From: Igor Lubashev <[email protected]>

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

Signed-off-by: Igor Lubashev <[email protected]>
Tested-by: Mathieu Poirier <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexey Budankov <[email protected]>
Cc: James Morris <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: [email protected]
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 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 359bb8f33e57..afe558449677 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 5970723cd55a..29e910fb2d9a 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 8ea62fd2591d..58a75dd3a571 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;
-- 
2.21.0

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