linux-kernel - [PATCH 02/10] perf tools: Fix perf record as non root with kptr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1411762787-26113-3-git-send-email-acme@kernel.org>
Date:	Fri, 26 Sep 2014 17:19:39 -0300
From:	Arnaldo Carvalho de Melo <acme@...nel.org>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com>,
	Jiri Olsa <jolsa@...hat.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 02/10] perf tools: Fix perf record as non root with kptr_restrict == 1

From: Andi Kleen <ak@...ux.intel.com>

Currently perf record always errors out when you run it as non-root with
kptr_restrict == 1, which is often the default.

Make it only warn instead and fix the kernel resolve code to not
segfault later. Profiling works still fine, except kernel symbols are
not resolved.

Signed-off-by: Andi Kleen <ak@...ux.intel.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/r/1411594794-7229-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/event.c   | 8 ++++++--
 tools/perf/util/session.c | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index ed558191c0b3..4af6b279e34a 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -558,13 +558,17 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 	struct map *map;
 	struct kmap *kmap;
 	int err;
+	union perf_event *event;
+
+	if (machine->vmlinux_maps[0] == NULL)
+		return -1;
+
 	/*
 	 * We should get this from /sys/kernel/sections/.text, but till that is
 	 * available use this, and after it is use this as a fallback for older
 	 * kernels.
 	 */
-	union perf_event *event = zalloc((sizeof(event->mmap) +
-					  machine->id_hdr_size));
+	event = zalloc((sizeof(event->mmap) + machine->id_hdr_size));
 	if (event == NULL) {
 		pr_debug("Not enough memory synthesizing mmap event "
 			 "for kernel modules\n");
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 6d2d50dea1d8..883406f4b381 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -119,7 +119,7 @@ struct perf_session *perf_session__new(struct perf_data_file *file,
 		 * kernel MMAP event, in perf_event__process_mmap().
 		 */
 		if (perf_session__create_kernel_maps(session) < 0)
-			goto out_delete;
+			pr_warning("Cannot read kernel map\n");
 	}
 
 	if (tool && tool->ordering_requires_timestamps &&
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/