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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-01-31 21:58:39 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-02-23 18:03:16 +0100 |
| commit | 57a2fe90fcdaa812ac1aa6c91ba0e591c30f461a (patch) | |
| tree | d8ccc4801bb561a55c0c31ab480f754c6ca4b3da | |
| parent | rcutorture: Abstract stutter_wait() (diff) | |
| download | linux-57a2fe90fcdaa812ac1aa6c91ba0e591c30f461a.tar.xz linux-57a2fe90fcdaa812ac1aa6c91ba0e591c30f461a.zip | |
rcutorture: Apply ACCESS_ONCE() to racy fullstop accesses
Because the fullstop variable can be accessed while it is being updated,
this commit avoids any resulting compiler mischief through use of
ACCESS_ONCE() for non-initialization accesses to this shared variable.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| -rw-r--r-- | kernel/torture.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/torture.c b/kernel/torture.c index b30c2ee78580..1bafd02d1eed 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -439,9 +439,9 @@ static int torture_shutdown_notify(struct notifier_block *unused1, unsigned long unused2, void *unused3) { mutex_lock(&fullstop_mutex); - if (fullstop == FULLSTOP_DONTSTOP) { + if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) { VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); - fullstop = FULLSTOP_SHUTDOWN; + ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN; } else { pr_warn("Concurrent rmmod and shutdown illegal!\n"); } @@ -575,13 +575,13 @@ EXPORT_SYMBOL_GPL(torture_init_end); bool torture_cleanup(void) { mutex_lock(&fullstop_mutex); - if (fullstop == FULLSTOP_SHUTDOWN) { + if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { pr_warn("Concurrent rmmod and shutdown illegal!\n"); mutex_unlock(&fullstop_mutex); schedule_timeout_uninterruptible(10); return true; } - fullstop = FULLSTOP_RMMOD; + ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD; mutex_unlock(&fullstop_mutex); unregister_reboot_notifier(&torture_shutdown_nb); torture_shuffle_cleanup(); @@ -605,6 +605,6 @@ EXPORT_SYMBOL_GPL(torture_must_stop); */ bool torture_must_stop_irq(void) { - return fullstop != FULLSTOP_DONTSTOP; + return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP; } EXPORT_SYMBOL_GPL(torture_must_stop_irq); |