perf top: Handle kptr_restrict
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/n/tip-cyl5zmi1nu35vyu7l5im2pyv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 375ed16..472f627 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -80,6 +80,7 @@
static int default_interval = 0;
+static bool kptr_restrict_warned;
static bool inherit = false;
static int realtime_prio = 0;
static bool group = false;
@@ -738,6 +739,20 @@
al.filtered)
return;
+ if (!kptr_restrict_warned &&
+ symbol_conf.kptr_restrict &&
+ al.cpumode == PERF_RECORD_MISC_KERNEL) {
+ ui__warning(
+"Kernel address maps (/proc/{kallsyms,modules}) are restricted.\n\n"
+"Check /proc/sys/kernel/kptr_restrict.\n\n"
+"Kernel%s samples will not be resolved.\n",
+ !RB_EMPTY_ROOT(&al.map->dso->symbols[MAP__FUNCTION]) ?
+ " modules" : "");
+ if (use_browser <= 0)
+ sleep(5);
+ kptr_restrict_warned = true;
+ }
+
if (al.sym == NULL) {
/*
* As we do lazy loading of symtabs we only will know if the