diff options
| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2016-11-10 10:46:38 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-18 10:48:34 +0100 |
| commit | e835220ed25f6bd1e62fb51e351f5ccc9a157554 (patch) | |
| tree | 0e137377e136c0a2d1b7d2bb3e642d4844b2e376 | |
| parent | 5c54f79ad234424b453ed34e6a7920777749e456 (diff) | |
coredump: fix unfreezable coredumping task
commit 70d78fe7c8b640b5acfad56ad341985b3810998a upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/coredump.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index dfc87c5f5a54..5d15c4975ba1 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> @@ -399,7 +400,9 @@ 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 |