/* GNU/Linux native-dependent code common to multiple platforms.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
- 2011 Free Software Foundation, Inc.
+ Copyright (C) 2001-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include <sys/ptrace.h>
#include "linux-nat.h"
#include "linux-ptrace.h"
+#include "linux-procfs.h"
#include "linux-fork.h"
#include "gdbthread.h"
#include "gdbcmd.h"
#include "terminal.h"
#include <sys/vfs.h>
#include "solib.h"
+#include "linux-osdata.h"
+#include "cli/cli-utils.h"
#ifndef SPUFS_MAGIC
#define SPUFS_MAGIC 0x23c9b64e
static struct target_ops linux_ops_saved;
/* The method to call, if any, when a new thread is attached. */
-static void (*linux_nat_new_thread) (ptid_t);
+static void (*linux_nat_new_thread) (struct lwp_info *);
+
+/* Hook to call prior to resuming a thread. */
+static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
/* The method to call, if any, when the siginfo object needs to be
converted between the layout returned by ptrace, and the layout in
value);
}
-static int debug_linux_nat_async = 0;
-static void
-show_debug_linux_nat_async (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
-{
- fprintf_filtered (file,
- _("Debugging of GNU/Linux async lwp module is %s.\n"),
- value);
-}
-
-static int disable_randomization = 1;
-
-static void
-show_disable_randomization (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
-{
-#ifdef HAVE_PERSONALITY
- fprintf_filtered (file,
- _("Disabling randomization of debuggee's "
- "virtual address space is %s.\n"),
- value);
-#else /* !HAVE_PERSONALITY */
- fputs_filtered (_("Disabling randomization of debuggee's "
- "virtual address space is unsupported on\n"
- "this platform.\n"), file);
-#endif /* !HAVE_PERSONALITY */
-}
-
-static void
-set_disable_randomization (char *args, int from_tty,
- struct cmd_list_element *c)
-{
-#ifndef HAVE_PERSONALITY
- error (_("Disabling randomization of debuggee's "
- "virtual address space is unsupported on\n"
- "this platform."));
-#endif /* !HAVE_PERSONALITY */
-}
-
struct simple_pid_list
{
int pid;
static int linux_supports_tracevforkdone_flag = -1;
-/* Async mode support. */
-
-/* Zero if the async mode, although enabled, is masked, which means
- linux_nat_wait should behave as if async mode was off. */
-static int linux_nat_async_mask_value = 1;
-
/* Stores the current used ptrace() options. */
static int current_ptrace_options = 0;
+/* Async mode support. */
+
/* The read/write ends of the pipe registered as waitable file in the
event loop. */
static int linux_nat_event_pipe[2] = { -1, -1 };
(enum inferior_event_type event_type,
void *context),
void *context);
-static int linux_nat_async_mask (int mask);
static int kill_lwp (int lwpid, int signo);
static int stop_callback (struct lwp_info *lp, void *data);
}
static int
+in_pid_list_p (struct simple_pid_list *list, int pid)
+{
+ struct simple_pid_list *p;
+
+ for (p = list; p != NULL; p = p->next)
+ if (p->pid == pid)
+ return 1;
+ return 0;
+}
+
+static int
pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
{
struct simple_pid_list **p;
return 0;
}
-static void
-linux_record_stopped_pid (int pid, int status)
-{
- add_to_pid_list (&stopped_pids, pid, status);
-}
-
\f
/* A helper function for linux_test_for_tracefork, called after fork (). */
linux_child_post_attach (int pid)
{
linux_enable_event_reporting (pid_to_ptid (pid));
- check_for_thread_db ();
linux_enable_tracesysgood (pid_to_ptid (pid));
}
linux_child_post_startup_inferior (ptid_t ptid)
{
linux_enable_event_reporting (ptid);
- check_for_thread_db ();
linux_enable_tracesysgood (ptid);
}
add_thread (inferior_ptid);
child_lp = add_lwp (inferior_ptid);
child_lp->stopped = 1;
- child_lp->resumed = 1;
+ child_lp->last_resume_kind = resume_stop;
/* If this is a vfork child, then the address-space is
shared with the parent. */
if (has_vforked)
{
- struct lwp_info *lp;
+ struct lwp_info *parent_lp;
struct inferior *parent_inf;
parent_inf = current_inferior ();
parent_inf->waiting_for_vfork_done = detach_fork;
parent_inf->pspace->breakpoints_not_allowed = detach_fork;
- lp = find_lwp_pid (pid_to_ptid (parent_pid));
+ parent_lp = find_lwp_pid (pid_to_ptid (parent_pid));
gdb_assert (linux_supports_tracefork_flag >= 0);
+
if (linux_supports_tracevforkdone (0))
{
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
"LCFF: waiting for VFORK_DONE on %d\n",
parent_pid);
-
- lp->stopped = 1;
- lp->resumed = 1;
+ parent_lp->stopped = 1;
/* We'll handle the VFORK_DONE event like any other
event, in target_wait. */
and leave it pending. The next linux_nat_resume call
will notice a pending event, and bypasses actually
resuming the inferior. */
- lp->status = 0;
- lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
- lp->stopped = 0;
- lp->resumed = 1;
+ parent_lp->status = 0;
+ parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
+ parent_lp->stopped = 1;
/* If we're in async mode, need to tell the event loop
there's something here to process. */
else
{
struct inferior *parent_inf, *child_inf;
- struct lwp_info *lp;
+ struct lwp_info *child_lp;
struct program_space *parent_pspace;
if (info_verbose || debug_linux_nat)
inferior_ptid = ptid_build (child_pid, child_pid, 0);
add_thread (inferior_ptid);
- lp = add_lwp (inferior_ptid);
- lp->stopped = 1;
- lp->resumed = 1;
+ child_lp = add_lwp (inferior_ptid);
+ child_lp->stopped = 1;
+ child_lp->last_resume_kind = resume_stop;
/* If this is a vfork child, then the address-space is shared
with the parent. If we detached from the parent, then we can
}
static int
+linux_child_remove_fork_catchpoint (int pid)
+{
+ return 0;
+}
+
+static int
linux_child_insert_vfork_catchpoint (int pid)
{
return !linux_supports_tracefork (pid);
}
static int
+linux_child_remove_vfork_catchpoint (int pid)
+{
+ return 0;
+}
+
+static int
linux_child_insert_exec_catchpoint (int pid)
{
return !linux_supports_tracefork (pid);
}
static int
+linux_child_remove_exec_catchpoint (int pid)
+{
+ return 0;
+}
+
+static int
linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
int table_size, int *table)
{
return buf;
}
+/* Destroy and free LP. */
+
+static void
+lwp_free (struct lwp_info *lp)
+{
+ xfree (lp->arch_private);
+ xfree (lp);
+}
+
/* Remove all LWPs belong to PID from the lwp list. */
static void
else
lpprev->next = lp->next;
- xfree (lp);
+ lwp_free (lp);
}
else
lpprev = lp;
memset (lp, 0, sizeof (struct lwp_info));
+ lp->last_resume_kind = resume_continue;
lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
lp->ptid = ptid;
lp->next = lwp_list;
lwp_list = lp;
+ /* Let the arch specific bits know about this new thread. Current
+ clients of this callback take the opportunity to install
+ watchpoints in the new thread. Don't do this for the first
+ thread though. If we're spawning a child ("run"), the thread
+ executes the shell wrapper first, and we shouldn't touch it until
+ it execs the program we want to debug. For "attach", it'd be
+ okay to call the callback, but it's not necessary, because
+ watchpoints can't yet have been inserted into the inferior. */
if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
- linux_nat_new_thread (ptid);
+ linux_nat_new_thread (lp);
return lp;
}
else
lwp_list = lp->next;
- xfree (lp);
+ lwp_free (lp);
}
/* Return a pointer to the structure describing the LWP corresponding
delete_lwp (lp->ptid);
}
-/* Return an lwp's tgid, found in `/proc/PID/status'. */
-
-int
-linux_proc_get_tgid (int lwpid)
-{
- FILE *status_file;
- char buf[100];
- int tgid = -1;
-
- snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
- status_file = fopen (buf, "r");
- if (status_file != NULL)
- {
- while (fgets (buf, sizeof (buf), status_file))
- {
- if (strncmp (buf, "Tgid:", 5) == 0)
- {
- tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
- break;
- }
- }
-
- fclose (status_file);
- }
-
- return tgid;
-}
-
/* Detect `T (stopped)' in `/proc/PID/status'.
Other states including `T (tracing stop)' are reported as false. */
return status;
}
-/* Attach to the LWP specified by PID. Return 0 if successful or -1
- if the new LWP could not be attached. */
+/* Attach to the LWP specified by PID. Return 0 if successful, -1 if
+ the new LWP could not be attached, or 1 if we're already auto
+ attached to this thread, but haven't processed the
+ PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
+ its existance, without considering it an error. */
int
lin_lwp_attach_lwp (ptid_t ptid)
{
struct lwp_info *lp;
sigset_t prev_mask;
+ int lwpid;
gdb_assert (is_lwp (ptid));
block_child_signals (&prev_mask);
lp = find_lwp_pid (ptid);
+ lwpid = GET_LWP (ptid);
/* We assume that we're already attached to any LWP that has an id
equal to the overall process id, and to any LWP that is already
and we've had PID wraparound since we last tried to stop all threads,
this assumption might be wrong; fortunately, this is very unlikely
to happen. */
- if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
+ if (lwpid != GET_PID (ptid) && lp == NULL)
{
int status, cloned = 0, signalled = 0;
- if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
+ if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
{
+ if (linux_supports_tracefork_flag)
+ {
+ /* If we haven't stopped all threads when we get here,
+ we may have seen a thread listed in thread_db's list,
+ but not processed the PTRACE_EVENT_CLONE yet. If
+ that's the case, ignore this new thread, and let
+ normal event handling discover it later. */
+ if (in_pid_list_p (stopped_pids, lwpid))
+ {
+ /* We've already seen this thread stop, but we
+ haven't seen the PTRACE_EVENT_CLONE extended
+ event yet. */
+ restore_child_signals_mask (&prev_mask);
+ return 0;
+ }
+ else
+ {
+ int new_pid;
+ int status;
+
+ /* See if we've got a stop for this new child
+ pending. If so, we're already attached. */
+ new_pid = my_waitpid (lwpid, &status, WNOHANG);
+ if (new_pid == -1 && errno == ECHILD)
+ new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG);
+ if (new_pid != -1)
+ {
+ if (WIFSTOPPED (status))
+ add_to_pid_list (&stopped_pids, lwpid, status);
+
+ restore_child_signals_mask (&prev_mask);
+ return 1;
+ }
+ }
+ }
+
/* If we fail to attach to the thread, issue a warning,
but continue. One way this can happen is if thread
creation is interrupted; as of Linux kernel 2.6.19, a
status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
if (!WIFSTOPPED (status))
- return -1;
+ {
+ restore_child_signals_mask (&prev_mask);
+ return 1;
+ }
lp = add_lwp (ptid);
lp->stopped = 1;
lp->stopped = 1;
}
+ lp->last_resume_kind = resume_stop;
restore_child_signals_mask (&prev_mask);
return 0;
}
/* Pass on any pending signal for this LWP. */
get_pending_status (lp, &status);
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
errno = 0;
if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
WSTOPSIG (status)) < 0)
target_pid_to_str (main_lwp->ptid));
}
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (main_lwp);
delete_lwp (main_lwp->ptid);
if (forks_exist_p ())
/* Resume LP. */
-static int
-resume_callback (struct lwp_info *lp, void *data)
+static void
+resume_lwp (struct lwp_info *lp, int step)
{
- struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
-
- if (lp->stopped && inf->vfork_child != NULL)
+ if (lp->stopped)
{
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "RC: Not resuming %s (vfork parent)\n",
- target_pid_to_str (lp->ptid));
+ struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
+
+ if (inf->vfork_child != NULL)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "RC: Not resuming %s (vfork parent)\n",
+ target_pid_to_str (lp->ptid));
+ }
+ else if (lp->status == 0
+ && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
+ target_pid_to_str (lp->ptid));
+
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
+ linux_ops->to_resume (linux_ops,
+ pid_to_ptid (GET_LWP (lp->ptid)),
+ step, TARGET_SIGNAL_0);
+ lp->stopped = 0;
+ lp->step = step;
+ memset (&lp->siginfo, 0, sizeof (lp->siginfo));
+ lp->stopped_by_watchpoint = 0;
+ }
+ else
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "RC: Not resuming sibling %s (has pending)\n",
+ target_pid_to_str (lp->ptid));
+ }
}
- else if (lp->stopped && lp->status == 0)
+ else
{
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
- target_pid_to_str (lp->ptid));
-
- linux_ops->to_resume (linux_ops,
- pid_to_ptid (GET_LWP (lp->ptid)),
- 0, TARGET_SIGNAL_0);
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
+ "RC: Not resuming sibling %s (not stopped)\n",
target_pid_to_str (lp->ptid));
- lp->stopped = 0;
- lp->step = 0;
- memset (&lp->siginfo, 0, sizeof (lp->siginfo));
- lp->stopped_by_watchpoint = 0;
}
- else if (lp->stopped && debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "RC: Not resuming sibling %s (has pending)\n",
- target_pid_to_str (lp->ptid));
- else if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "RC: Not resuming sibling %s (not stopped)\n",
- target_pid_to_str (lp->ptid));
+}
+static int
+resume_callback (struct lwp_info *lp, void *data)
+{
+ resume_lwp (lp, 0);
return 0;
}
resume_clear_callback (struct lwp_info *lp, void *data)
{
lp->resumed = 0;
+ lp->last_resume_kind = resume_stop;
return 0;
}
resume_set_callback (struct lwp_info *lp, void *data)
{
lp->resumed = 1;
+ lp->last_resume_kind = resume_continue;
return 0;
}
/* Remember if we're stepping. */
lp->step = step;
+ lp->last_resume_kind = step ? resume_step : resume_continue;
/* If we have a pending wait status for this thread, there is no
point in resuming the process. But first make sure that
/* Convert to something the lower layer understands. */
ptid = pid_to_ptid (GET_LWP (lp->ptid));
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, ptid, step, signo);
memset (&lp->siginfo, 0, sizeof (lp->siginfo));
lp->stopped_by_watchpoint = 0;
/* Note that gdbarch_get_syscall_number may access registers, hence
fill a regcache. */
registers_changed ();
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, TARGET_SIGNAL_0);
return 1;
ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LHEW: Got clone event "
+ "from LWP %d, new child is LWP %ld\n",
+ pid, new_pid);
+
new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
new_lp->cloned = 1;
new_lp->stopped = 1;
new_lp->signalled = 1;
}
else
- status = 0;
+ {
+ struct thread_info *tp;
+
+ /* When we stop for an event in some other thread, and
+ pull the thread list just as this thread has cloned,
+ we'll have seen the new thread in the thread_db list
+ before handling the CLONE event (glibc's
+ pthread_create adds the new thread to the thread list
+ before clone'ing, and has the kernel fill in the
+ thread's tid on the clone call with
+ CLONE_PARENT_SETTID). If that happened, and the core
+ had requested the new thread to stop, we'll have
+ killed it with SIGSTOP. But since SIGSTOP is not an
+ RT signal, it can only be queued once. We need to be
+ careful to not resume the LWP if we wanted it to
+ stop. In that case, we'll leave the SIGSTOP pending.
+ It will later be reported as TARGET_SIGNAL_0. */
+ tp = find_thread_ptid (new_lp->ptid);
+ if (tp != NULL && tp->stop_requested)
+ new_lp->last_resume_kind = resume_stop;
+ else
+ status = 0;
+ }
if (non_stop)
{
{
set_running (new_lp->ptid, 1);
set_executing (new_lp->ptid, 1);
+ /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
+ resume_stop. */
+ new_lp->last_resume_kind = resume_continue;
}
}
+ if (status != 0)
+ {
+ /* We created NEW_LP so it cannot yet contain STATUS. */
+ gdb_assert (new_lp->status == 0);
+
+ /* Save the wait status to report later. */
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LHEW: waitpid of new LWP %ld, "
+ "saving status %s\n",
+ (long) GET_LWP (new_lp->ptid),
+ status_to_str (status));
+ new_lp->status = status;
+ }
+
/* Note the need to use the low target ops to resume, to
handle resuming with PT_SYSCALL if we have syscall
catchpoints. */
if (!stopping)
{
- enum target_signal signo;
-
- new_lp->stopped = 0;
new_lp->resumed = 1;
- signo = (status
- ? target_signal_from_host (WSTOPSIG (status))
- : TARGET_SIGNAL_0);
-
- linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
- 0, signo);
- }
- else
- {
- if (status != 0)
+ if (status == 0)
{
- /* We created NEW_LP so it cannot yet contain STATUS. */
- gdb_assert (new_lp->status == 0);
-
- /* Save the wait status to report later. */
+ gdb_assert (new_lp->last_resume_kind == resume_continue);
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "LHEW: waitpid of new LWP %ld, "
- "saving status %s\n",
- (long) GET_LWP (new_lp->ptid),
- status_to_str (status));
- new_lp->status = status;
+ "LHEW: resuming new LWP %ld\n",
+ GET_LWP (new_lp->ptid));
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (new_lp);
+ linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
+ 0, TARGET_SIGNAL_0);
+ new_lp->stopped = 0;
}
}
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "LHEW: Got clone event "
- "from LWP %ld, resuming\n",
- GET_LWP (lp->ptid));
+ "LHEW: resuming parent LWP %d\n", pid);
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
0, TARGET_SIGNAL_0);
_("unknown ptrace event %d"), event);
}
+/* Return non-zero if LWP is a zombie. */
+
+static int
+linux_lwp_is_zombie (long lwp)
+{
+ char buffer[MAXPATHLEN];
+ FILE *procfile;
+ int retval;
+ int have_state;
+
+ xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp);
+ procfile = fopen (buffer, "r");
+ if (procfile == NULL)
+ {
+ warning (_("unable to open /proc file '%s'"), buffer);
+ return 0;
+ }
+
+ have_state = 0;
+ while (fgets (buffer, sizeof (buffer), procfile) != NULL)
+ if (strncmp (buffer, "State:", 6) == 0)
+ {
+ have_state = 1;
+ break;
+ }
+ retval = (have_state
+ && strcmp (buffer, "State:\tZ (zombie)\n") == 0);
+ fclose (procfile);
+ return retval;
+}
+
/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
exited. */
wait_lwp (struct lwp_info *lp)
{
pid_t pid;
- int status;
+ int status = 0;
int thread_dead = 0;
+ sigset_t prev_mask;
gdb_assert (!lp->stopped);
gdb_assert (lp->status == 0);
- pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
- if (pid == -1 && errno == ECHILD)
+ /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
+ block_child_signals (&prev_mask);
+
+ for (;;)
{
- pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
+ /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
+ was right and we should just call sigsuspend. */
+
+ pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG);
+ if (pid == -1 && errno == ECHILD)
+ pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG);
if (pid == -1 && errno == ECHILD)
{
/* The thread has previously exited. We need to delete it
fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
target_pid_to_str (lp->ptid));
}
+ if (pid != 0)
+ break;
+
+ /* Bugs 10970, 12702.
+ Thread group leader may have exited in which case we'll lock up in
+ waitpid if there are other threads, even if they are all zombies too.
+ Basically, we're not supposed to use waitpid this way.
+ __WCLONE is not applicable for the leader so we can't use that.
+ LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
+ process; it gets ESRCH both for the zombie and for running processes.
+
+ As a workaround, check if we're waiting for the thread group leader and
+ if it's a zombie, and avoid calling waitpid if it is.
+
+ This is racy, what if the tgl becomes a zombie right after we check?
+ Therefore always use WNOHANG with sigsuspend - it is equivalent to
+ waiting waitpid but the linux_lwp_is_zombie is safe this way. */
+
+ if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)
+ && linux_lwp_is_zombie (GET_LWP (lp->ptid)))
+ {
+ thread_dead = 1;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "WL: Thread group leader %s vanished.\n",
+ target_pid_to_str (lp->ptid));
+ break;
+ }
+
+ /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
+ get invoked despite our caller had them intentionally blocked by
+ block_child_signals. This is sensitive only to the loop of
+ linux_nat_wait_1 and there if we get called my_waitpid gets called
+ again before it gets to sigsuspend so we can safely let the handlers
+ get executed here. */
+
+ sigsuspend (&suspend_mask);
}
+ restore_child_signals_mask (&prev_mask);
+
if (!thread_dead)
{
gdb_assert (pid == GET_LWP (lp->ptid));
target_pid_to_str (lp->ptid),
status_to_str (status));
}
- }
- /* Check if the thread has exited. */
- if (WIFEXITED (status) || WIFSIGNALED (status))
- {
- thread_dead = 1;
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
- target_pid_to_str (lp->ptid));
+ /* Check if the thread has exited. */
+ if (WIFEXITED (status) || WIFSIGNALED (status))
+ {
+ thread_dead = 1;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
+ target_pid_to_str (lp->ptid));
+ }
}
if (thread_dead)
return 0;
}
+/* Request a stop on LWP. */
+
+void
+linux_stop_lwp (struct lwp_info *lwp)
+{
+ stop_callback (lwp, NULL);
+}
+
/* Return non-zero if LWP PID has a pending SIGINT. */
static int
static int
running_callback (struct lwp_info *lp, void *data)
{
- return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
+ return (!lp->stopped
+ || ((lp->status != 0
+ || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
+ && lp->resumed));
}
/* Count the LWP's that have had events. */
static int
select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
{
- if (lp->step && lp->status != 0)
+ if (lp->last_resume_kind == resume_step
+ && lp->status != 0)
return 1;
else
return 0;
return lp->resumed;
}
-/* Stop an active thread, verify it still exists, then resume it. */
+/* Stop an active thread, verify it still exists, then resume it. If
+ the thread ends up with a pending status, then it is not resumed,
+ and *DATA (really a pointer to int), is set. */
static int
stop_and_resume_callback (struct lwp_info *lp, void *data)
{
- struct lwp_info *ptr;
+ int *new_pending_p = data;
- if (!lp->stopped && !lp->signalled)
+ if (!lp->stopped)
{
+ ptid_t ptid = lp->ptid;
+
stop_callback (lp, NULL);
stop_wait_callback (lp, NULL);
- /* Resume if the lwp still exists. */
- for (ptr = lwp_list; ptr; ptr = ptr->next)
- if (lp == ptr)
- {
- resume_callback (lp, NULL);
- resume_set_callback (lp, NULL);
- }
+
+ /* Resume if the lwp still exists, and the core wanted it
+ running. */
+ lp = find_lwp_pid (ptid);
+ if (lp != NULL)
+ {
+ if (lp->last_resume_kind == resume_stop
+ && lp->status == 0)
+ {
+ /* The core wanted the LWP to stop. Even if it stopped
+ cleanly (with SIGSTOP), leave the event pending. */
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "SARC: core wanted LWP %ld stopped "
+ "(leaving SIGSTOP pending)\n",
+ GET_LWP (lp->ptid));
+ lp->status = W_STOPCODE (SIGSTOP);
+ }
+
+ if (lp->status == 0)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "SARC: re-resuming LWP %ld\n",
+ GET_LWP (lp->ptid));
+ resume_lwp (lp, lp->step);
+ }
+ else
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "SARC: not re-resuming LWP %ld "
+ "(has pending)\n",
+ GET_LWP (lp->ptid));
+ if (new_pending_p)
+ *new_pending_p = 1;
+ }
+ }
}
return 0;
}
/* Check if we should go on and pass this event to common code.
- Return the affected lwp if we are, or NULL otherwise. */
+ Return the affected lwp if we are, or NULL otherwise. If we stop
+ all lwps temporarily, we may end up with new pending events in some
+ other lwp. In that case set *NEW_PENDING_P to true. */
+
static struct lwp_info *
-linux_nat_filter_event (int lwpid, int status, int options)
+linux_nat_filter_event (int lwpid, int status, int *new_pending_p)
{
struct lwp_info *lp;
+ *new_pending_p = 0;
+
lp = find_lwp_pid (pid_to_ptid (lwpid));
/* Check for stop events reported by a process we didn't already
fork, vfork, and clone events, then we'll just add the
new one to our list and go back to waiting for the event
to be reported - the stopped process might be returned
- from waitpid before or after the event is. */
+ from waitpid before or after the event is.
+
+ But note the case of a non-leader thread exec'ing after the
+ leader having exited, and gone from our lists. The non-leader
+ thread changes its tid to the tgid. */
+
+ if (WIFSTOPPED (status) && lp == NULL
+ && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC))
+ {
+ /* A multi-thread exec after we had seen the leader exiting. */
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: Re-adding thread group leader LWP %d.\n",
+ lwpid);
+
+ lp = add_lwp (BUILD_LWP (lwpid, lwpid));
+ lp->stopped = 1;
+ lp->resumed = 1;
+ add_thread (lp->ptid);
+ }
+
if (WIFSTOPPED (status) && !lp)
{
- linux_record_stopped_pid (lwpid, status);
+ add_to_pid_list (&stopped_pids, lwpid, status);
return NULL;
}
if (!WIFSTOPPED (status) && !lp)
return NULL;
- /* NOTE drow/2003-06-17: This code seems to be meant for debugging
- CLONE_PTRACE processes which do not use the thread library -
- otherwise we wouldn't find the new LWP this way. That doesn't
- currently work, and the following code is currently unreachable
- due to the two blocks above. If it's fixed some day, this code
- should be broken out into a function so that we can also pick up
- LWPs from the new interface. */
- if (!lp)
- {
- lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
- if (options & __WCLONE)
- lp->cloned = 1;
-
- gdb_assert (WIFSTOPPED (status)
- && WSTOPSIG (status) == SIGSTOP);
- lp->signalled = 1;
-
- if (!in_thread_list (inferior_ptid))
- {
- inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
- GET_PID (inferior_ptid));
- add_thread (inferior_ptid);
- }
-
- add_thread (lp->ptid);
- }
-
- /* Handle GNU/Linux's syscall SIGTRAPs. */
- if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
+ /* Handle GNU/Linux's syscall SIGTRAPs. */
+ if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
{
/* No longer need the sysgood bit. The ptrace event ends up
recorded in lp->waitstatus if we care for it. We can carry
{
lp->stopped = 1;
iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
- stop_and_resume_callback, NULL);
+ stop_and_resume_callback, new_pending_p);
}
if (debug_linux_nat)
"LLW: Delayed SIGSTOP caught for %s.\n",
target_pid_to_str (lp->ptid));
- /* This is a delayed SIGSTOP. */
lp->signalled = 0;
- registers_changed ();
+ if (lp->last_resume_kind != resume_stop)
+ {
+ /* This is a delayed SIGSTOP. */
- linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
+ registers_changed ();
+
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
+ linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, TARGET_SIGNAL_0);
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
- lp->step ?
- "PTRACE_SINGLESTEP" : "PTRACE_CONT",
- target_pid_to_str (lp->ptid));
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
+ lp->step ?
+ "PTRACE_SINGLESTEP" : "PTRACE_CONT",
+ target_pid_to_str (lp->ptid));
- lp->stopped = 0;
- gdb_assert (lp->resumed);
+ lp->stopped = 0;
+ gdb_assert (lp->resumed);
- /* Discard the event. */
- return NULL;
+ /* Discard the event. */
+ return NULL;
+ }
}
/* Make sure we don't report a SIGINT that we have already displayed
lp->ignore_sigint = 0;
registers_changed ();
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, TARGET_SIGNAL_0);
if (debug_linux_nat)
return lp;
}
+/* Detect zombie thread group leaders, and "exit" them. We can't reap
+ their exits until all other threads in the group have exited. */
+
+static void
+check_zombie_leaders (void)
+{
+ struct inferior *inf;
+
+ ALL_INFERIORS (inf)
+ {
+ struct lwp_info *leader_lp;
+
+ if (inf->pid == 0)
+ continue;
+
+ leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
+ if (leader_lp != NULL
+ /* Check if there are other threads in the group, as we may
+ have raced with the inferior simply exiting. */
+ && num_lwps (inf->pid) > 1
+ && linux_lwp_is_zombie (inf->pid))
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "CZL: Thread group leader %d zombie "
+ "(it exited, or another thread execd).\n",
+ inf->pid);
+
+ /* A leader zombie can mean one of two things:
+
+ - It exited, and there's an exit status pending
+ available, or only the leader exited (not the whole
+ program). In the latter case, we can't waitpid the
+ leader's exit status until all other threads are gone.
+
+ - There are 3 or more threads in the group, and a thread
+ other than the leader exec'd. On an exec, the Linux
+ kernel destroys all other threads (except the execing
+ one) in the thread group, and resets the execing thread's
+ tid to the tgid. No exit notification is sent for the
+ execing thread -- from the ptracer's perspective, it
+ appears as though the execing thread just vanishes.
+ Until we reap all other threads except the leader and the
+ execing thread, the leader will be zombie, and the
+ execing thread will be in `D (disc sleep)'. As soon as
+ all other threads are reaped, the execing thread changes
+ it's tid to the tgid, and the previous (zombie) leader
+ vanishes, giving place to the "new" leader. We could try
+ distinguishing the exit and exec cases, by waiting once
+ more, and seeing if something comes out, but it doesn't
+ sound useful. The previous leader _does_ go away, and
+ we'll re-add the new one once we see the exec event
+ (which is just the same as what would happen if the
+ previous leader did exit voluntarily before some other
+ thread execs). */
+
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "CZL: Thread group leader %d vanished.\n",
+ inf->pid);
+ exit_lwp (leader_lp);
+ }
+ }
+}
+
static ptid_t
linux_nat_wait_1 (struct target_ops *ops,
ptid_t ptid, struct target_waitstatus *ourstatus,
int target_options)
{
static sigset_t prev_mask;
- struct lwp_info *lp = NULL;
- int options = 0;
- int status = 0;
- pid_t pid;
+ enum resume_kind last_resume_kind;
+ struct lwp_info *lp;
+ int status;
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
/* The first time we get here after starting a new inferior, we may
/* Make sure SIGCHLD is blocked. */
block_child_signals (&prev_mask);
- if (ptid_equal (ptid, minus_one_ptid))
- pid = -1;
- else if (ptid_is_pid (ptid))
- /* A request to wait for a specific tgid. This is not possible
- with waitpid, so instead, we wait for any child, and leave
- children we're not interested in right now with a pending
- status to report later. */
- pid = -1;
- else
- pid = GET_LWP (ptid);
-
retry:
lp = NULL;
status = 0;
- /* Make sure that of those LWPs we want to get an event from, there
- is at least one LWP that has been resumed. If there's none, just
- bail out. The core may just be flushing asynchronously all
- events. */
- if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
- {
- ourstatus->kind = TARGET_WAITKIND_IGNORE;
-
- if (debug_linux_nat_async)
- fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
-
- restore_child_signals_mask (&prev_mask);
- return minus_one_ptid;
- }
-
/* First check if there is a LWP with a wait status pending. */
- if (pid == -1)
+ if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
{
- /* Any LWP that's been resumed will do. */
+ /* Any LWP in the PTID group that's been resumed will do. */
lp = iterate_over_lwps (ptid, status_callback, NULL);
if (lp)
{
status_to_str (lp->status),
target_pid_to_str (lp->ptid));
}
-
- /* But if we don't find one, we'll have to wait, and check both
- cloned and uncloned processes. We start with the cloned
- processes. */
- options = __WCLONE | WNOHANG;
}
else if (is_lwp (ptid))
{
status_to_str (lp->status),
target_pid_to_str (lp->ptid));
- /* If we have to wait, take into account whether PID is a cloned
- process or not. And we have to convert it to something that
- the layer beneath us can understand. */
- options = lp->cloned ? __WCLONE : 0;
- pid = GET_LWP (ptid);
-
/* We check for lp->waitstatus in addition to lp->status,
because we can have pending process exits recorded in
lp->status and W_EXITCODE(0,0) == 0. We should probably have
lp = NULL;
}
- if (lp && lp->signalled)
+ if (lp && lp->signalled && lp->last_resume_kind != resume_stop)
{
/* A pending SIGSTOP may interfere with the normal stream of
events. In a typical case where interference is a problem,
/* Resume the thread. It should halt immediately returning the
pending SIGSTOP. */
registers_changed ();
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, TARGET_SIGNAL_0);
if (debug_linux_nat)
set_sigint_trap ();
}
- /* Translate generic target_wait options into waitpid options. */
- if (target_options & TARGET_WNOHANG)
- options |= WNOHANG;
+ /* But if we don't find a pending event, we'll have to wait. */
while (lp == NULL)
{
pid_t lwpid;
- lwpid = my_waitpid (pid, &status, options);
+ /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
+ quirks:
+
+ - If the thread group leader exits while other threads in the
+ thread group still exist, waitpid(TGID, ...) hangs. That
+ waitpid won't return an exit status until the other threads
+ in the group are reapped.
+
+ - When a non-leader thread execs, that thread just vanishes
+ without reporting an exit (so we'd hang if we waited for it
+ explicitly in that case). The exec event is reported to
+ the TGID pid. */
+
+ errno = 0;
+ lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG);
+ if (lwpid == 0 || (lwpid == -1 && errno == ECHILD))
+ lwpid = my_waitpid (-1, &status, WNOHANG);
+
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LNW: waitpid(-1, ...) returned %d, %s\n",
+ lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
if (lwpid > 0)
{
- gdb_assert (pid == -1 || lwpid == pid);
+ /* If this is true, then we paused LWPs momentarily, and may
+ now have pending events to handle. */
+ int new_pending;
if (debug_linux_nat)
{
(long) lwpid, status_to_str (status));
}
- lp = linux_nat_filter_event (lwpid, status, options);
+ lp = linux_nat_filter_event (lwpid, status, &new_pending);
/* STATUS is now no longer valid, use LP->STATUS instead. */
status = 0;
- if (lp
- && ptid_is_pid (ptid)
- && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
+ if (lp && !ptid_match (lp->ptid, ptid))
{
gdb_assert (lp->resumed);
/* Keep looking. */
lp = NULL;
- continue;
+ }
+
+ if (new_pending)
+ {
+ /* Some LWP now has a pending event. Go all the way
+ back to check it. */
+ goto retry;
}
if (lp)
- break;
- else
{
- if (pid == -1)
- {
- /* waitpid did return something. Restart over. */
- options |= __WCLONE;
- }
- continue;
+ /* We got an event to report to the core. */
+ break;
}
+
+ /* Retry until nothing comes out of waitpid. A single
+ SIGCHLD can indicate more than one child stopped. */
+ continue;
}
- if (pid == -1)
- {
- /* Alternate between checking cloned and uncloned processes. */
- options ^= __WCLONE;
+ /* Check for zombie thread group leaders. Those can't be reaped
+ until all other threads in the thread group are. */
+ check_zombie_leaders ();
- /* And every time we have checked both:
- In async mode, return to event loop;
- In sync mode, suspend waiting for a SIGCHLD signal. */
- if (options & __WCLONE)
- {
- if (target_options & TARGET_WNOHANG)
- {
- /* No interesting event. */
- ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ /* If there are no resumed children left, bail. We'd be stuck
+ forever in the sigsuspend call below otherwise. */
+ if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
- if (debug_linux_nat_async)
- fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
+ ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
- restore_child_signals_mask (&prev_mask);
- return minus_one_ptid;
- }
+ if (!target_can_async_p ())
+ clear_sigint_trap ();
- sigsuspend (&suspend_mask);
- }
+ restore_child_signals_mask (&prev_mask);
+ return minus_one_ptid;
}
- else if (target_options & TARGET_WNOHANG)
- {
- /* No interesting event for PID yet. */
- ourstatus->kind = TARGET_WAITKIND_IGNORE;
- if (debug_linux_nat_async)
+ /* No interesting event to report to the core. */
+
+ if (target_options & TARGET_WNOHANG)
+ {
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
restore_child_signals_mask (&prev_mask);
return minus_one_ptid;
}
/* We shouldn't end up here unless we want to try again. */
gdb_assert (lp == NULL);
+
+ /* Block until we get an event reported with SIGCHLD. */
+ sigsuspend (&suspend_mask);
}
if (!target_can_async_p ())
newly attached threads may cause an unwanted delay in
getting them running. */
registers_changed ();
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, signo);
if (debug_linux_nat)
from among those that have had events. Giving equal priority
to all LWPs that have had events helps prevent
starvation. */
- if (pid == -1)
+ if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
select_event_lwp (ptid, &lp, &status);
/* Now that we've selected our final event LWP, cancel any
why. */
iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
+ /* We'll need this to determine whether to report a SIGSTOP as
+ TARGET_WAITKIND_0. Need to take a copy because
+ resume_clear_callback clears it. */
+ last_resume_kind = lp->last_resume_kind;
+
/* In all-stop, from the core's perspective, all LWPs are now
stopped until a new resume action is sent over. */
iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
}
else
- lp->resumed = 0;
+ {
+ /* See above. */
+ last_resume_kind = lp->last_resume_kind;
+ resume_clear_callback (lp, NULL);
+ }
if (linux_nat_status_is_event (status))
{
else
store_waitstatus (ourstatus, status);
- if (debug_linux_nat_async)
+ if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
restore_child_signals_mask (&prev_mask);
+ if (last_resume_kind == resume_stop
+ && ourstatus->kind == TARGET_WAITKIND_STOPPED
+ && WSTOPSIG (status) == SIGSTOP)
+ {
+ /* A thread that has been requested to stop by GDB with
+ target_stop, and it stopped cleanly, so report as SIG0. The
+ use of SIGSTOP is an implementation detail. */
+ ourstatus->value.sig = TARGET_SIGNAL_0;
+ }
+
if (ourstatus->kind == TARGET_WAITKIND_EXITED
|| ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
lp->core = -1;
&& lp->status == 0
&& lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
{
+ struct regcache *regcache = get_thread_regcache (lp->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ CORE_ADDR pc = regcache_read_pc (regcache);
+
gdb_assert (is_executing (lp->ptid));
/* Don't bother if there's a breakpoint at PC that we'd hit
immediately, and we're not waiting for this LWP. */
if (!ptid_match (lp->ptid, *wait_ptid_p))
{
- struct regcache *regcache = get_thread_regcache (lp->ptid);
- CORE_ADDR pc = regcache_read_pc (regcache);
-
if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
return 0;
}
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "RSRL: resuming stopped-resumed LWP %s\n",
- target_pid_to_str (lp->ptid));
+ "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
+ target_pid_to_str (lp->ptid),
+ paddress (gdbarch, pc),
+ lp->step);
+ registers_changed ();
+ if (linux_nat_prepare_to_resume != NULL)
+ linux_nat_prepare_to_resume (lp);
linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
lp->step, TARGET_SIGNAL_0);
lp->stopped = 0;
may be more. If we requested a specific lwp or process, also
assume there may be more. */
if (target_can_async_p ()
- && (ourstatus->kind != TARGET_WAITKIND_IGNORE
+ && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
+ && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
|| !ptid_equal (ptid, minus_one_ptid)))
async_file_mark ();
static int
kill_callback (struct lwp_info *lp, void *data)
{
+ /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
+
+ errno = 0;
+ kill (GET_LWP (lp->ptid), SIGKILL);
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
+ target_pid_to_str (lp->ptid),
+ errno ? safe_strerror (errno) : "OK");
+
+ /* Some kernels ignore even SIGKILL for processes under ptrace. */
+
errno = 0;
ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
if (debug_linux_nat)
/* Implement the "info proc" command. */
+enum info_proc_what
+ {
+ /* Display the default cmdline, cwd and exe outputs. */
+ IP_MINIMAL,
+
+ /* Display `info proc mappings'. */
+ IP_MAPPINGS,
+
+ /* Display `info proc status'. */
+ IP_STATUS,
+
+ /* Display `info proc stat'. */
+ IP_STAT,
+
+ /* Display `info proc cmdline'. */
+ IP_CMDLINE,
+
+ /* Display `info proc exe'. */
+ IP_EXE,
+
+ /* Display `info proc cwd'. */
+ IP_CWD,
+
+ /* Display all of the above. */
+ IP_ALL
+ };
+
static void
-linux_nat_info_proc_cmd (char *args, int from_tty)
+linux_nat_info_proc_cmd_1 (char *args, enum info_proc_what what, int from_tty)
{
/* A long is used for pid instead of an int to avoid a loss of precision
compiler warning from the output of strtoul. */
long pid = PIDGET (inferior_ptid);
FILE *procfile;
- char **argv = NULL;
char buffer[MAXPATHLEN];
char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
- int cmdline_f = 1;
- int cwd_f = 1;
- int exe_f = 1;
- int mappings_f = 0;
- int status_f = 0;
- int stat_f = 0;
- int all = 0;
+ int cmdline_f = (what == IP_MINIMAL || what == IP_CMDLINE || what == IP_ALL);
+ int cwd_f = (what == IP_MINIMAL || what == IP_CWD || what == IP_ALL);
+ int exe_f = (what == IP_MINIMAL || what == IP_EXE || what == IP_ALL);
+ int mappings_f = (what == IP_MAPPINGS || what == IP_ALL);
+ int status_f = (what == IP_STATUS || what == IP_ALL);
+ int stat_f = (what == IP_STAT || what == IP_ALL);
struct stat dummy;
- if (args)
- {
- /* Break up 'args' into an argv array. */
- argv = gdb_buildargv (args);
- make_cleanup_freeargv (argv);
- }
- while (argv != NULL && *argv != NULL)
- {
- if (isdigit (argv[0][0]))
- {
- pid = strtoul (argv[0], NULL, 10);
- }
- else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
- {
- mappings_f = 1;
- }
- else if (strcmp (argv[0], "status") == 0)
- {
- status_f = 1;
- }
- else if (strcmp (argv[0], "stat") == 0)
- {
- stat_f = 1;
- }
- else if (strcmp (argv[0], "cmd") == 0)
- {
- cmdline_f = 1;
- }
- else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
- {
- exe_f = 1;
- }
- else if (strcmp (argv[0], "cwd") == 0)
- {
- cwd_f = 1;
- }
- else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
- {
- all = 1;
- }
- else
- {
- /* [...] (future options here). */
- }
- argv++;
- }
+ if (args && isdigit (args[0]))
+ pid = strtoul (args, &args, 10);
+
+ args = skip_spaces (args);
+ if (args && args[0])
+ error (_("Too many parameters: %s"), args);
+
if (pid == 0)
error (_("No current process: you must name one."));
error (_("No /proc directory: '%s'"), fname1);
printf_filtered (_("process %ld\n"), pid);
- if (cmdline_f || all)
+ if (cmdline_f)
{
sprintf (fname1, "/proc/%ld/cmdline", pid);
if ((procfile = fopen (fname1, "r")) != NULL)
else
warning (_("unable to open /proc file '%s'"), fname1);
}
- if (cwd_f || all)
+ if (cwd_f)
{
sprintf (fname1, "/proc/%ld/cwd", pid);
memset (fname2, 0, sizeof (fname2));
else
warning (_("unable to read link '%s'"), fname1);
}
- if (exe_f || all)
+ if (exe_f)
{
sprintf (fname1, "/proc/%ld/exe", pid);
memset (fname2, 0, sizeof (fname2));
else
warning (_("unable to read link '%s'"), fname1);
}
- if (mappings_f || all)
+ if (mappings_f)
{
sprintf (fname1, "/proc/%ld/maps", pid);
if ((procfile = fopen (fname1, "r")) != NULL)
else
warning (_("unable to open /proc file '%s'"), fname1);
}
- if (status_f || all)
+ if (status_f)
{
sprintf (fname1, "/proc/%ld/status", pid);
if ((procfile = fopen (fname1, "r")) != NULL)
else
warning (_("unable to open /proc file '%s'"), fname1);
}
- if (stat_f || all)
+ if (stat_f)
{
sprintf (fname1, "/proc/%ld/stat", pid);
if ((procfile = fopen (fname1, "r")) != NULL)
}
}
+/* Implement `info proc' when given without any futher parameters. */
+
+static void
+linux_nat_info_proc_cmd (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_MINIMAL, from_tty);
+}
+
+/* Implement `info proc mappings'. */
+
+static void
+linux_nat_info_proc_cmd_mappings (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_MAPPINGS, from_tty);
+}
+
+/* Implement `info proc stat'. */
+
+static void
+linux_nat_info_proc_cmd_stat (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_STAT, from_tty);
+}
+
+/* Implement `info proc status'. */
+
+static void
+linux_nat_info_proc_cmd_status (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_STATUS, from_tty);
+}
+
+/* Implement `info proc cwd'. */
+
+static void
+linux_nat_info_proc_cmd_cwd (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_CWD, from_tty);
+}
+
+/* Implement `info proc cmdline'. */
+
+static void
+linux_nat_info_proc_cmd_cmdline (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_CMDLINE, from_tty);
+}
+
+/* Implement `info proc exe'. */
+
+static void
+linux_nat_info_proc_cmd_exe (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_EXE, from_tty);
+}
+
+/* Implement `info proc all'. */
+
+static void
+linux_nat_info_proc_cmd_all (char *args, int from_tty)
+{
+ linux_nat_info_proc_cmd_1 (args, IP_ALL, from_tty);
+}
+
/* Implement the to_xfer_partial interface for memory reads using the /proc
filesystem. Because we can use a single read() call for /proc, this
can be much more efficient than banging away at PTRACE_PEEKTEXT,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
{
- /* We make the process list snapshot when the object starts to be
- read. */
- static const char *buf;
- static LONGEST len_avail = -1;
- static struct obstack obstack;
-
- DIR *dirp;
-
gdb_assert (object == TARGET_OBJECT_OSDATA);
- if (!annex)
- {
- if (offset == 0)
- {
- if (len_avail != -1 && len_avail != 0)
- obstack_free (&obstack, NULL);
- len_avail = 0;
- buf = NULL;
- obstack_init (&obstack);
- obstack_grow_str (&obstack, "<osdata type=\"types\">\n");
-
- obstack_xml_printf (&obstack,
- "<item>"
- "<column name=\"Type\">processes</column>"
- "<column name=\"Description\">"
- "Listing of all processes</column>"
- "</item>");
-
- obstack_grow_str0 (&obstack, "</osdata>\n");
- buf = obstack_finish (&obstack);
- len_avail = strlen (buf);
- }
-
- if (offset >= len_avail)
- {
- /* Done. Get rid of the obstack. */
- obstack_free (&obstack, NULL);
- buf = NULL;
- len_avail = 0;
- return 0;
- }
-
- if (len > len_avail - offset)
- len = len_avail - offset;
- memcpy (readbuf, buf + offset, len);
-
- return len;
- }
-
- if (strcmp (annex, "processes") != 0)
- return 0;
-
- gdb_assert (readbuf && !writebuf);
-
- if (offset == 0)
- {
- if (len_avail != -1 && len_avail != 0)
- obstack_free (&obstack, NULL);
- len_avail = 0;
- buf = NULL;
- obstack_init (&obstack);
- obstack_grow_str (&obstack, "<osdata type=\"processes\">\n");
-
- 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])
- || NAMELEN (dp) > sizeof ("4294967295") - 1)
- continue;
-
- sprintf (procentry, "/proc/%s", dp->d_name);
- if (stat (procentry, &statbuf) == 0
- && S_ISDIR (statbuf.st_mode))
- {
- char *pathname;
- FILE *f;
- char cmd[MAXPATHLEN + 1];
- struct passwd *entry;
-
- pathname = xstrprintf ("/proc/%s/cmdline", dp->d_name);
- entry = getpwuid (statbuf.st_uid);
-
- if ((f = fopen (pathname, "r")) != NULL)
- {
- size_t length = fread (cmd, 1, sizeof (cmd) - 1, f);
-
- if (length > 0)
- {
- int i;
-
- for (i = 0; i < length; i++)
- if (cmd[i] == '\0')
- cmd[i] = ' ';
- cmd[length] = '\0';
-
- obstack_xml_printf (
- &obstack,
- "<item>"
- "<column name=\"pid\">%s</column>"
- "<column name=\"user\">%s</column>"
- "<column name=\"command\">%s</column>"
- "</item>",
- dp->d_name,
- entry ? entry->pw_name : "?",
- cmd);
- }
- fclose (f);
- }
-
- xfree (pathname);
- }
- }
-
- closedir (dirp);
- }
-
- obstack_grow_str0 (&obstack, "</osdata>\n");
- buf = obstack_finish (&obstack);
- len_avail = strlen (buf);
- }
-
- if (offset >= len_avail)
- {
- /* Done. Get rid of the obstack. */
- obstack_free (&obstack, NULL);
- buf = NULL;
- len_avail = 0;
- return 0;
- }
-
- if (len > len_avail - offset)
- len = len_avail - offset;
- memcpy (readbuf, buf + offset, len);
-
- return len;
+ return linux_common_xfer_osdata (annex, readbuf, offset, len);
}
static LONGEST
linux_target_install_ops (struct target_ops *t)
{
t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
+ t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
+ t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
+ t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
t->to_post_startup_inferior = linux_child_post_startup_inferior;
/* NOTE: palves 2008-03-21: We're only async when the user requests
it explicitly with the "set target-async" command.
Someday, linux will always be async. */
- if (!target_async_permitted)
- return 0;
-
- /* See target.h/target_async_mask. */
- return linux_nat_async_mask_value;
+ return target_async_permitted;
}
/* target_can_async_p implementation. */
/* NOTE: palves 2008-03-21: We're only async when the user requests
it explicitly with the "set target-async" command.
Someday, linux will always be async. */
- if (!target_async_permitted)
- return 0;
-
- /* See target.h/target_async_mask. */
- return linux_nat_async_mask_value;
+ return target_async_permitted;
}
static int
return linux_multi_process;
}
-/* target_async_mask implementation. */
-
static int
-linux_nat_async_mask (int new_mask)
+linux_nat_supports_disable_randomization (void)
{
- int curr_mask = linux_nat_async_mask_value;
-
- if (curr_mask != new_mask)
- {
- if (new_mask == 0)
- {
- linux_nat_async (NULL, 0);
- linux_nat_async_mask_value = new_mask;
- }
- else
- {
- linux_nat_async_mask_value = new_mask;
-
- /* If we're going out of async-mask in all-stop, then the
- inferior is stopped. The next resume will call
- target_async. In non-stop, the target event source
- should be always registered in the event loop. Do so
- now. */
- if (non_stop)
- linux_nat_async (inferior_event_handler, 0);
- }
- }
-
- return curr_mask;
+#ifdef HAVE_PERSONALITY
+ return 1;
+#else
+ return 0;
+#endif
}
static int async_terminal_is_ours = 1;
{
int old_errno = errno;
- if (debug_linux_nat_async)
- fprintf_unfiltered (gdb_stdlog, "sigchld\n");
+ if (debug_linux_nat)
+ ui_file_write_async_safe (gdb_stdlog,
+ "sigchld\n", sizeof ("sigchld\n") - 1);
if (signo == SIGCHLD
&& linux_nat_event_pipe[0] != -1)
linux_nat_async (void (*callback) (enum inferior_event_type event_type,
void *context), void *context)
{
- if (linux_nat_async_mask_value == 0 || !target_async_permitted)
- internal_error (__FILE__, __LINE__,
- "Calling target_async when async is masked");
-
if (callback != NULL)
{
async_client_callback = callback;
target_pid_to_str (lwp->ptid));
- stop_callback (lwp, NULL);
- stop_wait_callback (lwp, NULL);
-
- /* If the lwp exits while we try to stop it, there's nothing
- else to do. */
- lwp = find_lwp_pid (ptid);
- if (lwp == NULL)
- return 0;
+ if (lwp->last_resume_kind == resume_stop)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "linux-nat: already stopping LWP %ld at "
+ "GDB's request\n",
+ ptid_get_lwp (lwp->ptid));
+ return 0;
+ }
- /* If we didn't collect any signal other than SIGSTOP while
- stopping the LWP, push a SIGNAL_0 event. In either case, the
- event-loop will end up calling target_wait which will collect
- these. */
- if (lwp->status == 0)
- lwp->status = W_STOPCODE (0);
- async_file_mark ();
+ stop_callback (lwp, NULL);
+ lwp->last_resume_kind = resume_stop;
}
else
{
linux_nat_close (int quitting)
{
/* Unregister from the event loop. */
- if (target_is_async_p ())
- target_async (NULL, 0);
-
- /* Reset the async_masking. */
- linux_nat_async_mask_value = 1;
+ if (linux_nat_is_async_p ())
+ linux_nat_async (NULL, 0);
if (linux_ops->to_close)
linux_ops->to_close (quitting);
t->to_is_async_p = linux_nat_is_async_p;
t->to_supports_non_stop = linux_nat_supports_non_stop;
t->to_async = linux_nat_async;
- t->to_async_mask = linux_nat_async_mask;
t->to_terminal_inferior = linux_nat_terminal_inferior;
t->to_terminal_ours = linux_nat_terminal_ours;
t->to_close = linux_nat_close;
t->to_supports_multi_process = linux_nat_supports_multi_process;
+ t->to_supports_disable_randomization
+ = linux_nat_supports_disable_randomization;
+
t->to_core_of_thread = linux_nat_core_of_thread;
/* We don't change the stratum; this target will sit at
/* Register a method to call whenever a new thread is attached. */
void
-linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
+linux_nat_set_new_thread (struct target_ops *t,
+ void (*new_thread) (struct lwp_info *))
{
/* Save the pointer. We only support a single registered instance
of the GNU/Linux native target, so we do not need to map this to
linux_nat_siginfo_fixup = siginfo_fixup;
}
+/* Register a method to call prior to resuming a thread. */
+
+void
+linux_nat_set_prepare_to_resume (struct target_ops *t,
+ void (*prepare_to_resume) (struct lwp_info *))
+{
+ /* Save the pointer. */
+ linux_nat_prepare_to_resume = prepare_to_resume;
+}
+
/* Return the saved siginfo associated with PTID. */
struct siginfo *
linux_nat_get_siginfo (ptid_t ptid)
void
_initialize_linux_nat (void)
{
- add_info ("proc", linux_nat_info_proc_cmd, _("\
+ static struct cmd_list_element *info_proc_cmdlist;
+
+ add_prefix_cmd ("proc", class_info, linux_nat_info_proc_cmd,
+ _("\
Show /proc process information about any running process.\n\
-Specify any process id, or use the program being debugged by default.\n\
-Specify any of the following keywords for detailed info:\n\
- mappings -- list of mapped memory regions.\n\
- stat -- list a bunch of random process info.\n\
- status -- list a different bunch of random process info.\n\
- all -- list all available /proc info."));
+Specify any process id, or use the program being debugged by default."),
+ &info_proc_cmdlist, "info proc ",
+ 1/*allow-unknown*/, &infolist);
+
+ add_cmd ("mappings", class_info, linux_nat_info_proc_cmd_mappings, _("\
+List of mapped memory regions."),
+ &info_proc_cmdlist);
+
+ add_cmd ("stat", class_info, linux_nat_info_proc_cmd_stat, _("\
+List process info from /proc/PID/stat."),
+ &info_proc_cmdlist);
+
+ add_cmd ("status", class_info, linux_nat_info_proc_cmd_status, _("\
+List process info from /proc/PID/status."),
+ &info_proc_cmdlist);
+
+ add_cmd ("cwd", class_info, linux_nat_info_proc_cmd_cwd, _("\
+List current working directory of the process."),
+ &info_proc_cmdlist);
+
+ add_cmd ("cmdline", class_info, linux_nat_info_proc_cmd_cmdline, _("\
+List command line arguments of the process."),
+ &info_proc_cmdlist);
+
+ add_cmd ("exe", class_info, linux_nat_info_proc_cmd_exe, _("\
+List absolute filename for executable of the process."),
+ &info_proc_cmdlist);
+
+ add_cmd ("all", class_info, linux_nat_info_proc_cmd_all, _("\
+List all available /proc info."),
+ &info_proc_cmdlist);
add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
&debug_linux_nat, _("\
show_debug_linux_nat,
&setdebuglist, &showdebuglist);
- add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
- &debug_linux_nat_async, _("\
-Set debugging of GNU/Linux async lwp module."), _("\
-Show debugging of GNU/Linux async lwp module."), _("\
-Enables printf debugging output."),
- NULL,
- show_debug_linux_nat_async,
- &setdebuglist, &showdebuglist);
-
/* Save this mask as the default. */
sigprocmask (SIG_SETMASK, NULL, &normal_mask);
sigdelset (&suspend_mask, SIGCHLD);
sigemptyset (&blocked_mask);
-
- add_setshow_boolean_cmd ("disable-randomization", class_support,
- &disable_randomization, _("\
-Set disabling of debuggee's virtual address space randomization."), _("\
-Show disabling of debuggee's virtual address space randomization."), _("\
-When this mode is on (which is the default), randomization of the virtual\n\
-address space is disabled. Standalone programs run with the randomization\n\
-enabled by default on some platforms."),
- &set_disable_randomization,
- &show_disable_randomization,
- &setlist, &showlist);
}
\f
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