From e9a6882f267a8105461066e3ea6b4b6b9be1b807 Mon Sep 17 00:00:00 2001 From: Igor Lubashev Date: Mon, 26 Aug 2019 21:39:12 -0400 Subject: [PATCH] perf event: Check ref_reloc_sym before using it Check for ref_reloc_sym before using it instead of checking symbol_conf.kptr_restrict and relying solely on that check. Reported-by: Mathieu Poirier Signed-off-by: Igor Lubashev Tested-by: Mathieu Poirier Cc: Alexander Shishkin Cc: Alexey Budankov Cc: James Morris Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1566869956-7154-2-git-send-email-ilubashe@akamai.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 33616ea..e33dd1a 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -913,11 +913,13 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, int err; union perf_event *event; - if (symbol_conf.kptr_restrict) - return -1; if (map == NULL) return -1; + kmap = map__kmap(map); + if (!kmap->ref_reloc_sym) + return -1; + /* * We should get this from /sys/kernel/sections/.text, but till that is * available use this, and after it is use this as a fallback for older @@ -940,7 +942,6 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL; } - kmap = map__kmap(map); size = snprintf(event->mmap.filename, sizeof(event->mmap.filename), "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1; size = PERF_ALIGN(size, sizeof(u64)); -- 2.7.4