perf tools: Build programs to copy 32-bit compatibility

perf tools copy VDSO out of memory.  However, on 64-bit machines there
may be 32-bit compatibility VDOs also.  To copy those requires separate
32-bit executables.

This patch adds to the build additional programs perf-read-vdso32 and
perf-read-vdsox32 for 32-bit and x32 respectively.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414061124-26830-15-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/tools/perf/util/find-vdso-map.c b/tools/perf/util/find-vdso-map.c
new file mode 100644
index 000000000000..95ef1cffc056
--- /dev/null
+++ b/tools/perf/util/find-vdso-map.c
@@ -0,0 +1,30 @@
+static int find_vdso_map(void **start, void **end)
+{
+        FILE *maps;
+        char line[128];
+        int found = 0;
+
+        maps = fopen("/proc/self/maps", "r");
+        if (!maps) {
+                fprintf(stderr, "vdso: cannot open maps\n");
+                return -1;
+        }
+
+        while (!found && fgets(line, sizeof(line), maps)) {
+                int m = -1;
+
+                /* We care only about private r-x mappings. */
+                if (2 != sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n",
+                                start, end, &m))
+                        continue;
+                if (m < 0)
+                        continue;
+
+                if (!strncmp(&line[m], VDSO__MAP_NAME,
+                             sizeof(VDSO__MAP_NAME) - 1))
+                        found = 1;
+        }
+
+        fclose(maps);
+        return !found;
+}