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drivers: perf: Fix smp_processor_id() use in preemptible code

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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: a8625217a0 ("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>
This commit is contained in:
Alexandre Ghiti 2024-08-26 18:52:10 +02:00 committed by Palmer Dabbelt
parent 1ff95eb2be
commit 2840dadf0d
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GPG Key ID: 2E1319F35FBB1889
1 changed files with 6 additions and 1 deletions
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7
drivers/perf/riscv_pmu_sbi.c
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@ -1373,11 +1373,15 @@ 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);
@ -1391,6 +1395,7 @@ 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);