From ed3077585f2f041e0db0fc41060b69673e98963b Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Thu, 16 Oct 2014 11:08:29 +0800 Subject: [PATCH] perf tools: Ensure return negative 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 # ======== # Cc: Adrian Hunter Cc: Ingo Molnar Cc: Jiri Olsa Cc: Li Zefan Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Waiman Long Link: http://lkml.kernel.org/r/1413428909-80017-1-git-send-email-wangnan0@huawei.com Signed-off-by: Wang Nan Signed-off-by: Arnaldo Carvalho de Melo --- 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 26f5b2fe5dc8..0ecf4a304cbc 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -601,8 +601,10 @@ static int __write_cpudesc(int fd, const char *cpuinfo_proc) break; } - if (ret) + if (ret) { + ret = -1; goto done; + } s = buf; @@ -965,7 +967,8 @@ 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; -- 2.34.1