diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2015-11-25 16:02:07 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-01-06 11:01:07 +0100 |
| commit | be958bdc96f18bc1356177bbb79d46ea0c037b96 (patch) | |
| tree | dea9e48ddcca9e6fb5d244485a900bfa5b1391f6 | |
| parent | 570f52412ae9432c56897472791ea8db420cbaf1 (diff) | |
sched/core: Fix unserialized r-m-w scribbling stuff
Some of the sched bitfieds (notably sched_reset_on_fork) can be set
on other than current, this can cause the r-m-w to race with other
updates.
Since all the sched bits are serialized by scheduler locks, pull them
in a separate word.
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: hannes@cmpxchg.org
Cc: mhocko@kernel.org
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/20151125150207.GM11639@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | include/linux/sched.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 9cf9dd1c4cbe..fa39434e3fdd 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1455,14 +1455,15 @@ struct task_struct { /* Used for emulating ABI behavior of previous Linux versions */ unsigned int personality; - unsigned in_execve:1; /* Tell the LSMs that the process is doing an - * execve */ - unsigned in_iowait:1; - - /* Revert to default priority/policy when forking */ + /* scheduler bits, serialized by scheduler locks */ unsigned sched_reset_on_fork:1; unsigned sched_contributes_to_load:1; unsigned sched_migrated:1; + unsigned :0; /* force alignment to the next boundary */ + + /* unserialized, strictly 'current' */ + unsigned in_execve:1; /* bit to tell LSMs we're in execve */ + unsigned in_iowait:1; #ifdef CONFIG_MEMCG unsigned memcg_may_oom:1; #endif |