From d06e5fad8c4692c6e5f1bd626056f23716bfe4a6 Mon Sep 17 00:00:00 2001 From: Igor Lubashev Date: Mon, 26 Aug 2019 21:39:16 -0400 Subject: [PATCH] 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 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/1566869956-7154-6-git-send-email-ilubashe@akamai.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 2 +- tools/perf/builtin-top.c | 2 +- tools/perf/builtin-trace.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 359bb8f..afe5584 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -2372,7 +2372,7 @@ int cmd_record(int argc, const char **argv) if (symbol_conf.kptr_restrict && !perf_evlist__exclude_kernel(rec->evlist)) pr_warning( "WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n" -"check /proc/sys/kernel/kptr_restrict.\n\n" +"check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid.\n\n" "Samples in kernel functions may not be resolved if a suitable vmlinux\n" "file is not found in the buildid cache or in the vmlinux path.\n\n" "Samples in kernel modules won't be resolved at all.\n\n" diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 5970723..29e910f 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -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" : ""); diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 8ea62fd..58a75dd 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1382,7 +1382,7 @@ static char *trace__machine__resolve_kernel_addr(void *vmachine, unsigned long l if (symbol_conf.kptr_restrict) { pr_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 samples will not be resolved.\n"); machine->kptr_restrict_warned = true; return NULL; -- 2.7.4