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Message-ID: <e385a095-c6ea-4db5-ab7c-7221593dc6c3@embeddedor.com>
Date:   Thu, 16 Nov 2023 08:18:43 -0600
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Subject: Re: [PATCH][next] Makefile: Enable -Wstringop-overflow globally
Content-Language: en-US
To:     Masahiro Yamada <masahiroy@kernel.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc:     Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
References: <ZVWMCZ/jb4nX3yHn@work>
 <CAK7LNAR1i8HP8E3UmmSggZMka+UbJswU_bVMyxmRt4CbQhoTAA@mail.gmail.com>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <CAK7LNAR1i8HP8E3UmmSggZMka+UbJswU_bVMyxmRt4CbQhoTAA@mail.gmail.com>
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On 11/16/23 05:23, Masahiro Yamada wrote:
> On Thu, Nov 16, 2023 at 12:27 PM Gustavo A. R. Silva
> <gustavoars@kernel.org> wrote:
>>
>> It seems that we have finished addressing all the remaining
>> issues regarding compiler option -Wstringop-overflow. So, we
>> are now in good shape to enable this compiler option globally.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>> ---
>>   Makefile                   | 3 +++
>>   scripts/Makefile.extrawarn | 2 --
>>   2 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index 690cde550acd..452b7d0e19e9 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -985,6 +985,9 @@ NOSTDINC_FLAGS += -nostdinc
>>   # perform bounds checking.
>>   KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
>>
>> +# We are now in good shape to enable this option.
> 
> Please remove this comment.
> 
> It it fine to mention it in the commit log, but
> not in the Makefile.

Sure thing. I'll change that and add this patch to my -next tree.

> 
> 
> 
> I hope somebody will double-check this patch in CI infrastructure.

I'll take care of that.

Thanks
--
Gustavo

> 
> 
> 
> 
>> +KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow)
>> +
>>   # disable invalid "can't wrap" optimizations for signed / pointers
>>   KBUILD_CFLAGS  += -fno-strict-overflow
>>
>> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
>> index 2fe6f2828d37..1527199161d7 100644
>> --- a/scripts/Makefile.extrawarn
>> +++ b/scripts/Makefile.extrawarn
>> @@ -106,7 +106,6 @@ KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
>>   KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
>>   KBUILD_CFLAGS += $(call cc-option, -Wformat-overflow)
>>   KBUILD_CFLAGS += $(call cc-option, -Wformat-truncation)
>> -KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow)
>>   KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
>>
>>   KBUILD_CPPFLAGS += -Wundef
>> @@ -122,7 +121,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
>>   KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
>>   KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
>>   KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
>> -KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
>>   KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
>>
>>   ifdef CONFIG_CC_IS_CLANG
>> --
>> 2.34.1
>>
> 
>