On Fri, May 27, 2022 at 06:04:14PM -0700, Linus Torvalds wrote:
> On Fri, May 27, 2022 at 4:41 PM Sudip Mukherjee
> <sudipm.mukherjee@xxxxxxxxx> wrote:
> >
> > I just tested with various values, sizeof(*edid) is 144 bytes at that place.
>
> Hmm. What compiler do you have? Because it seems very broken.
>
> You don't actually have to try with various sizes, you could have just
> done something like
>
> int size_of_edid(const struct edid *edid)
> {
> return sizeof(*edid);
> }
>
> and then "make drivers/gpu/drm/drm_edid.s" to generate assembly and
> see what it looks like (obviously removing the BUG_ON() in order to
> build).
just tried this with
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- drivers/gpu/drm/drm_edid.s
>
> That obviously generates code like
>
> movl $128, %eax
> ret
and for me it looks like:
.L1030:
.word .LC40
.word .LC41
.word -1431655765
.word .LC39
.size drm_edid_to_sad, .-drm_edid_to_sad
.align 2
.global size_of_edid
.syntax unified
.arm
.type size_of_edid, %function
size_of_edid:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 1, uses_anonymous_args = 0
mov ip, sp @,
push {fp, ip, lr, pc} @
sub fp, ip, #4 @,,
@ drivers/gpu/drm/drm_edid.c:1573: }
mov r0, #144 @,
ldmfd sp, {fp, sp, pc} @
.size size_of_edid, .-size_of_edid
--
Regards
Sudip
