From: Dawei Li <dawei.li@shingroup.cn> To: will@kernel.org, mark.rutland@arm.com Cc: xueshuai@linux.alibaba.com, renyu.zj@linux.alibaba.com, yangyicong@hisilicon.com, jonathan.cameron@huawei.com, andersson@kernel.org, konrad.dybcio@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Dawei Li <dawei.li@shingroup.cn> Subject: [PATCH 4/9] perf/arm_dsu: Avoid explicit cpumask var allocation from stack Date: Tue, 2 Apr 2024 18:56:05 +0800 [thread overview] Message-ID: <20240402105610.1695644-5-dawei.li@shingroup.cn> (raw) In-Reply-To: <20240402105610.1695644-1-dawei.li@shingroup.cn> For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask variable on stack is not recommended since it can cause potential stack overflow. Instead, kernel code should always use *cpumask_var API(s) to allocate cpumask var in config- neutral way, leaving allocation strategy to CONFIG_CPUMASK_OFFSTACK. Use *cpumask_var API(s) to address it. Signed-off-by: Dawei Li <dawei.li@shingroup.cn> --- drivers/perf/arm_dsu_pmu.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c index bae3ca37f846..87efdca05807 100644 --- a/drivers/perf/arm_dsu_pmu.c +++ b/drivers/perf/arm_dsu_pmu.c @@ -230,13 +230,21 @@ static const struct attribute_group *dsu_pmu_attr_groups[] = { NULL, }; -static int dsu_pmu_get_online_cpu_any_but(struct dsu_pmu *dsu_pmu, int cpu) +static unsigned int dsu_pmu_get_online_cpu_any_but(struct dsu_pmu *dsu_pmu, int cpu) { - struct cpumask online_supported; + cpumask_var_t online_supported; + unsigned int ret; - cpumask_and(&online_supported, - &dsu_pmu->associated_cpus, cpu_online_mask); - return cpumask_any_but(&online_supported, cpu); + if (!alloc_cpumask_var(&online_supported, GFP_KERNEL)) + return -ENOMEM; + + cpumask_and(online_supported, + &dsu_pmu->associated_cpus, cpu_online_mask); + ret = cpumask_any_but(&online_supported, cpu); + + free_cpumask_var(online_supported); + + return ret; } static inline bool dsu_pmu_counter_valid(struct dsu_pmu *dsu_pmu, u32 idx) -- 2.27.0
WARNING: multiple messages have this Message-ID (diff)
From: Dawei Li <dawei.li@shingroup.cn> To: will@kernel.org, mark.rutland@arm.com Cc: xueshuai@linux.alibaba.com, renyu.zj@linux.alibaba.com, yangyicong@hisilicon.com, jonathan.cameron@huawei.com, andersson@kernel.org, konrad.dybcio@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Dawei Li <dawei.li@shingroup.cn> Subject: [PATCH 4/9] perf/arm_dsu: Avoid explicit cpumask var allocation from stack Date: Tue, 2 Apr 2024 18:56:05 +0800 [thread overview] Message-ID: <20240402105610.1695644-5-dawei.li@shingroup.cn> (raw) In-Reply-To: <20240402105610.1695644-1-dawei.li@shingroup.cn> For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask variable on stack is not recommended since it can cause potential stack overflow. Instead, kernel code should always use *cpumask_var API(s) to allocate cpumask var in config- neutral way, leaving allocation strategy to CONFIG_CPUMASK_OFFSTACK. Use *cpumask_var API(s) to address it. Signed-off-by: Dawei Li <dawei.li@shingroup.cn> --- drivers/perf/arm_dsu_pmu.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c index bae3ca37f846..87efdca05807 100644 --- a/drivers/perf/arm_dsu_pmu.c +++ b/drivers/perf/arm_dsu_pmu.c @@ -230,13 +230,21 @@ static const struct attribute_group *dsu_pmu_attr_groups[] = { NULL, }; -static int dsu_pmu_get_online_cpu_any_but(struct dsu_pmu *dsu_pmu, int cpu) +static unsigned int dsu_pmu_get_online_cpu_any_but(struct dsu_pmu *dsu_pmu, int cpu) { - struct cpumask online_supported; + cpumask_var_t online_supported; + unsigned int ret; - cpumask_and(&online_supported, - &dsu_pmu->associated_cpus, cpu_online_mask); - return cpumask_any_but(&online_supported, cpu); + if (!alloc_cpumask_var(&online_supported, GFP_KERNEL)) + return -ENOMEM; + + cpumask_and(online_supported, + &dsu_pmu->associated_cpus, cpu_online_mask); + ret = cpumask_any_but(&online_supported, cpu); + + free_cpumask_var(online_supported); + + return ret; } static inline bool dsu_pmu_counter_valid(struct dsu_pmu *dsu_pmu, u32 idx) -- 2.27.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-04-02 10:58 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-02 10:56 [PATCH 0/9] perf: Avoid explicit cpumask var allocation from stack Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` [PATCH 1/9] perf/alibaba_uncore_drw: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 11:06 ` Mark Rutland 2024-04-02 11:06 ` Mark Rutland 2024-04-02 10:56 ` [PATCH 2/9] perf/arm-cmn: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-05 14:30 ` Robin Murphy 2024-04-05 14:30 ` Robin Murphy 2024-04-02 10:56 ` [PATCH 3/9] perf/arm_cspmu: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` Dawei Li [this message] 2024-04-02 10:56 ` [PATCH 4/9] perf/arm_dsu: " Dawei Li 2024-04-02 23:58 ` kernel test robot 2024-04-02 23:58 ` kernel test robot 2024-04-03 1:43 ` kernel test robot 2024-04-03 1:43 ` kernel test robot 2024-04-02 10:56 ` [PATCH 5/9] perf/dwc_pcie: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` [PATCH 6/9] perf/hisi_pcie: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` [PATCH 7/9] perf/hisi_uncore: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` [PATCH 8/9] perf/qcom_l2: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 10:56 ` [PATCH 9/9] perf/thunder_x2: " Dawei Li 2024-04-02 10:56 ` Dawei Li 2024-04-02 11:12 ` [PATCH 0/9] perf: " Mark Rutland 2024-04-02 11:12 ` Mark Rutland 2024-04-02 13:40 ` Dawei Li 2024-04-02 13:40 ` Dawei Li 2024-04-02 14:41 ` Mark Rutland 2024-04-02 14:41 ` Mark Rutland 2024-04-03 10:41 ` Dawei Li 2024-04-03 10:41 ` Dawei Li 2024-04-03 11:10 ` Mark Rutland 2024-04-03 11:10 ` Mark Rutland
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