6.10-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ghiti alexghiti@rivosinc.com
[ Upstream commit 2840dadf0dde92638d13b97998026c5fcddbdceb ]
As reported in [1], the use of smp_processor_id() in pmu_sbi_device_probe() must be protected by disabling the preemption, so simple use get_cpu()/put_cpu() instead.
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 Reviewed-by: Anup Patel anup@brainfault.org Tested-by: Nam Cao namcao@linutronix.de Fixes: a8625217a054 ("drivers/perf: riscv: Implement SBI PMU snapshot function") Reported-by: Andrea Parri parri.andrea@gmail.com Tested-by: Andrea Parri parri.andrea@gmail.com Link: https://lore.kernel.org/r/20240826165210.124696-1-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 | 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 11c7c85047ed..765bda7924f7 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -1368,11 +1368,15 @@ 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); if (ret) { /* Snapshot is an optional feature. Continue if not available */ pmu_sbi_snapshot_free(pmu); @@ -1386,6 +1390,7 @@ 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);