From 7ff917016a203cdff3074abfcf96c1553944af94 Mon Sep 17 00:00:00 2001
From: Dominique Quatravaux <dominique.quatravaux@epfl.ch>
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 <levraiphilippeblain@gmail.com>
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);
}