Messages in this thread | | | Date | Mon, 18 May 2015 11:12:07 +0100 | From | Colin Ian King <> | Subject | Re: [PATCH] ARM: 8351/1: perf: fix memory leak on return |
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On 16/05/15 08:09, Ingo Molnar wrote: > > * Colin King <colin.king@canonical.com> wrote: > >> From: Colin Ian King <colin.king@canonical.com> >> >> Recent commit 3b8786ff7a1b31645ae2c26a2ec32dbd42ac1094 >> ("ARM: 8352/1: perf: Fix the pmu node name in warning message") >> introduced a memory leak of irqs on the "Don't bother with PPIs" >> return path. This was picked up by static analysis by cppcheck: >> >> [arch/arm/kernel/perf_event_cpu.c:315]: (error) Memory leak: irqs >> >> simpele fix is to free irqs when returning. >> >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> arch/arm/kernel/perf_event_cpu.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c >> index 213919b..9e5b2a5 100644 >> --- a/arch/arm/kernel/perf_event_cpu.c >> +++ b/arch/arm/kernel/perf_event_cpu.c >> @@ -311,8 +311,10 @@ static int of_pmu_irq_cfg(struct platform_device *pdev) >> >> /* Don't bother with PPIs; they're already affine */ >> irq = platform_get_irq(pdev, 0); >> - if (irq >= 0 && irq_is_percpu(irq)) >> + if (irq >= 0 && irq_is_percpu(irq)) { >> + kfree(irqs); >> return 0; >> + } >> >> for (i = 0; i < pdev->num_resources; ++i) { >> struct device_node *dn; > > So returning from the middle of a function isn't very clean. > > Also, why do we return 0 in an error case?
I believe that's explained in commit 338d9dd3e2aee00a9198e8bf6e7d535d3feeaf32 ("ARM: 8351/1: perf: don't warn about missing interrupt-affinity property for PPIs"):
"PPIs are affine by nature, so the interrupt-affinity property is not used and therefore we shouldn't print a warning in its absence."
> > Furthermore, this function already has a (partially hidden) error > cleanup path: > > if (i == pdev->num_resources) > cpu_pmu->irq_affinity = irqs; > else > kfree(irqs); > > So this code should use proper goto driven cleanup. That's faster and > cleaner, and is less likely to result in bugs like the above. > > Thanks, > > Ingo >
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