[PATCH] arm: kernel/perf_event_cpu.c: fix error null pointer dereference check

Russell King - ARM Linux linux at arm.linux.org.uk
Mon Jan 14 12:23:46 EST 2013


On Mon, Jan 14, 2013 at 05:18:53PM +0000, Cong Ding wrote:
> the pointer cpu_pmu is used without null pointer dereference check, and is
> checked after the using of it, so we move the null pointer check to before the
> first use.

The NULL pointer check is not necessary.  cpu_pmu_init() is called
after cpu_pmu has already been dereferenced by its caller:

        cpu_pmu = pmu;
        cpu_pmu->plat_device = pdev;
        cpu_pmu_init(cpu_pmu);

So...

> -	/* Ensure the PMU has sane values out of reset. */
> -	if (cpu_pmu && cpu_pmu->reset)

Just replace this with:
	if (cpu_pmu->reset)



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