perf top: Use address pattern in lookup_sym_source

Because we may have aliases, like __GI___strcoll_l in
/lib64/libc-2.10.2.so that appears in objdump as:

$ objdump --start-address=0x0000003715a86420 \
           --stop-address=0x0000003715a872dc -dS /lib64/libc-2.10.2.so

0000003715a86420 <__strcoll_l>:
  3715a86420:	55                   	push   %rbp
  3715a86421:	48 89 e5             	mov    %rsp,%rbp
  3715a86424:	41 57                	push   %r15
[root@doppio linux-2.6-tip]#

So look for the address exactly at the start of the line instead
so that annotation can work for in these cases.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1265550376-12665-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-top.c

@@ -202,10 +202,9 @@ static void parse_source(struct sym_entry *syme)
 	len = sym->end - sym->start;
 
 	sprintf(command,
-		"objdump --start-address=0x%016Lx "
-			 "--stop-address=0x%016Lx -dS %s",
-		map__rip_2objdump(map, sym->start),
-		map__rip_2objdump(map, sym->end), path);
+		"objdump --start-address=%#0*Lx --stop-address=%#0*Lx -dS %s",
+		BITS_PER_LONG / 4, map__rip_2objdump(map, sym->start),
+		BITS_PER_LONG / 4, map__rip_2objdump(map, sym->end), path);
 
 	file = popen(command, "r");
 	if (!file)
@@ -292,13 +291,15 @@ static void lookup_sym_source(struct sym_entry *syme)
 {
 	struct symbol *symbol = sym_entry__symbol(syme);
 	struct source_line *line;
-	char pattern[PATH_MAX];
+	const size_t pattern_len = BITS_PER_LONG / 4 + 2;
+	char pattern[pattern_len + 1];
 
-	sprintf(pattern, "<%s>:", symbol->name);
+	sprintf(pattern, "%0*Lx <", BITS_PER_LONG / 4,
+		map__rip_2objdump(syme->map, symbol->start));
 
 	pthread_mutex_lock(&syme->src->lock);
 	for (line = syme->src->lines; line; line = line->next) {
-		if (strstr(line->line, pattern)) {
+		if (memcmp(line->line, pattern, pattern_len) == 0) {
 			syme->src->source = line;
 			break;
 		}