@@ -52,6 +52,26 @@
#define PT_SETREGSET 43 /* Set a target register set */
#endif
+/* Information stored about each inferior. */
+struct fbsd_inferior_info
+{
+ /* Filter for resumed LWPs which can report events from wait. */
+ ptid_t resumed_lwps = null_ptid;
+
+ /* Number of LWPs this process contains. */
+ unsigned int num_lwps = 0;
+
+ /* Number of LWPs currently running. */
+ unsigned int running_lwps = 0;
+
+ /* Have a pending SIGSTOP event that needs to be discarded. */
+ bool pending_sigstop = false;
+};
+
+/* Per-inferior data key. */
+
+static const registry<inferior>::key<fbsd_inferior_info> fbsd_inferior_data;
+
/* See fbsd-nat.h. */
void
@@ -76,14 +96,19 @@ fbsd_nat_target::have_pending_event (ptid_t filter)
/* See fbsd-nat.h. */
gdb::optional<fbsd_nat_target::pending_event>
-fbsd_nat_target::take_pending_event ()
+fbsd_nat_target::take_pending_event (ptid_t filter)
{
for (auto it = m_pending_events.begin (); it != m_pending_events.end (); it++)
- if (it->ptid.matches (m_resume_ptid))
+ if (it->ptid.matches (filter))
{
- pending_event event = *it;
- m_pending_events.erase (it);
- return event;
+ inferior *inf = find_inferior_ptid (this, it->ptid);
+ fbsd_inferior_info *info = fbsd_inferior_data.get (inf);
+ if (it->ptid.matches (info->resumed_lwps))
+ {
+ pending_event event = *it;
+ m_pending_events.erase (it);
+ return event;
+ }
}
return {};
}
@@ -773,6 +798,8 @@ show_fbsd_nat_debug (struct ui_file *file, int from_tty,
#define fbsd_nat_debug_printf(fmt, ...) \
debug_prefixed_printf_cond (debug_fbsd_nat, "fbsd-nat", fmt, ##__VA_ARGS__)
+#define fbsd_nat_debug_start_end(fmt, ...) \
+ scoped_debug_start_end (debug_fbsd_nat, "fbsd-nat", fmt, ##__VA_ARGS__)
/*
FreeBSD's first thread support was via a "reentrant" version of libc
@@ -930,6 +957,9 @@ fbsd_add_threads (fbsd_nat_target *target, pid_t pid)
if (nlwps == -1)
perror_with_name (("ptrace (PT_GETLWPLIST)"));
+ inferior *inf = find_inferior_ptid (target, ptid_t (pid));
+ fbsd_inferior_info *info = fbsd_inferior_data.get (inf);
+ gdb_assert (info != nullptr);
for (i = 0; i < nlwps; i++)
{
ptid_t ptid = ptid_t (pid, lwps[i]);
@@ -948,8 +978,14 @@ fbsd_add_threads (fbsd_nat_target *target, pid_t pid)
#endif
fbsd_lwp_debug_printf ("adding thread for LWP %u", lwps[i]);
add_thread (target, ptid);
+#ifdef PT_LWP_EVENTS
+ info->num_lwps++;
+#endif
}
}
+#ifndef PT_LWP_EVENTS
+ info->num_lwps = nlwps;
+#endif
}
/* Implement the "update_thread_list" target_ops method. */
@@ -1110,92 +1146,117 @@ fbsd_add_vfork_done (ptid_t pid)
#endif
#endif
-/* Implement the "resume" target_ops method. */
+/* Resume a single process. */
void
-fbsd_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo)
+fbsd_nat_target::resume_one_process (ptid_t ptid, int step,
+ enum gdb_signal signo)
{
fbsd_nat_debug_printf ("[%s], step %d, signo %d (%s)",
target_pid_to_str (ptid).c_str (), step, signo,
gdb_signal_to_name (signo));
+ inferior *inf = find_inferior_ptid (this, ptid);
+ fbsd_inferior_info *info = fbsd_inferior_data.get (inf);
+ info->resumed_lwps = ptid;
+ gdb_assert (info->running_lwps == 0);
+
/* Don't PT_CONTINUE a thread or process which has a pending event. */
- m_resume_ptid = ptid;
if (have_pending_event (ptid))
{
fbsd_nat_debug_printf ("found pending event");
return;
}
- if (ptid.lwp_p ())
+ for (thread_info *tp : inf->non_exited_threads ())
{
- /* If ptid is a specific LWP, suspend all other LWPs in the process. */
- inferior *inf = find_inferior_ptid (this, ptid);
+ int request;
- for (thread_info *tp : inf->non_exited_threads ())
- {
- int request;
-
- if (tp->ptid.lwp () == ptid.lwp ())
- request = PT_RESUME;
- else
- request = PT_SUSPEND;
-
- if (ptrace (request, tp->ptid.lwp (), NULL, 0) == -1)
- perror_with_name (request == PT_RESUME ?
- ("ptrace (PT_RESUME)") :
- ("ptrace (PT_SUSPEND)"));
- if (request == PT_RESUME)
- low_prepare_to_resume (tp);
- }
- }
- else
- {
- /* If ptid is a wildcard, resume all matching threads (they won't run
- until the process is continued however). */
- for (thread_info *tp : all_non_exited_threads (this, ptid))
+ /* If ptid is a specific LWP, suspend all other LWPs in the
+ process, otherwise resume all LWPs in the process.. */
+ if (!ptid.lwp_p() || tp->ptid.lwp () == ptid.lwp ())
{
if (ptrace (PT_RESUME, tp->ptid.lwp (), NULL, 0) == -1)
perror_with_name (("ptrace (PT_RESUME)"));
low_prepare_to_resume (tp);
+ info->running_lwps++;
}
+ else
+ {
+ if (ptrace (PT_SUSPEND, tp->ptid.lwp (), NULL, 0) == -1)
+ perror_with_name (("ptrace (PT_SUSPEND)"));
+ }
+ }
+
+ if (ptid.pid () != inferior_ptid.pid ())
+ {
+ step = 0;
+ signo = GDB_SIGNAL_0;
+ gdb_assert (!ptid.lwp_p ());
+ }
+ else
+ {
ptid = inferior_ptid;
- }
-
#if __FreeBSD_version < 1200052
- /* When multiple threads within a process wish to report STOPPED
- events from wait(), the kernel picks one thread event as the
- thread event to report. The chosen thread event is retrieved via
- PT_LWPINFO by passing the process ID as the request pid. If
- multiple events are pending, then the subsequent wait() after
- resuming a process will report another STOPPED event after
- resuming the process to handle the next thread event and so on.
+ /* When multiple threads within a process wish to report STOPPED
+ events from wait(), the kernel picks one thread event as the
+ thread event to report. The chosen thread event is retrieved
+ via PT_LWPINFO by passing the process ID as the request pid.
+ If multiple events are pending, then the subsequent wait()
+ after resuming a process will report another STOPPED event
+ after resuming the process to handle the next thread event
+ and so on.
- A single thread event is cleared as a side effect of resuming the
- process with PT_CONTINUE, PT_STEP, etc. In older kernels,
- however, the request pid was used to select which thread's event
- was cleared rather than always clearing the event that was just
- reported. To avoid clearing the event of the wrong LWP, always
- pass the process ID instead of an LWP ID to PT_CONTINUE or
- PT_SYSCALL.
+ A single thread event is cleared as a side effect of resuming
+ the process with PT_CONTINUE, PT_STEP, etc. In older
+ kernels, however, the request pid was used to select which
+ thread's event was cleared rather than always clearing the
+ event that was just reported. To avoid clearing the event of
+ the wrong LWP, always pass the process ID instead of an LWP
+ ID to PT_CONTINUE or PT_SYSCALL.
- In the case of stepping, the process ID cannot be used with
- PT_STEP since it would step the thread that reported an event
- which may not be the thread indicated by PTID. For stepping, use
- PT_SETSTEP to enable stepping on the desired thread before
- resuming the process via PT_CONTINUE instead of using
- PT_STEP. */
- if (step)
- {
- if (ptrace (PT_SETSTEP, get_ptrace_pid (ptid), NULL, 0) == -1)
- perror_with_name (("ptrace (PT_SETSTEP)"));
- step = 0;
- }
- ptid = ptid_t (ptid.pid ());
+ In the case of stepping, the process ID cannot be used with
+ PT_STEP since it would step the thread that reported an event
+ which may not be the thread indicated by PTID. For stepping,
+ use PT_SETSTEP to enable stepping on the desired thread
+ before resuming the process via PT_CONTINUE instead of using
+ PT_STEP. */
+ if (step)
+ {
+ if (ptrace (PT_SETSTEP, get_ptrace_pid (ptid), NULL, 0) == -1)
+ perror_with_name (("ptrace (PT_SETSTEP)"));
+ step = 0;
+ }
+ ptid = ptid_t (ptid.pid ());
#endif
+ }
+
inf_ptrace_target::resume (ptid, step, signo);
}
+/* Implement the "resume" target_ops method. */
+
+void
+fbsd_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo)
+{
+ fbsd_nat_debug_start_end ("[%s], step %d, signo %d (%s)",
+ target_pid_to_str (scope_ptid).c_str (), step, signo,
+ gdb_signal_to_name (signo));
+
+ gdb_assert (inferior_ptid.matches (scope_ptid));
+ gdb_assert (!scope_ptid.tid_p ());
+
+ if (scope_ptid == minus_one_ptid)
+ {
+ for (inferior *inf : all_non_exited_inferiors (this))
+ resume_one_process (ptid_t (inf->pid), step, signo);
+ }
+ else
+ {
+ resume_one_process (scope_ptid, step, signo);
+ }
+}
+
#ifdef USE_SIGTRAP_SIGINFO
/* Handle breakpoint and trace traps reported via SIGTRAP. If the
trap was a breakpoint or trace trap that should be reported to the
@@ -1263,10 +1324,7 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
if (ourstatus->kind () == TARGET_WAITKIND_STOPPED)
{
struct ptrace_lwpinfo pl;
- pid_t pid;
- int status;
-
- pid = wptid.pid ();
+ pid_t pid = wptid.pid ();
if (ptrace (PT_LWPINFO, pid, (caddr_t) &pl, sizeof pl) == -1)
perror_with_name (("ptrace (PT_LWPINFO)"));
@@ -1282,6 +1340,13 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
pl.pl_siginfo.si_code);
}
+ /* There may not be an inferior for this pid if this is a
+ PL_FLAG_CHILD event. */
+ inferior *inf = find_inferior_ptid (this, wptid);
+ fbsd_inferior_info *info = inf == nullptr ? nullptr :
+ fbsd_inferior_data.get (inf);
+ gdb_assert (info != NULL || pl.pl_flags & PL_FLAG_CHILD);
+
#ifdef PT_LWP_EVENTS
if (pl.pl_flags & PL_FLAG_EXITED)
{
@@ -1299,6 +1364,20 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
target_pid_to_str (wptid).c_str ());
low_delete_thread (thr);
delete_thread (thr);
+ info->num_lwps--;
+
+ /* If this LWP was the only resumed LWP from the
+ process, report an event to the core. */
+ if (wptid == info->resumed_lwps)
+ {
+ ourstatus->set_spurious ();
+ return wptid;
+ }
+
+ /* During process exit LWPs that were not resumed
+ will report exit events. */
+ if (wptid.matches (info->resumed_lwps))
+ info->running_lwps--;
}
if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
perror_with_name (("ptrace (PT_CONTINUE)"));
@@ -1331,6 +1410,10 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
fbsd_lwp_debug_printf ("adding thread for LWP %u",
pl.pl_lwpid);
add_thread (this, wptid);
+ info->num_lwps++;
+
+ if (wptid.matches(info->resumed_lwps))
+ info->running_lwps++;
}
ourstatus->set_spurious ();
return wptid;
@@ -1357,6 +1440,8 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
child_ptid = fbsd_is_child_pending (child);
if (child_ptid == null_ptid)
{
+ int status;
+
pid = waitpid (child, &status, 0);
if (pid == -1)
perror_with_name (("waitpid"));
@@ -1458,11 +1543,104 @@ fbsd_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus,
perror_with_name (("ptrace (PT_CONTINUE)"));
continue;
}
+
+ /* If this is a pending SIGSTOP event from an earlier call
+ to stop_process, discard the event and wait for another
+ event. */
+ if (ourstatus->sig () == GDB_SIGNAL_STOP && info->pending_sigstop)
+ {
+ fbsd_nat_debug_printf ("ignoring SIGSTOP for pid %u", pid);
+ info->pending_sigstop = false;
+ if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
+ perror_with_name (("ptrace (PT_CONTINUE)"));
+ continue;
+ }
}
+ else
+ fbsd_nat_debug_printf ("event [%s], [%s]",
+ target_pid_to_str (wptid).c_str (),
+ ourstatus->to_string ().c_str ());
return wptid;
}
}
+/* Stop a given process. If the process is already stopped, record
+ its pending event instead. */
+
+void
+fbsd_nat_target::stop_process (inferior *inf)
+{
+ fbsd_inferior_info *info = fbsd_inferior_data.get (inf);
+ gdb_assert (info != nullptr);
+
+ info->resumed_lwps = null_ptid;
+ if (info->running_lwps == 0)
+ return;
+
+ ptid_t ptid (inf->pid);
+ target_waitstatus status;
+ ptid_t wptid = wait_1 (ptid, &status, TARGET_WNOHANG);
+
+ if (wptid != minus_one_ptid)
+ {
+ /* Save the current event as a pending event. */
+ add_pending_event (wptid, status);
+ info->running_lwps = 0;
+ return;
+ }
+
+ /* If a SIGSTOP is already pending, don't send a new one, but tell
+ wait_1 to report a SIGSTOP. */
+ if (info->pending_sigstop)
+ {
+ fbsd_nat_debug_printf ("waiting for existing pending SIGSTOP for %u",
+ inf->pid);
+ info->pending_sigstop = false;
+ }
+ else
+ {
+ /* Ignore errors from kill as process exit might race with kill. */
+ fbsd_nat_debug_printf ("killing %u with SIGSTOP", inf->pid);
+ ::kill (inf->pid, SIGSTOP);
+ }
+
+ /* Wait for SIGSTOP (or some other event) to be reported. */
+ wptid = wait_1 (ptid, &status, 0);
+
+ switch (status.kind ())
+ {
+ case TARGET_WAITKIND_EXITED:
+ case TARGET_WAITKIND_SIGNALLED:
+ /* If the process has exited, we aren't going to get an
+ event for the SIGSTOP. Save the current event and
+ return. */
+ add_pending_event (wptid, status);
+ break;
+ case TARGET_WAITKIND_IGNORE:
+ /* wait() failed with ECHILD meaning the process no longer
+ exists. This means a bug happened elsewhere, but at least
+ the process is no longer running. */
+ break;
+ case TARGET_WAITKIND_STOPPED:
+ /* If this is the SIGSTOP event, discard it and return
+ leaving the process stopped. */
+ if (status.sig () == GDB_SIGNAL_STOP)
+ break;
+
+ /* FALLTHROUGH */
+ default:
+ /* Some other event has occurred. Save the current
+ event. */
+ add_pending_event (wptid, status);
+
+ /* Ignore the next SIGSTOP for this process. */
+ fbsd_nat_debug_printf ("ignoring next SIGSTOP for %u", inf->pid);
+ info->pending_sigstop = true;
+ break;
+ }
+ info->running_lwps = 0;
+}
+
ptid_t
fbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags target_options)
@@ -1471,9 +1649,13 @@ fbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_options_to_string (target_options).c_str ());
/* If there is a valid pending event, return it. */
- gdb::optional<pending_event> event = take_pending_event ();
+ gdb::optional<pending_event> event = take_pending_event (ptid);
if (event.has_value ())
{
+ /* Stop any other inferiors currently running. */
+ for (inferior *inf : all_non_exited_inferiors (this))
+ stop_process (inf);
+
fbsd_nat_debug_printf ("returning pending event [%s], [%s]",
target_pid_to_str (event->ptid).c_str (),
event->status.to_string ().c_str ());
@@ -1496,28 +1678,38 @@ fbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
|| ourstatus->kind () == TARGET_WAITKIND_NO_RESUMED)
break;
+ inferior *inf = find_inferior_ptid (this, wptid);
+ gdb_assert (inf != nullptr);
+ fbsd_inferior_info *info = fbsd_inferior_data.get (inf);
+ gdb_assert (info != nullptr);
+ gdb_assert (info->resumed_lwps != null_ptid);
+ gdb_assert (info->running_lwps > 0);
+
/* If an event is reported for a thread or process while
stepping some other thread, suspend the thread reporting the
event and defer the event until it can be reported to the
core. */
- if (!wptid.matches (m_resume_ptid))
+ if (!wptid.matches (info->resumed_lwps))
{
add_pending_event (wptid, *ourstatus);
fbsd_nat_debug_printf ("deferring event [%s], [%s]",
target_pid_to_str (wptid).c_str (),
ourstatus->to_string ().c_str ());
- if (wptid.pid () == m_resume_ptid.pid ())
- {
- fbsd_nat_debug_printf ("suspending thread [%s]",
- target_pid_to_str (wptid).c_str ());
- if (ptrace (PT_SUSPEND, wptid.lwp (), NULL, 0) == -1)
- perror_with_name (("ptrace (PT_SUSPEND)"));
- if (ptrace (PT_CONTINUE, wptid.pid (), (caddr_t) 1, 0) == -1)
- perror_with_name (("ptrace (PT_CONTINUE)"));
- }
+ if (ptrace (PT_SUSPEND, wptid.lwp (), NULL, 0) == -1)
+ perror_with_name (("ptrace (PT_SUSPEND)"));
+ if (ptrace (PT_CONTINUE, wptid.pid (), (caddr_t) 1, 0) == -1)
+ perror_with_name (("ptrace (PT_CONTINUE)"));
continue;
}
+ /* This process is no longer running. */
+ info->resumed_lwps = null_ptid;
+ info->running_lwps = 0;
+
+ /* Stop any other inferiors currently running. */
+ for (inferior *inf : all_non_exited_inferiors (this))
+ stop_process (inf);
+
break;
}
@@ -1622,23 +1814,49 @@ fbsd_nat_target::create_inferior (const char *exec_file,
(disable_randomization);
#endif
- /* Expect a wait for the new process. */
- m_resume_ptid = minus_one_ptid;
- fbsd_nat_debug_printf ("setting resume_ptid to [%s]",
- target_pid_to_str (m_resume_ptid).c_str ());
+ fbsd_inferior_info *info = fbsd_inferior_data.emplace (current_inferior ());
+ info->resumed_lwps = minus_one_ptid;
+ info->num_lwps = 1;
+ info->running_lwps = 1;
inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty);
}
void
fbsd_nat_target::attach (const char *args, int from_tty)
{
- /* Expect a wait for the new process. */
- m_resume_ptid = minus_one_ptid;
- fbsd_nat_debug_printf ("setting resume_ptid to [%s]",
- target_pid_to_str (m_resume_ptid).c_str ());
+ fbsd_inferior_info *info = fbsd_inferior_data.emplace (current_inferior ());
+ info->resumed_lwps = minus_one_ptid;
+ info->num_lwps = 1;
+ info->running_lwps = 1;
inf_ptrace_target::attach (args, from_tty);
}
+void
+fbsd_nat_target::mourn_inferior ()
+{
+ inferior *inf = current_inferior ();
+ gdb_assert (!have_pending_event (ptid_t (inf->pid)));
+ fbsd_inferior_data.clear (inf);
+ inf_ptrace_target::mourn_inferior ();
+}
+
+void
+fbsd_nat_target::follow_exec (inferior *follow_inf, ptid_t ptid,
+ const char *execd_pathname)
+{
+ inferior *orig_inf = current_inferior ();
+
+ inf_ptrace_target::follow_exec (follow_inf, ptid, execd_pathname);
+
+ if (orig_inf != follow_inf)
+ {
+ /* Migrate the inferior info to the new inferior. */
+ fbsd_inferior_info *info = fbsd_inferior_data.get (orig_inf);
+ fbsd_inferior_data.set (orig_inf, nullptr);
+ fbsd_inferior_data.set (follow_inf, info);
+ }
+}
+
#ifdef TDP_RFPPWAIT
/* Target hook for follow_fork. On entry and at return inferior_ptid is
the ptid of the followed inferior. */
@@ -1651,6 +1869,12 @@ fbsd_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid,
inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind,
follow_child, detach_fork);
+ if (child_inf != nullptr)
+ {
+ fbsd_inferior_info *info = fbsd_inferior_data.emplace (child_inf);
+ info->num_lwps = 1;
+ }
+
if (!follow_child && detach_fork)
{
pid_t child_pid = child_ptid.pid ();
@@ -81,6 +81,8 @@ class fbsd_nat_target : public inf_ptrace_target
void attach (const char *, int) override;
+ void mourn_inferior () override;
+
void resume (ptid_t, int, enum gdb_signal) override;
ptid_t wait (ptid_t, struct target_waitstatus *, target_wait_flags) override;
@@ -92,6 +94,8 @@ class fbsd_nat_target : public inf_ptrace_target
bool stopped_by_sw_breakpoint () override;
#endif
+ void follow_exec (inferior *, ptid_t, const char *) override;
+
#ifdef TDP_RFPPWAIT
void follow_fork (inferior *, ptid_t, target_waitkind, bool, bool) override;
@@ -135,6 +139,10 @@ class fbsd_nat_target : public inf_ptrace_target
private:
ptid_t wait_1 (ptid_t, struct target_waitstatus *, target_wait_flags);
+ void resume_one_process (ptid_t, int, enum gdb_signal);
+
+ void stop_process (inferior *);
+
/* Helper routines for use in fetch_registers and store_registers in
subclasses. These routines fetch and store a single set of
registers described by REGSET. The REGSET's 'regmap' field must
@@ -246,22 +254,15 @@ class fbsd_nat_target : public inf_ptrace_target
bool have_pending_event (ptid_t filter);
- /* Helper method called by the target wait method. Check if there
- is a pending event matching M_RESUME_PTID. If there is a
- matching event, the event is removed from the pending list and
- returned. */
+ /* Check if there is a pending event for a resumed process matching
+ FILTER. If there is a matching event, the event is removed from
+ the pending list and returned. */
- gdb::optional<pending_event> take_pending_event ();
+ gdb::optional<pending_event> take_pending_event (ptid_t filter);
/* List of pending events. */
std::list<pending_event> m_pending_events;
-
- /* Filter for ptid's allowed to report events from wait. Normally
- set in resume, but also reset to minus_one_ptid in
- create_inferior and attach. */
-
- ptid_t m_resume_ptid;
};
/* Fetch the signal information for PTID and store it in *SIGINFO.