[Mesa-dev] [PATCH] [RFC] mesa/glthread: misaligned address access

[Timothy Arceri]

On 04/04/17 05:12, Bartosz Tomczyk wrote:
> Address sanitizer reports lot of misaligned access:
> SUMMARY: AddressSanitizer: undefined-behavior main/marshal.c:276:31 in
> main/marshal.c:276:31: runtime error: load of misaligned address 0x631000104866 for type
> 'const GLuint' (aka 'const unsigned int'), which requires 4 byte alignment
> 0x631000104866: note: pointer points here
>  92 88 00 00 00 00  00 00 4a 03 0c 00 93 88  00 00 00 00 00 00 02 01  0c 00 40 8d 00 00 00 00  00 00
>              ^
> SUMMARY: AddressSanitizer: undefined-behavior main/marshal_generated.c:28725:12 in
> main/marshal_generated.c:28726:12: runtime error: member access within misaligned address 0x6310003fc874 for type
> 'struct marshal_cmd_VertexAttribPointer', which requires 8 byte alignment
> 0x6310003fc874: note: pointer points here
>   01 00 00 00 7a 02 20 00  00 00 00 00 be be be be  be be be be be be be be  be be be be be be be be
>               ^
> SUMMARY: AddressSanitizer: undefined-behavior main/marshal_generated.c:28726:12 in
> main/marshal_generated.c:28726:12: runtime error: store to misaligned address 0x6310003fc87c for type
> 'GLint' (aka 'int'), which requires 8 byte alignment
> 0x6310003fc87c: note: pointer points here
>   00 00 00 00 be be be be  be be be be be be be be  be be be be be be be be  be be be be be be be be
>
> This probably isn't issue for x86 as misaligned access shoul be as fast
> as aligned ones. But this could be issue for different architectures
> like ARM/MIPS, any exert here ?
>
> Any idea how to get correct aligment on different platforms ?

Thanks. I've had the same patch locally for a while, I think it makes 
sense to push this as is for now (which I've done). We can adjust for 
other platforms later if needed.