From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f74.google.com (mail-ej1-f74.google.com [209.85.218.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ABE4C274B23 for ; Wed, 27 May 2026 12:53:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779886387; cv=none; b=u+XkndqGJk9TZlnn/fdOog/I0O99QoBtcTKo7SGBXfb+oMSk3oWgw2Cv2k2/hXcLTT+mCgdJkqSd+Nk19DjULxpHvHDa41WSd6h7+cSRgSwT4bUSuUV0VqMNICQhjpFOrU+A/8IMNvKS1lALyaTBshc2lNFLG9Egr0dVNmHCmvA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779886387; c=relaxed/simple; bh=rKh7yFwfbu/igasiSX3RCH2Oso9JbKo1Z4xZmpDBbM0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=CQp6KrKRoL/pyNOTJXkHUtWgMP5TZJeNSMY0XkZVAuERaH75W0Ziqq+KX/XM6iZnOWsja+MJxcKILznQ3O36QWkwR4cjEVpXA/GAKKD+Qe/tImpRwbiF5ZkWjLTr4d/8apdn6D4/QXbAPeyV8+0n8CC99NirVobBlVffbEvXSfg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--sidnayyar.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=S5CAe03h; arc=none smtp.client-ip=209.85.218.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--sidnayyar.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="S5CAe03h" Received: by mail-ej1-f74.google.com with SMTP id a640c23a62f3a-bcc22a042b1so1232185266b.2 for ; Wed, 27 May 2026 05:53:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779886384; x=1780491184; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=mwM7tLigXa4SmZ+iBmv8/N7XkWuoA8HVKgKI0pJrdIE=; b=S5CAe03hG2Szfk5Jqs1lIdtY5a8gjiEG2ZQ20UCEfvmSeFArWVHlyGNBp4VWdl6c1A 05ujmZKAi1FKk0SlQMtBOgmLLiHAcsJ1L5zsVMDz5ya6MWiSdikZXPnwi931muGqgFdU QdQaUMHK/dKTKTdZuJz7oybzm+MGOjtu+iDyc2U7lBAkTmWxP+I32+YeE4WZQWyt92Ik ZGwZWfl40kIA/uFAzI6YOdC+lRBoZ+h7VtYodv7NKWRMliZCigisH7BftuDCeXPNR5Rv Q9iLfqp2gRBA432QbsW2S4CeQRbLtz6Km5Cqd7SxKgy7EyMa0oobZJhpgp0zqcagfx3j PQYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779886384; x=1780491184; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mwM7tLigXa4SmZ+iBmv8/N7XkWuoA8HVKgKI0pJrdIE=; b=KSr/n7YqQQkb2uBSkj9qTkWGeOZGOB0puwcpiWV1jO+CiEPYETggX/cp0Ylvc7mhcR CDyMhwh3zhnLBipNfU/pfpoW8K41jjMtJQhn9CDg9RcBKR7z3p0q66u5go/uKxkrhTVs SA3k1d4HTK36RAH6EnB7gAtT4lxSENS0nn/prmq9I51bOws3O+b+NY5Uzvo3noueClzc 6vatX8fgqaJuVj3eIjXCvcGPHDkk+bdbB78cznnc9+7zGNBLSzHinpjDUXi9967Ad2bw fnUEZDb8UDsKxR1d4uC+6a003DUA1TfKo8f6x+OqiVce/BQJZbBnWNTMypvat3ig1M8z Pp2A== X-Forwarded-Encrypted: i=1; AFNElJ+FeyHuXg/+wIXonVamv09E8qAzDqEwj11KWMg5ruhN+84xV5fwC6baUQZ7mPigae5DiHvGw1SlkpztyBM=@vger.kernel.org X-Gm-Message-State: AOJu0YySemAByq3dDyZsq47jqUNS1o4O1hygPkaz8X4mPP84njojrgFD mbp7es9IUW6rH8It9V2MLpKum1XWRokvJIme4v2RQVS3+l2g/zYDNEGuXKMwdSp7r+XUAi2te2E TLcZJTcP360g6rWGhQw== X-Received: from ejcag17.prod.google.com ([2002:a17:906:9a91:b0:bcb:8fd3:7db5]) (user=sidnayyar job=prod-delivery.src-stubby-dispatcher) by 2002:a17:907:9813:b0:bd4:9a55:18e2 with SMTP id a640c23a62f3a-bdd267c685cmr1405394266b.45.1779886383718; Wed, 27 May 2026 05:53:03 -0700 (PDT) Date: Wed, 27 May 2026 12:52:57 +0000 In-Reply-To: <20260527-libbpf-load-vmlinux-btf-in-gen_loader-mode-v4-0-27daa15487a9@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260527-libbpf-load-vmlinux-btf-in-gen_loader-mode-v4-0-27daa15487a9@google.com> X-Mailer: b4 0.14.3 Message-ID: <20260527-libbpf-load-vmlinux-btf-in-gen_loader-mode-v4-1-27daa15487a9@google.com> Subject: [PATCH v4 1/3] libbpf: load vmlinux BTF in gen_loader mode for struct_ops From: Siddharth Nayyar To: Andrii Nakryiko , Eduard Zingerman , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, gprocida@google.com, maennich@google.com, Siddharth Nayyar Content-Type: text/plain; charset="utf-8" During light skeleton generation (`bpftool gen skeleton -L`), libbpf runs in gen_loader mode. Previously, `bpf_object__load_vmlinux_btf()` completely bypassed loading the kernel vmlinux BTF (`obj->btf_vmlinux`) if `gen_loader` was active. However, BPF `struct_ops` maps (such as `sched_ext_ops` maps) require resolving the kernel-side struct type IDs and member sizes at compile/skeleton generation time. Without loading `btf_vmlinux`, libbpf cannot query the kernel BTF types, causing light skeleton generation for `struct_ops` to fail or omit crucial type information. Fix this by modifying the check to load `btf_vmlinux` even in `gen_loader` mode if the BPF object contains `struct_ops` maps. Signed-off-by: Siddharth Nayyar --- tools/lib/bpf/libbpf.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 3a80a018fc7d..b159faae7f9c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3544,15 +3544,20 @@ static bool prog_needs_vmlinux_btf(struct bpf_program *prog) return false; } -static bool map_needs_vmlinux_btf(struct bpf_map *map) +static bool obj_maps_need_vmlinux_btf(const struct bpf_object *obj) { - return bpf_map__is_struct_ops(map); + struct bpf_map *map; + + bpf_object__for_each_map(map, obj) { + if (bpf_map__is_struct_ops(map)) + return true; + } + return false; } static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) { struct bpf_program *prog; - struct bpf_map *map; int i; /* CO-RE relocations need kernel BTF, only when btf_custom_path @@ -3577,12 +3582,7 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) return true; } - bpf_object__for_each_map(map, obj) { - if (map_needs_vmlinux_btf(map)) - return true; - } - - return false; + return obj_maps_need_vmlinux_btf(obj); } static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) @@ -3590,7 +3590,11 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) int err; /* btf_vmlinux could be loaded earlier */ - if (obj->btf_vmlinux || obj->gen_loader) + if (obj->btf_vmlinux) + return 0; + + /* only struct_ops maps need btf_vmlinux in gen_loader */ + if (obj->gen_loader && !obj_maps_need_vmlinux_btf(obj)) return 0; if (!force && !obj_needs_vmlinux_btf(obj)) -- 2.54.0.746.g67dd491aae-goog