| Message ID | 20220202225327.1544295-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 2a55550fbba643f41318bb12ab20e6510c7df231 |
| Headers | show |
| Series | m68k: cmpxchg: Dereference matching size | expand |
Hi Kees, On Wed, Feb 2, 2022 at 11:53 PM Kees Cook <keescook@chromium.org> wrote: > Similar to the recent arm64 fix[1], avoid overly wide casts in the cmpxchg > implementation. Avoid 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 differences are seen from this change. > > [1] commit 3364c6ce23c6 ("arm64: atomics: lse: Dereference matching size") > > Signed-off-by: Kees Cook <keescook@chromium.org> Thanks for your patch! Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Do you want me to queue this in the m68k for-v5.18 branch, or do you want to take it yourself, together with commit a8712a32665f9b1a ("Makefile: Enable -Warray-bounds") in linux-next that triggers this? In case of the latter: Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Please let me know. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Thu, Feb 03, 2022 at 09:13:30AM +0100, Geert Uytterhoeven wrote: > Hi Kees, > > On Wed, Feb 2, 2022 at 11:53 PM Kees Cook <keescook@chromium.org> wrote: > > Similar to the recent arm64 fix[1], avoid overly wide casts in the cmpxchg > > implementation. Avoid 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 differences are seen from this change. > > > > [1] commit 3364c6ce23c6 ("arm64: atomics: lse: Dereference matching size") > > > > Signed-off-by: Kees Cook <keescook@chromium.org> > > Thanks for your patch! > > Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> > > Do you want me to queue this in the m68k for-v5.18 branch, or do > you want to take it yourself, together with commit a8712a32665f9b1a > ("Makefile: Enable -Warray-bounds") in linux-next that triggers this? > In case of the latter: > Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Given how -next is being ordered, it's probably best to go via my tree. Thanks for the review! -Kees > > Please let me know. Thanks! > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
diff --git a/arch/m68k/include/asm/cmpxchg.h b/arch/m68k/include/asm/cmpxchg.h index e8ca4b0ccefa..6cf464cdab06 100644 --- a/arch/m68k/include/asm/cmpxchg.h +++ b/arch/m68k/include/asm/cmpxchg.h @@ -4,8 +4,7 @@ #include <linux/irqflags.h> -struct __xchg_dummy { unsigned long a[100]; }; -#define __xg(x) ((volatile struct __xchg_dummy *)(x)) +#define __xg(type, x) ((volatile type *)(x)) extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int); @@ -50,7 +49,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "1:\n\t" "casb %0,%1,%2\n\t" "jne 1b" - : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); + : "=&d" (x) : "d" (x), "m" (*__xg(u8, ptr)) : "memory"); break; case 2: __asm__ __volatile__ @@ -58,7 +57,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "1:\n\t" "casw %0,%1,%2\n\t" "jne 1b" - : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); + : "=&d" (x) : "d" (x), "m" (*__xg(u16, ptr)) : "memory"); break; case 4: __asm__ __volatile__ @@ -66,7 +65,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "1:\n\t" "casl %0,%1,%2\n\t" "jne 1b" - : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); + : "=&d" (x) : "d" (x), "m" (*__xg(u32, ptr)) : "memory"); break; default: x = __invalid_xchg_size(x, ptr, size);
Similar to the recent arm64 fix[1], avoid overly wide casts in the cmpxchg implementation. Avoid 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 differences are seen from this change. [1] commit 3364c6ce23c6 ("arm64: atomics: lse: Dereference matching size") Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/m68k/include/asm/cmpxchg.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)