+ signal-trace_signal_deliver-when-signal_group_exit.patch added to -mm tree

+ signal-trace_signal_deliver-when-signal_group_exit.patch added to -mm tree

[akpm]

The patch titled
     Subject: kernel/signal.c: trace_signal_deliver when signal_group_exit
has been added to the -mm tree.  Its filename is
     signal-trace_signal_deliver-when-signal_group_exit.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/signal-trace_signal_deliver-when-signal_group_exit.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/signal-trace_signal_deliver-when-signal_group_exit.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Zhenliang Wei <weizhenliang@huawei.com>
Subject: kernel/signal.c: trace_signal_deliver when signal_group_exit

In the fixes commit, removing SIGKILL from each thread signal mask and
executing "goto fatal" directly will skip the call to
"trace_signal_deliver".  At this point, the delivery tracking of the
SIGKILL signal will be inaccurate.

Therefore, we need to add trace_signal_deliver before "goto fatal" after
executing sigdelset.

Note: SEND_SIG_NOINFO matches the fact that SIGKILL doesn't have any info.

Link: http://lkml.kernel.org/r/20190425025812.91424-1-weizhenliang@huawei.com
Fixes: cf43a757fd4944 ("signal: Restore the stop PTRACE_EVENT_EXIT")
Signed-off-by: Zhenliang Wei <weizhenliang@huawei.com>
Reviewed-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ivan Delalande <colona@arista.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/signal.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/kernel/signal.c~signal-trace_signal_deliver-when-signal_group_exit
+++ a/kernel/signal.c
@@ -2485,6 +2485,8 @@ relock:
 	if (signal_group_exit(signal)) {
 		ksig->info.si_signo = signr = SIGKILL;
 		sigdelset(&current->pending.signal, SIGKILL);
+		trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+				&sighand->action[SIGKILL - 1]);
 		recalc_sigpending();
 		goto fatal;
 	}
_

Patches currently in -mm which might be from weizhenliang@huawei.com are

signal-trace_signal_deliver-when-signal_group_exit.patch

+ signal-trace_signal_deliver-when-signal_group_exit.patch added to -mm tree

[akpm]

The patch titled
     Subject: signal: trace_signal_deliver when signal_group_exit
has been added to the -mm tree.  Its filename is
     signal-trace_signal_deliver-when-signal_group_exit.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/signal-trace_signal_deliver-when-signal_group_exit.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/signal-trace_signal_deliver-when-signal_group_exit.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Zhenliang Wei <weizhenliang@huawei.com>
Subject: signal: trace_signal_deliver when signal_group_exit

In the fixes commit, removing SIGKILL from each thread signal mask and
executing "goto fatal" directly will skip the call to
"trace_signal_deliver".  At this point, the delivery tracking of the
SIGKILL signal will be inaccurate.

Therefore, we need to add trace_signal_deliver before "goto fatal" after
executing sigdelset.

Note: The action[SIGKILL] must be SIG_DFL, and SEND_SIG_NOINFO matches the
fact that SIGKILL doesn't have any info.

Link: http://lkml.kernel.org/r/20190422145950.78056-1-weizhenliang@huawei.com
Fixes: cf43a757fd4944 ("signal: Restore the stop PTRACE_EVENT_EXIT")
Signed-off-by: Zhenliang Wei <weizhenliang@huawei.com>
Acked-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ivan Delalande <colona@arista.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/signal.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/signal.c~signal-trace_signal_deliver-when-signal_group_exit
+++ a/kernel/signal.c
@@ -2441,6 +2441,7 @@ relock:
 	if (signal_group_exit(signal)) {
 		ksig->info.si_signo = signr = SIGKILL;
 		sigdelset(&current->pending.signal, SIGKILL);
+		trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, SIG_DFL);
 		recalc_sigpending();
 		goto fatal;
 	}
_

Patches currently in -mm which might be from weizhenliang@huawei.com are

signal-trace_signal_deliver-when-signal_group_exit.patch