| Message ID | 20240829090034.15777-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [-fixes,v2] drivers: perf: Fix smp_processor_id() use in preemptible code | expand |
On 8/29/24 2:00 AM, Alexandre Ghiti wrote: > As reported in [1], the use of smp_processor_id() in > pmu_sbi_device_probe() must be protected by disabling the preemption, so > simply use get_cpu()/put_cpu() instead. > > Reported-by: Andrea Parri <parri.andrea@gmail.com> > Reported-by: Nam Cao <namcao@linutronix.de> > Closes: https://lore.kernel.org/linux-riscv/20240820074925.ReMKUPP3@linutronix.de/ [1] > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > --- > > Changes in v2: > - Do not disable the preemption in static_key_enable() (Will) > > drivers/perf/riscv_pmu_sbi.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > index 31a17a56eb3b..febd8e74a72f 100644 > --- a/drivers/perf/riscv_pmu_sbi.c > +++ b/drivers/perf/riscv_pmu_sbi.c > @@ -1373,11 +1373,16 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) > > /* SBI PMU Snapsphot is only available in SBI v2.0 */ > if (sbi_v2_available) { > + int cpu; > + > ret = pmu_sbi_snapshot_alloc(pmu); > if (ret) > goto out_unregister; > > - ret = pmu_sbi_snapshot_setup(pmu, smp_processor_id()); > + cpu = get_cpu(); > + ret = pmu_sbi_snapshot_setup(pmu, cpu); > + put_cpu(); > + > if (ret) { > /* Snapshot is an optional feature. Continue if not available */ > pmu_sbi_snapshot_free(pmu); Reviewed-by: Atish Patra <atishp@rivosinc.com>
On Thu, Aug 29, 2024 at 11:00:34AM +0200, Alexandre Ghiti wrote: > As reported in [1], the use of smp_processor_id() in > pmu_sbi_device_probe() must be protected by disabling the preemption, so > simply use get_cpu()/put_cpu() instead. > > Reported-by: Andrea Parri <parri.andrea@gmail.com> > Reported-by: Nam Cao <namcao@linutronix.de> > Closes: https://lore.kernel.org/linux-riscv/20240820074925.ReMKUPP3@linutronix.de/ [1] > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Nam Cao <namcao@linutronix.de> Best regards, Nam
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 31a17a56eb3b..febd8e74a72f 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -1373,11 +1373,16 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) /* SBI PMU Snapsphot is only available in SBI v2.0 */ if (sbi_v2_available) { + int cpu; + ret = pmu_sbi_snapshot_alloc(pmu); if (ret) goto out_unregister; - ret = pmu_sbi_snapshot_setup(pmu, smp_processor_id()); + cpu = get_cpu(); + ret = pmu_sbi_snapshot_setup(pmu, cpu); + put_cpu(); + if (ret) { /* Snapshot is an optional feature. Continue if not available */ pmu_sbi_snapshot_free(pmu);
As reported in [1], the use of smp_processor_id() in pmu_sbi_device_probe() must be protected by disabling the preemption, so simply use get_cpu()/put_cpu() instead. Reported-by: Andrea Parri <parri.andrea@gmail.com> Reported-by: Nam Cao <namcao@linutronix.de> Closes: https://lore.kernel.org/linux-riscv/20240820074925.ReMKUPP3@linutronix.de/ [1] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- Changes in v2: - Do not disable the preemption in static_key_enable() (Will) drivers/perf/riscv_pmu_sbi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)