perf tools: Check recorded kernel version when finding vmlinux

Currently vmlinux_path__init() only tries to find vmlinux file from
current directory, /boot and some canonical directories with version
number of the running kernel.  This can be a problem when reporting old
data recorded on a kernel version not running currently.

We can use --symfs option for this but it's annoying for user to do it
always.  As we already have the info in the perf.data file, it can be
changed to use it for the search automatically.

Before:

  $ perf report
  ...
  # Samples: 4K of event 'cpu-clock'
  # Event count (approx.): 1067250000
  #
  # Overhead  Command     Shared Object      Symbol
  # ........  ..........  .................  ..............................
      71.87%     swapper  [kernel.kallsyms]  [k] recover_probed_instruction

After:

  # Overhead  Command     Shared Object      Symbol
  # ........  ..........  .................  ....................
      71.87%     swapper  [kernel.kallsyms]  [k] native_safe_halt

This requires to change signature of symbol__init() to receive struct
perf_session_env *.

Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1407825645-24586-14-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 7f2b55513863..14d03edc81c2 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1064,7 +1064,7 @@ static int read_events(struct perf_kvm_stat *kvm)
 		return -EINVAL;
 	}
 
-	symbol__init();
+	symbol__init(&kvm->session->header.env);
 
 	if (!perf_session__has_traces(kvm->session, "kvm record"))
 		return -EINVAL;
@@ -1314,7 +1314,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
 	kvm->opts.target.uid_str = NULL;
 	kvm->opts.target.uid = UINT_MAX;
 
-	symbol__init();
+	symbol__init(NULL);
 	disable_buildid_cache();
 
 	use_browser = 0;