From dcd45b376d0ab07b987fa968a01e7a5b0c4bf837 Mon Sep 17 00:00:00 2001 From: Ian Rogers <irogers@google.com> Date: Fri, 2 Feb 2024 15:40:51 -0800 Subject: [PATCH] libperf cpumap: Ensure empty cpumap is NULL from alloc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Potential corner cases could cause a cpumap to be allocated with size 0, but an empty cpumap should be represented as NULL. Add a path in perf_cpu_map__alloc() to ensure this. Suggested-by: James Clark <james.clark@arm.com> Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: André Almeida <andrealmeid@igalia.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Atish Patra <atishp@rivosinc.com> Cc: Changbin Du <changbin.du@huawei.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paran Lee <p4ranlee@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Steinar H. Gunderson <sesse@google.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yang Jihong <yangjihong1@huawei.com> Cc: Yang Li <yang.lee@linux.alibaba.com> Cc: Yanteng Si <siyanteng@loongson.cn> Closes: https://lore.kernel.org/lkml/2cd09e7c-eb88-6726-6169-647dcd0a8101@arm.com/ Link: https://lore.kernel.org/r/20240202234057.2085863-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/lib/perf/cpumap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index ba49552952c5..cae799ad44e1 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -18,9 +18,13 @@ void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus) { - RC_STRUCT(perf_cpu_map) *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * 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); if (ADD_RC_CHK(result, cpus)) { cpus->nr = nr_cpus; refcount_set(&cpus->refcnt, 1); -- 2.30.9