From a51e14efe29d64a966161837e991193efb2e2457 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Mon, 21 Mar 2022 19:09:13 +0000 Subject: [PATCH] Implement GDB_THREAD_OPTION_EXIT support for native Linux This implements support for the new GDB_THREAD_OPTION_EXIT thread option for native Linux. Reviewed-By: Andrew Burgess Change-Id: Ia69fc0b9b96f9af7de7cefc1ddb1fba9bbb0bb90 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27338 --- gdb/linux-nat.c | 44 +++++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 13 deletions(-) diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 1e224e03ecb..8951b34e192 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -268,6 +268,18 @@ pending_status_str (lwp_info *lp) return status_to_str (lp->status); } +/* Return true if we should report exit events for LP. */ + +static bool +report_exit_events_for (lwp_info *lp) +{ + thread_info *thr = linux_target->find_thread (lp->ptid); + gdb_assert (thr != nullptr); + + return (report_thread_events + || (thr->thread_options () & GDB_THREAD_OPTION_EXIT) != 0); +} + /* LWP accessors. */ @@ -2148,8 +2160,7 @@ wait_lwp (struct lwp_info *lp) /* Check if the thread has exited. */ if (WIFEXITED (status) || WIFSIGNALED (status)) { - if (report_thread_events - || lp->ptid.pid () == lp->ptid.lwp ()) + if (report_exit_events_for (lp) || is_leader (lp)) { linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); @@ -2932,7 +2943,7 @@ linux_nat_filter_event (int lwpid, int status) /* Check if the thread has exited. */ if (WIFEXITED (status) || WIFSIGNALED (status)) { - if (!report_thread_events && !is_leader (lp)) + if (!report_exit_events_for (lp) && !is_leader (lp)) { linux_nat_debug_printf ("%s exited.", lp->ptid.to_string ().c_str ()); @@ -3142,10 +3153,11 @@ check_zombie_leaders (void) } } -/* Convenience function that is called when the kernel reports an exit - event. This decides whether to report the event to GDB as a - process exit event, a thread exit event, or to suppress the - event. */ +/* Convenience function that is called when we're about to return an + event to the core. If the event is an exit or signalled event, + then this decides whether to report it as process-wide event, as a + thread exit event, or to suppress it. All other event kinds are + passed through unmodified. */ static ptid_t filter_exit_event (struct lwp_info *event_child, @@ -3153,9 +3165,17 @@ filter_exit_event (struct lwp_info *event_child, { ptid_t ptid = event_child->ptid; + /* Note we must filter TARGET_WAITKIND_SIGNALLED as well, otherwise + if a non-leader thread exits with a signal, we'd report it to the + core which would interpret it as the whole-process exiting. + There is no TARGET_WAITKIND_THREAD_SIGNALLED event kind. */ + if (ourstatus->kind () != TARGET_WAITKIND_EXITED + && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) + return ptid; + if (!is_leader (event_child)) { - if (report_thread_events) + if (report_exit_events_for (event_child)) { ourstatus->set_thread_exited (0); /* Delete lwp, but not thread_info, infrun will need it to @@ -3388,10 +3408,7 @@ linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, else lp->core = linux_common_core_of_thread (lp->ptid); - if (ourstatus->kind () == TARGET_WAITKIND_EXITED) - return filter_exit_event (lp, ourstatus); - - return lp->ptid; + return filter_exit_event (lp, ourstatus); } /* Resume LWPs that are currently stopped without any pending status @@ -4513,7 +4530,8 @@ linux_nat_target::thread_events (int enable) bool linux_nat_target::supports_set_thread_options (gdb_thread_options options) { - constexpr gdb_thread_options supported_options = GDB_THREAD_OPTION_CLONE; + constexpr gdb_thread_options supported_options + = GDB_THREAD_OPTION_CLONE | GDB_THREAD_OPTION_EXIT; return ((options & supported_options) == options); } -- 2.30.2