On 22/12/2025 22:53, Michal Wilczynski wrote:
> The build fails on RISC-V using GCC because `SIZE_CHECK(struct
> rogue_fwif_hwrtdata, 384)` expects 384 bytes, but the compiler generates
> a 336-byte structure.
>
> This is due to an alignment conflict: the inner member `cleanup_state`
> requires 64-byte alignment, but the outer struct is explicitly marked
> `__aligned(8)`.
>
> While GCC on ARM64 implicitly pads the size to a multiple of 64, GCC on
> RISC-V strictly respects the 8-byte outer alignment, resulting in a size
> mismatch.
>
> Fix this by aligning the entire structure to 64 bytes, which resolves
> the contradiction and forces the correct 384 byte size on all
> architectures.
>
> Fixes: a26f067feac1 ("drm/imagination: Add FWIF headers")
> Reported-by: kernel test robot <[email protected]>
> Closes:
> https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Michal Wilczynski <[email protected]>Hi Michal, This looks fine to me. I'm surprised the behaviour of GCC differs by architecture though, is there a bug somewhere or is it UB to explicitly narrow the alignment like this? Either way: Reviewed-by: Matt Coster <[email protected]> And I'll take via drm-misc-fixes tomorrow. Cheers, Matt > --- > drivers/gpu/drm/imagination/pvr_rogue_fwif.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h > b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h > index > 172886be4c820a32ae1b08d62bf0814250f2a9bd..1ba2a167a38b31911e0846923e4dc70626f5ca65 > 100644 > --- a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h > +++ b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h > @@ -2170,7 +2170,7 @@ struct rogue_fwif_hwrtdata { > bool geom_caches_need_zeroing __aligned(4); > > struct rogue_fwif_cleanup_ctl cleanup_state __aligned(64); > -} __aligned(8); > +} __aligned(64); > > /* > > ****************************************************************************** > > --- > base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 > change-id: 20251222-fix_imagination-8ef0c94122c4 > > Best regards, -- Matt Coster E: [email protected]
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