Re: [Qemu-devel] [PATCH 02/40] elf: Add notes implementation

[Stefan Weil <weil@mail.berlios.de>]

Am 01.11.2010 20:51, schrieb Alexander Graf:
> On 01.11.2010, at 14:42, Stefan Weil wrote:
>
>    
>> Am 01.11.2010 19:29, schrieb Blue Swirl:
>>      
>>> On Mon, Nov 1, 2010 at 3:01 PM, Alexander Graf<agraf@suse.de>   wrote:
>>>
>>>        
>>>> ---
>>>>   hw/elf_ops.h |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>>>>   hw/loader.c  |    7 ++++++
>>>>   hw/loader.h  |    3 ++
>>>>   3 files changed, 70 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/hw/elf_ops.h b/hw/elf_ops.h
>>>> index 8b63dfc..645d058 100644
>>>> --- a/hw/elf_ops.h
>>>> +++ b/hw/elf_ops.h
>>>> @@ -189,6 +189,44 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
>>>>      return -1;
>>>>   }
>>>>
>>>> +static void glue(elf_read_notes, SZ)(uint8_t *data, int data_len,
>>>> +                                     ElfHandlers *handlers, int must_swab)
>>>> +{
>>>> +    uint8_t *p = data;
>>>> +
>>>> +    while ((ulong)&p[3]<   (ulong)&data[data_len]) {
>>>>
>>>>          
>>> Please use 'unsigned long'.
>>>
>>>        
>> Why is a type cast used here? I see no reason for it.
>>      
> Pointers can't be compared, you have to cast them to values first.
>
>
> Alex
>    

No. Pointers of same type which are not void pointers can be compared.

There is even a data type ptrdiff_t, so you can also compare their
difference with zero.

Regards,
Stefan