From: Jamie Iles <jamie.iles@oracle.com>
To: linux-kernel@vger.kernel.org, oleg@redhat.com
Cc: Jamie Iles <jamie.iles@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH] signal: don't remove SIGNAL_UNKILLABLE for traced tasks.
Date: Tue, 15 Aug 2017 12:28:06 +0100 [thread overview]
Message-ID: <20170815112806.10728-1-jamie.iles@oracle.com> (raw)
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.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jamie Iles <jamie.iles@oracle.com>
---
kernel/signal.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/signal.c b/kernel/signal.c
index 7e33f8c583e6..ed804a470dcd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1194,7 +1194,11 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
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);
--
2.13.3
next reply other threads:[~2017-08-15 11:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-15 11:28 Jamie Iles [this message]
2017-08-15 16:16 ` [PATCH] signal: don't remove SIGNAL_UNKILLABLE for traced tasks Oleg Nesterov
-- strict thread matches above, loose matches on Subject: below --
2017-05-04 12:51 Jamie Iles
2017-05-05 16:26 ` Oleg Nesterov
2017-05-05 16:34 ` Jamie Iles
2017-06-08 10:07 ` Jamie Iles
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170815112806.10728-1-jamie.iles@oracle.com \
--to=jamie.iles@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.