* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 16:09 ` Guenter Roeck
@ 2022-02-02 20:56 ` Kees Cook
2022-02-02 23:33 ` Guenter Roeck
2022-02-02 22:02 ` Kees Cook
2022-02-02 22:11 ` Kees Cook
2 siblings, 1 reply; 11+ messages in thread
From: Kees Cook @ 2022-02-02 20:56 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
> On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
> > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
> >
> > # Another good warning that we'll want to enable eventually
>
> alpha:defconfig:
>
> 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);
Thanks! I'll take a look. Every instance of the "[0, 0]" bounds means
the compiler believes there's a way for the destination to be determined
at compile-time to be NULL.
> xtensa:allmodconfig:
> --------------
> Error log:
> In file included from include/linux/uaccess.h:11,
> from include/linux/sched/task.h:11,
> from arch/xtensa/kernel/process.c:21:
> arch/xtensa/kernel/process.c: In function 'copy_thread':
> arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above array bounds of 'long unsigned int[16]'
I assume this is a weird cast. I will also check this one out.
Thanks!
--
Kees Cook
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 20:56 ` Kees Cook
@ 2022-02-02 23:33 ` Guenter Roeck
2022-02-03 3:03 ` Kees Cook
0 siblings, 1 reply; 11+ messages in thread
From: Guenter Roeck @ 2022-02-02 23:33 UTC (permalink / raw)
To: Kees Cook
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On 2/2/22 12:56, Kees Cook wrote:
> On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
>> On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
>>> --- a/Makefile
>>> +++ b/Makefile
>>> @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
>>> KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
>>>
>>> # Another good warning that we'll want to enable eventually
>>
>> alpha:defconfig:
>>
>> 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);
>
> Thanks! I'll take a look. Every instance of the "[0, 0]" bounds means
> the compiler believes there's a way for the destination to be determined
> at compile-time to be NULL.
>
>> xtensa:allmodconfig:
>> --------------
>> Error log:
>> In file included from include/linux/uaccess.h:11,
>> from include/linux/sched/task.h:11,
>> from arch/xtensa/kernel/process.c:21:
>> arch/xtensa/kernel/process.c: In function 'copy_thread':
>> arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above array bounds of 'long unsigned int[16]'
>
> I assume this is a weird cast. I will also check this one out.
>
int callinc = (regs->areg[0] >> 30) & 3;
int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
put_user(regs->areg[caller_ars+1],
^^^^^^^^^^^^^^^^^^^^^^^^
(unsigned __user*)(usp - 12));
I think the problem is that XCHAL_NUM_AREGS can be up to 64,
but the size of struct pt_regs->areg[] is fixed to 16.
Guenter
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 23:33 ` Guenter Roeck
@ 2022-02-03 3:03 ` Kees Cook
0 siblings, 0 replies; 11+ messages in thread
From: Kees Cook @ 2022-02-03 3:03 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On Wed, Feb 02, 2022 at 03:33:11PM -0800, Guenter Roeck wrote:
> On 2/2/22 12:56, Kees Cook wrote:
> > On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
> > > xtensa:allmodconfig:
> > > --------------
> > > Error log:
> > > In file included from include/linux/uaccess.h:11,
> > > from include/linux/sched/task.h:11,
> > > from arch/xtensa/kernel/process.c:21:
> > > arch/xtensa/kernel/process.c: In function 'copy_thread':
> > > arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above array bounds of 'long unsigned int[16]'
> >
> > I assume this is a weird cast. I will also check this one out.
> >
>
> int callinc = (regs->areg[0] >> 30) & 3;
> int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
> put_user(regs->areg[caller_ars+1],
> ^^^^^^^^^^^^^^^^^^^^^^^^
> (unsigned __user*)(usp - 12));
>
> I think the problem is that XCHAL_NUM_AREGS can be up to 64,
> but the size of struct pt_regs->areg[] is fixed to 16.
Yeah, that's what I found too. The comment about pt_regs::areg seems to
hint that things treat pt_regs differently. I've asked on the xtensa list:
https://lore.kernel.org/linux-hardening/202202021501.DA6594BFC@keescook/
--
Kees Cook
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 16:09 ` Guenter Roeck
2022-02-02 20:56 ` Kees Cook
@ 2022-02-02 22:02 ` Kees Cook
2022-02-02 22:11 ` Kees Cook
2 siblings, 0 replies; 11+ messages in thread
From: Kees Cook @ 2022-02-02 22:02 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
> On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
> > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
> >
> > # Another good warning that we'll want to enable eventually
>
> alpha:defconfig:
>
> 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);
Ugh, these all appear to be the same "gcc thinks a literal is an offset
from NULL" problem Arnd described:
https://lore.kernel.org/linux-hardening/CAK8P3a1CT+-3J7Ufv9TQwRiV4i_+FF=-+phwSjWafyGuPfG+AA@mail.gmail.com
What's annoying is that these values, if stored in a variable, aren't
treated that way:
https://pastebin.ubuntu.com/p/ZjZR2tzRpx/
I guess having a common way to convert from an integer (or literal) into
a void * that GCC doesn't freak out about would be generally nice.
-Kees
--
Kees Cook
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 16:09 ` Guenter Roeck
2022-02-02 20:56 ` Kees Cook
2022-02-02 22:02 ` Kees Cook
@ 2022-02-02 22:11 ` Kees Cook
2022-02-02 23:21 ` Guenter Roeck
2 siblings, 1 reply; 11+ messages in thread
From: Kees Cook @ 2022-02-02 22:11 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
> On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
> > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
> >
> > # Another good warning that we'll want to enable eventually
>
> alpha:defconfig:
>
> 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);
Ah! With Arnd and Nathan's help, I saw:
https://lore.kernel.org/all/20210912160149.2227137-3-linux@roeck-us.net/
which is solving the same problem (just manifested through different
diagnostics). The same solution works here. I'll get the patches sent...
--
Kees Cook
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 22:11 ` Kees Cook
@ 2022-02-02 23:21 ` Guenter Roeck
2022-02-03 3:02 ` Kees Cook
0 siblings, 1 reply; 11+ messages in thread
From: Guenter Roeck @ 2022-02-02 23:21 UTC (permalink / raw)
To: Kees Cook
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On 2/2/22 14:11, Kees Cook wrote:
> On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
>> On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
>>> --- a/Makefile
>>> +++ b/Makefile
>>> @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
>>> KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
>>>
>>> # Another good warning that we'll want to enable eventually
>>
>> alpha:defconfig:
>>
>> 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);
>
> Ah! With Arnd and Nathan's help, I saw:
> https://lore.kernel.org/all/20210912160149.2227137-3-linux@roeck-us.net/
Guilty as charged. Sorry, I didn't try to analyze the problem,
or I might have noticed (and saved you some work).
Guenter
> which is solving the same problem (just manifested through different
> diagnostics). The same solution works here. I'll get the patches sent...
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/5] Makefile: Enable -Warray-bounds
2022-02-02 23:21 ` Guenter Roeck
@ 2022-02-03 3:02 ` Kees Cook
0 siblings, 0 replies; 11+ messages in thread
From: Kees Cook @ 2022-02-03 3:02 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-kernel, Arnd Bergmann, Masahiro Yamada, linux-kbuild,
Gustavo A . R . Silva, clang-built-linux, linux-hardening
On Wed, Feb 02, 2022 at 03:21:49PM -0800, Guenter Roeck wrote:
> On 2/2/22 14:11, Kees Cook wrote:
> > On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote:
> > > On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
> > > > --- a/Makefile
> > > > +++ b/Makefile
> > > > @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
> > > > KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
> > > > # Another good warning that we'll want to enable eventually
> > >
> > > alpha:defconfig:
> > >
> > > 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);
> >
> > Ah! With Arnd and Nathan's help, I saw:
> > https://lore.kernel.org/all/20210912160149.2227137-3-linux@roeck-us.net/
>
> Guilty as charged. Sorry, I didn't try to analyze the problem,
> or I might have noticed (and saved you some work).
No worries! It manifests as a completely different warning. It just
happens to come from the same internal diagnostics info, I think. :)
I was just delighted to see it already had a solution!
-Kees
--
Kees Cook
^ permalink raw reply [flat|nested] 11+ messages in thread