Re: [Qemu-devel] [PATCH 1/3] block: Fix bdrv_iterate_format() sorting

[Eric Blake]

On 10/12/2016 03:49 PM, Max Reitz wrote:
> bdrv_iterate_format() did not actually sort the formats by name but by
> "pointer interpreted as string". That is probably not what we intended
> to do, so fix it (by changing qsort_strcmp() so it matches the example
> from qsort()'s manual page).
> 
> Signed-off-by: Max Reitz <address@hidden>
> ---
>  block.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I'm a bit surprised that code sanitizers like Coverity or ASAN aren't
(yet?) able to flag this.

Reviewed-by: Eric Blake <address@hidden>

> 
> diff --git a/block.c b/block.c
> index bb1f1ec..e46e4b2 100644
> --- a/block.c
> +++ b/block.c
> @@ -2789,7 +2789,7 @@ const char *bdrv_get_format_name(BlockDriverState *bs)
>  
>  static int qsort_strcmp(const void *a, const void *b)
>  {
> -    return strcmp(a, b);
> +    return strcmp(*(char *const *)a, *(char *const *)b);
>  }
>  
>  void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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