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From: Stefan Weil <sw@weilnetz.de>
To: qemu-devel <qemu-devel@nongnu.org>
Cc: qemu-trivial@nongnu.org, Stefan Weil <sw@weilnetz.de>,
	Anthony Liguori <aliguori@amazon.com>,
	Stefan Hajnoczi <stefanha@redhat.com>
Subject: [Qemu-devel] [PATCH] virtio: Remove unneeded memcpy
Date: Thu, 17 Oct 2013 21:23:26 +0200	[thread overview]
Message-ID: <1382037806-9393-1-git-send-email-sw@weilnetz.de> (raw)

Report from valgrind:

==19521== Source and destination overlap in memcpy(0x31d38938, 0x31d38938, 64)
==19521==    at 0x4A0A343: memcpy@@GLIBC_2.14 (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==19521==    by 0x42774E: virtio_blk_device_init (virtio-blk.c:686)
==19521==    by 0x46EE9E: virtio_device_init (virtio.c:1158)
==19521==    by 0x25405E: device_realize (qdev.c:178)
==19521==    by 0x2559B5: device_set_realized (qdev.c:699)
==19521==    by 0x3A819B: property_set_bool (object.c:1315)
==19521==    by 0x3A6CE0: object_property_set (object.c:803)

Valgrind is right: blk == &s->blks, so it is a memcpy of 64 byte with
source == destination which can be removed.

Reported-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
---
 hw/block/virtio-blk.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 49a23c3..13f6d82 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -703,7 +703,6 @@ static int virtio_blk_device_init(VirtIODevice *vdev)
 
     s->bs = blk->conf.bs;
     s->conf = &blk->conf;
-    memcpy(&(s->blk), blk, sizeof(struct VirtIOBlkConf));
     s->rq = NULL;
     s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1;
 
-- 
1.7.9.5

             reply	other threads:[~2013-10-17 19:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-17 19:23 Stefan Weil [this message]
2013-10-17 20:09 ` [Qemu-devel] [PATCH] virtio: Remove unneeded memcpy Peter Maydell
2013-10-18 11:03 ` Stefan Hajnoczi

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