From patchwork Mon Dec 10 11:26:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 153255 Delivered-To: patches@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp3447039ljp; Mon, 10 Dec 2018 03:26:52 -0800 (PST) X-Google-Smtp-Source: AFSGD/WhRSTf5OmJkmHDt7j3F4lCXffKpQ/dVKEFUi6FHT6XUUC5gJq2NQtYSZosxbNvTe+MaJ3R X-Received: by 2002:adf:e5c4:: with SMTP id a4mr8925229wrn.157.1544441212462; Mon, 10 Dec 2018 03:26:52 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544441212; cv=none; d=google.com; s=arc-20160816; b=C2/2Krstm64wUfG/ZilUlN8wGD5PHamOTIyyvsBppIeDEBGKux6SJj7wqbUSCXxe+y uw3g6F35kxlB51VfuKcTNsFTBJ0N9XPCVIxY/0ux9HHTtgUTyBgEVfshENomJC6OTUw9 6y598adrQmU14eYTKL7e2h4W/n9yAfJ8o4gHQMMgEaC1ShSRztyFxd8Ow3ysrm2iueXF YaRXQ5na3pqMi9QH83qKrLdxXyjJsTWEY8kmEdTG5FmWiWGE5OEhAGCPivU2rkhbs8OT +tCMmNKmm1rWuulwwyPWbFI6ZvvKDVhKDxjbLi2BFrobt704gjNF0k08DSwD66YZEZab sU6g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from; bh=CFT0+KtVmpJyBNFC5APck/reLWVSwQnk19htgu64LQk=; b=RTtP0VdyN9kP0pUOcq+wFhdEKdx+ZBExZD/2G/QI/UrKdWWJ916p7eYYpaajvB/Cy0 d1GT4pLbUHy5olCuO8Q8cVUuRpu+oZeEuD9u7sjiIdG3OqJal3Cd0aQny1PB8Gk2ZkCp nJQVMKG5CXsyXRPqwPSjzCmSyNqQv8G2NZZGzkWM2BP8JYlx0bXjaBRPXe6ApAyaPmMF 5xljUN46yfZqfr257uR6J/mRmLJxw7rb+2nZo6KfmKBQ1DY49Y3ODtvO9K6sOJa0tocT yXI5C4hfrJuueZSbo0kRk/bTBVBu9T96ki5QGGpK1PIvrqB9/l6IEn+GbY8g08dRUcsF SV1Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of pm215@archaic.org.uk designates 2001:8b0:1d0::2 as permitted sender) smtp.mailfrom=pm215@archaic.org.uk; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from orth.archaic.org.uk (orth.archaic.org.uk. [2001:8b0:1d0::2]) by mx.google.com with ESMTPS id t201si8166169wme.40.2018.12.10.03.26.52 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 10 Dec 2018 03:26:52 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of pm215@archaic.org.uk designates 2001:8b0:1d0::2 as permitted sender) client-ip=2001:8b0:1d0::2; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of pm215@archaic.org.uk designates 2001:8b0:1d0::2 as permitted sender) smtp.mailfrom=pm215@archaic.org.uk; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from pm215 by orth.archaic.org.uk with local (Exim 4.89) (envelope-from ) id 1gWJi7-0008Ch-IE; Mon, 10 Dec 2018 11:26:51 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Cc: patches@linaro.org, qemu-block@nongnu.org, Fam Zheng , Igor Mammedov , "Michael S. Tsirkin" , Ben Warren , Max Reitz , Kevin Wolf , Stefan Weil Subject: [PATCH 2/3] block/vdi: Don't take address of fields in packed structs Date: Mon, 10 Dec 2018 11:26:48 +0000 Message-Id: <20181210112649.11581-3-peter.maydell@linaro.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181210112649.11581-1-peter.maydell@linaro.org> References: <20181210112649.11581-1-peter.maydell@linaro.org> MIME-Version: 1.0 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. Instead of passing UUID related functions the address of a possibly unaligned QemuUUID struct, use local variables and then copy to/from the struct field as appropriate. Signed-off-by: Peter Maydell --- block/vdi.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) -- 2.19.2 diff --git a/block/vdi.c b/block/vdi.c index 2380daa583e..4cc726047c3 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -235,7 +235,8 @@ static void vdi_header_to_le(VdiHeader *header) static void vdi_header_print(VdiHeader *header) { - char uuid[37]; + char uuidstr[37]; + QemuUUID uuid; logout("text %s", header->text); logout("signature 0x%08x\n", header->signature); logout("header size 0x%04x\n", header->header_size); @@ -254,14 +255,18 @@ static void vdi_header_print(VdiHeader *header) logout("block extra 0x%04x\n", header->block_extra); logout("blocks tot. 0x%04x\n", header->blocks_in_image); logout("blocks all. 0x%04x\n", header->blocks_allocated); - qemu_uuid_unparse(&header->uuid_image, uuid); - logout("uuid image %s\n", uuid); - qemu_uuid_unparse(&header->uuid_last_snap, uuid); - logout("uuid snap %s\n", uuid); - qemu_uuid_unparse(&header->uuid_link, uuid); - logout("uuid link %s\n", uuid); - qemu_uuid_unparse(&header->uuid_parent, uuid); - logout("uuid parent %s\n", uuid); + uuid = header->uuid_image; + qemu_uuid_unparse(&uuid, uuidstr); + logout("uuid image %s\n", uuidstr); + uuid = header->uuid_last_snap; + qemu_uuid_unparse(&uuid, uuidstr); + logout("uuid snap %s\n", uuidstr); + uuid = header->uuid_link; + qemu_uuid_unparse(&uuid, uuidstr); + logout("uuid link %s\n", uuidstr); + uuid = header->uuid_parent; + qemu_uuid_unparse(&uuid, uuidstr); + logout("uuid parent %s\n", uuidstr); } static int coroutine_fn vdi_co_check(BlockDriverState *bs, BdrvCheckResult *res, @@ -368,6 +373,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, size_t bmap_size; int ret; Error *local_err = NULL; + QemuUUID uuid_link, uuid_parent; bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false, errp); @@ -395,6 +401,9 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + uuid_link = header.uuid_link; + uuid_parent = header.uuid_parent; + if (header.disk_size % SECTOR_SIZE != 0) { /* 'VBoxManage convertfromraw' can create images with odd disk sizes. We accept them but round the disk size to the next multiple of @@ -444,11 +453,11 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, (uint64_t)header.blocks_in_image * header.block_size); ret = -ENOTSUP; goto fail; - } else if (!qemu_uuid_is_null(&header.uuid_link)) { + } else if (!qemu_uuid_is_null(&uuid_link)) { error_setg(errp, "unsupported VDI image (non-NULL link UUID)"); ret = -ENOTSUP; goto fail; - } else if (!qemu_uuid_is_null(&header.uuid_parent)) { + } else if (!qemu_uuid_is_null(&uuid_parent)) { error_setg(errp, "unsupported VDI image (non-NULL parent UUID)"); ret = -ENOTSUP; goto fail; @@ -733,6 +742,7 @@ static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options, BlockDriverState *bs_file = NULL; BlockBackend *blk = NULL; uint32_t *bmap = NULL; + QemuUUID uuid; assert(create_options->driver == BLOCKDEV_DRIVER_VDI); vdi_opts = &create_options->u.vdi; @@ -819,8 +829,10 @@ static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options, if (image_type == VDI_TYPE_STATIC) { header.blocks_allocated = blocks; } - qemu_uuid_generate(&header.uuid_image); - qemu_uuid_generate(&header.uuid_last_snap); + qemu_uuid_generate(&uuid); + header.uuid_image = uuid; + qemu_uuid_generate(&uuid); + header.uuid_last_snap = uuid; /* There is no need to set header.uuid_link or header.uuid_parent here. */ if (VDI_DEBUG) { vdi_header_print(&header);