perf tools: Fix prefix matching for kernel maps

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.

Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1328461865-6127-1-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 73ddaf06b8e718e9dc7bd21765b9a2cf7250d8c0..2044324b755a51bc9b41536957dce8b35a11a6fd 100644 (file)
--- 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] == '[')) {