[libvirt] [PATCH] bitmap: reject zero-size bitmap

[Jim Fehlig]

Eric Blake wrote:
> * src/util/bitmap.c (virBitmapAlloc): Tighten sanity check.
> ---
>
>   
>>> For that matter, should virBitmapAlloc(0) return NULL, instead of it's
>>> current behavior of allocating an (empty) bitmap?
>>>   
>>>       
>> Yes, you are right - especially since there is no grow operation
>> :-).  I should have returned NULL for size 0 request in the original
>> version.
>>     
>
> Any objections to this?
>
>  src/util/bitmap.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/src/util/bitmap.c b/src/util/bitmap.c
> index 69094a5..44edb49 100644
> --- a/src/util/bitmap.c
> +++ b/src/util/bitmap.c
> @@ -1,6 +1,7 @@
>  /*
>   * bitmap.h: Simple bitmap operations
>   *
> + * Copyright (C) 2010 Red Hat, Inc.
>   * Copyright (C) 2010 Novell, Inc.
>   *
>   * This library is free software; you can redistribute it and/or
> @@ -58,7 +59,7 @@ virBitmapPtr virBitmapAlloc(size_t size)
>      virBitmapPtr bitmap;
>      size_t sz;
>
> -    if (SIZE_MAX - VIR_BITMAP_BITS_PER_UNIT < size)
> +    if (SIZE_MAX - VIR_BITMAP_BITS_PER_UNIT < size || size == 0)
>          return NULL;
>
>      sz = (size + VIR_BITMAP_BITS_PER_UNIT - 1) /
>   

ACK.

Thanks!
Jim