Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965885Ab2FAWSY (ORCPT ); Fri, 1 Jun 2012 18:18:24 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54296 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965657Ab2FAWQy (ORCPT ); Fri, 1 Jun 2012 18:16:54 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Namhyung Kim , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Sunjin Yang , Arnaldo Carvalho de Melo Subject: [PATCH 05/15] perf tools: Check if callchain is corrupted Date: Fri, 1 Jun 2012 19:16:29 -0300 Message-Id: <1338588999-32509-6-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.7.9.2.358.g22243 In-Reply-To: <1338588999-32509-1-git-send-email-acme@infradead.org> References: <1338588999-32509-1-git-send-email-acme@infradead.org> Content-Type: text/plain; charset="UTF-8" X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2593 Lines: 82 From: Namhyung Kim We faced segmentation fault on perf top -G at very high sampling rate due to a corrupted callchain. While the root cause was not revealed (I failed to figure it out), this patch tries to protect us from the segfault on such cases. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Sunjin Yang Link: http://lkml.kernel.org/r/1338443007-24857-2-git-send-email-namhyung.kim@lge.com Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/perf_event.h | 4 ++-- tools/perf/util/session.c | 14 +++++++++++++- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index f325786..1817d40 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -555,6 +555,8 @@ enum perf_event_type { PERF_RECORD_MAX, /* non-ABI */ }; +#define PERF_MAX_STACK_DEPTH 255 + enum perf_callchain_context { PERF_CONTEXT_HV = (__u64)-32, PERF_CONTEXT_KERNEL = (__u64)-128, @@ -609,8 +611,6 @@ struct perf_guest_info_callbacks { #include #include -#define PERF_MAX_STACK_DEPTH 255 - struct perf_callchain_entry { __u64 nr; __u64 ip[PERF_MAX_STACK_DEPTH]; diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 3b6f8e4..04d1e33 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -300,6 +300,11 @@ int machine__resolve_callchain(struct machine *self, callchain_cursor_reset(&callchain_cursor); + if (chain->nr > PERF_MAX_STACK_DEPTH) { + pr_warning("corrupted callchain. skipping...\n"); + return 0; + } + for (i = 0; i < chain->nr; i++) { u64 ip; struct addr_location al; @@ -318,7 +323,14 @@ int machine__resolve_callchain(struct machine *self, case PERF_CONTEXT_USER: cpumode = PERF_RECORD_MISC_USER; break; default: - break; + pr_debug("invalid callchain context: " + "%"PRId64"\n", (s64) ip); + /* + * It seems the callchain is corrupted. + * Discard all. + */ + callchain_cursor_reset(&callchain_cursor); + return 0; } continue; } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/