perf symbols: Fill in pgoff in mmap synthesized events

When we synthesize mmap events we need to fill in the pgoff field.

I wasn't able to test this completely since I couldn't find an
executable region with a non 0 offset. We will see it when we start
doing data profiling.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: David Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100403115331.GK5594@kryten>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -130,6 +130,7 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
 			continue;
 		pbf += n + 3;
 		if (*pbf == 'x') { /* vm_exec */
+			u64 vm_pgoff;
 			char *execname = strchr(bf, '/');
 
 			/* Catch VDSO */
@@ -139,6 +140,14 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
 			if (execname == NULL)
 				continue;
 
+			pbf += 3;
+			n = hex2u64(pbf, &vm_pgoff);
+			/* pgoff is in bytes, not pages */
+			if (n >= 0)
+				ev.mmap.pgoff = vm_pgoff << getpagesize();
+			else
+				ev.mmap.pgoff = 0;
+
 			size = strlen(execname);
 			execname[size - 1] = '\0'; /* Remove \n */
 			memcpy(ev.mmap.filename, execname, size);