Commit 70d78fe7 authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Linus Torvalds
Browse files

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: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Acked-by: default avatarOleg 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 60da81ea
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/file.h> #include <linux/file.h>
#include <linux/fdtable.h> #include <linux/fdtable.h>
#include <linux/freezer.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/stat.h> #include <linux/stat.h>
#include <linux/fcntl.h> #include <linux/fcntl.h>
...@@ -423,7 +424,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state) ...@@ -423,7 +424,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
if (core_waiters > 0) { if (core_waiters > 0) {
struct core_thread *ptr; struct core_thread *ptr;
freezer_do_not_count();
wait_for_completion(&core_state->startup); wait_for_completion(&core_state->startup);
freezer_count();
/* /*
* Wait for all the threads to become inactive, so that * Wait for all the threads to become inactive, so that
* all the thread context (extended register state, like * all the thread context (extended register state, like
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment