[Intel-gfx] [PATCH] drm/i915/mtl: avoid stringop-overflow warning

Andi Shyti andi.shyti at kernel.org
Tue Oct 24 17:41:53 UTC 2023


Hi Jani,

> >  static void rc6_res_reg_init(struct intel_rc6 *rc6)
> >  {
> > -	memset(rc6->res_reg, INVALID_MMIO_REG.reg, sizeof(rc6->res_reg));
> 
> That's just bollocks. memset() is byte granularity, while
> INVALID_MMIO_REG.reg is u32. If the value was anything other than 0,
> this would break.

Actually it's:

   void *memset(void *s, int c, size_t count)

> And you're not supposed to look at the guts of i915_reg_t to begin with,
> that's why it's a typedef. Basically any code that accesses the members
> of i915_reg_t outside of its implementation are doing it wrong.
> 
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

in any case, I agree with your argument, but why can't we simply
do:

   memset(rc6->res_reg, 0, sizeof(rc6->res_reg));

?

The patch looks to me like it's being more complex that it
should.

Andi


More information about the Intel-gfx mailing list