Hi all,

After merging the kspp-gustavo tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

In function 'do_byte_reverse',
    inlined from 'do_vec_store' at arch/powerpc/lib/sstep.c:722:3,
    inlined from 'emulate_loadstore' at arch/powerpc/lib/sstep.c:3510:9:
arch/powerpc/lib/sstep.c:287:23: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
  287 |                 up[3] = tmp;
      |                 ~~~~~~^~~~~
arch/powerpc/lib/sstep.c: In function 'emulate_loadstore':
arch/powerpc/lib/sstep.c:708:11: note: at offset [24, 39] into destination object 'u' of size 16
  708 |         } u;
      |           ^
In function 'do_byte_reverse',
    inlined from 'do_vec_store' at arch/powerpc/lib/sstep.c:722:3,
    inlined from 'emulate_loadstore' at arch/powerpc/lib/sstep.c:3510:9:
arch/powerpc/lib/sstep.c:289:23: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
  289 |                 up[2] = byterev_8(up[1]);
      |                 ~~~~~~^~~~~~~~~~~~~~~~~~
arch/powerpc/lib/sstep.c: In function 'emulate_loadstore':
arch/powerpc/lib/sstep.c:708:11: note: at offset 16 into destination object 'u' of size 16
  708 |         } u;
      |           ^
In function 'do_byte_reverse',
    inlined from 'do_vec_load' at arch/powerpc/lib/sstep.c:691:3,
    inlined from 'emulate_loadstore' at arch/powerpc/lib/sstep.c:3439:9:
arch/powerpc/lib/sstep.c:287:23: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
  287 |                 up[3] = tmp;
      |                 ~~~~~~^~~~~
arch/powerpc/lib/sstep.c: In function 'emulate_loadstore':
arch/powerpc/lib/sstep.c:681:11: note: at offset [24, 39] into destination object 'u' of size 16
  681 |         } u = {};
      |           ^
arch/powerpc/lib/sstep.c:681:11: note: at offset [24, 39] into destination object 'u' of size 16
arch/powerpc/lib/sstep.c:681:11: note: at offset [24, 39] into destination object 'u' of size 16
In function 'do_byte_reverse',
    inlined from 'do_vec_load' at arch/powerpc/lib/sstep.c:691:3,
    inlined from 'emulate_loadstore' at arch/powerpc/lib/sstep.c:3439:9:
arch/powerpc/lib/sstep.c:289:23: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
  289 |                 up[2] = byterev_8(up[1]);
      |                 ~~~~~~^~~~~~~~~~~~~~~~~~
arch/powerpc/lib/sstep.c: In function 'emulate_loadstore':
arch/powerpc/lib/sstep.c:681:11: note: at offset 16 into destination object 'u' of size 16
  681 |         } u = {};
      |           ^
arch/powerpc/lib/sstep.c:681:11: note: at offset 16 into destination object 'u' of size 16
arch/powerpc/lib/sstep.c:681:11: note: at offset 16 into destination object 'u' of size 16
cc1: all warnings being treated as errors

Caused by commit

  c94c73da81d7 ("Makefile: Enable -Wstringop-overflow globally")

I have used te kspp-gustavo tree from next-20231116 for today.

-- 
Cheers,
Stephen Rothwell