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author | Oleg Nesterov <oleg@redhat.com> | 2015-10-22 13:32:08 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-23 17:55:10 +0900 |
commit | 5211613978cb7353a3237e4372958c0e7514683f (patch) | |
tree | 01fae404b1b576e032245ef68ee50f0a92ea8090 /kernel/livepatch | |
parent | 8a70dd2669200ce83255ed8c5ebef7e59f9e8707 (diff) | |
download | linux-stable-5211613978cb7353a3237e4372958c0e7514683f.tar.gz linux-stable-5211613978cb7353a3237e4372958c0e7514683f.tar.bz2 linux-stable-5211613978cb7353a3237e4372958c0e7514683f.zip |
kmod: don't run async usermode helper as a child of kworker thread
call_usermodehelper_exec_sync() does fork() + wait() with "unignored"
SIGCHLD. What we have missed is that this worker thread can have other
children previously forked by call_usermodehelper_exec_work() without
UMH_WAIT_PROC. If such a child exits in between it becomes a zombie
because auto-reaping only works if SIGCHLD is ignored, and nobody can
reap it (unless/until this worker thread exits too).
Change the !UMH_WAIT_PROC case to use CLONE_PARENT.
Note: this is only first step. All PF_KTHREAD tasks, even created by
kernel_thread() should have ->parent == kthreadd by default.
Fixes: bb304a5c6fc63d8506c ("kmod: handle UMH_WAIT_PROC from system unbound workqueue")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/livepatch')
0 files changed, 0 insertions, 0 deletions