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| author |   Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> | 2012-05-04 14:06:02 -0700 |
|---|---|---|
| committer |   Len Brown <len.brown@intel.com> | 2012-06-01 16:07:23 -0400 |
| commit | 1b0a0e9a15b976d91f3b5ae619c6a8964c2818eb (patch) | |
| tree | 4408c6a983c18ca7c8cc1a9d55008b3dd5d33703 /drivers/cpuidle | |
| parent | cpuidle: remove unused hrtimer_peek_ahead_timers() call (diff) | |
| download | linux-dev-1b0a0e9a15b976d91f3b5ae619c6a8964c2818eb.tar.xz linux-dev-1b0a0e9a15b976d91f3b5ae619c6a8964c2818eb.zip | |
cpuidle: add checks to avoid NULL pointer dereference
The existing check for dev == NULL in __cpuidle_register_device() is
rendered useless because dev is dereferenced before the check itself.
Moreover, correctly speaking, it is the job of the callers of this
function, i.e., cpuidle_register_device() & cpuidle_enable_device() (which
also happen to be exported functions) to ensure that
__cpuidle_register_device() is called with a non-NULL dev.
So add the necessary dev == NULL checks in the two callers and remove the
(useless) check from __cpuidle_register_device().
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 588b44aa1de4..8ffef26ffdcf 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -285,6 +285,9 @@ int cpuidle_enable_device(struct cpuidle_device *dev) int ret, i; struct cpuidle_driver *drv = cpuidle_get_driver(); + if (!dev) + return -EINVAL; + if (dev->enabled) return 0; if (!drv || !cpuidle_curr_governor) @@ -369,8 +372,6 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver(); - if (!dev) - return -EINVAL; if (!try_module_get(cpuidle_driver->owner)) return -EINVAL; @@ -395,6 +396,9 @@ int cpuidle_register_device(struct cpuidle_device *dev) { int ret; + if (!dev) + return -EINVAL; + mutex_lock(&cpuidle_lock); if ((ret = __cpuidle_register_device(dev))) { |