From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60677) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cVyrf-0002mo-60 for qemu-devel@nongnu.org; Tue, 24 Jan 2017 06:02:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cVyre-0008TQ-Dr for qemu-devel@nongnu.org; Tue, 24 Jan 2017 06:02:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57620) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cVyre-0008TI-81 for qemu-devel@nongnu.org; Tue, 24 Jan 2017 06:02:14 -0500 From: "Daniel P. Berrange" Date: Tue, 24 Jan 2017 11:01:51 +0000 Message-Id: <20170124110151.937-9-berrange@redhat.com> In-Reply-To: <20170124110151.937-1-berrange@redhat.com> References: <20170124110151.937-1-berrange@redhat.com> Subject: [Qemu-devel] [PATCH v3 8/8] trace: improve error reporting when parsing simpletrace header List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , =?UTF-8?q?Llu=C3=ADs=20Vilanova?= , Paolo Bonzini , "Daniel P. Berrange" When loading a simpletrace binary file we just report "Not a valid trace file!" which is not very helpful. Report exactly which field we found to be invalid. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrange --- scripts/simpletrace.py | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py index 4ca903d..4c99004 100755 --- a/scripts/simpletrace.py +++ b/scripts/simpletrace.py @@ -73,10 +73,14 @@ def read_record(edict, idtoname, fobj): def read_trace_header(fobj): """Read and verify trace file header""" header = read_header(fobj, log_header_fmt) - if header is None or \ - header[0] != header_event_id or \ - header[1] != header_magic: + if header is None: raise ValueError('Not a valid trace file!') + if header[0] != header_event_id: + raise ValueError('Not a valid trace file, header id %d != %d' % + (header[0], header_event_id)) + if header[1] != header_magic: + raise ValueError('Not a valid trace file, header magic %d != %d' % + (header[1], header_magic)) log_version = header[2] if log_version not in [0, 2, 3, 4]: -- 2.9.3