oprofile: fix memory ordering
Regular bitops don't work as locks on all architectures.
Also: can use non-atomic unlock as no concurrent stores to the word.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c
index d962ba0..191a320 100644
--- a/drivers/oprofile/event_buffer.c
+++ b/drivers/oprofile/event_buffer.c
@@ -105,7 +105,7 @@
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (test_and_set_bit(0, &buffer_opened))
+ if (test_and_set_bit_lock(0, &buffer_opened))
return -EBUSY;
/* Register as a user of dcookies
@@ -129,7 +129,7 @@
fail:
dcookie_unregister(file->private_data);
out:
- clear_bit(0, &buffer_opened);
+ __clear_bit_unlock(0, &buffer_opened);
return err;
}
@@ -141,7 +141,7 @@
dcookie_unregister(file->private_data);
buffer_pos = 0;
atomic_set(&buffer_ready, 0);
- clear_bit(0, &buffer_opened);
+ __clear_bit_unlock(0, &buffer_opened);
return 0;
}