[U-Boot] [PATCH] part_efi: fix protective_mbr struct allocation

Palacios, Hector
2014-02-12T16:24:26Z

Hi Lukasz,

On 02/12/2014 04:56 PM, Lukasz Majewski wrote:
> Hi Hector,
>
>> The calloc() call was allocating space for the sizeof the struct
>> pointer rather than for the struct contents.
>>
>> Signed-off-by: Hector Palacios <hector.palacios@digi.com>
>> ---
>> disk/part_efi.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/disk/part_efi.c b/disk/part_efi.c
>> index 5dfaf490c89a..7fabec059d7a 100644
>> --- a/disk/part_efi.c
>> +++ b/disk/part_efi.c
>> @@ -232,7 +232,7 @@ static int set_protective_mbr(block_dev_desc_t
>> *dev_desc) legacy_mbr *p_mbr;
>>
>> /* Setup the Protective MBR */
>> - p_mbr = calloc(1, sizeof(p_mbr));
>> + p_mbr = calloc(1, sizeof(legacy_mbr));
>
> Thanks for spotting the error. _Damn_
>
> However, this is not enough.
>
> Since this buffer is passed to mmc for writing (and some targets may
> use cache) the legacy_mbr shall be defined as:
>
> ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, sizeof(legacy_mbr));
> memset(p_mbr, 0, sizeof(legacy_mbr));

Unfortunately this is causing unaligned access in my i.MX6.
I'm specifically passing the -mno-unaligned-access when building this file so I guess
it has to do with the macro and the packed structure.

>
> Would you like to prepare v2 of this patch or shall I prepare the fix?
>
>> if (p_mbr == NULL) {
>> printf("%s: calloc failed!\n", __func__);
>> return -1;
>
>
>