linux-kernel - [PATCH] perf tools: Provide backward compatibility with previous perf.data version

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1255032449-12022-1-git-send-email-fweisbec@gmail.com>
Date:	Thu,  8 Oct 2009 22:07:29 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Mike Galbraith <efault@....de>,
	Paul Mackerras <paulus@...ba.org>
Subject: [PATCH] perf tools: Provide backward compatibility with previous perf.data version

We have merged the trace.info file into perf.data by adding one section
in the perf headers. This makes it incompatible with previous version:
the new perf tools can't read the older perf.data.

To support the previous format, we check the headers size. If they
have the same size than in the previous format, then ignore the trace
info section that doesn't exist.

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Mike Galbraith <efault@....de>
Cc: Paul Mackerras <paulus@...ba.org>
---
 tools/perf/util/header.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 212fade..9aae360 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -287,10 +287,16 @@ struct perf_header *perf_header__read(int fd)
 	do_read(fd, &f_header, sizeof(f_header));
 
 	if (f_header.magic	!= PERF_MAGIC		||
-	    f_header.size	!= sizeof(f_header)	||
 	    f_header.attr_size	!= sizeof(f_attr))
 		die("incompatible file format");
 
+	if (f_header.size != sizeof(f_header)) {
+		/* Support the previous format */
+		if (f_header.size == offsetof(typeof(f_header), trace_info))
+			f_header.trace_info.size = 0;
+		else
+			die("incompatible file format");
+	}
 	nr_attrs = f_header.attrs.size / sizeof(f_attr);
 	lseek(fd, f_header.attrs.offset, SEEK_SET);
 
-- 
1.6.2.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/