6.11-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ghiti alexghiti@rivosinc.com
[ Upstream commit 57f7c7dc78cd09622b12920d92b40c1ce11b234e ]
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 Link: https://lore.kernel.org/r/20241112113422.617954-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 671dc55cbd3a8..bc562c759e1e9 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -1380,8 +1380,9 @@ 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); @@ -1395,7 +1396,6 @@ 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);