From 5a0c4a06eb4f4afcf885596ee97706c1045a8476 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 17 Jan 2022 11:27:36 -0500 Subject: gdb/linux-nat: remove check based on current_inferior in linux_handle_extended_wait The check removed by this patch, using current_inferior, looks wrong. When debugging multiple inferiors with the Linux native target and linux_handle_extended_wait is called, there's no guarantee about which is the current inferior. The vfork-done event we receive could be for any inferior. If the vfork-done event is for a non-current inferior, we end up wrongfully ignoring it. As a result, the core never processes a TARGET_WAITKIND_VFORK_DONE event, program_space::breakpoints_not_allowed is never cleared, and breakpoints are never reinserted. However, because the Linux native target decided to ignore the event, it resumed the thread - while breakpoints out. And that's bad. The proposed fix is to remove this check. Always report vfork-done events and let infrun's logic decide if it should be ignored. We don't save much cycles by filtering the event here. Add a test that replicates the situation described above. See comments in the test for more details. Change-Id: Ibe33c1716c3602e847be6c2093120696f2286fbf --- gdb/linux-nat.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) (limited to 'gdb/linux-nat.c') diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index a9b093c..dff8d07 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -1990,20 +1990,11 @@ linux_handle_extended_wait (struct lwp_info *lp, int status) if (event == PTRACE_EVENT_VFORK_DONE) { - if (current_inferior ()->waiting_for_vfork_done) - { - linux_nat_debug_printf - ("Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping", - lp->ptid.lwp ()); - - ourstatus->set_vfork_done (); - return 0; - } - linux_nat_debug_printf - ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld: ignoring", lp->ptid.lwp ()); - - return 1; + ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", + lp->ptid.lwp ()); + ourstatus->set_vfork_done (); + return 0; } internal_error (__FILE__, __LINE__, -- cgit v1.1