openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

drivers/cpuidle: Move dereference after NULL test 

It does not seem possible that ldev can be NULL, so drop the unnecessary
test.  If ldev can somehow be NULL, then the initialization of last_idx
should be moved below the test.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Julia Lawall 2009-12-14 18:00:09 -08:00 committed by Linus Torvalds
parent 471452104b
commit faa7b7ddca
1 changed files with 0 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/cpuidle/governors/ladder.c
View File

@ -69,9 +69,6 @@ static int ladder_select_state(struct cpuidle_device *dev)
int last_residency, last_idx = ldev->last_state_idx; int last_residency, last_idx = ldev->last_state_idx;
int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY); int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY);
if (unlikely(!ldev))
return 0;
/* Special case when user has set very strict latency requirement */ /* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0)) { if (unlikely(latency_req == 0)) {
ladder_do_selection(ldev, last_idx, 0); ladder_do_selection(ldev, last_idx, 0);