From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53618) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gCmwO-0001sm-PY for qemu-devel@nongnu.org; Wed, 17 Oct 2018 10:36:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gCmwN-0008HM-TE for qemu-devel@nongnu.org; Wed, 17 Oct 2018 10:36:52 -0400 Date: Wed, 17 Oct 2018 16:36:43 +0200 From: Kevin Wolf Message-ID: <20181017143643.GF31479@localhost.localdomain> References: <20181016170938.29303-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181016170938.29303-1-peter.maydell@linaro.org> Subject: Re: [Qemu-devel] [PATCH] block/vhdx: Don't take address of fields in packed structs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: qemu-devel@nongnu.org, patches@linaro.org, Jeff Cody , Max Reitz , qemu-block@nongnu.org Am 16.10.2018 um 19:09 hat Peter Maydell geschrieben: > Taking the address of a field in a packed struct is a bad idea, because > it might not be actually aligned enough for that pointer type (and > thus cause a crash on dereference on some host architectures). Newer > versions of clang warn about this. Avoid the bug by not using the > "modify in place" byte swapping functions. > > There are a few places where the in-place swap function is > used on something other than a packed struct field; we convert > those anyway, for consistency. > > Patch produced with scripts/coccinelle/inplace-byteswaps.cocci. > > Signed-off-by: Peter Maydell > --- > Usual disclaimer: produced with "make check" only, but purely > automated conversion should be safe. More relevant, qemu-iotests for vhdx passes, too. I don't think "make check" would run any of the modified code. Thanks, applied to the block branch Kevin