The patch titled
Subject: signal: don't remove SIGNAL_UNKILLABLE for traced tasks.
has been added to the -mm tree. Its filename is
signal-dont-remove-signal_unkillable-for-traced-tasks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/signal-dont-remove-signal_unkillable-for-traced-tasks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/signal-dont-remove-signal_unkillable-for-traced-tasks.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/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Jamie Iles <jamie.iles@xxxxxxxxxx>
Subject: signal: don't remove SIGNAL_UNKILLABLE for traced tasks.
When forcing a signal, SIGNAL_UNKILLABLE is removed to prevent recursive
faults, but this is undesirable when tracing. For example, debugging an
init process (whether global or namespace), hitting a breakpoint and
SIGTRAP will force SIGTRAP and then remove SIGNAL_UNKILLABLE. Everything
continues fine, but then once debugging has finished, the init process is
left killable which is unlikely what the user expects, resulting in either
an accidentally killed init or an init that stops reaping zombies.
Link: http://lkml.kernel.org/r/20170815112806.10728-1-jamie.iles@xxxxxxxxxx
Signed-off-by: Jamie Iles <jamie.iles@xxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/signal.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff -puN kernel/signal.c~signal-dont-remove-signal_unkillable-for-traced-tasks kernel/signal.c
--- a/kernel/signal.c~signal-dont-remove-signal_unkillable-for-traced-tasks
+++ a/kernel/signal.c
@@ -1194,7 +1194,11 @@ force_sig_info(int sig, struct siginfo *
recalc_sigpending_and_wake(t);
}
}
- if (action->sa.sa_handler == SIG_DFL)
+ /*
+ * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect
+ * debugging to leave init killable.
+ */
+ if (action->sa.sa_handler == SIG_DFL && !t->ptrace)
t->signal->flags &= ~SIGNAL_UNKILLABLE;
ret = specific_send_sig_info(sig, info, t);
spin_unlock_irqrestore(&t->sighand->siglock, flags);
_
Patches currently in -mm which might be from jamie.iles@xxxxxxxxxx are
signal-dont-remove-signal_unkillable-for-traced-tasks.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
