perf tools: Add perf_exe() helper to find perf binary

Also convert one existing user.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190224153722.27020-9-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a2323d777dae274885ed92daae1b5d2174dc79d0..01b324c275b9d1ba0bd771f30b49952550038295 100644 (file)
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -527,17 +527,11 @@ static int write_event_desc(struct feat_fd *ff,
 static int write_cmdline(struct feat_fd *ff,
                         struct perf_evlist *evlist __maybe_unused)
 {
-       char buf[MAXPATHLEN];
-       u32 n;
-       int i, ret;
+       char pbuf[MAXPATHLEN], *buf;
+       int i, ret, n;
 
        /* actual path to perf binary */
-       ret = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
-       if (ret <= 0)
-               return -1;
-
-       /* readlink() does not add null termination */
-       buf[ret] = '\0';
+       buf = perf_exe(pbuf, MAXPATHLEN);
 
        /* account for binary path */
        n = perf_env.nr_cmdline + 1;

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 706818693086d98bf2d714f43fa63ad6b0237aa9..d388f80d8703e914b2ce9040c340135286b7d921 100644 (file)
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -568,3 +568,13 @@ out:
 
        return tip;
 }
+
+char *perf_exe(char *buf, int len)
+{
+       int n = readlink("/proc/self/exe", buf, len);
+       if (n > 0) {
+               buf[n] = 0;
+               return buf;
+       }
+       return strcpy(buf, "perf");
+}

diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 01c538027c6f513ec452e5b133aba5476581d2f0..09c1b0f91f653019adb3260976642a2152c7b219 100644 (file)
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -77,6 +77,8 @@ extern bool perf_singlethreaded;
 void perf_set_singlethreaded(void);
 void perf_set_multithreaded(void);
 
+char *perf_exe(char *buf, int len);
+
 #ifndef O_CLOEXEC
 #ifdef __sparc__
 #define O_CLOEXEC      0x400000