* [PATCH -next] static-keys: Better error checking for static_key_enable/disable
@ 2015-08-27 20:57 Chuck Ebbert
2015-08-27 22:23 ` Peter Zijlstra
0 siblings, 1 reply; 2+ messages in thread
From: Chuck Ebbert @ 2015-08-27 20:57 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: linux-kernel
The warnings for static_key_enable/disable don't catch common
errors. For example, starting with a default enabled key and
calling enable doesn't cause a warning until the next enable
or disable. Check explicitly for zero or one instead of allowing
both values in every case. Generated code should be smaller too.
Signed-off-by: Chuck Ebbert <cebbert.lkml@gmail.com>
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 7f653e8..ba9ca0c 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -225,7 +225,7 @@ static inline void static_key_enable(struct static_key *key)
{
int count = static_key_count(key);
- WARN_ON_ONCE(count < 0 || count > 1);
+ WARN_ON_ONCE(count);
if (!count)
static_key_slow_inc(key);
@@ -235,7 +235,7 @@ static inline void static_key_disable(struct static_key *key)
{
int count = static_key_count(key);
- WARN_ON_ONCE(count < 0 || count > 1);
+ WARN_ON_ONCE(count != 1);
if (count)
static_key_slow_dec(key);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH -next] static-keys: Better error checking for static_key_enable/disable
2015-08-27 20:57 [PATCH -next] static-keys: Better error checking for static_key_enable/disable Chuck Ebbert
@ 2015-08-27 22:23 ` Peter Zijlstra
0 siblings, 0 replies; 2+ messages in thread
From: Peter Zijlstra @ 2015-08-27 22:23 UTC (permalink / raw)
To: Chuck Ebbert; +Cc: linux-kernel
On Thu, Aug 27, 2015 at 04:57:13PM -0400, Chuck Ebbert wrote:
> The warnings for static_key_enable/disable don't catch common
> errors. For example, starting with a default enabled key and
> calling enable doesn't cause a warning until the next enable
> or disable. Check explicitly for zero or one instead of allowing
> both values in every case. Generated code should be smaller too.
I explicitly intended to allow multiple consecutive static_key_enable()
calls (same for disable).
If its already enabled, calling enable should be a no-op.
^ permalink raw reply [flat|nested] 2+ messages in thread
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