[patch] linux_nat_kill() compat. with linux-2.4.x

[Jan Kratochvil <jan.kratochvil@redhat.com>]

Hi,

it had been already approved by Tom that time so I will check it in in some time.
	[patch] Fix SIGTERM signal safety (PR gdb/15358)
	https://sourceware.org/ml/gdb-patches/2013-07/msg00094.html
	Message-ID: <20130702200010.GA23478@host2.jankratochvil.net>

Doug has just asked to split it out of:
	Re: [patchv2] Fix SIGTERM signal safety (PR gdb/15358) [refresh]
	https://sourceware.org/ml/gdb-patches/2014-03/msg00342.html
	Message-ID: <21284.44419.745786.47756@ruffy.mtv.corp.google.com>

The testcase of the patch above still PASSes for me on Fedora 20 x86_64 even
without this patch, I guess this patch was needed only on that 2.4.x Linux
kernel it mentions.  I am no longer interested in 2.4.x so if anyone has any
concerns I am also fine with dropping this patch.


Thanks,
Jan


gdb/
2014-03-16  Jan Kratochvil  <jan.kratochvil@redhat.com>

	PR gdb/15358
        * linux-nat.c (linux_nat_kill): Use kill_callback first.
        Extend the comment for stop_callback.

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index b615423..ec84188 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -3777,8 +3777,15 @@ linux_nat_kill (struct target_ops *ops)
     {
       ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
 
+      /* Kill all LWP's before trying to stop them.  In rare cases the
+	 lwp_info state may not match the inferior and
+	 stop_wait_callback could lock up.  */
+      iterate_over_lwps (ptid, kill_callback, NULL);
+
       /* Stop all threads before killing them, since ptrace requires
-	 that the thread is stopped to sucessfully PTRACE_KILL.  */
+	 that the thread is stopped to sucessfully PTRACE_KILL.
+	 kill_callback normally already turned the inferior into a zombie
+	 except for old Linux kernels 2.4.x.  */
       iterate_over_lwps (ptid, stop_callback, NULL);
       /* ... and wait until all of them have reported back that
 	 they're no longer running.  */