perf tools: Warn that perf_event_paranoid can restrict kernel symbols

Warn that /proc/sys/kernel/perf_event_paranoid can also restrict kernel
symbols.

Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1566869956-7154-6-git-send-email-ilubashe@akamai.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Igor Lubashev
2019-08-26 21:39:16 -04:00
committed by Arnaldo Carvalho de Melo
parent 8859aedefe
commit d06e5fad8c
3 changed files with 3 additions and 3 deletions

View File

@@ -770,7 +770,7 @@ static void perf_event__process_sample(struct perf_tool *tool,
if (!perf_evlist__exclude_kernel(top->session->evlist)) {
ui__warning(
"Kernel address maps (/proc/{kallsyms,modules}) are restricted.\n\n"
"Check /proc/sys/kernel/kptr_restrict.\n\n"
"Check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid.\n\n"
"Kernel%s samples will not be resolved.\n",
al.map && map__has_symbols(al.map) ?
" modules" : "");