2011-05-28 15:41:44

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [tip:perf/urgent] perf top: Handle kptr_restrict

Commit-ID: 5f6f55809758e106eca72c6e01402c8080a88ee8
Gitweb: http://git.kernel.org/tip/5f6f55809758e106eca72c6e01402c8080a88ee8
Author: Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Fri, 27 May 2011 11:53:28 -0300
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Fri, 27 May 2011 16:02:25 -0300

perf top: Handle kptr_restrict

Reported-by: Ingo Molnar <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Tom Zanussi <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/builtin-top.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)

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 bool use_tui, use_stdio;

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 @@ static void perf_event__process_sample(const union perf_event *event,
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