/* Low level interface to ptrace, for the remote server for GDB.
- Copyright (C) 1995-2015 Free Software Foundation, Inc.
+ Copyright (C) 1995-2016 Free Software Foundation, Inc.
This file is part of GDB.
#include "filestuff.h"
#include "tracepoint.h"
#include "hostio.h"
+#include <inttypes.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
static int kill_lwp (unsigned long lwpid, int signo);
static void enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info);
static void complete_ongoing_step_over (void);
+static int linux_low_ptrace_options (int attached);
/* When the event-loop is doing a step-over, this points at the thread
being stepped. */
ptid_t step_over_bkpt;
-/* True if the low target can hardware single-step. Such targets
- don't need a BREAKPOINT_REINSERT_ADDR callback. */
+/* True if the low target can hardware single-step. */
static int
can_hardware_single_step (void)
{
- return (the_low_target.breakpoint_reinsert_addr == NULL);
+ if (the_low_target.supports_hardware_single_step != NULL)
+ return the_low_target.supports_hardware_single_step ();
+ else
+ return 0;
+}
+
+/* True if the low target can software single-step. Such targets
+ implement the GET_NEXT_PCS callback. */
+
+static int
+can_software_single_step (void)
+{
+ return (the_low_target.get_next_pcs != NULL);
}
/* True if the low target supports memory breakpoints. If so, we'll
static CORE_ADDR get_pc (struct lwp_info *lwp);
-/* Implement the arch_setup target_ops method. */
+/* Call the target arch_setup function on the current thread. */
static void
linux_arch_setup (void)
struct thread_info *event_thr = get_lwp_thread (event_lwp);
struct lwp_info *new_lwp;
+ gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE);
+
+ /* All extended events we currently use are mid-syscall. Only
+ PTRACE_EVENT_STOP is delivered more like a signal-stop, but
+ you have to be using PTRACE_SEIZE to get that. */
+ event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
+
if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK)
|| (event == PTRACE_EVENT_CLONE))
{
child_thr->last_status.kind = TARGET_WAITKIND_STOPPED;
/* If we're suspending all threads, leave this one suspended
- too. */
- if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
+ too. If the fork/clone parent is stepping over a breakpoint,
+ all other threads have been suspended already. Leave the
+ child suspended too. */
+ if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS
+ || event_lwp->bp_reinsert != 0)
{
if (debug_threads)
debug_printf ("HEW: leaving child suspended\n");
before calling linux_resume_one_lwp. */
new_lwp->stopped = 1;
- /* If we're suspending all threads, leave this one suspended
- too. */
- if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
+ /* If we're suspending all threads, leave this one suspended
+ too. If the fork/clone parent is stepping over a breakpoint,
+ all other threads have been suspended already. Leave the
+ child suspended too. */
+ if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS
+ || event_lwp->bp_reinsert != 0)
new_lwp->suspended = 1;
/* Normally we will get the pending SIGSTOP. But in some cases
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
+ else if (report_thread_events)
+ {
+ new_lwp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
+ new_lwp->status_pending_p = 1;
+ new_lwp->status_pending = status;
+ }
/* Don't report the event. */
return 1;
else if (event == PTRACE_EVENT_EXEC && report_exec_events)
{
struct process_info *proc;
+ VEC (int) *syscalls_to_catch;
ptid_t event_ptid;
pid_t event_pid;
event_ptid = ptid_of (event_thr);
event_pid = ptid_get_pid (event_ptid);
- /* Delete the execing process and all its threads. */
+ /* Save the syscall list from the execing process. */
proc = get_thread_process (event_thr);
+ syscalls_to_catch = proc->syscalls_to_catch;
+ proc->syscalls_to_catch = NULL;
+
+ /* Delete the execing process and all its threads. */
linux_mourn (proc);
current_thread = NULL;
event_thr->last_resume_kind = resume_continue;
event_thr->last_status.kind = TARGET_WAITKIND_IGNORE;
+ /* Update syscall state in the new lwp, effectively mid-syscall too. */
+ event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
+
+ /* Restore the list to catch. Don't rely on the client, which is free
+ to avoid sending a new list when the architecture doesn't change.
+ Also, for ANY_SYSCALL, the architecture doesn't really matter. */
+ proc->syscalls_to_catch = syscalls_to_catch;
+
/* Report the event. */
*orig_event_lwp = event_lwp;
return 0;
return pc;
}
-/* This function should only be called if LWP got a SIGTRAP.
- The SIGTRAP could mean several things.
+/* This function should only be called if LWP got a SYSCALL_SIGTRAP.
+ Fill *SYSNO with the syscall nr trapped. Fill *SYSRET with the
+ return code. */
- On i386, where decr_pc_after_break is non-zero:
+static void
+get_syscall_trapinfo (struct lwp_info *lwp, int *sysno, int *sysret)
+{
+ struct thread_info *saved_thread;
+ struct regcache *regcache;
- If we were single-stepping this process using PTRACE_SINGLESTEP, we
- will get only the one SIGTRAP. The value of $eip will be the next
- instruction. If the instruction we stepped over was a breakpoint,
- we need to decrement the PC.
+ if (the_low_target.get_syscall_trapinfo == NULL)
+ {
+ /* If we cannot get the syscall trapinfo, report an unknown
+ system call number and -ENOSYS return value. */
+ *sysno = UNKNOWN_SYSCALL;
+ *sysret = -ENOSYS;
+ return;
+ }
+
+ saved_thread = current_thread;
+ current_thread = get_lwp_thread (lwp);
+
+ regcache = get_thread_regcache (current_thread, 1);
+ (*the_low_target.get_syscall_trapinfo) (regcache, sysno, sysret);
- If we continue the process using PTRACE_CONT, we will get a
- SIGTRAP when we hit a breakpoint. The value of $eip will be
- the instruction after the breakpoint (i.e. needs to be
- decremented). If we report the SIGTRAP to GDB, we must also
- report the undecremented PC. If the breakpoint is removed, we
- must resume at the decremented PC.
+ if (debug_threads)
+ {
+ debug_printf ("get_syscall_trapinfo sysno %d sysret %d\n",
+ *sysno, *sysret);
+ }
+
+ current_thread = saved_thread;
+}
- On a non-decr_pc_after_break machine with hardware or kernel
- single-step:
+static int check_stopped_by_watchpoint (struct lwp_info *child);
- If we either single-step a breakpoint instruction, or continue and
- hit a breakpoint instruction, our PC will point at the breakpoint
- instruction. */
+/* Called when the LWP stopped for a signal/trap. If it stopped for a
+ trap check what caused it (breakpoint, watchpoint, trace, etc.),
+ and save the result in the LWP's stop_reason field. If it stopped
+ for a breakpoint, decrement the PC if necessary on the lwp's
+ architecture. Returns true if we now have the LWP's stop PC. */
static int
-check_stopped_by_breakpoint (struct lwp_info *lwp)
+save_stop_reason (struct lwp_info *lwp)
{
CORE_ADDR pc;
CORE_ADDR sw_breakpoint_pc;
{
if (siginfo.si_signo == SIGTRAP)
{
- if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
+ if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
+ && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
{
- if (debug_threads)
- {
- struct thread_info *thr = get_lwp_thread (lwp);
-
- debug_printf ("CSBB: %s stopped by software breakpoint\n",
- target_pid_to_str (ptid_of (thr)));
- }
-
- /* Back up the PC if necessary. */
- if (pc != sw_breakpoint_pc)
- {
- struct regcache *regcache
- = get_thread_regcache (current_thread, 1);
- (*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
- }
-
- lwp->stop_pc = sw_breakpoint_pc;
+ /* The si_code is ambiguous on this arch -- check debug
+ registers. */
+ if (!check_stopped_by_watchpoint (lwp))
+ lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
+ }
+ else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
+ {
+ /* If we determine the LWP stopped for a SW breakpoint,
+ trust it. Particularly don't check watchpoint
+ registers, because at least on s390, we'd find
+ stopped-by-watchpoint as long as there's a watchpoint
+ set. */
lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
- current_thread = saved_thread;
- return 1;
}
- else if (siginfo.si_code == TRAP_HWBKPT)
+ else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
{
- if (debug_threads)
- {
- struct thread_info *thr = get_lwp_thread (lwp);
-
- debug_printf ("CSBB: %s stopped by hardware "
- "breakpoint/watchpoint\n",
- target_pid_to_str (ptid_of (thr)));
- }
-
- lwp->stop_pc = pc;
- lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
- current_thread = saved_thread;
- return 1;
+ /* This can indicate either a hardware breakpoint or
+ hardware watchpoint. Check debug registers. */
+ if (!check_stopped_by_watchpoint (lwp))
+ lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
}
else if (siginfo.si_code == TRAP_TRACE)
{
- if (debug_threads)
- {
- struct thread_info *thr = get_lwp_thread (lwp);
-
- debug_printf ("CSBB: %s stopped by trace\n",
- target_pid_to_str (ptid_of (thr)));
- }
-
- lwp->stop_reason = TARGET_STOPPED_BY_SINGLE_STEP;
+ /* We may have single stepped an instruction that
+ triggered a watchpoint. In that case, on some
+ architectures (such as x86), instead of TRAP_HWBKPT,
+ si_code indicates TRAP_TRACE, and we need to check
+ the debug registers separately. */
+ if (!check_stopped_by_watchpoint (lwp))
+ lwp->stop_reason = TARGET_STOPPED_BY_SINGLE_STEP;
}
}
}
case we need to report the breakpoint PC. */
if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc)
&& (*the_low_target.breakpoint_at) (sw_breakpoint_pc))
+ lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
+
+ if (hardware_breakpoint_inserted_here (pc))
+ lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
+
+ if (lwp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
+ check_stopped_by_watchpoint (lwp);
+#endif
+
+ if (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
{
if (debug_threads)
{
/* Back up the PC if necessary. */
if (pc != sw_breakpoint_pc)
- {
+ {
struct regcache *regcache
= get_thread_regcache (current_thread, 1);
(*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
}
- lwp->stop_pc = sw_breakpoint_pc;
- lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
- current_thread = saved_thread;
- return 1;
+ /* Update this so we record the correct stop PC below. */
+ pc = sw_breakpoint_pc;
}
-
- if (hardware_breakpoint_inserted_here (pc))
+ else if (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
{
if (debug_threads)
{
debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
target_pid_to_str (ptid_of (thr)));
}
+ }
+ else if (lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
+ {
+ if (debug_threads)
+ {
+ struct thread_info *thr = get_lwp_thread (lwp);
- lwp->stop_pc = pc;
- lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
- current_thread = saved_thread;
- return 1;
+ debug_printf ("CSBB: %s stopped by hardware watchpoint\n",
+ target_pid_to_str (ptid_of (thr)));
+ }
+ }
+ else if (lwp->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
+ {
+ if (debug_threads)
+ {
+ struct thread_info *thr = get_lwp_thread (lwp);
+
+ debug_printf ("CSBB: %s stopped by trace\n",
+ target_pid_to_str (ptid_of (thr)));
+ }
}
-#endif
+ lwp->stop_pc = pc;
current_thread = saved_thread;
- return 0;
+ return 1;
}
static struct lwp_info *
close_most_fds ();
ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
-#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
- signal (__SIGRTMIN + 1, SIG_DFL);
-#endif
-
setpgid (0, 0);
/* If gdbserver is connected to gdb via stdio, redirect the inferior's
return pid;
}
+/* Implement the post_create_inferior target_ops method. */
+
+static void
+linux_post_create_inferior (void)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_thread);
+
+ linux_arch_setup ();
+
+ if (lwp->must_set_ptrace_flags)
+ {
+ struct process_info *proc = current_process ();
+ int options = linux_low_ptrace_options (proc->attached);
+
+ linux_enable_event_reporting (lwpid_of (current_thread), options);
+ lwp->must_set_ptrace_flags = 0;
+ }
+}
+
/* Attach to an inferior process. Returns 0 on success, ERRNO on
error. */
return 0;
}
+static void async_file_mark (void);
+
/* Attach to PID. If PID is the tgid, attach to it and all
of its threads. */
static int
linux_attach (unsigned long pid)
{
+ struct process_info *proc;
+ struct thread_info *initial_thread;
ptid_t ptid = ptid_build (pid, pid, 0);
int err;
error ("Cannot attach to process %ld: %s",
pid, linux_ptrace_attach_fail_reason_string (ptid, err));
- linux_add_process (pid, 1);
-
- if (!non_stop)
- {
- struct thread_info *thread;
+ proc = linux_add_process (pid, 1);
- /* Don't ignore the initial SIGSTOP if we just attached to this
- process. It will be collected by wait shortly. */
- thread = find_thread_ptid (ptid_build (pid, pid, 0));
- thread->last_resume_kind = resume_stop;
- }
+ /* Don't ignore the initial SIGSTOP if we just attached to this
+ process. It will be collected by wait shortly. */
+ initial_thread = find_thread_ptid (ptid_build (pid, pid, 0));
+ initial_thread->last_resume_kind = resume_stop;
/* We must attach to every LWP. If /proc is mounted, use that to
find them now. On the one hand, the inferior may be using raw
that once thread_db is loaded, we'll still use it to list threads
and associate pthread info with each LWP. */
linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback);
+
+ /* GDB will shortly read the xml target description for this
+ process, to figure out the process' architecture. But the target
+ description is only filled in when the first process/thread in
+ the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do
+ that now, otherwise, if GDB is fast enough, it could read the
+ target description _before_ that initial stop. */
+ if (non_stop)
+ {
+ struct lwp_info *lwp;
+ int wstat, lwpid;
+ ptid_t pid_ptid = pid_to_ptid (pid);
+
+ lwpid = linux_wait_for_event_filtered (pid_ptid, pid_ptid,
+ &wstat, __WALL);
+ gdb_assert (lwpid > 0);
+
+ lwp = find_lwp_pid (pid_to_ptid (lwpid));
+
+ if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGSTOP)
+ {
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
+ }
+
+ initial_thread->last_resume_kind = resume_continue;
+
+ async_file_mark ();
+
+ gdb_assert (proc->tdesc != NULL);
+ }
+
return 0;
}
ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
alternative is to kill with SIGKILL. We only need one SIGKILL
per process, not one for each thread. But since we still support
- linuxthreads, and we also support debugging programs using raw
- clone without CLONE_THREAD, we send one for each thread. For
- years, we used PTRACE_KILL only, so we're being a bit paranoid
- about some old kernels where PTRACE_KILL might work better
- (dubious if there are any such, but that's why it's paranoia), so
- we try SIGKILL first, PTRACE_KILL second, and so we're fine
- everywhere. */
+ support debugging programs using raw clone without CLONE_THREAD,
+ we send one for each thread. For years, we used PTRACE_KILL
+ only, so we're being a bit paranoid about some old kernels where
+ PTRACE_KILL might work better (dubious if there are any such, but
+ that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL
+ second, and so we're fine everywhere. */
errno = 0;
kill_lwp (pid, SIGKILL);
if (!lp->status_pending_p)
return 0;
- /* If we got a `vCont;t', but we haven't reported a stop yet, do
- report any status pending the LWP may have. */
- if (thread->last_resume_kind == resume_stop
- && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
- return 0;
-
if (thread->last_resume_kind != resume_stop
&& (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
|| lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
return 1;
}
+/* Returns true if LWP is resumed from the client's perspective. */
+
+static int
+lwp_resumed (struct lwp_info *lwp)
+{
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind != resume_stop)
+ return 1;
+
+ /* Did gdb send us a `vCont;t', but we haven't reported the
+ corresponding stop to gdb yet? If so, the thread is still
+ resumed/running from gdb's perspective. */
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE)
+ return 1;
+
+ return 0;
+}
+
/* Return 1 if this lwp has an interesting status pending. */
static int
status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
if (!ptid_match (ptid_of (thread), ptid))
return 0;
+ if (!lwp_resumed (lp))
+ return 0;
+
if (lp->status_pending_p
&& !thread_still_has_status_pending_p (thread))
{
if (report_exec_events)
options |= PTRACE_O_TRACEEXEC;
+ options |= PTRACE_O_TRACESYSGOOD;
+
return options;
}
{
if (debug_threads)
debug_printf ("LLFE: %d exited.\n", lwpid);
- if (num_lwps (pid_of (thread)) > 1)
+ /* If there is at least one more LWP, then the exit signal was
+ not the end of the debugged application and should be
+ ignored, unless GDB wants to hear about thread exits. */
+ if (report_thread_events
+ || last_thread_of_process_p (pid_of (thread)))
{
-
- /* If there is at least one more LWP, then the exit signal was
- not the end of the debugged application and should be
- ignored. */
- delete_lwp (child);
- return NULL;
+ /* Since events are serialized to GDB core, and we can't
+ report this one right now. Leave the status pending for
+ the next time we're able to report it. */
+ mark_lwp_dead (child, wstat);
+ return child;
}
else
{
- /* This was the last lwp in the process. Since events are
- serialized to GDB core, and we can't report this one
- right now, but GDB core and the other target layers will
- want to be notified about the exit code/signal, leave the
- status pending for the next time we're able to report
- it. */
- mark_lwp_dead (child, wstat);
- return child;
+ delete_lwp (child);
+ return NULL;
}
}
child->must_set_ptrace_flags = 0;
}
- /* Be careful to not overwrite stop_pc until
- check_stopped_by_breakpoint is called. */
+ /* Always update syscall_state, even if it will be filtered later. */
+ if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP)
+ {
+ child->syscall_state
+ = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
+ ? TARGET_WAITKIND_SYSCALL_RETURN
+ : TARGET_WAITKIND_SYSCALL_ENTRY);
+ }
+ else
+ {
+ /* Almost all other ptrace-stops are known to be outside of system
+ calls, with further exceptions in handle_extended_wait. */
+ child->syscall_state = TARGET_WAITKIND_IGNORE;
+ }
+
+ /* Be careful to not overwrite stop_pc until save_stop_reason is
+ called. */
if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
&& linux_is_extended_waitstatus (wstat))
{
}
}
- /* Check first whether this was a SW/HW breakpoint before checking
- watchpoints, because at least s390 can't tell the data address of
- hardware watchpoint hits, and returns stopped-by-watchpoint as
- long as there's a watchpoint set. */
- if (WIFSTOPPED (wstat) && linux_wstatus_maybe_breakpoint (wstat))
+ if (linux_wstatus_maybe_breakpoint (wstat))
{
- if (check_stopped_by_breakpoint (child))
+ if (save_stop_reason (child))
have_stop_pc = 1;
}
- /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
- or hardware watchpoint. Check which is which if we got
- TARGET_STOPPED_BY_HW_BREAKPOINT. Likewise, we may have single
- stepped an instruction that triggered a watchpoint. In that
- case, on some architectures (such as x86), instead of
- TRAP_HWBKPT, si_code indicates TRAP_TRACE, and we need to check
- the debug registers separately. */
- if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
- && child->stop_reason != TARGET_STOPPED_BY_SW_BREAKPOINT)
- check_stopped_by_watchpoint (child);
-
if (!have_stop_pc)
child->stop_pc = get_pc (child);
if (lp->stopped
&& !lp->suspended
&& !lp->status_pending_p
- && thread->last_resume_kind != resume_stop
&& thread->last_status.kind == TARGET_WAITKIND_IGNORE)
{
int step = thread->last_resume_kind == resume_step;
current_thread = event_thread;
- /* Check for thread exit. */
- if (! WIFSTOPPED (*wstatp))
- {
- gdb_assert (last_thread_of_process_p (pid_of (event_thread)));
-
- if (debug_threads)
- debug_printf ("LWP %d is the last lwp of process. "
- "Process %ld exiting.\n",
- pid_of (event_thread), lwpid_of (event_thread));
- return lwpid_of (event_thread);
- }
-
return lwpid_of (event_thread);
}
}
}
- find_inferior (&all_threads, unsuspend_one_lwp, NULL);
+ unsuspend_all_lwps (NULL);
stabilizing_threads = 0;
}
}
-static void async_file_mark (void);
-
/* Convenience function that is called when the kernel reports an
event that is not passed out to GDB. */
return null_ptid;
}
+/* Convenience function that is called when the kernel reports an exit
+ event. This decides whether to report the event to GDB as a
+ process exit event, a thread exit event, or to suppress the
+ event. */
+
+static ptid_t
+filter_exit_event (struct lwp_info *event_child,
+ struct target_waitstatus *ourstatus)
+{
+ struct thread_info *thread = get_lwp_thread (event_child);
+ ptid_t ptid = ptid_of (thread);
+
+ if (!last_thread_of_process_p (pid_of (thread)))
+ {
+ if (report_thread_events)
+ ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
+ else
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
+
+ delete_lwp (event_child);
+ }
+ return ptid;
+}
+
+/* Returns 1 if GDB is interested in any event_child syscalls. */
+
+static int
+gdb_catching_syscalls_p (struct lwp_info *event_child)
+{
+ struct thread_info *thread = get_lwp_thread (event_child);
+ struct process_info *proc = get_thread_process (thread);
+
+ return !VEC_empty (int, proc->syscalls_to_catch);
+}
+
+/* Returns 1 if GDB is interested in the event_child syscall.
+ Only to be called when stopped reason is SYSCALL_SIGTRAP. */
+
+static int
+gdb_catch_this_syscall_p (struct lwp_info *event_child)
+{
+ int i, iter;
+ int sysno, sysret;
+ struct thread_info *thread = get_lwp_thread (event_child);
+ struct process_info *proc = get_thread_process (thread);
+
+ if (VEC_empty (int, proc->syscalls_to_catch))
+ return 0;
+
+ if (VEC_index (int, proc->syscalls_to_catch, 0) == ANY_SYSCALL)
+ return 1;
+
+ get_syscall_trapinfo (event_child, &sysno, &sysret);
+ for (i = 0;
+ VEC_iterate (int, proc->syscalls_to_catch, i, iter);
+ i++)
+ if (iter == sysno)
+ return 1;
+
+ return 0;
+}
+
/* Wait for process, returns status. */
static ptid_t
int report_to_gdb;
int trace_event;
int in_step_range;
+ int any_resumed;
if (debug_threads)
{
in_step_range = 0;
ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ /* Find a resumed LWP, if any. */
+ if (find_inferior (&all_threads,
+ status_pending_p_callback,
+ &minus_one_ptid) != NULL)
+ any_resumed = 1;
+ else if ((find_inferior (&all_threads,
+ not_stopped_callback,
+ &minus_one_ptid) != NULL))
+ any_resumed = 1;
+ else
+ any_resumed = 0;
+
if (ptid_equal (step_over_bkpt, null_ptid))
pid = linux_wait_for_event (ptid, &w, options);
else
pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
}
- if (pid == 0)
+ if (pid == 0 || (pid == -1 && !any_resumed))
{
gdb_assert (target_options & TARGET_WNOHANG);
}
}
+ if (ourstatus->kind == TARGET_WAITKIND_EXITED)
+ return filter_exit_event (event_child, ourstatus);
+
return ptid_of (current_thread);
}
- /* If step-over executes a breakpoint instruction, it means a
- gdb/gdbserver breakpoint had been planted on top of a permanent
- breakpoint. The PC has been adjusted by
- check_stopped_by_breakpoint to point at the breakpoint address.
- Advance the PC manually past the breakpoint, otherwise the
- program would keep trapping the permanent breakpoint forever. */
+ /* If step-over executes a breakpoint instruction, in the case of a
+ hardware single step it means a gdb/gdbserver breakpoint had been
+ planted on top of a permanent breakpoint, in the case of a software
+ single step it may just mean that gdbserver hit the reinsert breakpoint.
+ The PC has been adjusted by save_stop_reason to point at
+ the breakpoint address.
+ So in the case of the hardware single step advance the PC manually
+ past the breakpoint and in the case of software single step advance only
+ if it's not the reinsert_breakpoint we are hitting.
+ This avoids that a program would keep trapping a permanent breakpoint
+ forever. */
if (!ptid_equal (step_over_bkpt, null_ptid)
- && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
+ && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
+ && (event_child->stepping
+ || !reinsert_breakpoint_inserted_here (event_child->stop_pc)))
{
int increment_pc = 0;
int breakpoint_kind = 0;
CORE_ADDR stop_pc = event_child->stop_pc;
- breakpoint_kind = the_target->breakpoint_kind_from_pc (&stop_pc);
+ breakpoint_kind =
+ the_target->breakpoint_kind_from_current_state (&stop_pc);
the_target->sw_breakpoint_from_kind (breakpoint_kind, &increment_pc);
if (debug_threads)
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)
debug_printf ("Hit a gdbserver breakpoint.\n");
-
- if (breakpoint_here (event_child->stop_pc))
- event_child->need_step_over = 1;
}
}
else
/* Check whether GDB would be interested in this event. */
+ /* Check if GDB is interested in this syscall. */
+ if (WIFSTOPPED (w)
+ && WSTOPSIG (w) == SYSCALL_SIGTRAP
+ && !gdb_catch_this_syscall_p (event_child))
+ {
+ if (debug_threads)
+ {
+ debug_printf ("Ignored syscall for LWP %ld.\n",
+ lwpid_of (current_thread));
+ }
+
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ 0, NULL);
+ return ignore_event (ourstatus);
+ }
+
/* 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
stepping - they may require special handling to skip the signal
handler. Also never ignore signals that could be caused by a
breakpoint. */
- /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
- thread library? */
if (WIFSTOPPED (w)
&& current_thread->last_resume_kind != resume_step
&& (
}
}
- if (current_thread->last_resume_kind == resume_stop
- && WSTOPSIG (w) == SIGSTOP)
+ if (WSTOPSIG (w) == SYSCALL_SIGTRAP)
+ {
+ int sysret;
+
+ get_syscall_trapinfo (event_child,
+ &ourstatus->value.syscall_number, &sysret);
+ ourstatus->kind = event_child->syscall_state;
+ }
+ else if (current_thread->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
debug_exit ();
}
+ if (ourstatus->kind == TARGET_WAITKIND_EXITED)
+ return filter_exit_event (event_child, ourstatus);
+
return ptid_of (current_thread);
}
static int
kill_lwp (unsigned long lwpid, int signo)
{
- /* 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. */
-
-#ifdef __NR_tkill
- {
- static int tkill_failed;
-
- if (!tkill_failed)
- {
- int ret;
-
- errno = 0;
- ret = syscall (__NR_tkill, lwpid, signo);
- if (errno != ENOSYS)
- return ret;
- tkill_failed = 1;
- }
- }
-#endif
+ int ret;
- return kill (lwpid, signo);
+ errno = 0;
+ ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno == ENOSYS)
+ {
+ /* If tkill fails, then we are not using nptl threads, a
+ configuration we no longer support. */
+ perror_with_name (("tkill"));
+ }
+ return ret;
}
void
lwp->pending_signals = p_sig;
}
+/* Install breakpoints for software single stepping. */
+
+static void
+install_software_single_step_breakpoints (struct lwp_info *lwp)
+{
+ int i;
+ CORE_ADDR pc;
+ struct regcache *regcache = get_thread_regcache (current_thread, 1);
+ VEC (CORE_ADDR) *next_pcs = NULL;
+ struct cleanup *old_chain = make_cleanup (VEC_cleanup (CORE_ADDR), &next_pcs);
+
+ next_pcs = (*the_low_target.get_next_pcs) (regcache);
+
+ for (i = 0; VEC_iterate (CORE_ADDR, next_pcs, i, pc); ++i)
+ set_reinsert_breakpoint (pc);
+
+ do_cleanups (old_chain);
+}
+
+/* Single step via hardware or software single step.
+ Return 1 if hardware single stepping, 0 if software single stepping
+ or can't single step. */
+
+static int
+single_step (struct lwp_info* lwp)
+{
+ int step = 0;
+
+ if (can_hardware_single_step ())
+ {
+ step = 1;
+ }
+ else if (can_software_single_step ())
+ {
+ install_software_single_step_breakpoints (lwp);
+ step = 0;
+ }
+ else
+ {
+ if (debug_threads)
+ debug_printf ("stepping is not implemented on this target");
+ }
+
+ return step;
+}
+
+/* The signal can be delivered to the inferior if we are not trying to
+ finish a fast tracepoint collect. Since signal can be delivered in
+ the step-over, the program may go to signal handler and trap again
+ after return from the signal handler. We can live with the spurious
+ double traps. */
+
+static int
+lwp_signal_can_be_delivered (struct lwp_info *lwp)
+{
+ return !lwp->collecting_fast_tracepoint;
+}
+
/* Resume execution of LWP. If STEP is nonzero, single-step it. If
SIGNAL is nonzero, give it that signal. */
struct thread_info *thread = get_lwp_thread (lwp);
struct thread_info *saved_thread;
int fast_tp_collecting;
+ int ptrace_request;
struct process_info *proc = get_thread_process (thread);
/* Note that target description may not be initialised
if (lwp->stopped == 0)
return;
+ gdb_assert (lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE);
+
fast_tp_collecting = lwp->collecting_fast_tracepoint;
gdb_assert (!stabilizing_threads || fast_tp_collecting);
}
/* 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. */
+ signal. Also enqueue the signal if it can't be delivered to the
+ inferior right now. */
if (signal != 0
&& (lwp->status_pending_p
|| lwp->pending_signals != NULL
- || lwp->bp_reinsert != 0
- || fast_tp_collecting))
+ || !lwp_signal_can_be_delivered (lwp)))
{
- struct pending_signals *p_sig = XNEW (struct pending_signals);
+ enqueue_pending_signal (lwp, signal, info);
- 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;
+ /* Postpone any pending signal. It was enqueued above. */
+ signal = 0;
}
if (lwp->status_pending_p)
{
if (debug_threads)
- debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
+ debug_printf ("Not resuming lwp %ld (%s, stop %s);"
" has pending status\n",
- lwpid_of (thread), step ? "step" : "continue", signal,
+ lwpid_of (thread), step ? "step" : "continue",
lwp->stop_expected ? "expected" : "not expected");
return;
}
saved_thread = current_thread;
current_thread = thread;
- if (debug_threads)
- debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
- lwpid_of (thread), 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
step = 1;
}
-
- /* Postpone any pending signal. It was enqueued above. */
- signal = 0;
}
if (fast_tp_collecting == 1)
debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
" (exit-jump-pad-bkpt)\n",
lwpid_of (thread));
-
- /* Postpone any pending signal. It was enqueued above. */
- signal = 0;
}
else if (fast_tp_collecting == 2)
{
"moving out of jump pad single-stepping"
" not implemented on this target");
}
-
- /* Postpone any pending signal. It was enqueued above. */
- signal = 0;
}
/* If we have while-stepping actions in this thread set it stepping.
address, continue, and carry on catching this while-stepping
action only when that breakpoint is hit. A future
enhancement. */
- if (thread->while_stepping != NULL
- && can_hardware_single_step ())
+ if (thread->while_stepping != NULL)
{
if (debug_threads)
debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
lwpid_of (thread));
- step = 1;
+
+ step = single_step (lwp);
}
if (proc->tdesc != NULL && the_low_target.get_pc != NULL)
}
}
- /* If we have pending signals, consume one unless we are trying to
- reinsert a breakpoint or we're trying to finish a fast tracepoint
- collect. */
- if (lwp->pending_signals != NULL
- && lwp->bp_reinsert == 0
- && fast_tp_collecting == 0)
+ /* If we have pending signals, consume one if it can be delivered to
+ the inferior. */
+ if (lwp->pending_signals != NULL && lwp_signal_can_be_delivered (lwp))
{
struct pending_signals **p_sig;
*p_sig = NULL;
}
+ if (debug_threads)
+ debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
+ lwpid_of (thread), step ? "step" : "continue", signal,
+ lwp->stop_expected ? "expected" : "not expected");
+
if (the_low_target.prepare_to_resume != NULL)
the_low_target.prepare_to_resume (lwp);
regcache_invalidate_thread (thread);
errno = 0;
lwp->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
+ if (step)
+ ptrace_request = PTRACE_SINGLESTEP;
+ else if (gdb_catching_syscalls_p (lwp))
+ ptrace_request = PTRACE_SYSCALL;
+ else
+ ptrace_request = PTRACE_CONT;
+ ptrace (ptrace_request,
+ lwpid_of (thread),
(PTRACE_TYPE_ARG3) 0,
/* Coerce to a uintptr_t first to avoid potential gcc warning
of coercing an 8 byte integer to a 4 byte pointer. */
return 0;
}
- if (!lwp->need_step_over)
- {
- if (debug_threads)
- debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread));
- }
-
if (lwp->status_pending_p)
{
if (debug_threads)
"Old stop_pc was 0x%s, PC is now 0x%s\n",
lwpid_of (thread),
paddress (lwp->stop_pc), paddress (pc));
+ return 0;
+ }
+
+ /* On software single step target, resume the inferior with signal
+ rather than stepping over. */
+ if (can_software_single_step ()
+ && lwp->pending_signals != NULL
+ && lwp_signal_can_be_delivered (lwp))
+ {
+ if (debug_threads)
+ debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
+ " signals.\n",
+ lwpid_of (thread));
- lwp->need_step_over = 0;
return 0;
}
that find_inferior stops looking. */
current_thread = saved_thread;
- /* If the step over is cancelled, this is set again. */
- lwp->need_step_over = 0;
return 1;
}
}
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. */
+ single-stepped by either hardware or software 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. */
static int
start_step_over (struct lwp_info *lwp)
uninsert_breakpoints_at (pc);
uninsert_fast_tracepoint_jumps_at (pc);
- if (can_hardware_single_step ())
- {
- step = 1;
- }
- else
- {
- CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
- set_reinsert_breakpoint (raddr);
- step = 0;
- }
+ step = single_step (lwp);
current_thread = saved_thread;
debug_printf ("linux_resume done\n");
debug_exit ();
}
+
+ /* We may have events that were pending that can/should be sent to
+ the client now. Trigger a linux_wait call. */
+ if (target_is_async_p ())
+ async_file_mark ();
}
/* This function is called once per thread. We check the thread's
#ifdef HAVE_LINUX_USRREGS
-int
+static int
register_addr (const struct usrregs_info *usrregs, int regnum)
{
int addr;
#endif
-void
+static void
linux_fetch_registers (struct regcache *regcache, int regno)
{
int use_regsets;
}
}
-void
+static void
linux_store_registers (struct regcache *regcache, int regno)
{
int use_regsets;
if (proc->priv->thread_db != NULL)
return;
- /* If the kernel supports tracing clones, then we don't need to
- use the magic thread event breakpoint to learn about
- threads. */
- thread_db_init (!linux_supports_traceclone ());
+ thread_db_init ();
#endif
}
return can_hardware_single_step ();
}
+static int
+linux_supports_software_single_step (void)
+{
+ return can_software_single_step ();
+}
+
static int
linux_stopped_by_watchpoint (void)
{
layout of the inferiors' architecture. */
static void
-siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
+siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
{
int done = 0;
{
int pid;
siginfo_t siginfo;
- char inf_siginfo[sizeof (siginfo_t)];
+ gdb_byte inf_siginfo[sizeof (siginfo_t)];
if (current_thread == NULL)
return -1;
#endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
static void
-linux_process_qsupported (const char *query)
+linux_process_qsupported (char **features, int count)
{
if (the_low_target.process_qsupported != NULL)
- the_low_target.process_qsupported (query);
+ the_low_target.process_qsupported (features, count);
+}
+
+static int
+linux_supports_catch_syscall (void)
+{
+ return (the_low_target.get_syscall_trapinfo != NULL
+ && linux_supports_tracesysgood ());
+}
+
+static int
+linux_get_ipa_tdesc_idx (void)
+{
+ if (the_low_target.get_ipa_tdesc_idx == NULL)
+ return 0;
+
+ return (*the_low_target.get_ipa_tdesc_idx) ();
}
static int
return (err == BTRACE_ERR_NONE ? 0 : -1);
}
-/* Encode an Intel(R) Processor Trace configuration. */
+/* Encode an Intel Processor Trace configuration. */
static void
linux_low_encode_pt_config (struct buffer *buffer,
return (*the_low_target.sw_breakpoint_from_kind) (kind, size);
}
+/* Implementation of the target_ops method
+ "breakpoint_kind_from_current_state". */
+
+static int
+linux_breakpoint_kind_from_current_state (CORE_ADDR *pcptr)
+{
+ if (the_low_target.breakpoint_kind_from_current_state != NULL)
+ return (*the_low_target.breakpoint_kind_from_current_state) (pcptr);
+ else
+ return linux_breakpoint_kind_from_pc (pcptr);
+}
+
+/* Default implementation of linux_target_ops method "set_pc" for
+ 32-bit pc register which is literally named "pc". */
+
+void
+linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc)
+{
+ uint32_t newpc = pc;
+
+ supply_register_by_name (regcache, "pc", &newpc);
+}
+
+/* Default implementation of linux_target_ops method "get_pc" for
+ 32-bit pc register which is literally named "pc". */
+
+CORE_ADDR
+linux_get_pc_32bit (struct regcache *regcache)
+{
+ uint32_t pc;
+
+ collect_register_by_name (regcache, "pc", &pc);
+ if (debug_threads)
+ debug_printf ("stop pc is 0x%" PRIx32 "\n", pc);
+ return pc;
+}
+
+/* Default implementation of linux_target_ops method "set_pc" for
+ 64-bit pc register which is literally named "pc". */
+
+void
+linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc)
+{
+ uint64_t newpc = pc;
+
+ supply_register_by_name (regcache, "pc", &newpc);
+}
+
+/* Default implementation of linux_target_ops method "get_pc" for
+ 64-bit pc register which is literally named "pc". */
+
+CORE_ADDR
+linux_get_pc_64bit (struct regcache *regcache)
+{
+ uint64_t pc;
+
+ collect_register_by_name (regcache, "pc", &pc);
+ if (debug_threads)
+ debug_printf ("stop pc is 0x%" PRIx64 "\n", pc);
+ return pc;
+}
+
+
static struct target_ops linux_target_ops = {
linux_create_inferior,
- linux_arch_setup,
+ linux_post_create_inferior,
linux_attach,
linux_kill,
linux_detach,
linux_mntns_unlink,
linux_mntns_readlink,
linux_breakpoint_kind_from_pc,
- linux_sw_breakpoint_from_kind
+ linux_sw_breakpoint_from_kind,
+ linux_proc_tid_get_name,
+ linux_breakpoint_kind_from_current_state,
+ linux_supports_software_single_step,
+ linux_supports_catch_syscall,
+ linux_get_ipa_tdesc_idx,
};
-static void
-linux_init_signals ()
-{
- /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
- to find what the cancel signal actually is. */
-#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
- signal (__SIGRTMIN+1, SIG_IGN);
-#endif
-}
-
#ifdef HAVE_LINUX_REGSETS
void
initialize_regsets_info (struct regsets_info *info)
memset (&sigchld_action, 0, sizeof (sigchld_action));
set_target_ops (&linux_target_ops);
- linux_init_signals ();
linux_ptrace_init_warnings ();
sigchld_action.sa_handler = sigchld_handler;
projects / deliverable / binutils-gdb.git / blobdiff