| Message ID | 20210827163015.3141722-5-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Fri, Aug 27, 2021 at 09:30:14AM -0700, Kees Cook wrote: > With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE > coverage, it is now possible to enable -Warray-bounds. Since both > GCC and Clang include -Warray-bounds in -Wall, we just need to stop > disabling it. > > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Masahiro Yamada <masahiroy@kernel.org> > Cc: linux-kbuild@vger.kernel.org > Co-developed-by: Gustavo A. R. Silva <gustavoars@kernel.org> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > Makefile | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/Makefile b/Makefile > index e4f5895badb5..8e7e73a642e2 100644 > --- a/Makefile > +++ b/Makefile > @@ -995,7 +995,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) > > # We'll want to enable this eventually, but it's not going away for 5.7 at least > KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) > -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) > This patch causes 'alpha' builds to fail when trying to build an image with gcc 11.2. In file included from include/linux/string.h:20, from include/linux/bitmap.h:11, from include/linux/cpumask.h:12, from include/linux/smp.h:13, from include/linux/lockdep.h:14, from include/linux/spinlock.h:63, from include/linux/mmzone.h:8, from include/linux/gfp.h:6, from include/linux/mm.h:10, from include/linux/pagemap.h:8, from arch/alpha/mm/init.c:10: In function '__memset', inlined from '__bad_pagetable' at arch/alpha/mm/init.c:79:2: arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] 37 | return __builtin_memset(s, c, n); | ^~~~~~~~~~~~~~~~~~~~~~~~~ In function '__memset', inlined from '__bad_page' at arch/alpha/mm/init.c:86:2: arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] 37 | return __builtin_memset(s, c, n); | ^~~~~~~~~~~~~~~~~~~~~~~~~ In function '__memset', inlined from 'paging_init' at arch/alpha/mm/init.c:256:2: arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] 37 | return __builtin_memset(s, c, n); Seen in next-20210830. Guenter
On Mon, Aug 30, 2021 at 09:31:28PM -0700, Guenter Roeck wrote: > On Fri, Aug 27, 2021 at 09:30:14AM -0700, Kees Cook wrote: > > With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE > > coverage, it is now possible to enable -Warray-bounds. Since both > > GCC and Clang include -Warray-bounds in -Wall, we just need to stop > > disabling it. > > > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Masahiro Yamada <masahiroy@kernel.org> > > Cc: linux-kbuild@vger.kernel.org > > Co-developed-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Signed-off-by: Kees Cook <keescook@chromium.org> > > --- > > Makefile | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/Makefile b/Makefile > > index e4f5895badb5..8e7e73a642e2 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -995,7 +995,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) > > > > # We'll want to enable this eventually, but it's not going away for 5.7 at least > > KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) > > -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) > > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) > > > > This patch causes 'alpha' builds to fail when trying to build an image with > gcc 11.2. > > In file included from include/linux/string.h:20, > from include/linux/bitmap.h:11, > from include/linux/cpumask.h:12, > from include/linux/smp.h:13, > from include/linux/lockdep.h:14, > from include/linux/spinlock.h:63, > from include/linux/mmzone.h:8, > from include/linux/gfp.h:6, > from include/linux/mm.h:10, > from include/linux/pagemap.h:8, > from arch/alpha/mm/init.c:10: > In function '__memset', > inlined from '__bad_pagetable' at arch/alpha/mm/init.c:79:2: > arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] > 37 | return __builtin_memset(s, c, n); > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > In function '__memset', > inlined from '__bad_page' at arch/alpha/mm/init.c:86:2: > arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] > 37 | return __builtin_memset(s, c, n); > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > In function '__memset', > inlined from 'paging_init' at arch/alpha/mm/init.c:256:2: > arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] > 37 | return __builtin_memset(s, c, n); > > Seen in next-20210830. Ah-ha, thanks for the report! I didn't see this in my builds -- what config target did you use for this? Looks like GCC isn't happy about an unsigned long->void * conversion here... include/asm/page.h:#define PAGE_OFFSET 0xfffffc0000000000UL ... include/uapi/asm/setup.h:#define KERNEL_START_PHYS 0x1000000 /* required: Wildfire/Titan/Marvel */ include/uapi/asm/setup.h:#define EMPTY_PGT (PAGE_OFFSET+KERNEL_START_PHYS+0x04000) ... mm/init.c: memset((void *) EMPTY_PGT, 0, PAGE_SIZE); I'll try to figure out the right annotations to fix this...
Hi Kees, On 8/31/21 10:46 AM, Kees Cook wrote: > On Mon, Aug 30, 2021 at 09:31:28PM -0700, Guenter Roeck wrote: >> On Fri, Aug 27, 2021 at 09:30:14AM -0700, Kees Cook wrote: >>> With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE >>> coverage, it is now possible to enable -Warray-bounds. Since both >>> GCC and Clang include -Warray-bounds in -Wall, we just need to stop >>> disabling it. >>> >>> Cc: Arnd Bergmann <arnd@arndb.de> >>> Cc: Masahiro Yamada <masahiroy@kernel.org> >>> Cc: linux-kbuild@vger.kernel.org >>> Co-developed-by: Gustavo A. R. Silva <gustavoars@kernel.org> >>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> >>> Signed-off-by: Kees Cook <keescook@chromium.org> >>> --- >>> Makefile | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/Makefile b/Makefile >>> index e4f5895badb5..8e7e73a642e2 100644 >>> --- a/Makefile >>> +++ b/Makefile >>> @@ -995,7 +995,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) >>> >>> # We'll want to enable this eventually, but it's not going away for 5.7 at least >>> KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) >>> -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) >>> KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) >>> >> >> This patch causes 'alpha' builds to fail when trying to build an image with >> gcc 11.2. >> >> In file included from include/linux/string.h:20, >> from include/linux/bitmap.h:11, >> from include/linux/cpumask.h:12, >> from include/linux/smp.h:13, >> from include/linux/lockdep.h:14, >> from include/linux/spinlock.h:63, >> from include/linux/mmzone.h:8, >> from include/linux/gfp.h:6, >> from include/linux/mm.h:10, >> from include/linux/pagemap.h:8, >> from arch/alpha/mm/init.c:10: >> In function '__memset', >> inlined from '__bad_pagetable' at arch/alpha/mm/init.c:79:2: >> arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] >> 37 | return __builtin_memset(s, c, n); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~ >> In function '__memset', >> inlined from '__bad_page' at arch/alpha/mm/init.c:86:2: >> arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] >> 37 | return __builtin_memset(s, c, n); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~ >> In function '__memset', >> inlined from 'paging_init' at arch/alpha/mm/init.c:256:2: >> arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds] >> 37 | return __builtin_memset(s, c, n); >> >> Seen in next-20210830. > > Ah-ha, thanks for the report! I didn't see this in my builds -- what > config target did you use for this? > The configuration doesn't matter; it fails for me for all configurations, including defconfig, alllnoconfig, and allmodconfig. Key is to use gcc 11.2. The image builds just fine with gcc 9.4 and 10.3. Guenter
On Tue, Aug 31, 2021 at 12:40:53PM -0700, Guenter Roeck wrote: > The configuration doesn't matter; it fails for me for all configurations, > including defconfig, alllnoconfig, and allmodconfig. > Key is to use gcc 11.2. The image builds just fine with gcc 9.4 and 10.3. Ah! Yes, heh. That would be my problem; I've got 10.3 for my builders. Thanks! I will give 11.2 a spin.
On 8/31/21 1:18 PM, Kees Cook wrote: > On Tue, Aug 31, 2021 at 12:40:53PM -0700, Guenter Roeck wrote: >> The configuration doesn't matter; it fails for me for all configurations, >> including defconfig, alllnoconfig, and allmodconfig. >> Key is to use gcc 11.2. The image builds just fine with gcc 9.4 and 10.3. > > Ah! Yes, heh. That would be my problem; I've got 10.3 for my builders. > Thanks! I will give 11.2 a spin. > In case you don't have gcc 11.2 available - I tested with 11.1 as well; that also fails. Guenter
diff --git a/Makefile b/Makefile index e4f5895badb5..8e7e73a642e2 100644 --- a/Makefile +++ b/Makefile @@ -995,7 +995,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds) KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Another good warning that we'll want to enable eventually