[PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[Zhouyi Zhou]

Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
---
 arch/x86/kernel/cpu/perf_event_amd_uncore.c |   32 +++++++++++++++------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
index 3bbdf4c..f60a50e 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
@@ -300,24 +300,28 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
 
 	if (amd_uncore_nb) {
 		uncore = amd_uncore_alloc(cpu);
-		uncore->cpu = cpu;
-		uncore->num_counters = NUM_COUNTERS_NB;
-		uncore->rdpmc_base = RDPMC_BASE_NB;
-		uncore->msr_base = MSR_F15H_NB_PERF_CTL;
-		uncore->active_mask = &amd_nb_active_mask;
-		uncore->pmu = &amd_nb_pmu;
-		*per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
+		if (uncore) {
+			uncore->cpu = cpu;
+			uncore->num_counters = NUM_COUNTERS_NB;
+			uncore->rdpmc_base = RDPMC_BASE_NB;
+			uncore->msr_base = MSR_F15H_NB_PERF_CTL;
+			uncore->active_mask = &amd_nb_active_mask;
+			uncore->pmu = &amd_nb_pmu;
+			*per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
+		}
 	}
 
 	if (amd_uncore_l2) {
 		uncore = amd_uncore_alloc(cpu);
-		uncore->cpu = cpu;
-		uncore->num_counters = NUM_COUNTERS_L2;
-		uncore->rdpmc_base = RDPMC_BASE_L2;
-		uncore->msr_base = MSR_F16H_L2I_PERF_CTL;
-		uncore->active_mask = &amd_l2_active_mask;
-		uncore->pmu = &amd_l2_pmu;
-		*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
+		if (uncore) {
+			uncore->cpu = cpu;
+			uncore->num_counters = NUM_COUNTERS_L2;
+			uncore->rdpmc_base = RDPMC_BASE_L2;
+			uncore->msr_base = MSR_F16H_L2I_PERF_CTL;
+			uncore->active_mask = &amd_l2_active_mask;
+			uncore->pmu = &amd_l2_pmu;
+			*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
+		}
 	}
 }
 
-- 
1.7.10.4

Re: [PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[Peter Zijlstra]

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On Tue, Jun 10, 2014 at 03:37:38PM +0800, Zhouyi Zhou wrote:

Less typing more thinking, this is wrong. You should fail when the
allocation fails.

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Re: [PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[Zhouyi Zhou]

Thanks Peter for reviewing, and sorry for not think it thoroughly
before submitting.
Is that ok that when amd_uncore_cpu_up_prepare is called from
amd_uncore_cpu_notifier
I return notifier_from_errno(-ENOMEM), and  when
amd_uncore_cpu_up_prepare is called from
amd_uncore_init I immediately return  -ENODEV?

On Tue, Jun 10, 2014 at 4:22 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Jun 10, 2014 at 03:37:38PM +0800, Zhouyi Zhou wrote:
>
> Less typing more thinking, this is wrong. You should fail when the
> allocation fails.

Re: [PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[Peter Zijlstra]

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On Tue, Jun 10, 2014 at 04:45:46PM +0800, Zhouyi Zhou wrote:
> Thanks Peter for reviewing, and sorry for not think it thoroughly
> before submitting.
> Is that ok that when amd_uncore_cpu_up_prepare is called from
> amd_uncore_cpu_notifier
> I return notifier_from_errno(-ENOMEM), and  when
> amd_uncore_cpu_up_prepare is called from
> amd_uncore_init I immediately return  -ENODEV?

That sounds about right. Thanks!

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[PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled

[Zhouyi Zhou]

Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
---
 arch/x86/kernel/cpu/perf_event_amd_uncore.c |   32 +++++++++++++++------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
index 3bbdf4c..f60a50e 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
@@ -300,24 +300,28 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
 
 	if (amd_uncore_nb) {
 		uncore = amd_uncore_alloc(cpu);
-		uncore->cpu = cpu;
-		uncore->num_counters = NUM_COUNTERS_NB;
-		uncore->rdpmc_base = RDPMC_BASE_NB;
-		uncore->msr_base = MSR_F15H_NB_PERF_CTL;
-		uncore->active_mask = &amd_nb_active_mask;
-		uncore->pmu = &amd_nb_pmu;
-		*per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
+		if (uncore) {
+			uncore->cpu = cpu;
+			uncore->num_counters = NUM_COUNTERS_NB;
+			uncore->rdpmc_base = RDPMC_BASE_NB;
+			uncore->msr_base = MSR_F15H_NB_PERF_CTL;
+			uncore->active_mask = &amd_nb_active_mask;
+			uncore->pmu = &amd_nb_pmu;
+			*per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
+		}
 	}
 
 	if (amd_uncore_l2) {
 		uncore = amd_uncore_alloc(cpu);
-		uncore->cpu = cpu;
-		uncore->num_counters = NUM_COUNTERS_L2;
-		uncore->rdpmc_base = RDPMC_BASE_L2;
-		uncore->msr_base = MSR_F16H_L2I_PERF_CTL;
-		uncore->active_mask = &amd_l2_active_mask;
-		uncore->pmu = &amd_l2_pmu;
-		*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
+		if (uncore) {
+			uncore->cpu = cpu;
+			uncore->num_counters = NUM_COUNTERS_L2;
+			uncore->rdpmc_base = RDPMC_BASE_L2;
+			uncore->msr_base = MSR_F16H_L2I_PERF_CTL;
+			uncore->active_mask = &amd_l2_active_mask;
+			uncore->pmu = &amd_l2_pmu;
+			*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
+		}
 	}
 }
 
-- 
1.7.10.4