Perf gets the number of supported counters from SBI. If it happens that
the number of returned counters more than RISCV_MAX_COUNTERS the code
trusts it. It does not lead to an immediate problem but can potentially
lead to it. Prevent getting more than RISCV_MAX_COUNTERS from SBI.
Signed-off-by: Viacheslav Mitrofanov <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Reviewed-by: Atish Patra <[email protected]>
---
Chnages in v3:
- Detail the output
Changes in v2:
- Add new line
- Substitute pr_warn for pr_info
drivers/perf/riscv_pmu_sbi.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 70cb50fd41c2..7bf494930e92 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -868,6 +868,12 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
goto out_free;
}
+ /* It is possible to get from SBI more than max number of counters */
+ if (num_counters > RISCV_MAX_COUNTERS) {
+ num_counters = RISCV_MAX_COUNTERS;
+ pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters);
+ }
+
/* cache all the information about counters now */
if (pmu_sbi_get_ctrinfo(num_counters, &cmask))
goto out_free;
--
2.37.2
On Fri, 05 May 2023 07:20:57 +0000, Viacheslav Mitrofanov wrote:
> Perf gets the number of supported counters from SBI. If it happens that
> the number of returned counters more than RISCV_MAX_COUNTERS the code
> trusts it. It does not lead to an immediate problem but can potentially
> lead to it. Prevent getting more than RISCV_MAX_COUNTERS from SBI.
>
>
Applied, thanks!
[1/1] perf: RISC-V: Limit the number of counters returned from SBI
https://git.kernel.org/palmer/c/ee95b88d71b9
Best regards,
--
Palmer Dabbelt <[email protected]>
Hello:
This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <[email protected]>:
On Fri, 5 May 2023 07:20:57 +0000 you wrote:
> Perf gets the number of supported counters from SBI. If it happens that
> the number of returned counters more than RISCV_MAX_COUNTERS the code
> trusts it. It does not lead to an immediate problem but can potentially
> lead to it. Prevent getting more than RISCV_MAX_COUNTERS from SBI.
>
> Signed-off-by: Viacheslav Mitrofanov <[email protected]>
> Reviewed-by: Andrew Jones <[email protected]>
> Reviewed-by: Atish Patra <[email protected]>
>
> [...]
Here is the summary with links:
- [v3,1/1] perf: RISC-V: Limit the number of counters returned from SBI
https://git.kernel.org/riscv/c/ee95b88d71b9
You are awesome, thank you!
--
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