Messages in this thread | | | Date | Thu, 29 Nov 2018 12:14:32 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH] perf: arm_spe: handle devm_kasprintf() failure |
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On Wed, Nov 28, 2018 at 12:24:47PM +0100, Nicholas Mc Guire wrote: > 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") > --- > > 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; > + }
In the other dev_err() messages, we use the form "failed to ...", e.g.
"failed to get IRQ (%d)\n" "failed to get PPI partition (%d)\n "failed to allocate spe_pmu\n"
... so for consistency could you please change the string to:
"failed to allocate spe_pmu name\n"
With that, feel free to add:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
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