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Subject[PATCH 5/5] perf: warn that perf_event_paranoid can restrict kernel symbols
Date
Warn that /proc/sys/kernel/perf_event_paranoid can also restrict kernel
symbols.

Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
---
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 f71631f2bcb5..18505d92ff69 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 bc44ed29e05a..9443b8e05810 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1381,7 +1381,7 @@ 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
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