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[195.23.151.163]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49fcd10273fsm229284935e9.7.2026.09.21.05.09.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Sep 2026 05:09:07 -0700 (PDT) Sender: Julian Braha Message-ID: <350cc022-2769-4052-93f4-029ef93fa41c@gmail.com> Date: Mon, 21 Sep 2026 13:09:05 +0100 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] kconfig: Replace "cc-option-bit" with "cc-option-str" To: Kees Cook , Nathan Chancellor Cc: Nicolas Schier , Matthew Maurer , Miguel Ojeda , Masahiro Yamada , "Borislav Petkov (AMD)" , Gary Guo , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , linux-kbuild@vger.kernel.org, "Lorenzo Stoakes (ARM)" , Jonathan Corbet , Shuah Khan , Randy Dunlap , Vegard Nossum , Nauman Sabir , Tejun Heo , Nicolas Pitre , Andy Shevchenko , Andrew Jones , Graham Roff , Arnd Bergmann , Krzysztof Kozlowski , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hardening@vger.kernel.org References: <20260919005923.i.879-kees@kernel.org> <20260919005929.4077729-2-kees@kernel.org> Content-Language: en-US From: Julian Braha In-Reply-To: <20260919005929.4077729-2-kees@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/19/26 01:59, Kees Cook wrote: > $(cc-option-bit) returns the flag it was given when the compiler accepts > it, and an empty string otherwise. It was originally only used > internally for machine bit flags, but it is generally useful[1]. > > Rename it to $(cc-option-str), which says what it returns rather than > what it was first used for, and extract the probe logic from the existing > $(cc-option) macro to reuse it. Additionally add support for an optional > fallback, much like the Kbuild cc-option macro. This can be used as: > > config CC_OPT_FOO > def_string "$(cc-option-str,-fnew-option,-fold-option)" > > If the fallback is omitted, it is just an empty string. > > Build tested ARCH=x86_64 defconfig with GCC 16.2.0. > > Assisted-by: LLM > Signed-off-by: Kees Cook Tested-by: Julian Braha Reviewed-by: Julian Braha