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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-01-09 15:10:59 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-01-09 15:10:59 -0800 |
| commit | b3d574aec7e7aa3ed545d7faf2b2cbaa8db4ce22 (patch) | |
| tree | 087cb7711ee899b5e0bc2a071a4417fb3048b323 /kernel | |
| parent | 11c8f01b423b2d9742ce21e44cb7da7b55429ad5 (diff) | |
| parent | 9e5e3661727eaf960d3480213f8e87c8d67b6956 (diff) | |
| download | cachepc-linux-b3d574aec7e7aa3ed545d7faf2b2cbaa8db4ce22.tar.gz cachepc-linux-b3d574aec7e7aa3ed545d7faf2b2cbaa8db4ce22.zip | |
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"12 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process being killed
memcg: fix destination cgroup leak on task charges migration
mm: memcontrol: switch soft limit default back to infinity
mm/debug_pagealloc: remove obsolete Kconfig options
vfs: renumber FMODE_NONOTIFY and add to uniqueness check
arch/blackfin/mach-bf533/boards/stamp.c: add linux/delay.h
ocfs2: fix the wrong directory passed to ocfs2_lookup_ino_from_name() when link file
MAINTAINERS: update rydberg's addresses
mm: protect set_page_dirty() from ongoing truncation
mm: prevent endless growth of anon_vma hierarchy
exit: fix race between wait_consider_task() and wait_task_zombie()
ocfs2: remove bogus check in dlm_process_recovery_data
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 1ea4369890a3..6806c55475ee 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1287,9 +1287,15 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) static int wait_consider_task(struct wait_opts *wo, int ptrace, struct task_struct *p) { + /* + * We can race with wait_task_zombie() from another thread. + * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition + * can't confuse the checks below. + */ + int exit_state = ACCESS_ONCE(p->exit_state); int ret; - if (unlikely(p->exit_state == EXIT_DEAD)) + if (unlikely(exit_state == EXIT_DEAD)) return 0; ret = eligible_child(wo, p); @@ -1310,7 +1316,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, return 0; } - if (unlikely(p->exit_state == EXIT_TRACE)) { + if (unlikely(exit_state == EXIT_TRACE)) { /* * ptrace == 0 means we are the natural parent. In this case * we should clear notask_error, debugger will notify us. @@ -1337,7 +1343,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, } /* slay zombie? */ - if (p->exit_state == EXIT_ZOMBIE) { + if (exit_state == EXIT_ZOMBIE) { /* we don't reap group leaders with subthreads */ if (!delay_group_leader(p)) { /* |