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 E6BFC1EA7FF; Sat, 4 Oct 2025 08:51:46 +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=1759567907; cv=none; b=ImGKD3Q/vNtESYH9af8+jdfrGYTtyxdsDboTdtbyENLg6RYfm8f8bz3Xc8C66bsHC2mGuOTKrZrrZ8yfjKGEfQWQWM31S/w7r/8UZN0xrX7/DaQtOPRtMMVs8L/WjvPoSOCYy3koEapVKRfEKrbHd4lOXV3r0qJk8l52Q01dSpw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759567907; c=relaxed/simple; bh=/IB8ujFWe6EWSDPEJq2XqSK0nAWZ0LrB0KZJrYSGi/U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hKfT0MdcwtnV6R6E3PA6rXX231a7PUsNfqzVktElHXG9eGYcKXPagqQ4iWHfIEqUOpgJGy1GGivei0fSuHD5L46ji8/40POKxvwvpv2LWdZBPphzOPmbXMLV2QcQ3gY2AQt0XFRhDGk+R+8vpdIfRGVCfNePJ1kWRPFcYp1zk/Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FgJ+ExF2; 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="FgJ+ExF2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE98DC4CEF1; Sat, 4 Oct 2025 08:51:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759567906; bh=/IB8ujFWe6EWSDPEJq2XqSK0nAWZ0LrB0KZJrYSGi/U=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FgJ+ExF2Fvcgfnb8bgsANiVdaAauxX/DFvwDKucflo/ZyQDcBhmvZZRGOMQ25u3vG 48SH8I6Z/0GMFrOQ55Rbq5YOJGGuOAfupXoEQBuvjM6XpslL6WC1q/0VPb1Uzn0a0g UMIXxnkesdOSVa0+dvpLNjrIfUIyiReYdHJcXLbmjQNUeUUr/e6cmV6HDdGwoDQnXo 3NQMK3PWCirg6AG6nk8Sa7ECe8WhvQvZiR/+5TVE2bHnWOI7L7cLsDPZpO3U2EsADt r0ByAmxQBONbT/KL+urq4sU+ztZa2kWWLSMDdk8MR3MIv2oLR/ZOAAvlm0dFesWnuT lyr2lq+WuO3lA== Message-ID: <8b49ca48-ff6b-40ed-8322-e0c9791d1d17@kernel.org> Date: Sat, 4 Oct 2025 10:51:36 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH bpf] selftests/bpf: fix implicit-function-declaration errors Content-Language: en-GB, fr-BE To: Eduard Zingerman , ihor.solodrai@linux.dev, alan.maguire@oracle.com Cc: bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt References: <20251003-bpf-sft-fix-build-err-6-18-v1-1-2a71170861ef@kernel.org> 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Eduard, On 04/10/2025 01:37, Eduard Zingerman wrote: > On Fri, 2025-10-03 at 17:24 +0200, Matthieu Baerts (NGI0) wrote: >> When trying to build the latest BPF selftests, with a debug kernel >> config, Pahole 1.30 and CLang 20.1.8 (and GCC 15.2), I got these errors: >> >> progs/dynptr_success.c:579:9: error: call to undeclared function 'bpf_dynptr_slice'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] >> 579 | data = bpf_dynptr_slice(&ptr, 0, NULL, 1); >> | ^ >> progs/dynptr_success.c:579:9: note: did you mean 'bpf_dynptr_size'? >> .virtme/build-debug-btf//tools/include/vmlinux.h:120280:14: note: 'bpf_dynptr_size' declared here >> 120280 | extern __u32 bpf_dynptr_size(const struct bpf_dynptr *p) __weak __ksym; >> | ^ >> progs/dynptr_success.c:579:7: error: incompatible integer to pointer conversion assigning to '__u64 *' (aka 'unsigned long long *') from 'int' [-Wint-conversion] >> 579 | data = bpf_dynptr_slice(&ptr, 0, NULL, 1); >> | ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> progs/dynptr_success.c:596:9: error: call to undeclared function 'bpf_dynptr_slice'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] >> 596 | data = bpf_dynptr_slice(&ptr, 0, NULL, 10); >> | ^ >> progs/dynptr_success.c:596:7: error: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion] >> 596 | data = bpf_dynptr_slice(&ptr, 0, NULL, 10); >> | ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> I don't have these errors without the debug kernel config from >> kernel/configs/debug.config. With the debug kernel, bpf_dynptr_slice() >> is not declared in vmlinux.h. It is declared there without debug.config. >> >> The fix is similar to what is done in dynptr_fail.c which is also using >> bpf_dynptr_slice(): bpf_kfuncs.h is now included. >> >> Signed-off-by: Matthieu Baerts (NGI0) >> --- > > I can reproduce similar issue when including > kernel/configs/debug.config with my regular dev config, but for > different functions: bpf_rcu_read_{un,}lock(). Thank you for having checked! I also had issues with these functions on my side, when testing on top of 'net'. > However, this is not a way to fix this. > Kfuncs are not supposed to just disappear from DWARF. Indeed. But strange it was fine before. Or fine without debug.config. Cheers, Matt -- Sponsored by the NGI0 Core fund.