From: Oleg Nesterov <oleg@redhat.com>
To: Tycho Andersen <tycho@tycho.ws>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Kees Cook <keescook@chromium.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
Subject: Re: siginfo pid not populated from ptrace?
Date: Mon, 10 Dec 2018 15:57:16 +0100 [thread overview]
Message-ID: <20181210145716.GC4177@redhat.com> (raw)
In-Reply-To: <20181206192059.GD10086@cisco>
On 12/06, Tycho Andersen wrote:
>
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -1056,11 +1056,14 @@ static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struc
> goto ret;
>
> result = TRACE_SIGNAL_DELIVERED;
> +
> /*
> - * Skip useless siginfo allocation for SIGKILL SIGSTOP,
> - * and kernel threads.
> + * Skip useless siginfo allocation for SIGKILL and kernel threads.
> + * SIGSTOP is visible to tracers, so only skip allocation when the task
> + * is not traced.
> */
> - if (sig_kernel_only(sig) || (t->flags & PF_KTHREAD))
> + if ((sig == SIGKILL) || (!task_is_traced(t) && sig == SIGSTOP) ||
^^^^^^^^^^^^^^
task_is_traced() checks task->state, probably you meant t->ptrace != 0.
However, in multithreaded case t->ptrace won't help too, unless the signal
is private you do not know which thread will actually dequeue this signal
and possibly report to debugger.
Oleg.
prev parent reply other threads:[~2018-12-10 14:57 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 17:11 siginfo pid not populated from ptrace? Tycho Andersen
2018-11-12 18:30 ` Eric W. Biederman
2018-11-12 18:55 ` Tycho Andersen
2018-11-12 19:22 ` Eric W. Biederman
2018-11-12 19:24 ` Tycho Andersen
2018-11-27 23:21 ` Tycho Andersen
2018-11-28 0:38 ` Kees Cook
2018-11-28 1:17 ` Kees Cook
2018-11-28 4:44 ` Eric W. Biederman
2018-11-29 21:17 ` Kees Cook
2018-11-29 23:22 ` Tycho Andersen
2018-12-01 15:04 ` Eric W. Biederman
2018-12-06 1:00 ` Kees Cook
2018-12-06 14:40 ` Eric W. Biederman
2018-12-06 18:48 ` Linus Torvalds
2018-12-06 19:20 ` Tycho Andersen
2018-12-06 21:11 ` Eric W. Biederman
2018-12-06 21:34 ` Kees Cook
2018-12-06 22:43 ` Eric W. Biederman
2018-12-06 22:55 ` Kees Cook
2018-12-10 15:37 ` Oleg Nesterov
2018-12-10 15:44 ` Tycho Andersen
2018-12-10 17:36 ` Eric W. Biederman
2018-12-10 14:57 ` Oleg Nesterov [this message]
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