From: Vladimir Davydov <[email protected]> commit 69828dce7af2cb6d08ef5a03de687d422fb7ec1f upstream.
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 <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Cc: Vinson Lee <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> --- kernel/signal.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 4d1f7fa..7b81c53 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3004,11 +3004,9 @@ 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. */ @@ -3053,12 +3051,10 @@ 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); -- 2.8.0.rc2.1.gbe9624a
