From: Alexandre Ghiti Date: Tue, 12 Nov 2024 11:34:22 +0000 (+0100) Subject: drivers: perf: Fix wrong put_cpu() placement X-Git-Tag: v6.12~6^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57f7c7dc78cd09622b12920d92b40c1ce11b234e;p=thirdparty%2Fkernel%2Flinux.git drivers: perf: Fix wrong put_cpu() placement 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 Link: https://lore.kernel.org/all/20240827125335.GD4772@willie-the-truck/ [1] Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20241112113422.617954-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt --- diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 391ca1422caec..1aa303f76cc7a 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);