Hi Arnaldo,
On 4/25/25 23:16, Arnaldo Carvalho de Melo wrote:
On Fri, Apr 25, 2025 at 08:19:02PM +0530, Athira Rajeev wrote:
On 14 Apr 2025, at 7:08 AM, Madhavan Srinivasan<ma...@linux.ibm.com> wrote:
On 4/7/25 5:38 PM, Venkat Rao Bagalkote wrote:
On 07/04/25 12:10 am, Athira Rajeev wrote:
On 6 Apr 2025, at 10:04 PM, Likhitha Korrapati<likhi...@linux.ibm.com> wrote:
perf build break observed when using gcc 13-3 (FC39 ppc64le)
with the following error.
cpumap.c: In function 'perf_cpu_map__merge':
cpumap.c:414:20: error: argument 1 range [18446744069414584320,
18446744073709551614] exceeds maximum object size 9223372036854775807
[-Werror=alloc-size-larger-than=]
414 | tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from cpumap.c:4:
/usr/include/stdlib.h:672:14: note: in a call to allocation function 'malloc'
declared here
672 | extern void *malloc (size_t __size) __THROW __attribute_malloc__
| ^~~~~~
cc1: all warnings being treated as errors
Error happens to be only in gcc13-3 and not in latest gcc 14.
Even though git-bisect pointed bad commit as:
'commit f5b07010c13c ("libperf: Don't remove -g when EXTRA_CFLAGS are used")',
issue is with tmp_len being "int". It holds number of cpus and making
it "unsigned int" fixes the issues.
After the fix:
CC util/pmu-flex.o
CC util/expr-flex.o
LD util/perf-util-in.o
LD perf-util-in.o
AR libperf-util.a
LINK perf
GEN python/perf.cpython-312-powerpc64le-linux-gnu.so
Signed-off-by: Likhitha Korrapati<likhi...@linux.ibm.com>
Looks good to me
Reviewed-by: Athira Rajeev<atraj...@linux.ibm.com>
Tested this patch on perf-tools-next repo, and this patch fixes the issue.
Tested-by: Venkat Rao Bagalkote<venka...@linux.ibm.com>
Arnaldo, Namhyung,
can you consider pulling this fix? since it is breaking the build in gcc13-3 or
if you have any comments do let us know.
This isn't the only place in that file where this pattern exists:
⬢ [acme@toolbx perf-tools-next]$ grep malloc tools/lib/perf/cpumap.c
cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
⬢ [acme@toolbx perf-tools-next]$
struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
{
RC_STRUCT(perf_cpu_map) *cpus;
struct perf_cpu_map *result;
if (nr_cpus == 0)
return NULL;
cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
{
struct perf_cpu *tmp_cpus;
int tmp_len;
int i, j, k;
struct perf_cpu_map *merged;
if (perf_cpu_map__is_subset(*orig, other))
return 0;
if (perf_cpu_map__is_subset(other, *orig)) {
perf_cpu_map__put(*orig);
*orig = perf_cpu_map__get(other);
return 0;
}
tmp_len = __perf_cpu_map__nr(*orig) + __perf_cpu_map__nr(other);
tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
struct perf_cpu_map *other)
{
struct perf_cpu *tmp_cpus;
int tmp_len;
int i, j, k;
struct perf_cpu_map *merged = NULL;
if (perf_cpu_map__is_subset(other, orig))
return perf_cpu_map__get(orig);
if (perf_cpu_map__is_subset(orig, other))
return perf_cpu_map__get(other);
tmp_len = max(__perf_cpu_map__nr(orig), __perf_cpu_map__nr(other));
tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
I'm trying to figure out why its only in perf_cpu_map__merge() that this
triggers :-\
Maybe that max() call in perf_cpu_map__intersect() somehow makes the
compiler happy.
And in perf_cpu_map__alloc() all calls seems to validate it.
But wouldn't turning this into a calloc() be better?
I have tried using calloc() instead of malloc() and the issue still
exists even using calloc(). cpumap.c: In function ‘perf_cpu_map__merge’:
cpumap.c:414:20: error: argument 1 range [18446744071562067968,
18446744073709551615] exceeds maximum object size 9223372036854775807
[-Werror=alloc-size-larger-than=]
414 | tmp_cpus = calloc(tmp_len , sizeof(struct perf_cpu));
Like:
diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c
index 4454a5987570cfbc..99d21618a252ac0e 100644
--- a/tools/lib/perf/cpumap.c
+++ b/tools/lib/perf/cpumap.c
@@ -411,7 +411,7 @@ int perf_cpu_map__merge(struct perf_cpu_map **orig, struct
perf_cpu_map *other)
}
tmp_len = __perf_cpu_map__nr(*orig) + __perf_cpu_map__nr(other);
- tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
+ tmp_cpus = calloc(tmp_len, sizeof(struct perf_cpu));
if (!tmp_cpus)
return -ENOMEM;
⬢ [acme@toolbx perf-tools-next]$
And better, do the max size that the compiler is trying to help us
catch?
- Arnaldo
I have tried using max and it compiles with that. I am doing testing
with this change and will be posting a V2.
Thanks
Likhitha.
