From 0fb0d615f310410502f7eac3b241374fbe8d9be8 Mon Sep 17 00:00:00 2001 From: Ian Rogers <irogers@google.com> Date: Sat, 30 May 2020 01:20:15 -0700 Subject: [PATCH] perf test: Initialize memory in dwarf-unwind Avoid a false positive caused by assembly code in arch/x86. In tests, zero the perf_event to avoid uninitialized memory uses. Warnings were caught using clang with -fsanitize=memory. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Monnet <quentin@isovalent.com> Cc: Stephane Eranian <eranian@google.com> Cc: clang-built-linux@googlegroups.com Link: http://lore.kernel.org/lkml/20200530082015.39162-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/arch/x86/tests/dwarf-unwind.c | 8 ++++++++ tools/perf/tests/dwarf-unwind.c | 1 + 2 files changed, 9 insertions(+) diff --git a/tools/perf/arch/x86/tests/dwarf-unwind.c b/tools/perf/arch/x86/tests/dwarf-unwind.c index ef43be9b6ec27..4e40402a4f81c 100644 --- a/tools/perf/arch/x86/tests/dwarf-unwind.c +++ b/tools/perf/arch/x86/tests/dwarf-unwind.c @@ -55,6 +55,14 @@ int test__arch_unwind_sample(struct perf_sample *sample, return -1; } +#ifdef MEMORY_SANITIZER + /* + * Assignments to buf in the assembly function perf_regs_load aren't + * seen by memory sanitizer. Zero the memory to convince memory + * sanitizer the memory is initialized. + */ + memset(buf, 0, sizeof(u64) * PERF_REGS_MAX); +#endif perf_regs_load(buf); regs->abi = PERF_SAMPLE_REGS_ABI; regs->regs = buf; diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c index 2a0dac81f44c1..2491d167bf764 100644 --- a/tools/perf/tests/dwarf-unwind.c +++ b/tools/perf/tests/dwarf-unwind.c @@ -37,6 +37,7 @@ static int init_live_machine(struct machine *machine) union perf_event event; pid_t pid = getpid(); + memset(&event, 0, sizeof(event)); return perf_event__synthesize_mmap_events(NULL, &event, pid, pid, mmap_handler, machine, true); } -- 2.30.2