[PATCH] perf, tool: Fix prefix matching for kernel maps

[Jiri Olsa <jolsa@redhat.com>]

In some perf ancient versions we used '[kernel.kallsyms._text]' as
the name for the kernel map.

This got changed with commit:
  perf: 'perf kvm' tool for monitoring guest performance from host
  commit a1645ce12adb6c9cc9e19d7695466204e3f017fe
  Author: Zhang, Yanmin <yanmin_zhang@linux.intel.com>

and we started to use following name '[kernel.kallsyms]_text'.

This name change is important for the report code dealing with ancient
perf data. When processing the kernel map event, we need to recognize
the old naming (dont match the last ']') and initialize the kernel map
correctly.

The subsequent call to maps__set_kallsyms_ref_reloc_sym deals with the
superfluous ']' to get correct symbol name.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 tools/perf/util/event.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 73ddaf0..2044324 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -554,7 +554,7 @@ static int perf_event__process_kernel_mmap(struct perf_tool *tool __used,
 
 	is_kernel_mmap = memcmp(event->mmap.filename,
 				kmmap_prefix,
-				strlen(kmmap_prefix)) == 0;
+				strlen(kmmap_prefix) - 1) == 0;
 	if (event->mmap.filename[0] == '/' ||
 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
 
-- 
1.7.4.4