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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>
This commit is contained in:
parent
0aeb9cac6f
commit
1b0a0e9a15
1 changed files with 6 additions and 2 deletions
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@ -285,6 +285,9 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
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int ret, i;
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int ret, i;
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struct cpuidle_driver *drv = cpuidle_get_driver();
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struct cpuidle_driver *drv = cpuidle_get_driver();
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if (!dev)
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return -EINVAL;
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if (dev->enabled)
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if (dev->enabled)
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return 0;
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return 0;
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if (!drv || !cpuidle_curr_governor)
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if (!drv || !cpuidle_curr_governor)
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@ -369,8 +372,6 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
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struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
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struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
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struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
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struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
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if (!dev)
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return -EINVAL;
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if (!try_module_get(cpuidle_driver->owner))
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if (!try_module_get(cpuidle_driver->owner))
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return -EINVAL;
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return -EINVAL;
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@ -395,6 +396,9 @@ int cpuidle_register_device(struct cpuidle_device *dev)
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{
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{
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int ret;
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int ret;
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if (!dev)
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return -EINVAL;
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mutex_lock(&cpuidle_lock);
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mutex_lock(&cpuidle_lock);
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if ((ret = __cpuidle_register_device(dev))) {
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if ((ret = __cpuidle_register_device(dev))) {
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