m68k: cmpxchg: Dereference matching size
Similar to the recent arm64 fix[1], avoid overly wide casts in the m68k
cmpxchg implementation. Avoids this warning under -Warray-bounds with
GCC 11:
net/sched/cls_tcindex.c: In function 'tcindex_set_parms':
./arch/m68k/include/asm/cmpxchg.h:64:17: warning: array subscript 'volatile struct __xchg_dummy[0]' is partly outside array bounds of 'struct tcf_result[1]' [-Warray-bounds]
64 | __asm__ __volatile__
| ^~~~~~~
net/sched/cls_tcindex.c:338:27: note: while referencing 'cr'
338 | struct tcf_result cr = {};
| ^~
No binary output difference are seen from this change.
[1] commit
3364c6ce23c6 ("arm64: atomics: lse: Dereference matching size")
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/lkml/CAMuHMdVRrD+2zKoHxAaQdDuiK5JFDanbv0SJ91OdWfx+eyekPQ@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>