From 6cce28d5332ad52ae9ec531ae382667bb03cbeb6 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 2 Jun 2014 13:54:44 +0200 Subject: [PATCH 27/31] qcow1: Make padding in the header explicit RH-Author: Kevin Wolf Message-id: <1401717288-3918-3-git-send-email-kwolf@redhat.com> Patchwork-id: 59097 O-Subject: [RHEL-7.1/7.0.z qemu-kvm PATCH 2/6] qcow1: Make padding in the header explicit Bugzilla: 1097229 1097230 RH-Acked-by: Max Reitz RH-Acked-by: Fam Zheng RH-Acked-by: Miroslav Rezanina RH-Acked-by: Stefan Hajnoczi Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1097230 We were relying on all compilers inserting the same padding in the header struct that is used for the on-disk format. Let's not do that. Mark the struct as packed and insert an explicit padding field for compatibility. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Reviewed-by: Benoit Canet (cherry picked from commit ea54feff58efedc809641474b25a3130309678e7) --- block/qcow.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Signed-off-by: Miroslav Rezanina --- block/qcow.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/block/qcow.c b/block/qcow.c index b57b900..220ac04 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -48,9 +48,10 @@ typedef struct QCowHeader { uint64_t size; /* in bytes */ uint8_t cluster_bits; uint8_t l2_bits; + uint16_t padding; uint32_t crypt_method; uint64_t l1_table_offset; -} QCowHeader; +} QEMU_PACKED QCowHeader; #define L2_CACHE_SIZE 16 -- 1.7.1