6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
[ 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@xxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20240827125335.GD4772@willie-the-truck/ [1]
Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241112113422.617954-1-alexghiti@xxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
--
2.43.0
