signal: remove warning about using SI_TKILL in rt_[tg]sigqueueinfo (69828dce) · Commits · 戴 / test

Sending SI_TKILL from rt_[tg]sigqueueinfo was deprecated, so now we issue a warning on the first attempt of doing it. We use WARN_ON_ONCE, which is not informative and, what is worse, taints the kernel, making the trinity syscall fuzzer complain false-positively from time to time. It does not look like we need this warning at all, because the behaviour changed quite a long time ago (2.6.39), and if an application relies on the old API, it gets EPERM anyway and can issue a warning by itself. So let us zap the warning in kernel. Signed-off-by:

Vladimir Davydov <vdavydov@parallels.com> Acked-by:

Oleg Nesterov <oleg@redhat.com> Cc: Richard Weinberger <richard@nod.at> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c

+5 −9

Original line number	Diff line number	Diff line
		@@ -2992,11 +2992,9 @@ static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info)
		* Nor can they impersonate a kill()/tgkill(), which adds source info.
		*/
		if ((info->si_code >= 0 \|\| info->si_code == SI_TKILL) &&
		(task_pid_vnr(current) != pid)) {
		/* We used to allow any < 0 si_code */
		WARN_ON_ONCE(info->si_code < 0);
		(task_pid_vnr(current) != pid))
		return -EPERM;
		}

		info->si_signo = sig;

		/* POSIX.1b doesn't mention process groups. */
		@@ -3041,12 +3039,10 @@ static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
		/* Not even root can pretend to send signals from the kernel.
		* Nor can they impersonate a kill()/tgkill(), which adds source info.
		*/
		if (((info->si_code >= 0 \|\| info->si_code == SI_TKILL)) &&
		(task_pid_vnr(current) != pid)) {
		/* We used to allow any < 0 si_code */
		WARN_ON_ONCE(info->si_code < 0);
		if ((info->si_code >= 0 \|\| info->si_code == SI_TKILL) &&
		(task_pid_vnr(current) != pid))
		return -EPERM;
		}

		info->si_signo = sig;

		return do_send_specific(tgid, pid, sig, info);

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