From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 436B722652D; Mon, 20 Oct 2025 15:59:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760975958; cv=none; b=VRGaiwivGFjVHgEDu3PM5KfCILzliVXgHXMLxGmzVoXXx/VchQLCZmjvJ7bPIzrfNHzz0HVi/h5oWXSdJNMdiNY9pGs4a/F94XI9RAe2TH+0m/yKZ9wciX5905pGoKY9LJ/YG3AIzjJNpnodOK6ic19BSAHMBEXjH4J8QdiOGiM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760975958; c=relaxed/simple; bh=z9AgmlNOJT3LEVbLAQG9gIGGqSSqCri2xopx34BdR7g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YsRLrFO9oZu9XOBHMdcMvWwOYW0NX6eV6ijuSkUSEB4hKdqt7C0kJGgJ9adDrx5S+tdi8lDx/Gf48aDMZR4045eF6G6xCcZPFyckc7ESAJxGv+pDIQ5Aw9oLk59awS7Y5Vwu0lY9v7dr7VStz528n/lUx1qnTNKdMmbaGuE+wtU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sOfrCbL7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sOfrCbL7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5800DC4CEF9; Mon, 20 Oct 2025 15:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760975956; bh=z9AgmlNOJT3LEVbLAQG9gIGGqSSqCri2xopx34BdR7g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=sOfrCbL7Gnlyc2u9qKcuWdhUj2vdfiYwEfbvl/5UGyfTDhRPvasrNjMK7fz+63uIK W1diSE6ahzcIb7QdDYlAe+oCRxftjjAhSztPcc3iJo7irsVyBTrvyVj5svsUbTQ64s RgYCLfJUNU6jKWcuM41fahE8xepGaz3MWT065XJYt5jIs/2LmPjYLV1d8gE5s6QcGL BcEp9c9kT41yT06eHmaBgrKhhQ8wmNRmMK72Zeit7fPVfDRO+9wXO+00/Awl87HCpW SBRB8eIMIrxrWNLN06YSjQ8XV9eBLNDW9VIFX/AidEE9b3aUu/kxhMXkvmY3lyhQuJ NbaQjbSftyQaQ== Message-ID: Date: Mon, 20 Oct 2025 17:59:09 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 5.4.y 0/5] v5.4: fix build with GCC 15 Content-Language: en-GB, fr-BE To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, Sasha Levin , MPTCP Upstream , Nathan Chancellor , Kostadin Shishmanov , Jakub Jelinek , Dave Hansen , Ard Biesheuvel , Alexey Dobriyan , Ingo Molnar , "H. Peter Anvin (Intel)" , Arnd Bergmann , Nathan Chancellor , Andrew Morton , Thomas Gleixner , Linus Torvalds References: <20251017-v5-4-gcc-15-v1-0-6d6367ee50a1@kernel.org> <2025102004-throwaway-compare-75c2@gregkh> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <2025102004-throwaway-compare-75c2@gregkh> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Greg, Thank you for your reply! On 20/10/2025 15:29, Greg Kroah-Hartman wrote: > On Fri, Oct 17, 2025 at 07:33:37PM +0200, Matthieu Baerts (NGI0) wrote: >> Two backports linked to build issues with GCC 15 have failed in this >> version: >> >> - ee2ab467bddf ("x86/boot: Use '-std=gnu11' to fix build with GCC 15") >> - 8ba14d9f490a ("efi: libstub: Use '-std=gnu11' to fix build with GCC 15") >> >> Conflicts have been solved, and described. >> >> After that, this kernel version still didn't build with GCC 15: >> >> In file included from include/uapi/linux/posix_types.h:5, >> from include/uapi/linux/types.h:14, >> from include/linux/types.h:6, >> from arch/x86/realmode/rm/wakeup.h:11, >> from arch/x86/realmode/rm/wakemain.c:2: >> include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant >> 11 | false = 0, >> | ^~~~~ >> include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards >> include/linux/types.h:30:33: error: 'bool' cannot be defined via 'typedef' >> 30 | typedef _Bool bool; >> | ^~~~ >> include/linux/types.h:30:33: note: 'bool' is a keyword with '-std=c23' onwards >> include/linux/types.h:30:1: warning: useless type name in empty declaration >> 30 | typedef _Bool bool; >> | ^~~~~~~ >> >> I initially fixed this by adding -std=gnu11 in arch/x86/Makefile, then I >> realised this fix was already done in an upstream commit, created before >> the GCC 15 release and not mentioning the error I had. This is patch 3. >> >> When I was investigating my error, I noticed other commits were already >> backported to stable versions. They were all adding -std=gnu11 in >> different Makefiles. In their commit message, they were mentioning >> 'gnu11' was picked to use the same as the one from the main Makefile. >> But this is not the case in this kernel version. Patch 4 fixes that. >> >> Finally, I noticed extra warnings I didn't have in v5.10. Patch 5 fixes >> that. > > 5.4 is only going to be alive for about 1 more month, so I really don't > think trying to "downgrade" things here is worth it at all. Anyone > still stuck on this old, obsolete, and very insecure kernel tree isn't > going to be attempting to build it using the bleeding edge gcc release :) Fine by me for v5.4. I only suggested these very small patches because I had issues with GCC 15 when building v5.15, and I did the small work for older kernels. Please note that the two last patches are not directly linked to GCC 15: - Patch 4/5 fixes the possible bump to C11 standard for some arch. So if I'm not mistaken, it changes the minimal requirements from GCC 4.6 to GCC 4.9. Is it not an issue for such old kernel? (Note: this patch depends on the parents ones, but can be adapted) - Patch 5/5 fixes a warning I saw, but I don't know from which version GCC complains about that. Cheers, Matt -- Sponsored by the NGI0 Core fund.