/* Low level interface to ptrace, for the remote server for GDB.
Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006
- Free Software Foundation, Inc.
+ 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "server.h"
#include "linux-low.h"
#include <sys/wait.h>
#include <stdio.h>
#include <sys/param.h>
-#include <sys/dir.h>
#include <sys/ptrace.h>
-#include <sys/user.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/syscall.h>
+#include <sched.h>
+#include <ctype.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/vfs.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
+#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. */
+#endif
+
+#ifndef W_STOPCODE
+#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
+#endif
+
+#ifdef __UCLIBC__
+#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
+#define HAS_NOMMU
+#endif
+#endif
+
+/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
+ representation of the thread ID.
+
+ ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
+ the same as the LWP ID.
-/* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead,
- however. This requires changing the ID in place when we go from !using_threads
- to using_threads, immediately.
+ ``all_processes'' is keyed by the "overall process ID", which
+ GNU/Linux calls tgid, "thread group ID". */
- ``all_processes'' is keyed by the process ID - which on Linux is (presently)
- the same as the LWP ID. */
+struct inferior_list all_lwps;
-struct inferior_list all_processes;
+/* A list of all unknown processes which receive stop signals. Some other
+ process will presumably claim each of these as forked children
+ momentarily. */
+
+struct inferior_list stopped_pids;
/* FIXME this is a bit of a hack, and could be removed. */
int stopping_threads;
/* FIXME make into a target method? */
-int using_threads;
+int using_threads = 1;
+
+/* 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 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 (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 int linux_core_of_thread (ptid_t ptid);
+static void proceed_all_lwps (void);
+static void unstop_all_lwps (struct lwp_info *except);
+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);
+
+/* 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 void linux_resume_one_process (struct inferior_list_entry *entry,
- int step, int signal);
-static void linux_resume (struct thread_resume *resume_info);
-static void stop_all_processes (void);
-static int linux_wait_for_event (struct thread_info *child);
+static int
+supports_breakpoints (void)
+{
+ return (the_low_target.get_pc != NULL);
+}
struct pending_signals
{
int signal;
+ siginfo_t info;
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 use_regsets_p = 1;
+static char *disabled_regsets;
+static int num_regsets;
#endif
-int debug_threads = 0;
+/* 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 wait_for_sigstop (struct inferior_list_entry *entry);
+
+/* Accepts an integer PID; Returns a string representing a file that
+ can be opened to get info for the child process.
+ Space for the result is malloc'd, caller must free. */
+
+char *
+linux_child_pid_to_exec_file (int pid)
+{
+ char *name1, *name2;
+
+ name1 = xmalloc (MAXPATHLEN);
+ name2 = xmalloc (MAXPATHLEN);
+ memset (name2, 0, MAXPATHLEN);
+
+ sprintf (name1, "/proc/%d/exe", pid);
+ if (readlink (name1, name2, MAXPATHLEN) > 0)
+ {
+ free (name1);
+ return name2;
+ }
+ else
+ {
+ free (name2);
+ return name1;
+ }
+}
+
+/* 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. */
+
+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);
+}
+
+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;
+}
+
+/* Remove a process from the common process list,
+ also freeing all private data. */
+
+static void
+linux_remove_process (struct process_info *process)
+{
+ struct process_info_private *priv = process->private;
+
+ free (priv->arch_private);
+ free (priv);
+ remove_process (process);
+}
+
+/* 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). */
+
+static void
+handle_extended_wait (struct lwp_info *event_child, int wstat)
+{
+ int event = wstat >> 16;
+ struct lwp_info *new_lwp;
+
+ if (event == PTRACE_EVENT_CLONE)
+ {
+ ptid_t ptid;
+ unsigned long new_pid;
+ int ret, status = W_STOPCODE (SIGSTOP);
+
+ 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))
+ {
+ /* The new child has a pending SIGSTOP. We can't affect it until it
+ hits the SIGSTOP, but we're already attached. */
+
+ ret = my_waitpid (new_pid, &status, __WALL);
+
+ if (ret == -1)
+ perror_with_name ("waiting for new child");
+ else if (ret != new_pid)
+ warning ("wait returned unexpected PID %d", ret);
+ else if (!WIFSTOPPED (status))
+ warning ("wait returned unexpected status 0x%x", status);
+ }
+
+ ptrace (PTRACE_SETOPTIONS, new_pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+
+ ptid = ptid_build (pid_of (event_child), new_pid, 0);
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, 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 we do get another signal, be sure not to lose it. */
+ if (WSTOPSIG (status) == SIGSTOP)
+ {
+ if (stopping_threads)
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
+ else
+ linux_resume_one_lwp (new_lwp, 0, 0, NULL);
+ }
+ else
+ {
+ new_lwp->stop_expected = 1;
+
+ if (stopping_threads)
+ {
+ 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? */
+ 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, event_child->stepping, 0, NULL);
+ }
+}
+
+/* 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);
-#define pid_of(proc) ((proc)->head.id)
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
-/* FIXME: Delete eventually. */
-#define inferior_pid (pid_of (get_thread_process (current_inferior)))
+ 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 the process got a SIGTRAP.
+/* 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_process (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)
+ 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_process (unsigned long pid)
+add_lwp (ptid_t ptid)
{
- struct process_info *process;
+ struct lwp_info *lwp;
+
+ lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
+ memset (lwp, 0, sizeof (*lwp));
- process = (struct process_info *) malloc (sizeof (*process));
- memset (process, 0, sizeof (*process));
+ lwp->head.id = ptid;
- process->head.id = pid;
+ lwp->last_resume_kind = resume_continue;
- /* Default to tid == lwpid == pid. */
- process->tid = pid;
- process->lwpid = pid;
+ if (the_low_target.new_thread != NULL)
+ lwp->arch_private = the_low_target.new_thread ();
- add_inferior_to_list (&all_processes, &process->head);
+ add_inferior_to_list (&all_lwps, &lwp->head);
- return process;
+ return lwp;
}
/* Start an inferior process and returns its pid.
static int
linux_create_inferior (char *program, char **allargs)
{
- void *new_process;
+ struct lwp_info *new_lwp;
int pid;
+ ptid_t ptid;
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
+ pid = vfork ();
+#else
pid = fork ();
+#endif
if (pid < 0)
perror_with_name ("fork");
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
+#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN + 1, SIG_DFL);
+#endif
setpgid (0, 0);
execv (program, allargs);
+ if (errno == ENOENT)
+ execvp (program, allargs);
fprintf (stderr, "Cannot exec %s: %s.\n", program,
strerror (errno));
_exit (0177);
}
- new_process = add_process (pid);
- add_thread (pid, new_process, pid);
+ 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, unsigned long tid)
+static void
+linux_attach_lwp_1 (unsigned long lwpid, int initial)
{
- struct process_info *new_process;
+ ptid_t ptid;
+ struct lwp_info *new_lwp;
- if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
+ if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
{
- fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
+ if (!initial)
+ {
+ /* If we fail to attach to an LWP, just warn. */
+ 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", lwpid,
strerror (errno), errno);
- fflush (stderr);
+ }
- /* If we fail to attach to an LWP, just return. */
- if (!using_threads)
- _exit (0177);
- return;
+ if (initial)
+ /* NOTE/FIXME: This lwp might have not been the tgid. */
+ 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);
}
- new_process = (struct process_info *) add_process (pid);
- add_thread (tid, new_process, pid);
+ new_lwp = (struct lwp_info *) add_lwp (ptid);
+ add_thread (ptid, 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;
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
- brings it to a halt. We should ignore that SIGSTOP and resume the process
- (unless this is the first process, in which case the flag will be cleared
- in linux_attach).
+ brings it to a halt.
+
+ There are several cases to consider here:
+
+ 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,
+ and the fact that add_lwp 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 set last_resume_kind ==
+ resume_stop after we return.
+ ??? If the process already has several threads we leave the other
+ threads running.
+
+ 3) GDB is connecting to gdbserver and is requesting an enumeration of all
+ existing threads.
+ In this case we want the thread to stop.
+ FIXME: This case is currently not properly handled.
+ We should wait for the SIGSTOP but don't. Things work apparently
+ because enough time passes between when we ptrace (ATTACH) and when
+ gdb makes the next ptrace call on the thread.
On the other hand, if we are currently trying to stop all threads, we
should treat the new thread as if we had sent it a SIGSTOP. This works
- because we are guaranteed that add_process 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_process->stop_expected = 1;
+ 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). */
+ new_lwp->stop_expected = 1;
+}
+
+void
+linux_attach_lwp (unsigned long lwpid)
+{
+ linux_attach_lwp_1 (lwpid, 0);
}
int
linux_attach (unsigned long pid)
{
- struct process_info *process;
+ struct lwp_info *lwp;
+
+ linux_attach_lwp_1 (pid, 1);
- linux_attach_lwp (pid, pid);
+ linux_add_process (pid, 1);
- /* Don't ignore the initial SIGSTOP if we just attached to this process. */
- process = (struct process_info *) find_inferior_id (&all_processes, pid);
- process->stop_expected = 0;
+ 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,
+ ptid_build (pid, pid, 0));
+ lwp->last_resume_kind = resume_stop;
+ }
return 0;
}
-/* Kill the inferior process. Make us have no inferior. */
+struct counter
+{
+ int pid;
+ int count;
+};
-static void
-linux_kill_one_process (struct inferior_list_entry *entry)
+static int
+second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
+{
+ struct counter *counter = args;
+
+ 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 the inferior lwp. */
+
+static int
+linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
{
struct thread_info *thread = (struct thread_info *) entry;
- struct process_info *process = get_thread_process (thread);
+ 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 (entry == all_threads.head)
- return;
+
+ 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;
+ }
+
+ /* 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
{
- ptrace (PTRACE_KILL, pid_of (process), 0, 0);
+ ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
/* Make sure it died. The loop is most likely unnecessary. */
- wstat = linux_wait_for_event (thread);
- } while (WIFSTOPPED (wstat));
+ 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 = get_thread_process (thread);
+ struct process_info *process;
+ struct lwp_info *lwp;
+ struct thread_info *thread;
int wstat;
+ int lwpid;
+
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
- for_each_inferior (&all_threads, linux_kill_one_process);
+ find_inferior (&all_threads, linux_kill_one_lwp, &pid);
- /* See the comment in linux_kill_one_process. We did not kill the first
+ /* See the comment in linux_kill_one_lwp. We did not kill the first
thread in the list, so do so now. */
+ lwp = find_lwp_pid (pid_to_ptid (pid));
+ thread = get_lwp_thread (lwp);
+
+ 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
{
- ptrace (PTRACE_KILL, pid_of (process), 0, 0);
+ ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
/* Make sure it died. The loop is most likely unnecessary. */
- wstat = linux_wait_for_event (thread);
- } while (WIFSTOPPED (wstat));
+ lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ } while (lwpid > 0 && WIFSTOPPED (wstat));
+
+#ifdef USE_THREAD_DB
+ thread_db_free (process, 0);
+#endif
+ delete_lwp (lwp);
+ linux_remove_process (process);
+ return 0;
}
-static void
-linux_detach_one_process (struct inferior_list_entry *entry)
+static int
+linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
{
struct thread_info *thread = (struct thread_info *) entry;
- struct process_info *process = get_thread_process (thread);
+ struct lwp_info *lwp = get_thread_lwp (thread);
+ int pid = * (int *) args;
- ptrace (PTRACE_DETACH, pid_of (process), 0, 0);
-}
+ if (ptid_get_pid (entry->id) != pid)
+ return 0;
-static void
-linux_detach (void)
-{
- for_each_inferior (&all_threads, linux_detach_one_process);
+ /* If we're detaching from a running inferior, make sure it is
+ stopped first, as PTRACE_DETACH will not work otherwise. */
+ if (!lwp->stopped)
+ {
+ int lwpid = lwpid_of (lwp);
+
+ stopping_threads = 1;
+ send_sigstop (&lwp->head);
+
+ /* 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;
+
+ /* If LWP exits while we're trying to stop it, there's nothing
+ left to do. */
+ lwp = find_lwp_pid (pid_to_ptid (lwpid));
+ if (lwp == NULL)
+ 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 (lwp->stop_expected)
+ {
+ int wstat;
+ /* Clear stop_expected, so that the SIGSTOP will be reported. */
+ lwp->stop_expected = 0;
+ if (lwp->stopped)
+ linux_resume_one_lwp (lwp, 0, 0, NULL);
+ linux_wait_for_event (lwp->head.id, &wstat, __WALL);
+ }
+
+ /* Flush any pending changes to the process's registers. */
+ regcache_invalidate_one ((struct inferior_list_entry *)
+ get_lwp_thread (lwp));
+
+ /* Finally, let it resume. */
+ ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
+
+ delete_lwp (lwp);
+ return 0;
}
-/* Return nonzero if the given thread is still alive. */
static int
-linux_thread_alive (unsigned long tid)
+any_thread_of (struct inferior_list_entry *entry, void *args)
{
- if (find_inferior_id (&all_threads, tid) != NULL)
+ int *pid_p = args;
+
+ if (ptid_get_pid (entry->id) == *pid_p)
return 1;
- else
- return 0;
+
+ 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. */
static int
-check_removed_breakpoint (struct process_info *event_child)
+linux_detach (int pid)
{
- CORE_ADDR stop_pc;
- struct thread_info *saved_inferior;
+ struct process_info *process;
- if (event_child->pending_is_breakpoint == 0)
- return 0;
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return -1;
- if (debug_threads)
- fprintf (stderr, "Checking for breakpoint.\n");
+#ifdef USE_THREAD_DB
+ thread_db_free (process, 1);
+#endif
- saved_inferior = current_inferior;
- current_inferior = get_process_thread (event_child);
+ current_inferior =
+ (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
- stop_pc = get_stop_pc ();
+ delete_all_breakpoints ();
+ find_inferior (&all_threads, linux_detach_one_lwp, &pid);
+ linux_remove_process (process);
+ return 0;
+}
- /* 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.\n");
+static void
+linux_join (int pid)
+{
+ int status, ret;
+ struct process_info *process;
- event_child->pending_is_breakpoint = 0;
- current_inferior = saved_inferior;
- return 0;
- }
+ process = find_process_pid (pid);
+ if (process == NULL)
+ return;
- /* 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;
- }
+ do {
+ ret = my_waitpid (pid, &status, 0);
+ if (WIFEXITED (status) || WIFSIGNALED (status))
+ break;
+ } while (ret != -1 || errno != ECHILD);
+}
- if (debug_threads)
- fprintf (stderr, "Removed breakpoint.\n");
+/* Return nonzero if the given thread is still alive. */
+static int
+linux_thread_alive (ptid_t ptid)
+{
+ struct lwp_info *lwp = find_lwp_pid (ptid);
- /* 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);
+ /* 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;
+}
- /* We consumed the pending SIGTRAP. */
- event_child->pending_is_breakpoint = 0;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
+/* Return 1 if this lwp has an interesting status pending. */
+static int
+status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ ptid_t ptid = * (ptid_t *) arg;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ /* 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;
- current_inferior = saved_inferior;
- return 1;
+ thread = get_lwp_thread (lwp);
+
+ /* If we got a `vCont;t', but we haven't reported a stop yet, do
+ report any status pending the LWP may have. */
+ if (lwp->last_resume_kind == resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_STOPPED)
+ return 0;
+
+ return lwp->status_pending_p;
}
-/* Return 1 if this process has an interesting status pending. This function
- may silently resume an inferior process. */
static int
-status_pending_p (struct inferior_list_entry *entry, void *dummy)
+same_lwp (struct inferior_list_entry *entry, void *data)
{
- struct process_info *process = (struct process_info *) entry;
+ ptid_t ptid = *(ptid_t *) data;
+ int lwp;
- if (process->status_pending_p)
- if (check_removed_breakpoint (process))
- {
- /* 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_process (&process->head, 0, 0);
- return 0;
- }
+ if (ptid_get_lwp (ptid) != 0)
+ lwp = ptid_get_lwp (ptid);
+ else
+ lwp = ptid_get_pid (ptid);
- return process->status_pending_p;
+ if (ptid_get_lwp (entry->id) == lwp)
+ return 1;
+
+ return 0;
}
-static void
-linux_wait_for_process (struct process_info **childp, int *wstatp)
+struct lwp_info *
+find_lwp_pid (ptid_t ptid)
+{
+ return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
+}
+
+static struct lwp_info *
+linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
{
int ret;
int to_wait_for = -1;
+ struct lwp_info *child = NULL;
- if (*childp != NULL)
- to_wait_for = (*childp)->lwpid;
-
- while (1)
- {
- ret = waitpid (to_wait_for, wstatp, WNOHANG);
+ if (debug_threads)
+ fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
- if (ret == -1)
- {
- if (errno != ECHILD)
- perror_with_name ("waitpid");
- }
- else if (ret > 0)
- break;
+ if (ptid_equal (ptid, minus_one_ptid))
+ to_wait_for = -1; /* any child */
+ else
+ to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
- ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE);
+ options |= __WALL;
- if (ret == -1)
- {
- if (errno != ECHILD)
- perror_with_name ("waitpid (WCLONE)");
- }
- else if (ret > 0)
- break;
+retry:
- usleep (1000);
- }
+ ret = my_waitpid (to_wait_for, wstatp, options);
+ if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
+ return NULL;
+ else if (ret == -1)
+ perror_with_name ("waitpid");
if (debug_threads
&& (!WIFSTOPPED (*wstatp)
&& WSTOPSIG (*wstatp) != 33)))
fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
- if (to_wait_for == -1)
- *childp = (struct process_info *) find_inferior_id (&all_processes, 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.
+ - A process we are controlling has forked and the new child's stop
+ was reported to us by the kernel. Save its PID. */
+ if (child == NULL && WIFSTOPPED (*wstatp))
+ {
+ add_pid_to_list (&stopped_pids, ret);
+ goto retry;
+ }
+ else if (child == NULL)
+ goto retry;
+
+ child->stopped = 1;
+
+ child->last_status = *wstatp;
+
+ /* Architecture-specific setup after inferior is running.
+ This needs to happen after we have attached to the inferior
+ and it is stopped for the first time, but before we access
+ any inferior registers. */
+ if (new_inferior)
+ {
+ the_low_target.arch_setup ();
+#ifdef HAVE_LINUX_REGSETS
+ memset (disabled_regsets, 0, num_regsets);
+#endif
+ 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;
+ }
- (*childp)->stopped = 1;
- (*childp)->pending_is_breakpoint = 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)
{
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, (*childp)->tid);
- /* For testing only; i386_stop_pc prints out a diagnostic. */
- if (the_low_target.get_pc != NULL)
- get_stop_pc ();
+ struct thread_info *saved_inferior = current_inferior;
+ 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;
}
+/* 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. */
+
static int
-linux_wait_for_event (struct thread_info *child)
+cancel_breakpoint (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc;
- struct process_info *event_child;
- int wstat;
+ struct thread_info *saved_inferior;
+ struct regcache *regcache;
+
+ /* There's nothing to do if we don't support breakpoints. */
+ if (!supports_breakpoints ())
+ return 0;
+
+ if (lwp->stepping)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: [%s] is stepping\n",
+ target_pid_to_str (lwp->head.id));
+ return 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 (child == NULL)
+ regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
+
+ /* breakpoint_at reads from current inferior. */
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ 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 (lwp->head.id));
+
+ /* Back up the PC if necessary. */
+ if (the_low_target.decr_pc_after_break)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (get_lwp_thread (lwp), 1);
+ (*the_low_target.set_pc) (regcache, lwp->stop_pc);
+ }
+
+ 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 (lwp->head.id));
+ }
+
+ current_inferior = saved_inferior;
+ return 0;
+}
+
+/* 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 int
+linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
+{
+ struct lwp_info *event_child, *requested_child;
+
+ event_child = NULL;
+ requested_child = NULL;
+
+ /* Check for a lwp with a pending status. */
+
+ if (ptid_equal (ptid, minus_one_ptid)
+ || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
{
- event_child = (struct process_info *)
- find_inferior (&all_processes, status_pending_p, NULL);
+ 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", event_child->lwpid);
+ fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
}
else
{
- event_child = get_thread_process (child);
- if (event_child->status_pending_p
- && check_removed_breakpoint (event_child))
- event_child = NULL;
+ requested_child = find_lwp_pid (ptid);
+
+ if (requested_child->status_pending_p)
+ event_child = requested_child;
}
if (event_child != NULL)
{
- if (event_child->status_pending_p)
- {
- if (debug_threads)
- fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
- event_child->lwpid, event_child->status_pending);
- wstat = event_child->status_pending;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
- current_inferior = get_process_thread (event_child);
- return wstat;
- }
+ 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);
}
/* We only enter this loop if no process has a pending wait status. Thus
events. */
while (1)
{
- if (child == NULL)
- event_child = NULL;
- else
- event_child = get_thread_process (child);
+ event_child = linux_wait_for_lwp (ptid, wstat, options);
- linux_wait_for_process (&event_child, &wstat);
+ if ((options & WNOHANG) && event_child == NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "WNOHANG set, no event found\n");
+ return 0;
+ }
if (event_child == NULL)
error ("event from unknown child");
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, event_child->tid);
+ current_inferior = get_lwp_thread (event_child);
- if (using_threads)
+ /* Check for thread exit. */
+ if (! WIFSTOPPED (*wstat))
{
- /* Check for thread exit. */
- if (! WIFSTOPPED (wstat))
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
+
+ /* If the last thread is exiting, just return. */
+ if (last_thread_of_process_p (current_inferior))
{
if (debug_threads)
- fprintf (stderr, "Thread %ld (LWP %ld) exiting\n",
- event_child->tid, event_child->head.id);
-
- /* If the last thread is exiting, just return. */
- if (all_threads.head == all_threads.tail)
- return wstat;
-
- dead_thread_notify (event_child->tid);
-
- remove_inferior (&all_processes, &event_child->head);
- free (event_child);
- remove_thread (current_inferior);
- current_inferior = (struct thread_info *) all_threads.head;
-
- /* If we were waiting for this particular child to do something...
- well, it did something. */
- if (child != NULL)
- return wstat;
-
- /* Wait for a more interesting event. */
- continue;
+ fprintf (stderr, "LWP %ld is last lwp of process\n",
+ lwpid_of (event_child));
+ return lwpid_of (event_child);
}
- if (WIFSTOPPED (wstat)
- && WSTOPSIG (wstat) == SIGSTOP
- && event_child->stop_expected)
+ if (!non_stop)
{
+ current_inferior = (struct thread_info *) all_threads.head;
if (debug_threads)
- fprintf (stderr, "Expected stop.\n");
- event_child->stop_expected = 0;
- linux_resume_one_process (&event_child->head,
- event_child->stepping, 0);
- continue;
+ fprintf (stderr, "Current inferior is now %ld\n",
+ lwpid_of (get_thread_lwp (current_inferior)));
}
-
- /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
- thread library? */
- if (WIFSTOPPED (wstat)
- && (WSTOPSIG (wstat) == __SIGRTMIN
- || WSTOPSIG (wstat) == __SIGRTMIN + 1))
+ else
{
+ current_inferior = NULL;
if (debug_threads)
- fprintf (stderr, "Ignored signal %d for %ld (LWP %ld).\n",
- WSTOPSIG (wstat), event_child->tid,
- event_child->head.id);
- linux_resume_one_process (&event_child->head,
- event_child->stepping,
- WSTOPSIG (wstat));
- continue;
+ fprintf (stderr, "Current inferior is now <NULL>\n");
}
- }
- /* If this event was not handled above, and is not a SIGTRAP, report
- it. */
- if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP)
- return wstat;
+ /* 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 (event_child);
+ delete_lwp (event_child);
+ return lwpid;
+ }
- /* 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 wstat;
+ delete_lwp (event_child);
- stop_pc = get_stop_pc ();
+ /* Wait for a more interesting event. */
+ continue;
+ }
- /* 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 (event_child->must_set_ptrace_flags)
{
- if (debug_threads)
- fprintf (stderr, "Reinserted breakpoint.\n");
- reinsert_breakpoint (event_child->bp_reinsert);
- event_child->bp_reinsert = 0;
+ ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
+ 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
+ event_child->must_set_ptrace_flags = 0;
+ }
- /* Clear the single-stepping flag and SIGTRAP as we resume. */
- linux_resume_one_process (&event_child->head, 0, 0);
+ if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
+ && *wstat >> 16 != 0)
+ {
+ handle_extended_wait (event_child, *wstat);
continue;
}
- if (debug_threads)
- fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n");
-
- if (check_breakpoints (stop_pc) != 0)
+ /* 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
+ && (
+#if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
+ (current_process ()->private->thread_db != NULL
+ && (WSTOPSIG (*wstat) == __SIGRTMIN
+ || WSTOPSIG (*wstat) == __SIGRTMIN + 1))
+ ||
+#endif
+ (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
+ && !(WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected))))
{
- /* 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;
-
- /* Now we 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. */
- if (the_low_target.breakpoint_reinsert_addr == NULL)
- {
- event_child->bp_reinsert = stop_pc;
- uninsert_breakpoint (stop_pc);
- linux_resume_one_process (&event_child->head, 1, 0);
- }
- else
- {
- reinsert_breakpoint_by_bp
- (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
- linux_resume_one_process (&event_child->head, 0, 0);
- }
+ siginfo_t info, *info_p;
+ if (debug_threads)
+ fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
+ WSTOPSIG (*wstat), lwpid_of (event_child));
+
+ if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
+ info_p = &info;
+ else
+ info_p = NULL;
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ WSTOPSIG (*wstat), info_p);
continue;
}
- /* If we were single-stepping, we definitely want to report the
- SIGTRAP. The single-step operation has completed, so also
- clear the stepping flag; in general this does not matter,
- because the SIGTRAP will be reported to the client, which
- will give us a new action for this thread, but clear it for
- consistency anyway. It's safe to clear the stepping flag
- because the only consumer of get_stop_pc () after this point
- is check_removed_breakpoint, and pending_is_breakpoint is not
- set. It might be wiser to use a step_completed flag instead. */
- if (event_child->stepping)
+ if (WIFSTOPPED (*wstat)
+ && WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected)
{
- event_child->stepping = 0;
- return wstat;
- }
+ int should_stop;
- /* 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))
- {
- event_child->pending_is_breakpoint = 1;
- event_child->pending_stop_pc = stop_pc;
+ if (debug_threads)
+ fprintf (stderr, "Expected stop.\n");
+ event_child->stop_expected = 0;
+
+ should_stop = (event_child->last_resume_kind == resume_stop
+ || stopping_threads);
+
+ if (!should_stop)
+ {
+ linux_resume_one_lwp (event_child,
+ event_child->stepping, 0, NULL);
+ continue;
+ }
}
- return wstat;
+ return lwpid_of (event_child);
}
/* NOTREACHED */
return 0;
}
-/* Wait for process, returns status. */
-
-static unsigned char
-linux_wait (char *status)
+static int
+linux_wait_for_event (ptid_t ptid, int *wstat, int options)
{
- int w;
- struct thread_info *child = NULL;
+ ptid_t wait_ptid;
-retry:
- /* 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 (cont_thread != 0 && cont_thread != -1)
+ if (ptid_is_pid (ptid))
{
- child = (struct thread_info *) find_inferior_id (&all_threads,
- cont_thread);
-
- /* No stepping, no signal - unless one is pending already, of course. */
- if (child == NULL)
- {
- struct thread_resume resume_info;
- resume_info.thread = -1;
- resume_info.step = resume_info.sig = resume_info.leave_stopped = 0;
- linux_resume (&resume_info);
- }
+ /* 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;
- enable_async_io ();
- unblock_async_io ();
- w = linux_wait_for_event (child);
- stop_all_processes ();
- disable_async_io ();
-
- /* 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.
+ while (1)
+ {
+ int event_pid;
- Report the exit status of the last thread to exit. This matches
- LinuxThreads' behavior. */
+ event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
- if (all_threads.head == all_threads.tail)
- {
- if (WIFEXITED (w))
- {
- fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
- *status = 'W';
- clear_inferiors ();
- free (all_processes.head);
- all_processes.head = all_processes.tail = NULL;
- return ((unsigned char) WEXITSTATUS (w));
- }
- else if (!WIFSTOPPED (w))
+ if (event_pid > 0
+ && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
{
- fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
- *status = 'X';
- clear_inferiors ();
- free (all_processes.head);
- all_processes.head = all_processes.tail = NULL;
- return ((unsigned char) WTERMSIG (w));
+ struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
+
+ if (! WIFSTOPPED (*wstat))
+ mark_lwp_dead (event_child, *wstat);
+ else
+ {
+ event_child->status_pending_p = 1;
+ event_child->status_pending = *wstat;
+ }
}
+ else
+ return event_pid;
}
- else
- {
- if (!WIFSTOPPED (w))
- goto retry;
- }
-
- *status = 'T';
- return ((unsigned char) WSTOPSIG (w));
}
-/* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
- thread groups are in use, we need to use tkill. */
+
+/* Count the LWP's that have had events. */
static int
-kill_lwp (unsigned long lwpid, int signo)
+count_events_callback (struct inferior_list_entry *entry, void *data)
{
- static int tkill_failed;
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ int *count = data;
- errno = 0;
+ gdb_assert (count != NULL);
-#ifdef SYS_tkill
- if (!tkill_failed)
- {
- int ret = syscall (SYS_tkill, lwpid, signo);
- if (errno != ENOSYS)
- return ret;
- errno = 0;
- tkill_failed = 1;
- }
-#endif
+ /* Count only resumed LWPs that have a SIGTRAP event pending that
+ should be reported to GDB. */
+ if (get_lwp_thread (lp)->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->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 kill (lwpid, signo);
+ return 0;
}
-static void
-send_sigstop (struct inferior_list_entry *entry)
+/* Select the LWP (if any) that is currently being single-stepped. */
+
+static int
+select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
{
- struct process_info *process = (struct process_info *) entry;
+ struct lwp_info *lp = (struct lwp_info *) entry;
- if (process->stopped)
- return;
+ if (get_lwp_thread (lp)->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->last_resume_kind == resume_step
+ && lp->status_pending_p)
+ return 1;
+ else
+ return 0;
+}
- /* If we already have a pending stop signal for this process, don't
- send another. */
- if (process->stop_expected)
- {
- process->stop_expected = 0;
- return;
- }
+/* Select the Nth LWP that has had a SIGTRAP event that should be
+ reported to GDB. */
- if (debug_threads)
- fprintf (stderr, "Sending sigstop to process %ld\n", process->head.id);
+static int
+select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ int *selector = data;
+
+ gdb_assert (selector != NULL);
- kill_lwp (process->head.id, SIGSTOP);
- process->sigstop_sent = 1;
+ /* Select only resumed LWPs that have a SIGTRAP event pending. */
+ if (lp->last_resume_kind != resume_stop
+ && get_lwp_thread (lp)->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 0;
}
-static void
-wait_for_sigstop (struct inferior_list_entry *entry)
+static int
+cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
{
- struct process_info *process = (struct process_info *) entry;
- struct thread_info *saved_inferior, *thread;
- int wstat;
- unsigned long saved_tid;
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct lwp_info *event_lp = data;
- if (process->stopped)
- return;
+ /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
+ if (lp == event_lp)
+ return 0;
- saved_inferior = current_inferior;
- saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
- thread = (struct thread_info *) find_inferior_id (&all_threads,
- process->tid);
- wstat = linux_wait_for_event (thread);
+ /* 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 (lp->last_resume_kind != resume_stop
+ && get_lwp_thread (lp)->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && cancel_breakpoint (lp))
+ /* Throw away the SIGTRAP. */
+ lp->status_pending_p = 0;
- /* 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)
+ return 0;
+}
+
+/* Select one LWP out of those that have events pending. */
+
+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, "Stopped with non-sigstop signal\n");
- process->status_pending_p = 1;
- process->status_pending = wstat;
- process->stop_expected = 1;
+ fprintf (stderr,
+ "SEL: Select single-step %s\n",
+ target_pid_to_str (ptid_of (event_lp)));
}
-
- if (linux_thread_alive (saved_tid))
- current_inferior = saved_inferior;
else
{
- if (debug_threads)
- fprintf (stderr, "Previously current thread died.\n");
+ /* No single-stepping LWP. Select one at random, out of those
+ which have had SIGTRAP events. */
+
+ /* First see how many SIGTRAP events we have. */
+ find_inferior (&all_lwps, count_events_callback, &num_events);
+
+ /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
+ random_selector = (int)
+ ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
+
+ if (debug_threads && num_events > 1)
+ fprintf (stderr,
+ "SEL: Found %d SIGTRAP events, selecting #%d\n",
+ num_events, random_selector);
+
+ event_lp = (struct lwp_info *) find_inferior (&all_lwps,
+ select_event_lwp_callback,
+ &random_selector);
+ }
- /* Set a valid thread as current. */
- set_desired_inferior (0);
+ if (event_lp != NULL)
+ {
+ /* Switch the event LWP. */
+ *orig_lp = event_lp;
}
}
+/* Set this inferior LWP's state as "want-stopped". We won't resume
+ this LWP until the client gives us another action for it. */
+
static void
-stop_all_processes (void)
+gdb_wants_lwp_stopped (struct inferior_list_entry *entry)
{
- stopping_threads = 1;
- for_each_inferior (&all_processes, send_sigstop);
- for_each_inferior (&all_processes, wait_for_sigstop);
- stopping_threads = 0;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ /* Most threads are stopped implicitly (all-stop); tag that with
+ signal 0. The thread being explicitly reported stopped to the
+ client, gets it's status fixed up afterwards. */
+ thread->last_status.kind = TARGET_WAITKIND_STOPPED;
+ thread->last_status.value.sig = TARGET_SIGNAL_0;
+
+ lwp->last_resume_kind = resume_stop;
}
-/* Resume execution of the inferior process.
- If STEP is nonzero, single-step it.
- If SIGNAL is nonzero, give it that signal. */
+/* Set all LWP's states as "want-stopped". */
static void
-linux_resume_one_process (struct inferior_list_entry *entry,
- int step, int signal)
+gdb_wants_all_stopped (void)
{
- struct process_info *process = (struct process_info *) entry;
- struct thread_info *saved_inferior;
+ for_each_inferior (&all_lwps, gdb_wants_lwp_stopped);
+}
- if (process->stopped == 0)
- return;
+/* Wait for process, returns status. */
- /* 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
- && (process->status_pending_p || process->pending_signals != NULL
- || process->bp_reinsert != 0))
+static ptid_t
+linux_wait_1 (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
+{
+ int w;
+ struct thread_info *thread = NULL;
+ struct lwp_info *event_child = NULL;
+ int options;
+ int pid;
+ int step_over_finished;
+ int bp_explains_trap;
+ int maybe_internal_trap;
+ int report_to_gdb;
+
+ /* Translate generic target options into linux options. */
+ options = __WALL;
+ if (target_options & TARGET_WNOHANG)
+ options |= WNOHANG;
+
+retry:
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
+
+ /* 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 pending_signals *p_sig;
- p_sig = malloc (sizeof (*p_sig));
- p_sig->prev = process->pending_signals;
- p_sig->signal = signal;
- process->pending_signals = p_sig;
+ thread = (struct thread_info *) find_inferior_id (&all_threads,
+ cont_thread);
+
+ /* 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;
}
- if (process->status_pending_p && !check_removed_breakpoint (process))
- return;
+ 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);
+ }
- saved_inferior = current_inferior;
- current_inferior = get_process_thread (process);
+ if (pid == 0) /* only if TARGET_WNOHANG */
+ return null_ptid;
- if (debug_threads)
- fprintf (stderr, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid,
- step ? "step" : "continue", signal,
- process->stop_expected ? "expected" : "not expected");
+ event_child = get_thread_lwp (current_inferior);
- /* 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.
+ /* 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.
- Making this stack would also shrink the window in which breakpoints are
- uninserted (see comment in linux_wait_for_process) but not enough for
- complete correctness, so it won't solve that problem. It may be
- worthwhile just to solve this one, however. */
- if (process->bp_reinsert != 0)
+ Report the exit status of the last thread to exit. This matches
+ LinuxThreads' behavior. */
+
+ if (last_thread_of_process_p (current_inferior))
{
- if (debug_threads)
- fprintf (stderr, " pending reinsert at %08lx", (long)process->bp_reinsert);
- if (step == 0)
- fprintf (stderr, "BAD - reinserting but not stepping.\n");
- step = 1;
+ if (WIFEXITED (w) || WIFSIGNALED (w))
+ {
+ int pid = pid_of (event_child);
+ struct process_info *process = find_process_pid (pid);
- /* Postpone any pending signal. It was enqueued above. */
- signal = 0;
- }
+#ifdef USE_THREAD_DB
+ thread_db_free (process, 0);
+#endif
+ delete_lwp (event_child);
+ linux_remove_process (process);
- check_removed_breakpoint (process);
+ current_inferior = NULL;
- if (debug_threads && the_low_target.get_pc != NULL)
+ if (WIFEXITED (w))
+ {
+ ourstatus->kind = TARGET_WAITKIND_EXITED;
+ ourstatus->value.integer = WEXITSTATUS (w);
+
+ 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));
+
+ if (debug_threads)
+ fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+
+ }
+
+ return pid_to_ptid (pid);
+ }
+ }
+ else
{
- fprintf (stderr, " ");
- (long) (*the_low_target.get_pc) ();
+ if (!WIFSTOPPED (w))
+ goto retry;
}
- /* If we have pending signals, consume one unless we are trying to reinsert
- a breakpoint. */
- if (process->pending_signals != NULL && process->bp_reinsert == 0)
+ /* 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)
{
- struct pending_signals **p_sig;
+ /* Handle anything that requires bookkeeping before deciding to
+ report the event or continue waiting. */
- p_sig = &process->pending_signals;
- while ((*p_sig)->prev != NULL)
- p_sig = &(*p_sig)->prev;
+ /* 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);
- signal = (*p_sig)->signal;
- free (*p_sig);
- *p_sig = NULL;
+ /* 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);
+
+ 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");
+
+ 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);
}
- regcache_invalidate_one ((struct inferior_list_entry *)
- get_process_thread (process));
- errno = 0;
- process->stopped = 0;
- process->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, process->lwpid, 0, signal);
+ /* We have all the data we need. Either report the event to GDB, or
+ resume threads and keep waiting for more. */
+
+ /* Check If GDB would be interested in this event. If GDB wanted
+ this thread to single step, we always want to report the SIGTRAP,
+ and let GDB handle it. */
+ report_to_gdb = (!maybe_internal_trap
+ || event_child->last_resume_kind == resume_step
+ || event_child->stopped_by_watchpoint
+ || (!step_over_finished && !bp_explains_trap));
+
+ /* 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)
+ {
+ if (bp_explains_trap)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ if (step_over_finished)
+ fprintf (stderr, "Step-over finished.\n");
+ }
- current_inferior = saved_inferior;
- if (errno)
- perror_with_name ("ptrace");
-}
+ /* We're not reporting this breakpoint to GDB, so apply the
+ decr_pc_after_break adjustment to the inferior's regcache
+ ourselves. */
-static struct thread_resume *resume_ptr;
+ 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);
+ }
-/* 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.
+ /* We've finished stepping over a breakpoint. We've stopped 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");
+ proceed_all_lwps ();
+ goto retry;
+ }
- This algorithm is O(threads * resume elements), but resume elements
- is small (and will remain small at least until GDB supports thread
- suspension). */
-static void
-linux_set_resume_request (struct inferior_list_entry *entry)
-{
- struct process_info *process;
- struct thread_info *thread;
- int ndx;
+ if (debug_threads)
+ {
+ if (event_child->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 (debug_threads)
+ fprintf (stderr, "Hit a non-gdbserver trap event.\n");
+ }
- thread = (struct thread_info *) entry;
- process = get_thread_process (thread);
+ /* Alright, we're going to report a stop. */
- ndx = 0;
- while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id)
- ndx++;
+ if (!non_stop)
+ {
+ /* In all-stop, stop all threads. */
+ stop_all_lwps ();
+
+ /* 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;
- process->resume = &resume_ptr[ndx];
-}
+ select_event_lwp (&event_child);
-/* 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. */
+ event_child->status_pending_p = 0;
+ w = event_child->status_pending;
+ }
-static void
-linux_continue_one_thread (struct inferior_list_entry *entry)
-{
- struct process_info *process;
- struct thread_info *thread;
- int step;
+ /* 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);
+ }
+ 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 (event_child);
+ }
- thread = (struct thread_info *) entry;
- process = get_thread_process (thread);
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
- if (process->resume->leave_stopped)
- return;
+ /* Do this before the gdb_wants_all_stopped calls below, since they
+ always set last_resume_kind to resume_stop. */
+ if (event_child->last_resume_kind == resume_stop && 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 (event_child->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));
+ }
+ else
+ {
+ ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
+ }
+
+ gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
- if (process->resume->thread == -1)
- step = process->stepping || process->resume->step;
+ if (!non_stop)
+ {
+ /* From GDB's perspective, all-stop mode always stops all
+ threads implicitly. Tag all threads as "want-stopped". */
+ gdb_wants_all_stopped ();
+ }
else
- step = process->resume->step;
+ {
+ /* We're reporting this LWP as stopped. Update it's
+ "want-stopped" state to what the client wants, until it gets
+ a new resume action. */
+ gdb_wants_lwp_stopped (&event_child->head);
+ }
- linux_resume_one_process (&process->head, step, process->resume->sig);
+ 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);
- process->resume = NULL;
+ get_lwp_thread (event_child)->last_status = *ourstatus;
+ return ptid_of (event_child);
}
-/* 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. 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. */
+/* Get rid of any pending event in the pipe. */
+static void
+async_file_flush (void)
+{
+ int ret;
+ char buf;
+ do
+ ret = read (linux_event_pipe[0], &buf, 1);
+ while (ret >= 0 || (ret == -1 && errno == EINTR));
+}
+
+/* Put something in the pipe, so the event loop wakes up. */
static void
-linux_queue_one_thread (struct inferior_list_entry *entry)
+async_file_mark (void)
{
- struct process_info *process;
- struct thread_info *thread;
+ int ret;
- thread = (struct thread_info *) entry;
- process = get_thread_process (thread);
+ async_file_flush ();
- if (process->resume->leave_stopped)
- return;
+ do
+ ret = write (linux_event_pipe[1], "+", 1);
+ while (ret == 0 || (ret == -1 && errno == EINTR));
- /* If we have a new signal, enqueue the signal. */
- if (process->resume->sig != 0)
- {
- struct pending_signals *p_sig;
- p_sig = malloc (sizeof (*p_sig));
- p_sig->prev = process->pending_signals;
- p_sig->signal = process->resume->sig;
- process->pending_signals = p_sig;
- }
+ /* Ignore EAGAIN. If the pipe is full, the event loop will already
+ be awakened anyway. */
+}
+
+static ptid_t
+linux_wait (ptid_t ptid,
+ struct target_waitstatus *ourstatus, int target_options)
+{
+ ptid_t event_ptid;
+
+ if (debug_threads)
+ fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
+
+ /* 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 ();
- process->resume = NULL;
+ return event_ptid;
}
-/* Set DUMMY if this process has an interesting status pending. */
+/* Send a signal to an LWP. */
+
static int
-resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
+kill_lwp (unsigned long lwpid, int signo)
{
- struct process_info *process = (struct process_info *) entry;
+ /* 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. */
- /* Processes which will not be resumed are not interesting, because
- we might not wait for them next time through linux_wait. */
- if (process->resume->leave_stopped)
- return 0;
+#ifdef __NR_tkill
+ {
+ static int tkill_failed;
- /* 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 (process->status_pending_p)
- check_removed_breakpoint (process);
-
- if (process->status_pending_p)
- * (int *) flag_p = 1;
+ if (!tkill_failed)
+ {
+ int ret;
- return 0;
+ errno = 0;
+ ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno != ENOSYS)
+ return ret;
+ tkill_failed = 1;
+ }
+ }
+#endif
+
+ return kill (lwpid, signo);
}
static void
-linux_resume (struct thread_resume *resume_info)
+send_sigstop (struct inferior_list_entry *entry)
{
- int pending_flag;
-
- /* Yes, the use of a global here is rather ugly. */
- resume_ptr = resume_info;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ int pid;
- for_each_inferior (&all_threads, linux_set_resume_request);
+ if (lwp->stopped)
+ return;
- /* 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. */
- pending_flag = 0;
- find_inferior (&all_processes, resume_status_pending_p, &pending_flag);
+ pid = lwpid_of (lwp);
- if (debug_threads)
+ /* If we already have a pending stop signal for this process, don't
+ send another. */
+ if (lwp->stop_expected)
{
- if (pending_flag)
- fprintf (stderr, "Not resuming, pending status\n");
- else
- fprintf (stderr, "Resuming, no pending status\n");
- }
+ if (debug_threads)
+ fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
- if (pending_flag)
- for_each_inferior (&all_threads, linux_queue_one_thread);
- else
- {
- block_async_io ();
- enable_async_io ();
- for_each_inferior (&all_threads, linux_continue_one_thread);
+ return;
}
-}
-#ifdef HAVE_LINUX_USRREGS
+ if (debug_threads)
+ fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
-int
-register_addr (int regnum)
+ lwp->stop_expected = 1;
+ kill_lwp (pid, SIGSTOP);
+}
+
+static void
+mark_lwp_dead (struct lwp_info *lwp, int wstat)
{
- int addr;
+ /* It's dead, really. */
+ lwp->dead = 1;
- if (regnum < 0 || regnum >= the_low_target.num_regs)
- error ("Invalid register number %d.", regnum);
+ /* Store the exit status for later. */
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
- addr = the_low_target.regmap[regnum];
+ /* Prevent trying to stop it. */
+ lwp->stopped = 1;
- return addr;
+ /* No further stops are expected from a dead lwp. */
+ lwp->stop_expected = 0;
}
-/* Fetch one register. */
static void
-fetch_register (int regno)
+wait_for_sigstop (struct inferior_list_entry *entry)
{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
+ 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 (regno >= the_low_target.num_regs)
- return;
- if ((*the_low_target.cannot_fetch_register) (regno))
- return;
+ if (lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
+ lwpid_of (lwp));
+ 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);
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+ 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))
{
- 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)
+ if (debug_threads)
+ fprintf (stderr, "LWP %ld stopped with signal %d\n",
+ lwpid_of (lwp), WSTOPSIG (wstat));
+
+ if (WSTOPSIG (wstat) != SIGSTOP)
+ {
+ 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);
+
+ lwp = find_lwp_pid (pid_to_ptid (pid));
+ if (lwp)
{
- /* 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;
+ /* 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);
}
}
- if (the_low_target.left_pad_xfer
- && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
- supply_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
- - register_size (regno)));
+
+ if (saved_inferior == NULL || linux_thread_alive (saved_tid))
+ current_inferior = saved_inferior;
else
- supply_register (regno, buf);
+ {
+ if (debug_threads)
+ fprintf (stderr, "Previously current thread died.\n");
-error_exit:;
+ 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);
+ }
+ }
}
-/* Fetch all registers, or just one, from the child process. */
static void
-usr_fetch_inferior_registers (int regno)
+stop_all_lwps (void)
{
- if (regno == -1 || regno == 0)
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- fetch_register (regno);
- else
- fetch_register (regno);
+ stopping_threads = 1;
+ for_each_inferior (&all_lwps, send_sigstop);
+ for_each_inferior (&all_lwps, wait_for_sigstop);
+ stopping_threads = 0;
}
-/* 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). */
+/* Resume execution of the inferior process.
+ If STEP is nonzero, single-step it.
+ If SIGNAL is nonzero, give it that signal. */
+
static void
-usr_store_inferior_registers (int regno)
+linux_resume_one_lwp (struct lwp_info *lwp,
+ int step, int signal, siginfo_t *info)
{
- CORE_ADDR regaddr;
- int i, size;
- char *buf;
+ struct thread_info *saved_inferior;
- if (regno >= 0)
+ 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))
{
- if (regno >= the_low_target.num_regs)
- return;
+ 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 ((*the_low_target.cannot_store_register) (regno) == 1)
- return;
+ 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;
+ }
- regaddr = register_addr (regno);
- if (regaddr == -1)
+ 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 (step == 0)
+ fprintf (stderr, "BAD - reinserting but not stepping.\n");
+
+ step = 1;
+ }
+
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
+ }
+
+ 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. */
+ if (lwp->pending_signals != NULL && lwp->bp_reinsert == 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;
+ }
+
+ 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;
- errno = 0;
- size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
- & - sizeof (PTRACE_XFER_TYPE);
- buf = alloca (size);
- memset (buf, 0, size);
- if (the_low_target.left_pad_xfer
- && register_size (regno) < sizeof (PTRACE_XFER_TYPE))
- collect_register (regno, (buf + sizeof (PTRACE_XFER_TYPE)
- - register_size (regno)));
- else
- collect_register (regno, buf);
- for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
+
+ 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))))
{
- errno = 0;
- ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
- *(PTRACE_XFER_TYPE *) (buf + i));
- if (errno != 0)
+ if (r->resume[ndx].kind == resume_stop
+ && lwp->last_resume_kind == resume_stop)
{
- 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;
- }
+ 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;
}
- regaddr += sizeof (PTRACE_XFER_TYPE);
+
+ lwp->resume = &r->resume[ndx];
+ lwp->last_resume_kind = lwp->resume->kind;
+ return 0;
}
}
- else
- for (regno = 0; regno < the_low_target.num_regs; regno++)
- usr_store_inferior_registers (regno);
+
+ /* No resume action for this thread. */
+ lwp->resume = NULL;
+
+ return 0;
}
-#endif /* HAVE_LINUX_USRREGS */
+/* 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;
-#ifdef HAVE_LINUX_REGSETS
+ /* 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
-regsets_fetch_inferior_registers ()
+need_step_over_p (struct inferior_list_entry *entry, void *dummy)
{
- struct regset_info *regset;
- int saw_general_regs = 0;
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
- regset = target_regsets;
+ /* LWPs which will not be resumed are not interesting, because we
+ might not wait for them next time through linux_wait. */
- while (regset->size >= 0)
+ if (!lwp->stopped)
{
- void *buf;
- int res;
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, not stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
- if (regset->size == 0)
- {
- regset ++;
- continue;
- }
+ if (lwp->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;
+ }
- buf = malloc (regset->size);
- res = ptrace (regset->get_request, inferior_pid, 0, buf);
- if (res < 0)
- {
- if (errno == EIO)
- {
- /* If we get EIO on the first regset, do not try regsets again.
- If we get EIO on a later regset, disable that regset. */
- if (regset == target_regsets)
- {
- use_regsets_p = 0;
- return -1;
- }
- else
- {
- regset->size = 0;
- 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 (!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 = get_lwp_thread (lwp);
+
+ /* We only step over our breakpoints. */
+ if (breakpoint_here (pc))
+ {
+ 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 ();
+
+ 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);
+
+ 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);
+
+ 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->head);
+ }
+ 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. */
+ send_sigstop (&lwp->head);
+ }
+
+ /* For stop requests, we're done. */
+ lwp->resume = NULL;
+ get_lwp_thread (lwp)->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);
+ get_lwp_thread (lwp)->last_status.kind = TARGET_WAITKIND_IGNORE;
+ }
+ 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;
+ }
+ }
+
+ 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 void
+proceed_one_lwp (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp;
+ int step;
+
+ lwp = (struct lwp_info *) entry;
+
+ 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;
+ }
+
+ if (lwp->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, " client wants LWP %ld stopped\n", lwpid_of (lwp));
+ return;
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
+
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
+ return;
+ }
+
+ step = lwp->last_resume_kind == resume_step;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+}
+
+/* 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");
+
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+}
+
+/* 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 (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");
+ }
+
+ /* Make sure proceed_one_lwp doesn't try to resume this thread. */
+ if (except != NULL)
+ ++except->suspended;
+
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+
+ if (except != NULL)
+ --except->suspended;
+}
+
+#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;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ 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))
+ {
+ 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);
+}
+
+/* Fetch all registers, or just one, from the child process. */
+static void
+usr_fetch_inferior_registers (struct regcache *regcache, int regno)
+{
+ if (regno == -1)
+ for (regno = 0; regno < the_low_target.num_regs; 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.
+ Otherwise, REGNO specifies which register (so we can save time). */
+static void
+usr_store_inferior_registers (struct regcache *regcache, int regno)
+{
+ CORE_ADDR regaddr;
+ int i, size;
+ char *buf;
+ int pid;
+
+ if (regno >= 0)
+ {
+ if (regno >= the_low_target.num_regs)
+ return;
+
+ if ((*the_low_target.cannot_store_register) (regno) == 1)
+ return;
+
+ 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);
+
+ 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);
+ }
+ }
+ else
+ for (regno = 0; regno < the_low_target.num_regs; regno++)
+ usr_store_inferior_registers (regcache, regno);
+}
+#endif /* HAVE_LINUX_USRREGS */
+
+
+
+#ifdef HAVE_LINUX_REGSETS
+
+static int
+regsets_fetch_inferior_registers (struct regcache *regcache)
+{
+ struct regset_info *regset;
+ int saw_general_regs = 0;
+ int pid;
+
+ regset = target_regsets;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ while (regset->size >= 0)
+ {
+ void *buf;
+ int res;
+
+ if (regset->size == 0 || disabled_regsets[regset - target_regsets])
+ {
+ regset ++;
+ continue;
+ }
+
+ buf = xmalloc (regset->size);
+#ifndef __sparc__
+ res = ptrace (regset->get_request, pid, 0, buf);
+#else
+ res = ptrace (regset->get_request, pid, buf, 0);
+#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;
+
+ regset = target_regsets;
+
+ pid = lwpid_of (get_thread_lwp (current_inferior));
+ while (regset->size >= 0)
+ {
+ void *buf;
+ int 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. */
+#ifndef __sparc__
+ res = ptrace (regset->get_request, pid, 0, buf);
+#else
+ res = ptrace (regset->get_request, pid, buf, 0);
+#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, 0, buf);
+#else
+ res = ptrace (regset->set_request, pid, buf, 0);
+#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;
+ return 0;
+}
+
+#endif /* HAVE_LINUX_REGSETS */
+
+
+void
+linux_fetch_registers (struct regcache *regcache, int regno)
+{
+#ifdef HAVE_LINUX_REGSETS
+ if (regsets_fetch_inferior_registers (regcache) == 0)
+ return;
+#endif
+#ifdef HAVE_LINUX_USRREGS
+ usr_fetch_inferior_registers (regcache, regno);
+#endif
+}
+
+void
+linux_store_registers (struct regcache *regcache, int regno)
+{
+#ifdef HAVE_LINUX_REGSETS
+ if (regsets_store_inferior_registers (regcache) == 0)
+ return;
+#endif
+#ifdef HAVE_LINUX_USRREGS
+ usr_store_inferior_registers (regcache, regno);
+#endif
+}
+
+
+/* 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;
+
+/* 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, 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));
+
+ snprintf (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
+#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;
}
- if (saw_general_regs)
- return 0;
- else
- return 1;
+#endif
+ return 0;
}
+#endif
static int
-regsets_store_inferior_registers ()
+compare_ints (const void *xa, const void *xb)
{
- struct regset_info *regset;
- int saw_general_regs = 0;
+ int a = *(const int *)xa;
+ int b = *(const int *)xb;
- regset = target_regsets;
+ return a - b;
+}
- while (regset->size >= 0)
- {
- void *buf;
- int res;
+static int *
+unique (int *b, int *e)
+{
+ int *d = b;
+ while (++b != e)
+ if (*d != *b)
+ *++d = *b;
+ return ++d;
+}
- if (regset->size == 0)
- {
- regset ++;
- continue;
- }
+/* Given PID, iterates over all threads in that process.
- buf = malloc (regset->size);
+ Information about each thread, in a format suitable for qXfer:osdata:thread
+ is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
+ initialized, and the caller is responsible for finishing and appending '\0'
+ to it.
- /* 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. */
- res = ptrace (regset->get_request, inferior_pid, 0, buf);
+ The list of cores that threads are running on is assigned to *CORES, if it
+ is not NULL. If no cores are found, *CORES will be set to NULL. Caller
+ should free *CORES. */
- if (res == 0)
+static void
+list_threads (int pid, struct buffer *buffer, char **cores)
+{
+ int count = 0;
+ int allocated = 10;
+ int *core_numbers = xmalloc (sizeof (int) * allocated);
+ char pathname[128];
+ DIR *dir;
+ struct dirent *dp;
+ struct stat statbuf;
+
+ sprintf (pathname, "/proc/%d/task", pid);
+ if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+ {
+ dir = opendir (pathname);
+ if (!dir)
{
- /* Then overlay our cached registers on that. */
- regset->fill_function (buf);
-
- /* Only now do we write the register set. */
- res = ptrace (regset->set_request, inferior_pid, 0, buf);
+ free (core_numbers);
+ return;
}
- if (res < 0)
+ while ((dp = readdir (dir)) != NULL)
{
- if (errno == EIO)
+ unsigned long lwp = strtoul (dp->d_name, NULL, 10);
+
+ if (lwp != 0)
{
- /* If we get EIO on the first regset, do not try regsets again.
- If we get EIO on a later regset, disable that regset. */
- if (regset == target_regsets)
+ unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
+
+ if (core != -1)
{
- use_regsets_p = 0;
- return -1;
+ char s[sizeof ("4294967295")];
+ sprintf (s, "%u", core);
+
+ if (count == allocated)
+ {
+ allocated *= 2;
+ core_numbers = realloc (core_numbers,
+ sizeof (int) * allocated);
+ }
+ core_numbers[count++] = core;
+ if (buffer)
+ buffer_xml_printf (buffer,
+ "<item>"
+ "<column name=\"pid\">%d</column>"
+ "<column name=\"tid\">%s</column>"
+ "<column name=\"core\">%s</column>"
+ "</item>", pid, dp->d_name, s);
}
else
{
- regset->size = 0;
- continue;
+ if (buffer)
+ buffer_xml_printf (buffer,
+ "<item>"
+ "<column name=\"pid\">%d</column>"
+ "<column name=\"tid\">%s</column>"
+ "</item>", pid, dp->d_name);
}
}
- 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;
- return 0;
-}
-#endif /* HAVE_LINUX_REGSETS */
+ if (cores)
+ {
+ *cores = NULL;
+ if (count > 0)
+ {
+ struct buffer buffer2;
+ int *b;
+ int *e;
+ qsort (core_numbers, count, sizeof (int), compare_ints);
+ /* Remove duplicates. */
+ b = core_numbers;
+ e = unique (b, core_numbers + count);
-void
-linux_fetch_registers (int regno)
-{
-#ifdef HAVE_LINUX_REGSETS
- if (use_regsets_p)
- {
- if (regsets_fetch_inferior_registers () == 0)
- return;
+ buffer_init (&buffer2);
+
+ for (b = core_numbers; b != e; ++b)
+ {
+ char number[sizeof ("4294967295")];
+ sprintf (number, "%u", *b);
+ buffer_xml_printf (&buffer2, "%s%s",
+ (b == core_numbers) ? "" : ",", number);
+ }
+ buffer_grow_str0 (&buffer2, "");
+
+ *cores = buffer_finish (&buffer2);
+ }
}
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_fetch_inferior_registers (regno);
-#endif
+ free (core_numbers);
}
-void
-linux_store_registers (int regno)
+static void
+show_process (int pid, const char *username, struct buffer *buffer)
{
-#ifdef HAVE_LINUX_REGSETS
- if (use_regsets_p)
+ char pathname[128];
+ FILE *f;
+ char cmd[MAXPATHLEN + 1];
+
+ sprintf (pathname, "/proc/%d/cmdline", pid);
+
+ if ((f = fopen (pathname, "r")) != NULL)
{
- if (regsets_store_inferior_registers () == 0)
- return;
+ size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
+ if (len > 0)
+ {
+ char *cores = 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\">%d</column>"
+ "<column name=\"user\">%s</column>"
+ "<column name=\"command\">%s</column>",
+ pid,
+ username,
+ cmd);
+
+ /* This only collects core numbers, and does not print threads. */
+ list_threads (pid, NULL, &cores);
+
+ if (cores)
+ {
+ buffer_xml_printf (buffer,
+ "<column name=\"cores\">%s</column>", cores);
+ free (cores);
+ }
+
+ buffer_xml_printf (buffer, "</item>");
+ }
+ fclose (f);
}
-#endif
-#ifdef HAVE_LINUX_USRREGS
- usr_store_inferior_registers (regno);
-#endif
}
-
-/* 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)
+linux_qxfer_osdata (const char *annex,
+ unsigned char *readbuf, unsigned const char *writebuf,
+ CORE_ADDR offset, 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));
+ /* 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;
+ int processes = 0;
+ int threads = 0;
+
+ DIR *dirp;
+
+ if (strcmp (annex, "processes") == 0)
+ processes = 1;
+ else if (strcmp (annex, "threads") == 0)
+ threads = 1;
+ else
+ return 0;
- /* Read all the longwords */
- for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ if (!readbuf || writebuf)
+ return 0;
+
+ if (offset == 0)
{
- errno = 0;
- buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0);
- if (errno)
- return errno;
+ if (len_avail != -1 && len_avail != 0)
+ buffer_free (&buffer);
+ len_avail = 0;
+ buf = NULL;
+ buffer_init (&buffer);
+ if (processes)
+ buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+ else if (threads)
+ buffer_grow_str (&buffer, "<osdata type=\"threads\">");
+
+ 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))
+ {
+ int pid = (int) strtoul (dp->d_name, NULL, 10);
+
+ if (processes)
+ {
+ struct passwd *entry = getpwuid (statbuf.st_uid);
+ show_process (pid, entry ? entry->pw_name : "?", &buffer);
+ }
+ else if (threads)
+ {
+ list_threads (pid, &buffer, NULL);
+ }
+ }
+ }
+
+ closedir (dirp);
+ }
+ buffer_grow_str0 (&buffer, "</osdata>\n");
+ buf = buffer_finish (&buffer);
+ len_avail = strlen (buf);
}
- /* Copy appropriate bytes out of the buffer. */
- memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len);
+ if (offset >= len_avail)
+ {
+ /* Done. Get rid of the data. */
+ buffer_free (&buffer);
+ buf = NULL;
+ len_avail = 0;
+ return 0;
+ }
- return 0;
+ if (len > len_avail - offset)
+ len = len_avail - offset;
+ memcpy (readbuf, buf + offset, len);
+
+ return len;
}
-/* 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. */
+/* Convert a native/host siginfo object, into/from the siginfo in the
+ layout of the inferiors' architecture. */
-static int
-linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
+static void
+siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
{
- 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));
- extern int errno;
+ int done = 0;
- if (debug_threads)
+ 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)
{
- fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
+ if (direction == 1)
+ memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
+ else
+ memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
}
+}
- /* Fill start and end extra bytes of buffer with existing memory data. */
+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)];
- buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) addr, 0);
+ if (current_inferior == NULL)
+ return -1;
- if (count > 1)
- {
- buffer[count - 1]
- = ptrace (PTRACE_PEEKTEXT, inferior_pid,
- (PTRACE_ARG3_TYPE) (addr + (count - 1)
- * sizeof (PTRACE_XFER_TYPE)),
- 0);
- }
+ pid = lwpid_of (get_thread_lwp (current_inferior));
- /* Copy data to be written over corresponding part of buffer */
+ if (debug_threads)
+ fprintf (stderr, "%s siginfo for lwp %d.\n",
+ readbuf != NULL ? "Reading" : "Writing",
+ pid);
- memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
+ if (offset > sizeof (siginfo))
+ return -1;
- /* Write the entire buffer. */
+ if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
+ return -1;
- for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ /* 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
{
- errno = 0;
- ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
- if (errno)
- return errno;
+ 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 0;
+ 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
-linux_look_up_symbols (void)
+sigchld_handler (int signo)
{
-#ifdef USE_THREAD_DB
- if (using_threads)
- return;
+ int old_errno = errno;
- using_threads = thread_db_init ();
-#endif
+ if (debug_threads)
+ /* fprintf is not async-signal-safe, so call write directly. */
+ write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
+
+ if (target_is_async_p ())
+ async_file_mark (); /* trigger a linux_wait */
+
+ errno = old_errno;
}
-static void
-linux_send_signal (int signum)
+static int
+linux_supports_non_stop (void)
{
- extern unsigned long signal_pid;
+ return 1;
+}
+
+static int
+linux_async (int enable)
+{
+ int previous = (linux_event_pipe[0] != -1);
- if (cont_thread != 0 && cont_thread != -1)
+ if (previous != enable)
{
- struct process_info *process;
+ sigset_t mask;
+ sigemptyset (&mask);
+ sigaddset (&mask, SIGCHLD);
- process = get_thread_process (current_inferior);
- kill_lwp (process->lwpid, signum);
- }
- else
- kill_lwp (signal_pid, signum);
-}
+ sigprocmask (SIG_BLOCK, &mask, NULL);
-/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
- to debugger memory starting at MYADDR. */
+ if (enable)
+ {
+ if (pipe (linux_event_pipe) == -1)
+ fatal ("creating event pipe failed.");
-static int
-linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
-{
- char filename[PATH_MAX];
- int fd, n;
+ fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
+ fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
- snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid);
+ /* Register the event loop handler. */
+ add_file_handler (linux_event_pipe[0],
+ handle_target_event, NULL);
- fd = open (filename, O_RDONLY);
- if (fd < 0)
- return -1;
+ /* Always trigger a linux_wait. */
+ async_file_mark ();
+ }
+ else
+ {
+ delete_file_handler (linux_event_pipe[0]);
- if (offset != (CORE_ADDR) 0
- && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
- n = -1;
- else
- n = read (fd, myaddr, len);
+ close (linux_event_pipe[0]);
+ close (linux_event_pipe[1]);
+ linux_event_pipe[0] = -1;
+ linux_event_pipe[1] = -1;
+ }
- close (fd);
+ sigprocmask (SIG_UNBLOCK, &mask, NULL);
+ }
- return n;
+ return previous;
}
-/* These watchpoint related wrapper functions simply pass on the function call
- if the target has registered a corresponding function. */
+static int
+linux_start_non_stop (int nonstop)
+{
+ /* Register or unregister from event-loop accordingly. */
+ linux_async (nonstop);
+ return 0;
+}
static int
-linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
+linux_supports_multi_process (void)
{
- if (the_low_target.insert_watchpoint != NULL)
- return the_low_target.insert_watchpoint (type, addr, len);
- else
- /* Unsupported (see target.h). */
- return 1;
+ return 1;
}
+
+/* Enumerate spufs IDs for process PID. */
static int
-linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
+spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
{
- if (the_low_target.remove_watchpoint != NULL)
- return the_low_target.remove_watchpoint (type, addr, len);
- else
- /* Unsupported (see target.h). */
- return 1;
+ 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;
+
+ rewinddir (dir);
+ while ((entry = readdir (dir)) != NULL)
+ {
+ 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;
+ }
+
+ closedir (dir);
+ return written;
}
+/* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
+ object type, using the /proc file system. */
static int
-linux_stopped_by_watchpoint (void)
+linux_qxfer_spu (const char *annex, unsigned char *readbuf,
+ unsigned const char *writebuf,
+ CORE_ADDR offset, int len)
{
- if (the_low_target.stopped_by_watchpoint != NULL)
- return the_low_target.stopped_by_watchpoint ();
+ long pid = lwpid_of (get_thread_lwp (current_inferior));
+ char buf[128];
+ int fd = 0;
+ int ret = 0;
+
+ if (!writebuf && !readbuf)
+ return -1;
+
+ if (!*annex)
+ {
+ if (!readbuf)
+ return -1;
+ else
+ return spu_enumerate_spu_ids (pid, readbuf, offset, len);
+ }
+
+ sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
+ fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
+ if (fd <= 0)
+ return -1;
+
+ if (offset != 0
+ && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
+ {
+ close (fd);
+ return 0;
+ }
+
+ if (writebuf)
+ ret = write (fd, writebuf, (size_t) len);
else
- return 0;
+ ret = read (fd, readbuf, (size_t) len);
+
+ close (fd);
+ return ret;
}
-static CORE_ADDR
-linux_stopped_data_address (void)
+static int
+linux_core_of_thread (ptid_t ptid)
{
- if (the_low_target.stopped_data_address != NULL)
- return the_low_target.stopped_data_address ();
- else
- return 0;
+ char filename[sizeof ("/proc//task//stat")
+ + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
+ + 1];
+ FILE *f;
+ char *content = NULL;
+ char *p;
+ char *ts = 0;
+ int content_read = 0;
+ int i;
+ int core;
+
+ sprintf (filename, "/proc/%d/task/%ld/stat",
+ ptid_get_pid (ptid), ptid_get_lwp (ptid));
+ f = fopen (filename, "r");
+ if (!f)
+ return -1;
+
+ for (;;)
+ {
+ int n;
+ content = realloc (content, content_read + 1024);
+ n = fread (content + content_read, 1, 1024, f);
+ content_read += n;
+ if (n < 1024)
+ {
+ content[content_read] = '\0';
+ break;
+ }
+ }
+
+ p = strchr (content, '(');
+ p = strchr (p, ')') + 2; /* skip ")" and a whitespace. */
+
+ p = strtok_r (p, " ", &ts);
+ for (i = 0; i != 36; ++i)
+ p = strtok_r (NULL, " ", &ts);
+
+ if (sscanf (p, "%d", &core) == 0)
+ core = -1;
+
+ free (content);
+ fclose (f);
+
+ return core;
}
static struct target_ops linux_target_ops = {
linux_attach,
linux_kill,
linux_detach,
+ linux_join,
linux_thread_alive,
linux_resume,
linux_wait,
linux_read_memory,
linux_write_memory,
linux_look_up_symbols,
- linux_send_signal,
+ 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)
+ linux_read_offsets,
+#else
+ NULL,
+#endif
+#ifdef USE_THREAD_DB
+ thread_db_get_tls_address,
+#else
+ NULL,
+#endif
+ 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_core_of_thread
};
static void
{
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
to find what the cancel signal actually is. */
+#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN+1, SIG_IGN);
+#endif
}
void
initialize_low (void)
{
- using_threads = 0;
+ struct sigaction sigchld_action;
+ memset (&sigchld_action, 0, sizeof (sigchld_action));
set_target_ops (&linux_target_ops);
set_breakpoint_data (the_low_target.breakpoint,
the_low_target.breakpoint_len);
- init_registers ();
linux_init_signals ();
+ linux_test_for_tracefork ();
+#ifdef HAVE_LINUX_REGSETS
+ for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
+ ;
+ disabled_regsets = xmalloc (num_regsets);
+#endif
+
+ sigchld_action.sa_handler = sigchld_handler;
+ sigemptyset (&sigchld_action.sa_mask);
+ sigchld_action.sa_flags = SA_RESTART;
+ sigaction (SIGCHLD, &sigchld_action, NULL);
}