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Diffstat (limited to 'gdb/gdbserver/linux-low.c')
-rw-r--r--gdb/gdbserver/linux-low.c157
1 files changed, 152 insertions, 5 deletions
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 47f0f9d..7c77a2f 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -461,6 +461,11 @@ handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat)
gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE);
+ /* All extended events we currently use are mid-syscall. Only
+ PTRACE_EVENT_STOP is delivered more like a signal-stop, but
+ you have to be using PTRACE_SEIZE to get that. */
+ event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
+
if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK)
|| (event == PTRACE_EVENT_CLONE))
{
@@ -611,6 +616,7 @@ handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat)
else if (event == PTRACE_EVENT_EXEC && report_exec_events)
{
struct process_info *proc;
+ VEC (int) *syscalls_to_catch;
ptid_t event_ptid;
pid_t event_pid;
@@ -624,8 +630,12 @@ handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat)
event_ptid = ptid_of (event_thr);
event_pid = ptid_get_pid (event_ptid);
- /* Delete the execing process and all its threads. */
+ /* Save the syscall list from the execing process. */
proc = get_thread_process (event_thr);
+ syscalls_to_catch = proc->syscalls_to_catch;
+ proc->syscalls_to_catch = NULL;
+
+ /* Delete the execing process and all its threads. */
linux_mourn (proc);
current_thread = NULL;
@@ -648,6 +658,14 @@ handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat)
event_thr->last_resume_kind = resume_continue;
event_thr->last_status.kind = TARGET_WAITKIND_IGNORE;
+ /* Update syscall state in the new lwp, effectively mid-syscall too. */
+ event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
+
+ /* Restore the list to catch. Don't rely on the client, which is free
+ to avoid sending a new list when the architecture doesn't change.
+ Also, for ANY_SYSCALL, the architecture doesn't really matter. */
+ proc->syscalls_to_catch = syscalls_to_catch;
+
/* Report the event. */
*orig_event_lwp = event_lwp;
return 0;
@@ -682,6 +700,40 @@ get_pc (struct lwp_info *lwp)
return pc;
}
+/* This function should only be called if LWP got a SYSCALL_SIGTRAP.
+ Fill *SYSNO with the syscall nr trapped. Fill *SYSRET with the
+ return code. */
+
+static void
+get_syscall_trapinfo (struct lwp_info *lwp, int *sysno, int *sysret)
+{
+ struct thread_info *saved_thread;
+ struct regcache *regcache;
+
+ if (the_low_target.get_syscall_trapinfo == NULL)
+ {
+ /* If we cannot get the syscall trapinfo, report an unknown
+ system call number and -ENOSYS return value. */
+ *sysno = UNKNOWN_SYSCALL;
+ *sysret = -ENOSYS;
+ return;
+ }
+
+ saved_thread = current_thread;
+ current_thread = get_lwp_thread (lwp);
+
+ regcache = get_thread_regcache (current_thread, 1);
+ (*the_low_target.get_syscall_trapinfo) (regcache, sysno, sysret);
+
+ if (debug_threads)
+ {
+ debug_printf ("get_syscall_trapinfo sysno %d sysret %d\n",
+ *sysno, *sysret);
+ }
+
+ current_thread = saved_thread;
+}
+
/* This function should only be called if LWP got a SIGTRAP.
The SIGTRAP could mean several things.
@@ -2236,6 +2288,8 @@ linux_low_ptrace_options (int attached)
if (report_exec_events)
options |= PTRACE_O_TRACEEXEC;
+ options |= PTRACE_O_TRACESYSGOOD;
+
return options;
}
@@ -2364,6 +2418,21 @@ linux_low_filter_event (int lwpid, int wstat)
child->must_set_ptrace_flags = 0;
}
+ /* Always update syscall_state, even if it will be filtered later. */
+ if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP)
+ {
+ child->syscall_state
+ = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
+ ? TARGET_WAITKIND_SYSCALL_RETURN
+ : TARGET_WAITKIND_SYSCALL_ENTRY);
+ }
+ else
+ {
+ /* Almost all other ptrace-stops are known to be outside of system
+ calls, with further exceptions in handle_extended_wait. */
+ child->syscall_state = TARGET_WAITKIND_IGNORE;
+ }
+
/* Be careful to not overwrite stop_pc until
check_stopped_by_breakpoint is called. */
if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
@@ -2973,6 +3042,44 @@ filter_exit_event (struct lwp_info *event_child,
return ptid;
}
+/* Returns 1 if GDB is interested in any event_child syscalls. */
+
+static int
+gdb_catching_syscalls_p (struct lwp_info *event_child)
+{
+ struct thread_info *thread = get_lwp_thread (event_child);
+ struct process_info *proc = get_thread_process (thread);
+
+ return !VEC_empty (int, proc->syscalls_to_catch);
+}
+
+/* Returns 1 if GDB is interested in the event_child syscall.
+ Only to be called when stopped reason is SYSCALL_SIGTRAP. */
+
+static int
+gdb_catch_this_syscall_p (struct lwp_info *event_child)
+{
+ int i, iter;
+ int sysno, sysret;
+ struct thread_info *thread = get_lwp_thread (event_child);
+ struct process_info *proc = get_thread_process (thread);
+
+ if (VEC_empty (int, proc->syscalls_to_catch))
+ return 0;
+
+ if (VEC_index (int, proc->syscalls_to_catch, 0) == ANY_SYSCALL)
+ return 1;
+
+ get_syscall_trapinfo (event_child, &sysno, &sysret);
+ for (i = 0;
+ VEC_iterate (int, proc->syscalls_to_catch, i, iter);
+ i++)
+ if (iter == sysno)
+ return 1;
+
+ return 0;
+}
+
/* Wait for process, returns status. */
static ptid_t
@@ -3307,6 +3414,22 @@ linux_wait_1 (ptid_t ptid,
/* Check whether GDB would be interested in this event. */
+ /* Check if GDB is interested in this syscall. */
+ if (WIFSTOPPED (w)
+ && WSTOPSIG (w) == SYSCALL_SIGTRAP
+ && !gdb_catch_this_syscall_p (event_child))
+ {
+ if (debug_threads)
+ {
+ debug_printf ("Ignored syscall for LWP %ld.\n",
+ lwpid_of (current_thread));
+ }
+
+ linux_resume_one_lwp (event_child, event_child->stepping,
+ 0, NULL);
+ return ignore_event (ourstatus);
+ }
+
/* If GDB is not interested in this signal, don't stop other
threads, and don't report it to GDB. Just resume the inferior
right away. We do this for threading-related signals as well as
@@ -3559,8 +3682,16 @@ linux_wait_1 (ptid_t ptid,
}
}
- if (current_thread->last_resume_kind == resume_stop
- && WSTOPSIG (w) == SIGSTOP)
+ if (WSTOPSIG (w) == SYSCALL_SIGTRAP)
+ {
+ int sysret;
+
+ get_syscall_trapinfo (event_child,
+ &ourstatus->value.syscall_number, &sysret);
+ ourstatus->kind = event_child->syscall_state;
+ }
+ else if (current_thread->last_resume_kind == resume_stop
+ && WSTOPSIG (w) == SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
and it stopped cleanly, so report as SIG0. The use of
@@ -4017,6 +4148,7 @@ linux_resume_one_lwp_throw (struct lwp_info *lwp,
struct thread_info *thread = get_lwp_thread (lwp);
struct thread_info *saved_thread;
int fast_tp_collecting;
+ int ptrace_request;
struct process_info *proc = get_thread_process (thread);
/* Note that target description may not be initialised
@@ -4204,7 +4336,14 @@ linux_resume_one_lwp_throw (struct lwp_info *lwp,
regcache_invalidate_thread (thread);
errno = 0;
lwp->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
+ if (step)
+ ptrace_request = PTRACE_SINGLESTEP;
+ else if (gdb_catching_syscalls_p (lwp))
+ ptrace_request = PTRACE_SYSCALL;
+ else
+ ptrace_request = PTRACE_CONT;
+ ptrace (ptrace_request,
+ lwpid_of (thread),
(PTRACE_TYPE_ARG3) 0,
/* Coerce to a uintptr_t first to avoid potential gcc warning
of coercing an 8 byte integer to a 4 byte pointer. */
@@ -6286,6 +6425,13 @@ linux_process_qsupported (char **features, int count)
}
static int
+linux_supports_catch_syscall (void)
+{
+ return (the_low_target.get_syscall_trapinfo != NULL
+ && linux_supports_tracesysgood ());
+}
+
+static int
linux_supports_tracepoints (void)
{
if (*the_low_target.supports_tracepoints == NULL)
@@ -7209,7 +7355,8 @@ static struct target_ops linux_target_ops = {
linux_sw_breakpoint_from_kind,
linux_proc_tid_get_name,
linux_breakpoint_kind_from_current_state,
- linux_supports_software_single_step
+ linux_supports_software_single_step,
+ linux_supports_catch_syscall,
};
#ifdef HAVE_LINUX_REGSETS
generated by cgit v1.1 at 2024-12-23 01:05:01 +0000