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 <hof...@osadl.org> Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension") --- 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-rc3 (localversion-next is next-20181128) 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, "Allocation of name failed\n"); + return -ENOMEM; + } + return perf_pmu_register(&spe_pmu->pmu, name, -1); } -- 2.1.4