[tip:perf/core] perf header: Add is_perf_magic() func

tip-bot for Feng Tang
2012-10-30T12:11:21Z

Commit-ID: e84ba4e26833991d1c1c15a592b1474ee2b6dfdb
Gitweb: http://git.kernel.org/tip/e84ba4e26833991d1c1c15a592b1474ee2b6dfdb
Author: Feng Tang <feng.tang@intel.com>
AuthorDate: Tue, 30 Oct 2012 11:56:07 +0800
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 29 Oct 2012 11:56:59 -0200

perf header: Add is_perf_magic() func

With this function, other modules can basically check whether a file is
a legal perf data file by checking its first 8 bytes against all
possible perf magic numbers.

Change the function name from check_perf_magic to more meaningful
is_perf_magic as suggested by acme.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1351569369-26732-7-git-send-email-feng.tang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/header.c | 10 ++++++++++
tools/perf/util/header.h | 1 +
2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 514ed1b..195a47a 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2341,6 +2341,16 @@ static int try_all_pipe_abis(uint64_t hdr_sz, struct perf_header *ph)
return -1;
}

+bool is_perf_magic(u64 magic)
+{
+ if (!memcmp(&magic, __perf_magic1, sizeof(magic))
+ || magic == __perf_magic2
+ || magic == __perf_magic2_sw)
+ return true;
+
+ return false;
+}
+
static int check_magic_endian(u64 magic, uint64_t hdr_sz,
bool is_pipe, struct perf_header *ph)
{
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 879d215..5f1cd68 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -154,6 +154,7 @@ int perf_event__synthesize_build_id(struct perf_tool *tool,
int perf_event__process_build_id(struct perf_tool *tool,
union perf_event *event,
struct perf_session *session);
+bool is_perf_magic(u64 magic);

/*
* arch specific callback