From 7ff917016a203cdff3074abfcf96c1553944af94 Mon Sep 17 00:00:00 2001 From: Dominique Quatravaux Date: Thu, 24 Feb 2022 09:23:21 -0500 Subject: [PATCH] gdb/darwin: skip over WIFSTOPPED wait4 status On modern Darwin's, there appears to be a new circumstance in which a MACH_NOTIFY_DEAD_NAME message can be received, and which was not previously accounted for: to signal the WIFSTOPPED condition in the debuggee. In that case the debuggee is not dead yet (and in fact, counting it as dead would cause a zombie leak - A process in such a state reparents to PID 1, but cannot be killed). - Read and ignore such messages (counting on the next exception message to let us know of the inferior's new state again) - Refactor logging so as to clearly distinguish between the MACH_NOTIFY_DEAD_NAME cases (WIFEXITED, WIFSTOPPED, signal, or something else), and warn in the last case Co-authored-by: Louis-He <1726110778@qq.com> Co-authored-by: Philippe Blain Change-Id: Ie86904a894e9bd154e6b674b1bfbfbaee7fde3e1 --- gdb/darwin-nat.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c index 8b0ecfd5b77..adbe7474c68 100644 --- a/gdb/darwin-nat.c +++ b/gdb/darwin-nat.c @@ -1063,7 +1063,7 @@ darwin_nat_target::decode_message (mach_msg_header_t *hdr, } else if (hdr->msgh_id == 0x48) { - /* MACH_NOTIFY_DEAD_NAME: notification for exit. */ + /* MACH_NOTIFY_DEAD_NAME: notification for exit *or* WIFSTOPPED. */ int res; res = darwin_decode_notify_message (hdr, &inf); @@ -1103,15 +1103,34 @@ darwin_nat_target::decode_message (mach_msg_header_t *hdr, return minus_one_ptid; } if (WIFEXITED (wstatus)) - status->set_exited (WEXITSTATUS (wstatus)); - else + { + status->set_exited (WEXITSTATUS (wstatus)); + inferior_debug (4, _("darwin_wait: pid=%d exit, status=0x%x\n"), + res_pid, wstatus); + } + else if (WIFSTOPPED (wstatus)) + { + /* Ignore stopped state, it will be handled by the next + exception. */ + status->set_ignore (); + inferior_debug (4, _("darwin_wait: pid %d received WIFSTOPPED\n"), + res_pid); + return minus_one_ptid; + } + else if (WIFSIGNALED (wstatus)) { status->set_signalled (gdb_signal_from_host (WTERMSIG (wstatus))); + inferior_debug (4, _("darwin_wait: pid=%d received signal %d\n"), + res_pid, status->sig()); + } + else + { + status->set_ignore (); + warning (_("Unexpected wait status after MACH_NOTIFY_DEAD_NAME " + "notification: 0x%x"), wstatus); + return minus_one_ptid; } - - inferior_debug (4, _("darwin_wait: pid=%d exit, status=0x%x\n"), - res_pid, wstatus); return ptid_t (inf->pid); } -- 2.30.2