| Message ID | 20241112113422.617954-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [-fixes] drivers: perf: Fix wrong put_cpu() placement | expand |
On Tue, Nov 12, 2024 at 3:34 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > Unfortunately, the wrong patch version was merged which places the > put_cpu() after enabling a static key, which is not safe as pointed by > Will [1], so move put_cpu() before to avoid this. > > Fixes: 2840dadf0dde ("drivers: perf: Fix smp_processor_id() use in preemptible code") > Reported-by: Atish Patra <atishp@rivosinc.com> > Link: https://lore.kernel.org/all/20240827125335.GD4772@willie-the-truck/ [1] > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > --- > drivers/perf/riscv_pmu_sbi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > index 391ca1422cae..1aa303f76cc7 100644 > --- a/drivers/perf/riscv_pmu_sbi.c > +++ b/drivers/perf/riscv_pmu_sbi.c > @@ -1393,8 +1393,9 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) > goto out_unregister; > > 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); > @@ -1408,7 +1409,6 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) > */ > static_branch_enable(&sbi_pmu_snapshot_available); > } > - put_cpu(); > } > > register_sysctl("kernel", sbi_pmu_sysctl_table); > -- > 2.39.2 > Reviewed-by: Atish Patra <atishp@rivosinc.com> Tested-by: Atish Patra <atishp@rivosinc.com>
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Tue, 12 Nov 2024 12:34:22 +0100 you wrote: > Unfortunately, the wrong patch version was merged which places the > put_cpu() after enabling a static key, which is not safe as pointed by > Will [1], so move put_cpu() before to avoid this. > > Fixes: 2840dadf0dde ("drivers: perf: Fix smp_processor_id() use in preemptible code") > Reported-by: Atish Patra <atishp@rivosinc.com> > Link: https://lore.kernel.org/all/20240827125335.GD4772@willie-the-truck/ [1] > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > [...] Here is the summary with links: - [-fixes] drivers: perf: Fix wrong put_cpu() placement https://git.kernel.org/riscv/c/57f7c7dc78cd You are awesome, thank you!
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 391ca1422cae..1aa303f76cc7 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -1393,8 +1393,9 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) goto out_unregister; 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); @@ -1408,7 +1409,6 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) */ static_branch_enable(&sbi_pmu_snapshot_available); } - put_cpu(); } register_sysctl("kernel", sbi_pmu_sysctl_table);
Unfortunately, the wrong patch version was merged which places the put_cpu() after enabling a static key, which is not safe as pointed by Will [1], so move put_cpu() before to avoid this. Fixes: 2840dadf0dde ("drivers: perf: Fix smp_processor_id() use in preemptible code") Reported-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/all/20240827125335.GD4772@willie-the-truck/ [1] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- drivers/perf/riscv_pmu_sbi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)