Commit ac928b8e authored by Peter Maydell's avatar Peter Maydell Committed by Kevin Wolf
Browse files

block/vdi: Don't take address of fields in packed structs 



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: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 0dbaaa79

block/vdi.c

+25 −13
Original line number Diff line number Diff line
@@ -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);