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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-11-15 22:47:13 +0300 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-11-17 19:39:12 +0300 |
| commit | 5768d8906bc23d512b1a736c1e198aa833a6daa4 (patch) | |
| tree | e875cf8c82219bc4bb0aeecca2d461c509251fc9 /fs/signalfd.c | |
| parent | e7f7c99ba911f56bc338845c1cd72954ba591707 (diff) | |
| download | linux-5768d8906bc23d512b1a736c1e198aa833a6daa4.tar.xz | |
signal: Requeue signals in the appropriate queue
In the event that a tracer changes which signal needs to be delivered
and that signal is currently blocked then the signal needs to be
requeued for later delivery.
With the advent of CLONE_THREAD the kernel has 2 signal queues per
task. The per process queue and the per task queue. Update the code
so that if the signal is removed from the per process queue it is
requeued on the per process queue. This is necessary to make it
appear the signal was never dequeued.
The rr debugger reasonably believes that the state of the process from
the last ptrace_stop it observed until PTRACE_EVENT_EXIT can be recreated
by simply letting a process run. If a SIGKILL interrupts a ptrace_stop
this is not true today.
So return signals to their original queue in ptrace_signal so that
signals that are not delivered appear like they were never dequeued.
Fixes: 794aa320b79d ("[PATCH] sigfix-2.5.40-D6")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.gi
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87zgq4d5r4.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/signalfd.c')
| -rw-r--r-- | fs/signalfd.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/signalfd.c b/fs/signalfd.c index 040e1cf90528..74f134cd1ff6 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -165,11 +165,12 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info, int nonblock) { + enum pid_type type; ssize_t ret; DECLARE_WAITQUEUE(wait, current); spin_lock_irq(¤t->sighand->siglock); - ret = dequeue_signal(current, &ctx->sigmask, info); + ret = dequeue_signal(current, &ctx->sigmask, info, &type); switch (ret) { case 0: if (!nonblock) @@ -184,7 +185,7 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info add_wait_queue(¤t->sighand->signalfd_wqh, &wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); - ret = dequeue_signal(current, &ctx->sigmask, info); + ret = dequeue_signal(current, &ctx->sigmask, info, &type); if (ret != 0) break; if (signal_pending(current)) { |