_map_offsets lmo_32bit_offsets =
{
- sigset_t mask;
- sigemptyset (&mask);
- sigaddset (&mask, SIGCHLD);
-
- sigprocmask (SIG_BLOCK, &mask, NULL);
+ 0, /* r_version offset. */
+ 4, /* r_debug.r_map offset. */
+ 0, /* l_addr offset in link_map. */
+ 4, /* l_name offset in link_map. */
+ 8, /* l_ld offset in link_map. */
+ 12, /* l_next offset in link_map. */
+ 16 /* l_prev offset in link_map. */
+ };
+
+ static const struct link_map_offsets lmo_64bit_offsets =
+ {
+ 0, /* r_version offset. */
+ 8, /* r_debug.r_map offset. */
+ 0, /* l_addr offset in link_map. */
+ 8, /* l_name offset in link_map. */
+ 16, /* l_ld offset in link_map. */
+ 24, /* l_next offset in link_map. */
+ 32 /* l_prev offset in link_map. */
+ };
+ const struct link_map_offsets *lmo;
+
+ if (writebuf != NULL)
+ return -2;
+ if (readbuf == NULL)
+ return -1;
- if (enable)
- {
- if (pipe (linux_event_pipe) == -1)
- fatal ("creating event pipe failed.");
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
+ is_elf64 = elf_64_file_p (filename);
+ lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
- fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
- fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
+ if (priv->r_debug == 0)
+ priv->r_debug = get_r_debug (pid, is_elf64);
- /* Register the event loop handler. */
- add_file_handler (linux_event_pipe[0],
- handle_target_event, NULL);
+ if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0)
+ {
+ document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
+ }
+ else
+ {
+ int allocated = 1024;
+ char *p;
+ const int ptr_size = is_elf64 ? 8 : 4;
+ CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
+ int r_version, header_done = 0;
+
+ document = xmalloc (allocated);
+ strcpy (document, "<library-list-svr4 version=\"1.0\"");
+ p = document + strlen (document);
+
+ r_version = 0;
+ if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
+ (unsigned char *) &r_version,
+ sizeof (r_version)) != 0
+ || r_version != 1)
+ {
+ warning ("unexpected r_debug version %d", r_version);
+ goto done;
+ }
- /* Always trigger a linux_wait. */
- async_file_mark ();
+ if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
+ &lm_addr, ptr_size) != 0)
+ {
+ warning ("unable to read r_map from 0x%lx",
+ (long) priv->r_debug + lmo->r_map_offset);
+ goto done;
}
- else
+
+ lm_prev = 0;
+ while (read_one_ptr (lm_addr + lmo->l_name_offset,
+ &l_name, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_addr_offset,
+ &l_addr, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_ld_offset,
+ &l_ld, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_prev_offset,
+ &l_prev, ptr_size) == 0
+ && read_one_ptr (lm_addr + lmo->l_next_offset,
+ &l_next, ptr_size) == 0)
{
- delete_file_handler (linux_event_pipe[0]);
+ unsigned char libname[PATH_MAX];
- close (linux_event_pipe[0]);
- close (linux_event_pipe[1]);
- linux_event_pipe[0] = -1;
- linux_event_pipe[1] = -1;
- }
+ if (lm_prev != l_prev)
+ {
+ warning ("Corrupted shared library list: 0x%lx != 0x%lx",
+ (long) lm_prev, (long) l_prev);
+ break;
+ }
- sigprocmask (SIG_UNBLOCK, &mask, NULL);
+ /* Not checking for error because reading may stop before
+ we've got PATH_MAX worth of characters. */
+ libname[0] = '\0';
+ linux_read_memory (l_name, libname, sizeof (libname) - 1);
+ libname[sizeof (libname) - 1] = '\0';
+ if (libname[0] != '\0')
+ {
+ /* 6x the size for xml_escape_text below. */
+ size_t len = 6 * strlen ((char *) libname);
+ char *name;
+
+ if (!header_done)
+ {
+ /* Terminate `<library-list-svr4'. */
+ *p++ = '>';
+ header_done = 1;
+ }
+
+ while (allocated < p - document + len + 200)
+ {
+ /* Expand to guarantee sufficient storage. */
+ uintptr_t document_len = p - document;
+
+ document = xrealloc (document, 2 * allocated);
+ allocated *= 2;
+ p = document + document_len;
+ }
+
+ name = xml_escape_text ((char *) libname);
+ p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
+ "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
+ name, (unsigned long) lm_addr,
+ (unsigned long) l_addr, (unsigned long) l_ld);
+ free (name);
+ }
+ else if (lm_prev == 0)
+ {
+ sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
+ p = p + strlen (p);
+ }
+
+ if (l_next == 0)
+ break;
+
+ lm_prev = lm_addr;
+ lm_addr = l_next;
+ }
+ done:
+ strcpy (p, "</library-list-svr4>");
}
- return previous;
-}
+ document_len = strlen (document);
+ if (offset < document_len)
+ document_len -= offset;
+ else
+ document_len = 0;
+ if (len > document_len)
+ len = document_len;
-static int
-linux_start_non_stop (int nonstop)
-{
- /* Register or unregister from event-loop accordingly. */
- linux_async (nonstop);
- return 0;
+ memcpy (readbuf, document + offset, len);
+ xfree (document);
+
+ return len;
}
static struct target_ops linux_target_ops = {
linux_attach,
linux_kill,
linux_detach,
+ linux_mourn,
linux_join,
linux_thread_alive,
linux_resume,
linux_wait,
linux_fetch_registers,
linux_store_registers,
+ linux_prepare_to_access_memory,
+ linux_done_accessing_memory,
linux_read_memory,
linux_write_memory,
linux_look_up_symbols,
linux_request_interrupt,
linux_read_auxv,
- linux_insert_watchpoint,
- linux_remove_watchpoint,
+ linux_insert_point,
+ linux_remove_point,
linux_stopped_by_watchpoint,
linux_stopped_data_address,
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
#else
NULL,
#endif
- NULL,
+ linux_qxfer_spu,
hostio_last_error_from_errno,
linux_qxfer_osdata,
linux_xfer_siginfo,
linux_supports_non_stop,
linux_async,
linux_start_non_stop,
+ linux_supports_multi_process,
+#ifdef USE_THREAD_DB
+ thread_db_handle_monitor_command,
+#else
+ NULL,
+#endif
+ linux_common_core_of_thread,
+ linux_read_loadmap,
+ linux_process_qsupported,
+ linux_supports_tracepoints,
+ linux_read_pc,
+ linux_write_pc,
+ linux_thread_stopped,
+ NULL,
+ linux_pause_all,
+ linux_unpause_all,
+ linux_cancel_breakpoints,
+ linux_stabilize_threads,
+ linux_install_fast_tracepoint_jump_pad,
+ linux_emit_ops,
+ linux_supports_disable_randomization,
+ linux_get_min_fast_tracepoint_insn_len,
+ linux_qxfer_libraries_svr4,
+ linux_supports_agent,
};
static void
{
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
to find what the cancel signal actually is. */
+#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN+1, SIG_IGN);
+#endif
}
void
{
struct sigaction sigchld_action;
memset (&sigchld_action, 0, sizeof (sigchld_action));
- thread_db_active = 0;
set_target_ops (&linux_target_ops);
set_breakpoint_data (the_low_target.breakpoint,
the_low_target.breakpoint_len);
projects / deliverable / binutils-gdb.git / blobdiff