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authorEric W. Biederman <ebiederm@xmission.com>2021-03-21 16:37:48 +0100
committerJens Axboe <axboe@kernel.dk>2021-03-21 16:41:07 +0100
commit4db4b1a0d1779dc159f7b87feb97030ec0b12597 (patch)
tree4a5fda2de8bfda249c99f791346d0f2faff9d4ed
parentsignal: don't allow sending any signals to PF_IO_WORKER threads (diff)
downloadlinux-4db4b1a0d1779dc159f7b87feb97030ec0b12597.tar.xz
linux-4db4b1a0d1779dc159f7b87feb97030ec0b12597.zip
signal: don't allow STOP on PF_IO_WORKER threads
Just like we don't allow normal signals to IO threads, don't deliver a STOP to a task that has PF_IO_WORKER set. The IO threads don't take signals in general, and have no means of flushing out a stop either. Longer term, we may want to look into allowing stop of these threads, as it relates to eg process freezing. For now, this prevents a spin issue if a SIGSTOP is delivered to the parent task. Reported-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
-rw-r--r--kernel/signal.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 11cabcf20e7a..f2a1b898da29 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -288,7 +288,8 @@ bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask)
JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING));
BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK));
- if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING)))
+ if (unlikely(fatal_signal_pending(task) ||
+ (task->flags & (PF_EXITING | PF_IO_WORKER))))
return false;
if (mask & JOBCTL_STOP_SIGMASK)