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 4481E126F0A; Mon, 20 Oct 2025 16:00:37 +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=1760976038; cv=none; b=GvfiA0QPfX4DFipxC3TGGgAXsB2OyIAROrGvPuSbZfl7qnRmEGgPbcaV2AZR4A9z5PJyAIa3Um6txoggPc2A/TLJXtu3JlGm2S2L9dOaGjc5dJiPnrfugte5RLH10m/Jtq083Xxxjv+RdrDrCw0wAI5p/Rf+ODflZZ8kLAteuaM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760976038; c=relaxed/simple; bh=1AXYnq9xSwQ258113idomVcoI59tyc8h40X8Q37iYvk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TzMEm0dymeSdJsx0J5f+FWMFMcBC7rdETUOWaEqkSTUkGKNhVtfolZ+u3snwRfcBgcGpb0rR79hI/zVG5c5tucbpr3vcORSVUsAxa8lNmULAjt4w+wr4IneY/fr6oT8oAyoe1nyWjNkOl4b0Vp/XBKVZBZyZpL2soKdAfxM2hc0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OW6vWd0+; 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="OW6vWd0+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81A76C4CEF9; Mon, 20 Oct 2025 16:00:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760976037; bh=1AXYnq9xSwQ258113idomVcoI59tyc8h40X8Q37iYvk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OW6vWd0+yJp4fZWfv0X+BIDLwQ1+kLs+aM5d+icfvbrrktAknrdQTurM9mHAPZ1Jk V7cIOztRT6ZhMgAkwlOL66T+2fGh0f5RwwP8c2A7OH48EDThFLn6mNazIzihW5RRA7 zO7Tq7FvaNDCKMgQpZULYQMXlpl+J1II74lOKjKbBZBQ5EusThDjVwc5ITsUwRazlY wVQSzxlqnBW/8rxnIHUQchRzkcogoFJ0ghLKXMBw1zHZlEjTmDHx31U/OOM/vR3+vw YaWpMtSNDM7TIAK2RIgqEaG+DVtp6Gm2TBJw8F+nMiDfRpdWVzKPaEZHdmCGFsymJI 7ZXIQUJ7lAvFA== Message-ID: <4aba3d11-923d-4e4a-81a2-75bcafea38d4@kernel.org> Date: Mon, 20 Oct 2025 18:00:31 +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 5.10.y 0/3] v5.10: fix build with GCC 15 Content-Language: en-GB, fr-BE To: Greg Kroah-Hartman Cc: stable@vger.kernel.org, Sasha Levin , MPTCP Upstream , Alexey Dobriyan , Ingo Molnar , "H. Peter Anvin (Intel)" , Nathan Chancellor , Dave Hansen , Ard Biesheuvel , Arnd Bergmann , Douglas Raillard , "Masami Hiramatsu (Google)" , "Steven Rostedt (Google)" , Mathieu Desnoyers References: <20251017-v5-10-gcc-15-v1-0-cdbbfe1a2100@kernel.org> <2025102055-result-magnolia-96ba@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: <2025102055-result-magnolia-96ba@gregkh> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Greg, Thank you for your reply! On 20/10/2025 15:32, Greg Kroah-Hartman wrote: > On Fri, Oct 17, 2025 at 06:53:24PM +0200, Matthieu Baerts (NGI0) wrote: >> This kernel version doesn'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 the first >> patch. >> >> 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 2 fixes that. >> >> Finally, I noticed an extra warning that I didn't have in v5.15. Patch 3 >> fixes that. > > As with 5.4.y, this kernel isn't going to be around all that much > longer, and I strongly doubt anyone that relies on it is also using > gcc15 with it. Normally near the end of the 6 year window of kernels, > we are "stuck" with using older gcc releases with that, and not newer > ones, and that's fine, as that's what the users of those kernels are > also doing. > > So I don't think the effort is worth it. gcc14 will be around in > distros for the next year so all should be ok here. Just like gcc13 was > around long enough for us to keep 4.19.y working just fine with that > maximum compiler release as well. Fine by me, but just to avoid confusions, I would like to add: - Only the first patch fixes the GCC 15 support, and it only adds '-std=gnu11' in x86/boot. All the other GCC 15 specific patches have already been backported, only that one didn't have a Fixes tag and was missing in <= v5.15. - Patch 2/3 fixes the (accidental) switch to C11 standard for some arch. It should not be a problem in v5.10, because GCC minimal version is 4.9 which supports C11 if I'm not mistaken. It is just to be consistent with what is done in the main Makefile, but it can be drop if preferred. - Patch 3/3 is not linked to GCC 15 support, it fixes an ISO C90 warning. Cheers, Matt -- Sponsored by the NGI0 Core fund.