6.10-stable review patch. If anyone has any objections, please let me know.
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From: Junhao He hejunhao3@huawei.com
[ Upstream commit dd9a426eade634bf794c7e0f1b0c6659f556942f ]
In the previous loop, all the members in the aliases[j-1] have been freed and set to NULL. But in this loop, the function pmu_alias_is_duplicate() compares the aliases[j] with the aliases[j-1] that has already been disposed, so the function will always return false and duplicate aliases will never be discarded.
If we find duplicate aliases, it skips the zfree aliases[j], which is accompanied by a memory leak.
We can use the next aliases[j+1] to theck for duplicate aliases to fixes the aliases NULL pointer dereference, then goto zfree code snippet to release it.
After patch testing: $ perf list --unit=hisi_sicl,cpa pmu
uncore cpa: cpa_p0_rd_dat_32b [Number of read ops transmitted by the P0 port which size is 32 bytes. Unit: hisi_sicl,cpa] cpa_p0_rd_dat_64b [Number of read ops transmitted by the P0 port which size is 64 bytes. Unit: hisi_sicl,cpa]
Fixes: c3245d2093c1 ("perf pmu: Abstract alias/event struct") Signed-off-by: Junhao He hejunhao3@huawei.com Cc: ravi.bangoria@amd.com Cc: james.clark@arm.com Cc: prime.zeng@hisilicon.com Cc: cuigaosheng1@huawei.com Cc: jonathan.cameron@huawei.com Cc: linuxarm@huawei.com Cc: yangyicong@huawei.com Cc: robh@kernel.org Cc: renyu.zj@linux.alibaba.com Cc: kjain@linux.ibm.com Cc: john.g.garry@oracle.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Namhyung Kim namhyung@kernel.org Link: https://lore.kernel.org/r/20240614094318.11607-1-hejunhao3@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/pmus.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c index b9b4c5eb50027..6907e3e7fbd16 100644 --- a/tools/perf/util/pmus.c +++ b/tools/perf/util/pmus.c @@ -477,8 +477,8 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p qsort(aliases, len, sizeof(struct sevent), cmp_sevent); for (int j = 0; j < len; j++) { /* Skip duplicates */ - if (j > 0 && pmu_alias_is_duplicate(&aliases[j], &aliases[j - 1])) - continue; + if (j < len - 1 && pmu_alias_is_duplicate(&aliases[j], &aliases[j + 1])) + goto free;
print_cb->print_event(print_state, aliases[j].pmu_name, @@ -491,6 +491,7 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p aliases[j].desc, aliases[j].long_desc, aliases[j].encoding_desc); +free: zfree(&aliases[j].name); zfree(&aliases[j].alias); zfree(&aliases[j].scale_unit);