linux-kernel - [PATCH] perf tools: ensure return negitive value when write header error

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-next>] [day] [month] [year] [list]

Message-ID: <1413428909-80017-1-git-send-email-wangnan0@huawei.com>
Date:	Thu, 16 Oct 2014 11:08:29 +0800
From:	Wang Nan <wangnan0@...wei.com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Jiri Olsa <jolsa@...hat.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Namhyung Kim <namhyung.kim@....com>,
	Wang Nan <wangnan0@...wei.com>,
	Waiman Long <Waiman.Long@...com>
CC:	<linux-kernel@...r.kernel.org>, Li Zefan <lizefan@...wei.com>
Subject: [PATCH] perf tools: ensure return negitive value when write header error

When 'perf record' write headers, it calls write_xxx in
tools/perf/util/header.c, and check return value. It rolls back all
working only when return value is negative.

This patch ensures write_cpudesc() and write_total_mem() return negative number
when error. Without this patch, headers reported by 'perf report' header is
error in some platform. Following output is caputured on ARM, which doesn't
contain "Processor" field in /proc/cpuinfo. See "cpudesc", "total memory" and
"cmdline" field.

   bash-4.2# perf record ls
   ...
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.001 MB perf.data (~36 samples) ]
   bash-4.2# perf report --stdio --header
   Error:
   The perf.data file has no samples!
   # ========
   # captured on: Fri Sep 12 10:09:10 2014
   # hostname : arma15el
   # os release : 3.17.0+
   # perf version : 3.10.53
   # arch : armv7l
   # nrcpus online : 4
   # nrcpus avail : 1
   # cpudesc : (null)
   # total memory : 0 kB
   # cmdline :
   # event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, excl_host = 0, excl_guest = 1, precise_ip = 0
   # pmu mappings: not available
   # ========
   #

Signed-off-by: Wang Nan <wangnan0@...wei.com>
---
 tools/perf/util/header.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index ce0de00..39b80ac 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -605,8 +605,10 @@ static int write_cpudesc(int fd, struct perf_header *h __maybe_unused,
 			break;
 	}
 
-	if (ret)
+	if (ret) {
+		ret = -1;
 		goto done;
+	}
 
 	s = buf;
 
@@ -950,7 +952,8 @@ static int write_total_mem(int fd, struct perf_header *h __maybe_unused,
 		n = sscanf(buf, "%*s %"PRIu64, &mem);
 		if (n == 1)
 			ret = do_write(fd, &mem, sizeof(mem));
-	}
+	} else
+		ret = -1;
 	free(buf);
 	fclose(fp);
 	return ret;
-- 
1.8.4

--
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/