[PATCH 5/6] gdbserver/Linux: internal error when killing a process that is already gone

Pedro Alves
2015-03-06T19:58:18Z

If the process disappears (e.g., killed with "kill -9" from the shell)
while it was stopped under GDBserver's control, and the GDBserver
tries to kill it, GDBserver asserts:

(gdb) shell kill -9 23084
(gdb) kill
...
Killing process(es): 23084
/home/pedro/gdb/mygit/src/gdb/gdbserver/linux-low.c:972: A problem internal to GDBserver has been detected.
kill_wait_lwp: Assertion `res > 0' failed.
...

gdb/gdbserver/ChangeLog:
2015-03-06 Pedro Alves <palves@redhat.com>

* linux-low.c (kill_wait_lwp): Don't assert if waitpid fails.
Instead, ignore ECHILD, and throw an error for other errnos.
---
gdb/gdbserver/linux-low.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index f9c4079..e536a51 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -970,7 +970,10 @@ kill_wait_lwp (struct lwp_info *lwp)
res = my_waitpid (lwpid, &wstat, __WCLONE);
} while (res > 0 && WIFSTOPPED (wstat));

- gdb_assert (res > 0);
+ /* Even if it was stopped, the child may have already disappeared.
+ E.g., if it was killed by SIGKILL. */
+ if (res < 0 && errno != ECHILD)
+ perror_with_name ("kill_wait_lwp");
}

/* Callback for `find_inferior'. Kills an lwp of a given process,
--
1.9.3