Messages in this thread Patch in this message | | | From | Nicholas Mc Guire <> | Subject | [PATCH V2] perf: arm_spe: handle devm_kasprintf() failure | Date | Thu, 29 Nov 2018 13:55:30 +0100 |
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devm_kasprintf() may return NULL on failure of internal allocation thus the assignment to name is not safe if unchecked. if NULL is passed in for name then perf_pmu_register() would not fail but rather silently jump to skip_type which is not the intent here. As perf_pmu_register() may also return -ENOMEM returning -ENOMEM in the (unlikely) failure case of devm_kasprintf() should be fine here as well.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension") Acked-by: Mark Rutland <mark.rutland@arm.com> ---
V2: Changed error message to keep error messages consistent as suggested by Mark Rutland <mark.rutland@arm.com> - thanks !
Problem located with an experimental coccinelle script
The dev_err() might seem a bit much for this unlikely error but as perf_pmu_register() may also return -ENOMEM it would be hard to figure out what went wrong without this message.
Patch was compile tested with: defconfig (ARCH=arm64) + ARM_SPE_PMU=y
Patch is against 4.20-rc4 (localversion-next is next-20181129)
drivers/perf/arm_spe_pmu.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index 54ec278..f1ea00c 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -927,6 +927,11 @@ static int arm_spe_pmu_perf_init(struct arm_spe_pmu *spe_pmu) idx = atomic_inc_return(&pmu_idx); name = devm_kasprintf(dev, GFP_KERNEL, "%s_%d", PMUNAME, idx); + if (!name) { + dev_err(dev, "failed to allocate spe_pmu name\n"); + return -ENOMEM; + } + return perf_pmu_register(&spe_pmu->pmu, name, -1); } -- 2.1.4
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