On Wed, 20 Apr 2022 02:31:33 PDT (-0700), [email protected] wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 59250f8a7f3a60a2661b84cbafc1e0eb5d05ec9b
> commit: e9991434596f5373dfd75857b445eb92a9253c56 RISC-V: Add perf platform driver based on SBI PMU extension
> config: riscv-randconfig-m031-20220416 (https://download.01.org/0day-ci/archive/20220416/[email protected]/config)
> compiler: riscv32-linux-gcc (GCC) 11.2.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
>
> smatch warnings:
> drivers/perf/riscv_pmu_sbi.c:464 pmu_sbi_get_ctrinfo() warn: potentially one past the end of array 'pmu_ctr_list[i]'
> drivers/perf/riscv_pmu_sbi.c:464 pmu_sbi_get_ctrinfo() warn: potentially one past the end of array 'pmu_ctr_list[i]'
>
> vim +464 drivers/perf/riscv_pmu_sbi.c
>
> e9991434596f53 Atish Patra 2022-02-18 444 static int pmu_sbi_get_ctrinfo(int nctr)
> e9991434596f53 Atish Patra 2022-02-18 445 {
> e9991434596f53 Atish Patra 2022-02-18 446 struct sbiret ret;
> e9991434596f53 Atish Patra 2022-02-18 447 int i, num_hw_ctr = 0, num_fw_ctr = 0;
> e9991434596f53 Atish Patra 2022-02-18 448 union sbi_pmu_ctr_info cinfo;
> e9991434596f53 Atish Patra 2022-02-18 449
> e9991434596f53 Atish Patra 2022-02-18 450 pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL);
> ^^^^
>
> e9991434596f53 Atish Patra 2022-02-18 451 if (!pmu_ctr_list)
> e9991434596f53 Atish Patra 2022-02-18 452 return -ENOMEM;
> e9991434596f53 Atish Patra 2022-02-18 453
> e9991434596f53 Atish Patra 2022-02-18 454 for (i = 0; i <= nctr; i++) {
> ^^^^^^^^^
> The <= should be <
>
> e9991434596f53 Atish Patra 2022-02-18 455 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
> e9991434596f53 Atish Patra 2022-02-18 456 if (ret.error)
> e9991434596f53 Atish Patra 2022-02-18 457 /* The logical counter ids are not expected to be contiguous */
> e9991434596f53 Atish Patra 2022-02-18 458 continue;
> e9991434596f53 Atish Patra 2022-02-18 459 cinfo.value = ret.value;
> e9991434596f53 Atish Patra 2022-02-18 460 if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
> e9991434596f53 Atish Patra 2022-02-18 461 num_fw_ctr++;
> e9991434596f53 Atish Patra 2022-02-18 462 else
> e9991434596f53 Atish Patra 2022-02-18 463 num_hw_ctr++;
> e9991434596f53 Atish Patra 2022-02-18 @464 pmu_ctr_list[i].value = cinfo.value;
> ^^^^^^^^^^^^^^^
> Off by one
>
> e9991434596f53 Atish Patra 2022-02-18 465 }
> e9991434596f53 Atish Patra 2022-02-18 466
> e9991434596f53 Atish Patra 2022-02-18 467 pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
> e9991434596f53 Atish Patra 2022-02-18 468
> e9991434596f53 Atish Patra 2022-02-18 469 return 0;
> e9991434596f53 Atish Patra 2022-02-18 470 }
I think this should do it
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index a1317a483512..50394ef1adef 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -457,7 +457,7 @@ static int pmu_sbi_get_ctrinfo(int nctr)
if (!pmu_ctr_list)
return -ENOMEM;
- for (i = 0; i <= nctr; i++) {
+ for (i = 0; i < nctr; i++) {
ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
if (ret.error)
/* The logical counter ids are not expected to be contiguous */
but I'm not super familiar with the perf code and there's frequently this
pattern of "0 is reserved as a special value" in the RISC-V specs (interrupt
numbers, for example) so I may be wrong here. IIUC none of that is going on
here, as these are all indirect/non-contiguous, but I'll let Atish take a look.
Thanks!
On Wed, Apr 20, 2022 at 3:38 PM Palmer Dabbelt <[email protected]> wrote:
>
> On Wed, 20 Apr 2022 02:31:33 PDT (-0700), [email protected] wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head: 59250f8a7f3a60a2661b84cbafc1e0eb5d05ec9b
> > commit: e9991434596f5373dfd75857b445eb92a9253c56 RISC-V: Add perf platform driver based on SBI PMU extension
> > config: riscv-randconfig-m031-20220416 (https://download.01.org/0day-ci/archive/20220416/[email protected]/config)
> > compiler: riscv32-linux-gcc (GCC) 11.2.0
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <[email protected]>
> > Reported-by: Dan Carpenter <[email protected]>
> >
> > smatch warnings:
> > drivers/perf/riscv_pmu_sbi.c:464 pmu_sbi_get_ctrinfo() warn: potentially one past the end of array 'pmu_ctr_list[i]'
> > drivers/perf/riscv_pmu_sbi.c:464 pmu_sbi_get_ctrinfo() warn: potentially one past the end of array 'pmu_ctr_list[i]'
> >
> > vim +464 drivers/perf/riscv_pmu_sbi.c
> >
> > e9991434596f53 Atish Patra 2022-02-18 444 static int pmu_sbi_get_ctrinfo(int nctr)
> > e9991434596f53 Atish Patra 2022-02-18 445 {
> > e9991434596f53 Atish Patra 2022-02-18 446 struct sbiret ret;
> > e9991434596f53 Atish Patra 2022-02-18 447 int i, num_hw_ctr = 0, num_fw_ctr = 0;
> > e9991434596f53 Atish Patra 2022-02-18 448 union sbi_pmu_ctr_info cinfo;
> > e9991434596f53 Atish Patra 2022-02-18 449
> > e9991434596f53 Atish Patra 2022-02-18 450 pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL);
> > ^^^^
> >
> > e9991434596f53 Atish Patra 2022-02-18 451 if (!pmu_ctr_list)
> > e9991434596f53 Atish Patra 2022-02-18 452 return -ENOMEM;
> > e9991434596f53 Atish Patra 2022-02-18 453
> > e9991434596f53 Atish Patra 2022-02-18 454 for (i = 0; i <= nctr; i++) {
> > ^^^^^^^^^
> > The <= should be <
> >
> > e9991434596f53 Atish Patra 2022-02-18 455 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
> > e9991434596f53 Atish Patra 2022-02-18 456 if (ret.error)
> > e9991434596f53 Atish Patra 2022-02-18 457 /* The logical counter ids are not expected to be contiguous */
> > e9991434596f53 Atish Patra 2022-02-18 458 continue;
> > e9991434596f53 Atish Patra 2022-02-18 459 cinfo.value = ret.value;
> > e9991434596f53 Atish Patra 2022-02-18 460 if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
> > e9991434596f53 Atish Patra 2022-02-18 461 num_fw_ctr++;
> > e9991434596f53 Atish Patra 2022-02-18 462 else
> > e9991434596f53 Atish Patra 2022-02-18 463 num_hw_ctr++;
> > e9991434596f53 Atish Patra 2022-02-18 @464 pmu_ctr_list[i].value = cinfo.value;
> > ^^^^^^^^^^^^^^^
> > Off by one
> >
> > e9991434596f53 Atish Patra 2022-02-18 465 }
> > e9991434596f53 Atish Patra 2022-02-18 466
> > e9991434596f53 Atish Patra 2022-02-18 467 pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
> > e9991434596f53 Atish Patra 2022-02-18 468
> > e9991434596f53 Atish Patra 2022-02-18 469 return 0;
> > e9991434596f53 Atish Patra 2022-02-18 470 }
>
> I think this should do it
>
> diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
> index a1317a483512..50394ef1adef 100644
> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -457,7 +457,7 @@ static int pmu_sbi_get_ctrinfo(int nctr)
> if (!pmu_ctr_list)
> return -ENOMEM;
>
> - for (i = 0; i <= nctr; i++) {
> + for (i = 0; i < nctr; i++) {
> ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
> if (ret.error)
> /* The logical counter ids are not expected to be contiguous */
>
> but I'm not super familiar with the perf code and there's frequently this
> pattern of "0 is reserved as a special value" in the RISC-V specs (interrupt
> numbers, for example) so I may be wrong here. IIUC none of that is going on
> here, as these are all indirect/non-contiguous, but I'll let Atish take a look.
>
You are right. This was just a typo/oversight on my part. I will send
a fix asap.
> Thanks!