[Mesa-dev] [PATCH 03/39] llvmpipe: Fix overflow for 32 bits available memory computation

[Axel Davy]

On 16/05/2016 23:28, Rob Herring wrote:
> On Sun, May 15, 2016 at 5:45 AM, Axel Davy <axel.davy at ens.fr> wrote:
>> And cap to 2 GB on 32 bits.
>>
>> Fixes https://bugs.freedesktop.org/show_bug.cgi?id=94561
>>
>> Signed-off-by: Axel Davy <axel.davy at ens.fr>
>> ---
>>   src/gallium/auxiliary/os/os_misc.c       | 2 +-
>>   src/gallium/drivers/llvmpipe/lp_screen.c | 5 +++++
>>   2 files changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/gallium/auxiliary/os/os_misc.c b/src/gallium/auxiliary/os/os_misc.c
>> index d6b83e9..cf2ef95 100644
>> --- a/src/gallium/auxiliary/os/os_misc.c
>> +++ b/src/gallium/auxiliary/os/os_misc.c
>> @@ -117,7 +117,7 @@ os_get_total_physical_memory(uint64_t *size)
>>      const long phys_pages = sysconf(_SC_PHYS_PAGES);
>>      const long page_size = sysconf(_SC_PAGE_SIZE);
>>
>> -   *size = phys_pages * page_size;
>> +   *size = (int64_t)phys_pages * (int64_t)page_size;
>>      return (phys_pages > 0 && page_size > 0);
>>   #elif defined(PIPE_OS_APPLE) || defined(PIPE_OS_BSD)
>>      size_t len = sizeof(*size);
>> diff --git a/src/gallium/drivers/llvmpipe/lp_screen.c b/src/gallium/drivers/llvmpipe/lp_screen.c
>> index 4f61de8..2f84b75 100644
>> --- a/src/gallium/drivers/llvmpipe/lp_screen.c
>> +++ b/src/gallium/drivers/llvmpipe/lp_screen.c
>> @@ -279,6 +279,11 @@ llvmpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
>>         if (!os_get_total_physical_memory(&system_memory))
>>            return 0;
>>
>> +#ifdef PIPE_ARCH_X86
>> +      /* cap to 2 GB on 32 bits system */
> What about non-x86 32-bit systems?
>
> Rob
>
Do you have a suggestion for a better check ?


I could add in p_config.h a PIPE_ARCH_32 (and PIPE_ARCH_64), but I'm not 
sure what to put in there,

since it is possible to have a 32 bits processor with 64 bits memory 
addressing.