arch/x86/events/amd/uncore.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
Fix the following warning:
CC [M] arch/x86/events/amd/uncore.o
arch/x86/events/amd/uncore.c: In function ‘amd_uncore_umc_ctx_init’:
arch/x86/events/amd/uncore.c:951:52: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=]
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~
arch/x86/events/amd/uncore.c:951:43: note: directive argument in the range [0, 2147483647]
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~~~~~~~~~~~
arch/x86/events/amd/uncore.c:951:4: note: ‘snprintf’ output between 10 and 19 bytes into a destination of size 16
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As far as I can see, there can't be more than UNCORE_GROUP_MAX (256)
groups and each group can't have more than 255 PMU, so the number
printed by this %d can't exceed 65279, that's only 5 digits and would
fit into the buffer. So it's a false positive warning. But we can
make the compiler happy by declaring index as a 16-bit number.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
---
Changes in v2:
* Use the proper printf conversion specifier, to be on the safe side.
An alternative fix would be to extend UNCORE_NAME_LEN to 20, the
downside being an increased memory consumption. Depends whether we
expect UNCORE_GROUP_MAX to ever be increased, or groups to ever
support more than 255 PMU.
arch/x86/events/amd/uncore.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- linux-6.12-rc6.orig/arch/x86/events/amd/uncore.c
+++ linux-6.12-rc6/arch/x86/events/amd/uncore.c
@@ -916,7 +916,8 @@ int amd_uncore_umc_ctx_init(struct amd_u
u8 group_num_pmcs[UNCORE_GROUP_MAX] = { 0 };
union amd_uncore_info info;
struct amd_uncore_pmu *pmu;
- int index = 0, gid, i;
+ int gid, i;
+ u16 index = 0;
if (pmu_version < 2)
return 0;
@@ -948,7 +949,7 @@ int amd_uncore_umc_ctx_init(struct amd_u
for_each_set_bit(gid, gmask, UNCORE_GROUP_MAX) {
for (i = 0; i < group_num_pmus[gid]; i++) {
pmu = &uncore->pmus[index];
- snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
+ snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%hu", index);
pmu->num_counters = group_num_pmcs[gid] / group_num_pmus[gid];
pmu->msr_base = MSR_F19H_UMC_PERF_CTL + i * pmu->num_counters * 2;
pmu->rdpmc_base = -1;
--
Jean Delvare
SUSE L3 SupportOn 11/5/2024 2:22 PM, Jean Delvare wrote: > Fix the following warning: > CC [M] arch/x86/events/amd/uncore.o > arch/x86/events/amd/uncore.c: In function ‘amd_uncore_umc_ctx_init’: > arch/x86/events/amd/uncore.c:951:52: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=] > snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index); > ^~ > arch/x86/events/amd/uncore.c:951:43: note: directive argument in the range [0, 2147483647] > snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index); > ^~~~~~~~~~~~ > arch/x86/events/amd/uncore.c:951:4: note: ‘snprintf’ output between 10 and 19 bytes into a destination of size 16 > snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > As far as I can see, there can't be more than UNCORE_GROUP_MAX (256) > groups and each group can't have more than 255 PMU, so the number > printed by this %d can't exceed 65279, that's only 5 digits and would > fit into the buffer. So it's a false positive warning. But we can > make the compiler happy by declaring index as a 16-bit number. > > Signed-off-by: Jean Delvare <jdelvare@suse.de> > --- > Changes in v2: > * Use the proper printf conversion specifier, to be on the safe side. > > An alternative fix would be to extend UNCORE_NAME_LEN to 20, the > downside being an increased memory consumption. Depends whether we > expect UNCORE_GROUP_MAX to ever be increased, or groups to ever > support more than 255 PMU. > Its very unlikely for UNCORE_GROUP_MAX to change and the current solution looks good to me. Reviewed-by: Sandipan Das <sandipan.das@amd.com>
The following commit has been merged into the perf/core branch of tip:
Commit-ID: 2e71e8bc6f02275a67bcb882779ab6d21abc68c4
Gitweb: https://git.kernel.org/tip/2e71e8bc6f02275a67bcb882779ab6d21abc68c4
Author: Jean Delvare <jdelvare@suse.de>
AuthorDate: Tue, 05 Nov 2024 09:52:53 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 11 Nov 2024 11:49:47 +01:00
perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
Fix the following warning:
CC [M] arch/x86/events/amd/uncore.o
arch/x86/events/amd/uncore.c: In function ‘amd_uncore_umc_ctx_init’:
arch/x86/events/amd/uncore.c:951:52: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 8 [-Wformat-truncation=]
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~
arch/x86/events/amd/uncore.c:951:43: note: directive argument in the range [0, 2147483647]
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~~~~~~~~~~~
arch/x86/events/amd/uncore.c:951:4: note: ‘snprintf’ output between 10 and 19 bytes into a destination of size 16
snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As far as I can see, there can't be more than UNCORE_GROUP_MAX (256)
groups and each group can't have more than 255 PMU, so the number
printed by this %d can't exceed 65279, that's only 5 digits and would
fit into the buffer. So it's a false positive warning. But we can
make the compiler happy by declaring index as a 16-bit number.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20241105095253.18f34b4d@endymion.delvare
---
arch/x86/events/amd/uncore.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 0bfde2e..49c26ce 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -916,7 +916,8 @@ int amd_uncore_umc_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
u8 group_num_pmcs[UNCORE_GROUP_MAX] = { 0 };
union amd_uncore_info info;
struct amd_uncore_pmu *pmu;
- int index = 0, gid, i;
+ int gid, i;
+ u16 index = 0;
if (pmu_version < 2)
return 0;
@@ -948,7 +949,7 @@ int amd_uncore_umc_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
for_each_set_bit(gid, gmask, UNCORE_GROUP_MAX) {
for (i = 0; i < group_num_pmus[gid]; i++) {
pmu = &uncore->pmus[index];
- snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%d", index);
+ snprintf(pmu->name, sizeof(pmu->name), "amd_umc_%hu", index);
pmu->num_counters = group_num_pmcs[gid] / group_num_pmus[gid];
pmu->msr_base = MSR_F19H_UMC_PERF_CTL + i * pmu->num_counters * 2;
pmu->rdpmc_base = -1;© 2016 - 2024 Red Hat, Inc.