Re: [Qemu-devel] [PATCH] block/vdi: Fix wrong size in conditionally used memset, memcmp

[Anthony Liguori <anthony@codemonkey.ws>]

On 02/04/2011 02:01 PM, Stefan Weil wrote:
> Error report from cppcheck:
> block/vdi.c:122: error: Using sizeof for array given as function argument returns the size of pointer.
> block/vdi.c:128: error: Using sizeof for array given as function argument returns the size of pointer.
>
> Fix both by setting the correct size.
>
> The buggy code is only used when QEMU is build without uuid support.
> The bug is not critical, so there is no urgent need to apply it to
> old versions of QEMU.
>
> Cc: Kevin Wolf<kwolf@redhat.com>
> Signed-off-by: Stefan Weil<weil@mail.berlios.de>
>    

Huh, I wouldn't have thought this was the case.  I almost feel that 
doing a #define UUID_SIZE may be better because sizeof(typeof(v)) != 
sizeof(v) is weird even by C standards.

Regards,

Anthony Liguori

> ---
>   block/vdi.c |    4 ++--
>   1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/vdi.c b/block/vdi.c
> index 83b9c04..083266e 100644
> --- a/block/vdi.c
> +++ b/block/vdi.c
> @@ -119,13 +119,13 @@ void uuid_unparse(const uuid_t uu, char *out);
>   #if !defined(CONFIG_UUID)
>   void uuid_generate(uuid_t out)
>   {
> -    memset(out, 0, sizeof(out));
> +    memset(out, 0, sizeof(uuid_t));
>   }
>
>   int uuid_is_null(const uuid_t uu)
>   {
>       uuid_t null_uuid = { 0 };
> -    return memcmp(uu, null_uuid, sizeof(uu)) == 0;
> +    return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0;
>   }
>
>   void uuid_unparse(const uuid_t uu, char *out)
>