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authorAndrey Ryabinin <aryabinin@virtuozzo.com>2016-11-10 10:46:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-11-11 08:12:37 -0800
commit70d78fe7c8b640b5acfad56ad341985b3810998a (patch)
treeebcdf4e54b1c2ab369ab58a73573683cb04edf1e
parent60da81ea61201f43387793d1cc3f501609d922ed (diff)
downloadlinux-sh-70d78fe7c8b640b5acfad56ad341985b3810998a.tar.gz
coredump: fix unfreezable coredumping task
It could be not possible to freeze coredumping task when it waits for 'core_state->startup' completion, because threads are frozen in get_signal() before they got a chance to complete 'core_state->startup'. Inability to freeze a task during suspend will cause suspend to fail. Also CRIU uses cgroup freezer during dump operation. So with an unfreezable task the CRIU dump will fail because it waits for a transition from 'FREEZING' to 'FROZEN' state which will never happen. Use freezer_do_not_count() to tell freezer to ignore coredumping task while it waits for core_state->startup completion. Link: http://lkml.kernel.org/r/1475225434-3753-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/coredump.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/coredump.c b/fs/coredump.c
index 281b768000e6..eb9c92c9b20f 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -1,6 +1,7 @@
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/fdtable.h>
+#include <linux/freezer.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
@@ -423,7 +424,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
if (core_waiters > 0) {
struct core_thread *ptr;
+ freezer_do_not_count();
wait_for_completion(&core_state->startup);
+ freezer_count();
/*
* Wait for all the threads to become inactive, so that
* all the thread context (extended register state, like