#include "linux-low.h"
#include "nat/linux-osdata.h"
#include "agent.h"
+#include "tdesc.h"
#include "nat/linux-nat.h"
#include "nat/linux-waitpid.h"
} Elf64_auxv_t;
#endif
+/* LWP accessors. */
+
+/* See nat/linux-nat.h. */
+
+ptid_t
+ptid_of_lwp (struct lwp_info *lwp)
+{
+ return ptid_of (get_lwp_thread (lwp));
+}
+
+/* See nat/linux-nat.h. */
+
+void
+lwp_set_arch_private_info (struct lwp_info *lwp,
+ struct arch_lwp_info *info)
+{
+ lwp->arch_private = info;
+}
+
+/* See nat/linux-nat.h. */
+
+struct arch_lwp_info *
+lwp_arch_private_info (struct lwp_info *lwp)
+{
+ return lwp->arch_private;
+}
+
+/* See nat/linux-nat.h. */
+
+int
+lwp_is_stopped (struct lwp_info *lwp)
+{
+ return lwp->stopped;
+}
+
+/* See nat/linux-nat.h. */
+
+enum target_stop_reason
+lwp_stop_reason (struct lwp_info *lwp)
+{
+ return lwp->stop_reason;
+}
+
/* A list of all unknown processes which receive stop signals. Some
other process will presumably claim each of these as forked
children momentarily. */
static CORE_ADDR get_pc (struct lwp_info *lwp);
/* Handle a GNU/Linux extended wait response. If we see a clone
- event, we need to add the new LWP to our list (and not report the
- trap to higher layers). */
+ event, we need to add the new LWP to our list (and return 0 so as
+ not to report the trap to higher layers). */
-static void
-handle_extended_wait (struct lwp_info *event_child, int wstat)
+static int
+handle_extended_wait (struct lwp_info *event_lwp, int wstat)
{
int event = linux_ptrace_get_extended_event (wstat);
- struct thread_info *event_thr = get_lwp_thread (event_child);
+ struct thread_info *event_thr = get_lwp_thread (event_lwp);
struct lwp_info *new_lwp;
- if (event == PTRACE_EVENT_CLONE)
+ if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_CLONE))
{
ptid_t ptid;
unsigned long new_pid;
int ret, status;
+ /* Get the pid of the new lwp. */
ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0,
&new_pid);
warning ("wait returned unexpected status 0x%x", status);
}
+ if (event == PTRACE_EVENT_FORK)
+ {
+ struct process_info *parent_proc;
+ struct process_info *child_proc;
+ struct lwp_info *child_lwp;
+ struct target_desc *tdesc;
+
+ ptid = ptid_build (new_pid, new_pid, 0);
+
+ if (debug_threads)
+ {
+ debug_printf ("HEW: Got fork event from LWP %ld, "
+ "new child is %d\n",
+ ptid_get_lwp (ptid_of (event_thr)),
+ ptid_get_pid (ptid));
+ }
+
+ /* Add the new process to the tables and clone the breakpoint
+ lists of the parent. We need to do this even if the new process
+ will be detached, since we will need the process object and the
+ breakpoints to remove any breakpoints from memory when we
+ detach, and the client side will access registers. */
+ child_proc = linux_add_process (new_pid, 0);
+ gdb_assert (child_proc != NULL);
+ child_lwp = add_lwp (ptid);
+ gdb_assert (child_lwp != NULL);
+ child_lwp->stopped = 1;
+ parent_proc = get_thread_process (event_thr);
+ child_proc->attached = parent_proc->attached;
+ clone_all_breakpoints (&child_proc->breakpoints,
+ &child_proc->raw_breakpoints,
+ parent_proc->breakpoints);
+
+ tdesc = xmalloc (sizeof (struct target_desc));
+ copy_target_description (tdesc, parent_proc->tdesc);
+ child_proc->tdesc = tdesc;
+ child_lwp->must_set_ptrace_flags = 1;
+
+ /* Clone arch-specific process data. */
+ if (the_low_target.new_fork != NULL)
+ the_low_target.new_fork (parent_proc, child_proc);
+
+ /* Save fork info in the parent thread. */
+ event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED;
+ event_lwp->waitstatus.value.related_pid = ptid;
+ /* The status_pending field contains bits denoting the
+ extended event, so when the pending event is handled,
+ the handler will look at lwp->waitstatus. */
+ event_lwp->status_pending_p = 1;
+ event_lwp->status_pending = wstat;
+
+ /* Report the event. */
+ return 0;
+ }
+
if (debug_threads)
debug_printf ("HEW: Got clone event "
"from LWP %ld, new child is LWP %ld\n",
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
+
+ /* Don't report the event. */
+ return 1;
}
+
+ internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event);
}
/* Return the PC as read from the regcache of LWP, without any
{
struct thread_info *thr = get_lwp_thread (lwp);
- debug_printf ("CSBB: Push back software breakpoint for %s\n",
+ debug_printf ("CSBB: %s stopped by software breakpoint\n",
target_pid_to_str (ptid_of (thr)));
}
{
struct thread_info *thr = get_lwp_thread (lwp);
- debug_printf ("CSBB: Push back hardware "
- "breakpoint/watchpoint for %s\n",
+ debug_printf ("CSBB: %s stopped by hardware "
+ "breakpoint/watchpoint\n",
target_pid_to_str (ptid_of (thr)));
}
current_thread = saved_thread;
return 1;
}
+ 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)));
+ }
+ }
}
}
#else
memset (lwp, 0, sizeof (*lwp));
if (the_low_target.new_thread != NULL)
- lwp->arch_private = the_low_target.new_thread ();
+ the_low_target.new_thread (lwp);
lwp->thread = add_thread (ptid, lwp);
return count;
}
+/* The arguments passed to iterate_over_lwps. */
+
+struct iterate_over_lwps_args
+{
+ /* The FILTER argument passed to iterate_over_lwps. */
+ ptid_t filter;
+
+ /* The CALLBACK argument passed to iterate_over_lwps. */
+ iterate_over_lwps_ftype *callback;
+
+ /* The DATA argument passed to iterate_over_lwps. */
+ void *data;
+};
+
+/* Callback for find_inferior used by iterate_over_lwps to filter
+ calls to the callback supplied to that function. Returning a
+ nonzero value causes find_inferiors to stop iterating and return
+ the current inferior_list_entry. Returning zero indicates that
+ find_inferiors should continue iterating. */
+
+static int
+iterate_over_lwps_filter (struct inferior_list_entry *entry, void *args_p)
+{
+ struct iterate_over_lwps_args *args
+ = (struct iterate_over_lwps_args *) args_p;
+
+ if (ptid_match (entry->id, args->filter))
+ {
+ struct thread_info *thr = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thr);
+
+ return (*args->callback) (lwp, args->data);
+ }
+
+ return 0;
+}
+
+/* See nat/linux-nat.h. */
+
+struct lwp_info *
+iterate_over_lwps (ptid_t filter,
+ iterate_over_lwps_ftype callback,
+ void *data)
+{
+ struct iterate_over_lwps_args args = {filter, callback, data};
+ struct inferior_list_entry *entry;
+
+ entry = find_inferior (&all_threads, iterate_over_lwps_filter, &args);
+ if (entry == NULL)
+ return NULL;
+
+ return get_thread_lwp ((struct thread_info *) entry);
+}
+
/* Detect zombie thread group leaders, and "exit" them. We can't reap
their exits until all other threads in the group have exited. */
return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
}
+/* Return the ptrace options that we want to try to enable. */
+
+static int
+linux_low_ptrace_options (int attached)
+{
+ int options = 0;
+
+ if (!attached)
+ options |= PTRACE_O_EXITKILL;
+
+ if (report_fork_events)
+ options |= PTRACE_O_TRACEFORK;
+
+ return options;
+}
+
/* Do low-level handling of the event, and check if we should go on
and pass it to caller code. Return the affected lwp if we are, or
NULL otherwise. */
if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags)
{
struct process_info *proc = find_process_pid (pid_of (thread));
+ int options = linux_low_ptrace_options (proc->attached);
- linux_enable_event_reporting (lwpid, proc->attached);
+ linux_enable_event_reporting (lwpid, options);
child->must_set_ptrace_flags = 0;
}
&& linux_is_extended_waitstatus (wstat))
{
child->stop_pc = get_pc (child);
- handle_extended_wait (child, wstat);
- return NULL;
+ if (handle_extended_wait (child, wstat))
+ {
+ /* The event has been handled, so just return without
+ reporting it. */
+ return NULL;
+ }
}
/* Check first whether this was a SW/HW breakpoint before checking
{
/* We want to report the stop to the core. Treat the
SIGSTOP as a normal event. */
+ if (debug_threads)
+ debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
+ target_pid_to_str (ptid_of (thread)));
}
else if (stopping_threads != NOT_STOPPING_THREADS)
{
/* Stopping threads. We don't want this SIGSTOP to end up
pending. */
+ if (debug_threads)
+ debug_printf ("LLW: SIGSTOP caught for %s "
+ "while stopping threads.\n",
+ target_pid_to_str (ptid_of (thread)));
return NULL;
}
else
{
- /* Filter out the event. */
+ /* This is a delayed SIGSTOP. Filter out the event. */
+ if (debug_threads)
+ debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
+ child->stepping ? "step" : "continue",
+ target_pid_to_str (ptid_of (thread)));
+
linux_resume_one_lwp (child, child->stepping, 0, NULL);
return NULL;
}
count_events_callback (struct inferior_list_entry *entry, void *data)
{
struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lp = get_thread_lwp (thread);
int *count = data;
gdb_assert (count != NULL);
/* Count only resumed LWPs that have an event pending. */
if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
- && thread->last_resume_kind != resume_stop
- && thread->status_pending_p)
+ && lp->status_pending_p)
(*count)++;
return 0;
return 0;
}
-/* Select the Nth LWP that has had a SIGTRAP event that should be
- reported to GDB. */
+/* Select the Nth LWP that has had an event. */
static int
select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
{
struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lp = get_thread_lwp (thread);
int *selector = data;
gdb_assert (selector != NULL);
/* Select only resumed LWPs that have an event pending. */
- if (thread->last_resume_kind != resume_stop
- && thread->last_status.kind == TARGET_WAITKIND_IGNORE
- && thread->status_pending_p)
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p)
if ((*selector)-- == 0)
return 1;
if (event_thread == NULL)
{
/* No single-stepping LWP. Select one at random, out of those
- which have had SIGTRAP events. */
+ which have had events. */
- /* First see how many SIGTRAP events we have. */
+ /* First see how many events we have. */
find_inferior (&all_threads, count_events_callback, &num_events);
+ gdb_assert (num_events > 0);
- /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
+ /* Now randomly pick a LWP out of those that have had
+ events. */
random_selector = (int)
((num_events * (double) rand ()) / (RAND_MAX + 1.0));
return null_ptid;
}
+/* Return non-zero if WAITSTATUS reflects an extended linux
+ event. Otherwise, return zero. */
+
+static int
+extended_event_reported (const struct target_waitstatus *waitstatus)
+{
+ if (waitstatus == NULL)
+ return 0;
+
+ return (waitstatus->kind == TARGET_WAITKIND_FORKED);
+}
+
/* Wait for process, returns status. */
static ptid_t
&& !bp_explains_trap && !trace_event)
|| (gdb_breakpoint_here (event_child->stop_pc)
&& gdb_condition_true_at_breakpoint (event_child->stop_pc)
- && gdb_no_commands_at_breakpoint (event_child->stop_pc)));
+ && gdb_no_commands_at_breakpoint (event_child->stop_pc))
+ || extended_event_reported (&event_child->waitstatus));
run_breakpoint_commands (event_child->stop_pc);
paddress (event_child->stop_pc),
paddress (event_child->step_range_start),
paddress (event_child->step_range_end));
+ if (extended_event_reported (&event_child->waitstatus))
+ {
+ char *str = target_waitstatus_to_string (ourstatus);
+ debug_printf ("LWP %ld: extended event with waitstatus %s\n",
+ lwpid_of (get_lwp_thread (event_child)), str);
+ xfree (str);
+ }
}
/* We're not reporting this breakpoint to GDB, so apply the
unstop_all_lwps (1, event_child);
}
- ourstatus->kind = TARGET_WAITKIND_STOPPED;
+ if (extended_event_reported (&event_child->waitstatus))
+ {
+ /* If the reported event is a fork, vfork or exec, let GDB know. */
+ ourstatus->kind = event_child->waitstatus.kind;
+ ourstatus->value = event_child->waitstatus.value;
+
+ /* Clear the event lwp's waitstatus since we handled it already. */
+ event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE;
+ }
+ else
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
/* Now that we've selected our final event LWP, un-adjust its PC if
it was a software breakpoint, and the client doesn't know we can
but, it stopped for other reasons. */
ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
}
- else
+ else if (ourstatus->kind == TARGET_WAITKIND_STOPPED)
{
ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
}
}
}
-/* Resume execution of the inferior process.
- If STEP is nonzero, single-step it.
- If SIGNAL is nonzero, give it that signal. */
+/* Resume execution of LWP. If STEP is nonzero, single-step it. If
+ SIGNAL is nonzero, give it that signal. */
static void
-linux_resume_one_lwp (struct lwp_info *lwp,
- int step, int signal, siginfo_t *info)
+linux_resume_one_lwp_throw (struct lwp_info *lwp,
+ int step, int signal, siginfo_t *info)
{
struct thread_info *thread = get_lwp_thread (lwp);
struct thread_info *saved_thread;
regcache_invalidate_thread (thread);
errno = 0;
- lwp->stopped = 0;
- lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
lwp->stepping = step;
ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
(PTRACE_TYPE_ARG3) 0,
current_thread = saved_thread;
if (errno)
+ perror_with_name ("resuming thread");
+
+ /* Successfully resumed. Clear state that no longer makes sense,
+ and mark the LWP as running. Must not do this before resuming
+ otherwise if that fails other code will be confused. E.g., we'd
+ later try to stop the LWP and hang forever waiting for a stop
+ status. Note that we must not throw after this is cleared,
+ otherwise handle_zombie_lwp_error would get confused. */
+ lwp->stopped = 0;
+ lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
+}
+
+/* Called when we try to resume a stopped LWP and that errors out. If
+ the LWP is no longer in ptrace-stopped state (meaning it's zombie,
+ or about to become), discard the error, clear any pending status
+ the LWP may have, and return true (we'll collect the exit status
+ soon enough). Otherwise, return false. */
+
+static int
+check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
+{
+ struct thread_info *thread = get_lwp_thread (lp);
+
+ /* If we get an error after resuming the LWP successfully, we'd
+ confuse !T state for the LWP being gone. */
+ gdb_assert (lp->stopped);
+
+ /* We can't just check whether the LWP is in 'Z (Zombie)' state,
+ because even if ptrace failed with ESRCH, the tracee may be "not
+ yet fully dead", but already refusing ptrace requests. In that
+ case the tracee has 'R (Running)' state for a little bit
+ (observed in Linux 3.18). See also the note on ESRCH in the
+ ptrace(2) man page. Instead, check whether the LWP has any state
+ other than ptrace-stopped. */
+
+ /* Don't assume anything if /proc/PID/status can't be read. */
+ if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0)
{
- /* ESRCH from ptrace either means that the thread was already
- running (an error) or that it is gone (a race condition). If
- it's gone, we will get a notification the next time we wait,
- so we can ignore the error. We could differentiate these
- two, but it's tricky without waiting; the thread still exists
- as a zombie, so sending it signal 0 would succeed. So just
- ignore ESRCH. */
- if (errno == ESRCH)
- return;
+ lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
+ lp->status_pending_p = 0;
+ return 1;
+ }
+ return 0;
+}
+
+/* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
+ disappears while we try to resume it. */
- perror_with_name ("ptrace");
+static void
+linux_resume_one_lwp (struct lwp_info *lwp,
+ int step, int signal, siginfo_t *info)
+{
+ TRY
+ {
+ linux_resume_one_lwp_throw (lwp, step, signal, info);
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (!check_ptrace_stopped_lwp_gone (lwp))
+ throw_exception (ex);
}
+ END_CATCH
}
struct thread_resume_array
val = val & 0xffff;
else if (len == 3)
val = val & 0xffffff;
- debug_printf ("Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
- val, (long)memaddr);
+ debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
+ 2 * ((len < 4) ? len : 4), val, (long)memaddr, pid);
}
/* Fill start and end extra bytes of buffer with existing memory data. */
linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
- if (the_low_target.insert_point != NULL)
+ if (type == raw_bkpt_type_sw)
+ return insert_memory_breakpoint (bp);
+ else if (the_low_target.insert_point != NULL)
return the_low_target.insert_point (type, addr, size, bp);
else
/* Unsupported (see target.h). */
linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
- if (the_low_target.remove_point != NULL)
+ if (type == raw_bkpt_type_sw)
+ return remove_memory_breakpoint (bp);
+ else if (the_low_target.remove_point != NULL)
return the_low_target.remove_point (type, addr, size, bp);
else
/* Unsupported (see target.h). */
return USE_SIGTRAP_SIGINFO;
}
+/* Implement the supports_conditional_breakpoints target_ops
+ method. */
+
+static int
+linux_supports_conditional_breakpoints (void)
+{
+ /* GDBserver needs to step over the breakpoint if the condition is
+ false. GDBserver software single step is too simple, so disable
+ conditional breakpoints if the target doesn't have hardware single
+ step. */
+ return can_hardware_single_step ();
+}
+
static int
linux_stopped_by_watchpoint (void)
{
linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
{
unsigned long text, text_end, data;
- int pid = lwpid_of (get_thread_lwp (current_thread));
+ int pid = lwpid_of (current_thread);
errno = 0;
return 1;
}
+/* Check if fork events are supported. */
+
+static int
+linux_supports_fork_events (void)
+{
+ return linux_supports_tracefork ();
+}
+
+/* Check if vfork events are supported. */
+
+static int
+linux_supports_vfork_events (void)
+{
+ return linux_supports_tracefork ();
+}
+
+/* Callback for 'find_inferior'. Set the (possibly changed) ptrace
+ options for the specified lwp. */
+
+static int
+reset_lwp_ptrace_options_callback (struct inferior_list_entry *entry,
+ void *args)
+{
+ struct thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thread);
+
+ if (!lwp->stopped)
+ {
+ /* Stop the lwp so we can modify its ptrace options. */
+ lwp->must_set_ptrace_flags = 1;
+ linux_stop_lwp (lwp);
+ }
+ else
+ {
+ /* Already stopped; go ahead and set the ptrace options. */
+ struct process_info *proc = find_process_pid (pid_of (thread));
+ int options = linux_low_ptrace_options (proc->attached);
+
+ linux_enable_event_reporting (lwpid_of (thread), options);
+ lwp->must_set_ptrace_flags = 0;
+ }
+
+ return 0;
+}
+
+/* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
+ ptrace flags for all inferiors. This is in case the new GDB connection
+ doesn't support the same set of events that the previous one did. */
+
+static void
+linux_handle_new_gdb_connection (void)
+{
+ pid_t pid;
+
+ /* Request that all the lwps reset their ptrace options. */
+ find_inferior (&all_threads, reset_lwp_ptrace_options_callback , &pid);
+}
+
static int
linux_supports_disable_randomization (void)
{
break;
len = sep - annex;
- if (len == 5 && strncmp (annex, "start", 5) == 0)
+ if (len == 5 && startswith (annex, "start"))
addrp = &lm_addr;
- else if (len == 4 && strncmp (annex, "prev", 4) == 0)
+ else if (len == 4 && startswith (annex, "prev"))
addrp = &lm_prev;
else
{
}
#endif /* HAVE_LINUX_BTRACE */
+/* See nat/linux-nat.h. */
+
+ptid_t
+current_lwp_ptid (void)
+{
+ return ptid_of (current_thread);
+}
+
static struct target_ops linux_target_ops = {
linux_create_inferior,
linux_attach,
linux_supports_stopped_by_sw_breakpoint,
linux_stopped_by_hw_breakpoint,
linux_supports_stopped_by_hw_breakpoint,
+ linux_supports_conditional_breakpoints,
linux_stopped_by_watchpoint,
linux_stopped_data_address,
#if defined(__UCLIBC__) && defined(HAS_NOMMU) \
linux_async,
linux_start_non_stop,
linux_supports_multi_process,
+ linux_supports_fork_events,
+ linux_supports_vfork_events,
+ linux_handle_new_gdb_connection,
#ifdef USE_THREAD_DB
thread_db_handle_monitor_command,
#else
NULL,
#endif
linux_supports_range_stepping,
+ linux_proc_pid_to_exec_file,
};
static void
sigaction (SIGCHLD, &sigchld_action, NULL);
initialize_low_arch ();
+
+ linux_check_ptrace_features ();
}
projects / deliverable / binutils-gdb.git / blobdiff