From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792444217; b=4Q2oYogUAcN49iEaV1PV6eXVWgd7N+5jYyn5rVn+/3c6NbnYPl/66vn7a+rKh2D3xTxE MRegQ/U6sIii3I7MXhr4IoX6eh2RhabAOjdDbyIyfDF6RppPPfGMcfp63nvW5lbb7bAV2 V3qXEPvLO2/2RFs+8G73HCgNEEOEp4BpeG8fZeGwpVoR/IxbCjSKHBdAwmZlM4jMKo0I5 0un5p26Cf9UdegYgDTd+GfRYiU7mc2MoeCD/i4peLxIf37a4TOFw7NleoN/h5xopuTWak ZLUhk7gjGGK4VcecOz3RAqoY/2GIC8t+HPHoR3ft9Ofui3xj45IJ/lPp0w8JhVQUf7Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792444217; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=YhI+AK81XLCtdL59lTKeYo77+ymjLGfVFWvDZPKBf20=; b=l2GqnaWTfRFiYUzONcPyGubiSTNMBDm04xxNyURnwBKKRZcMks7OzMQlitKE/bQcn9kh xFHszqvGKF9HWl4Ft84UDwmkhWJdP4Uh+QFN+f144tcQjRzAeS7TM5yj1WL1ffWCX8UHA aqsZdPTvG+P+WRTs8bgU7vqACO3r4/OHtxNzFYbfhQlMuN2l5U/aUC5L8rZVyd3k4OpF6 PP38l2ARWsY6Kxg6/EZDiWu9Vwz+2xhb7IUJtFtTlWdiJmeyGjq1cJykxIm/erxJFV/9k BtrqZQPThwDNCpdZ7YYawDPYkH+nM3Z9NZntppbNuhfRNKSOMi+5DmuOzkEnEBOeMxw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="nM/SRvyV"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 145D8606A323; Mon, 19 Oct 2026 21:10:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nM/SRvyV Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CB8C1F000C4; Mon, 19 Oct 2026 21:10:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792444216; bh=YhI+AK81XLCtdL59lTKeYo77+ymjLGfVFWvDZPKBf20=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nM/SRvyVZ0Gv8bi/pylE2bHe1ifDVtvl4k47e5rRHluJ8VOQLN3jt+ABrt38eQ33M FXDF8sYE1K3r+b4ZR8nU8K7kuQ5w01I+F0jvSHdBU53NUxe/QeoAoqvQ4ZbuNQn+x5 Q/lvGGQFBjlUsr4ZSrHG5CbJpQZVwYwNJITvdhS90rgk9HSMKU1yQglMCx66M//xUE 8AsGNQ7BK0biQfnpLVRv7E/RTy3yGgKDiX6kdB5FDZ2zhQ7UFXyxXwnhBmjFhPTqdy gLSXPteD5SbW7ja0Z1JSN5nX4G1x/h3NEhUqx10LVxzfNSG92kse3HSavti3qBw1Sd LfuAIcIl8xhmw== From: Sasha Levin To: bpf@vger.kernel.org Cc: Sasha Levin , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , Eric Dumazet , Kuniyuki Iwashima , Paolo Abeni , Willem de Bruijn , "David S. Miller" , Jakub Kicinski , Simon Horman , Amery Hung , Puranjay Mohan , Stanislav Fomichev , Mahe Tardy , Jiayuan Chen , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Petr Pavlu , Leon Hwang Subject: [PATCH bpf-next 2/3] bpf: Don't reference arena kfuncs when arena isn't built Date: Mon, 19 Oct 2026 17:10:05 -0400 Message-ID: <20261019211006.2574350-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261019211006.2574350-1-sashal@kernel.org> References: <20261019211006.2574350-1-sashal@kernel.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit kernel/bpf/Makefile builds arena.o only for CONFIG_MMU && CONFIG_64BIT, but special_kfunc_list references bpf_arena_alloc_pages() and bpf_arena_free_pages() unconditionally, so on 32-bit and !MMU kernels resolve_btfids can't resolve them: WARN: resolve_btfids: unresolved symbol bpf_arena_free_pages WARN: resolve_btfids: unresolved symbol bpf_arena_alloc_pages Since commit 201a454df948 ("resolve_btfids: Fix the --fatal_warnings exit status") these warnings fail the build with CONFIG_WERROR=y, which breaks i386 builds with CONFIG_DEBUG_INFO_BTF=y: Failed to generate BTF for vmlinux Try to disable CONFIG_DEBUG_INFO_BTF Only reference them under the condition arena.o is built with, and use BTF_ID_UNUSED otherwise to keep the list in sync with enum special_kfunc_type. An unresolved ID is zero, like BTF_ID_UNUSED, so the contents of the list don't change. Fixes: b8467290edab ("bpf: arena: make arena kfuncs any context safe") Assisted-by: LLM Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 22f095b9dca2d..12229713a4528 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13639,8 +13639,13 @@ BTF_ID(func, bpf_task_work_schedule_signal) BTF_ID(func, bpf_task_work_schedule_resume) BTF_ID(func, bpf_call_rcu) BTF_ID(func, bpf_call_rcu_tasks_trace) +#if defined(CONFIG_MMU) && defined(CONFIG_64BIT) BTF_ID(func, bpf_arena_alloc_pages) BTF_ID(func, bpf_arena_free_pages) +#else +BTF_ID_UNUSED +BTF_ID_UNUSED +#endif #ifdef CONFIG_BPF_EVENTS BTF_ID(func, bpf_session_is_return) #else -- 2.53.0