From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.229.6 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793529159; b=QcDo/s6e3aaKmBKk7s7rU1O5FTRLxpLyMapI/OnWoi86ZH/p1V6boHP8J/zWwDbCyK7s wkZWvH+O+4FFNxoxZGDZQDDzvFtRFVQoE0UbcDfDGFmczh0+xO5JJVyV17fA4VrZQRi/T y38hh+ftLrE/+i9ebRhZVz6PP5YuZp7iK3QCbNGLdPNQTVTkvnJfNSA5X5G1rsaVI+T5Z o5CFA1d92uX8mfHDMmoojmcnNkhs77v7o+Bvcsq/AvVtIC0bIKdy5D5kypIejPHOdp7Y4 mfb+88b7IrRYF3R5yBFIrxUKSafRqN6NjQ+8cTnt55XKU12BUdDPRv3IGyeqawz5tVA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793529159; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=7idC5jXJA5zuKx9XSKl0bY7AYg4yh09bXWbxriqp4fs=; b=vJxddLBQTQ1OU8ATbIvrsMecIWqW+tg87UdYZTTeYKyoiFdNU55rGgFscM8LzTAd47NO DVW8lK65YPwuhBLOkUY6fT0oRUDfQilWVoa6SFk+Jwab4HVEc0jihUhpRKWiEjfthvDGt quekNsxO4w2z0fc6JEy3oEncWdPbdK/ehF6plGbWCQDouExVT+7v3PoPan32KRM63MiGU S1/pIVOav1wk0KOVQ2w8H2pmcZOgVaidpjUzIItKFUcDxCfS0Ua6WF4GZCf5wepTNkskb Wtjz77LgG0EW27eEzu87BvsipIYdoHogeZ1f2Xpyfpp4OWTCc/uWRN95C4/5DqW1qnQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=GNVbTM2W; arc=none smtp.remote-ip=74.125.229.6 Received: from mail-dy2-f6.google.com (mail-dy2-f6.google.com [74.125.229.6]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5BC3606A336 for ; Sun, 1 Nov 2026 10:32:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A5BC3606A336 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=GNVbTM2W Received: by mail-dy2-f6.google.com with SMTP id 5a478bee46e88-33e48934fa8so737917eec.0 for ; Sun, 01 Nov 2026 02:32:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793529158; x=1794133958; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=7idC5jXJA5zuKx9XSKl0bY7AYg4yh09bXWbxriqp4fs=; b=GNVbTM2W0Z86IBRKkWpp3WDWlg0YOyfeAgw/vDuz7Vfq+z//0hwbeedgRq+KWK3gm4 JH6c4K1ukoDGWc6UjU+oCSuHV26bkFE+8Ko27MnrCNWzBWEFj1L6Hj17+vp6hQQeglc2 wf7xgLrGnuWinTIQSkpbGx3cVTtkOlBd0NvfEX7yrc2vlDgG5jCcRCcLwhIYDFE2joaH MWfXK1frK6V/1XuEDYbfUlC/ZkQweTtvsBBslxXC6qq54A3e3CzqcuHStMg3DQd+Xo4a EArfJsEiWF+jwqvc4U5pYkLWtCt4qW+D5mpm4NXDHRzzZxVvtaNYzdJpXhlm+p5kHA1H Wx2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793529158; x=1794133958; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=7idC5jXJA5zuKx9XSKl0bY7AYg4yh09bXWbxriqp4fs=; b=xVj/7+Dwh7rpRsgzwvXEOLteGMZFqDPsXPEFaMBomQNxNC8JUZEHzz9MPlK1l/60Dj f+lhFhgk0AZhuRFmvDntoYN/MR07HmthSnsKphtwMtus5HMXhuhYvc7f1A6dQ8ypqHWb 0rwB3k7KXQ+r4uWjgX12HtS80kRst3YEXuR2QNgCIPkXgD9f2G6BJY80y2juRyOWEWO1 uetZuT+I0WSOdH7/YKInx0Ws/jTyAdgi5duFQ8cdXQKisq/YdPhJE4uST/VNoajE7G1l Dv3LVDbs6jKnIyXI9LcX1I09ScDLsis0khYi6IyWHezw5kMaAJal5oozhJ2KqRVwxRq3 vlXg== X-Forwarded-Encrypted: i=1; AKwUvByB6TKfJJO9FGBjIGEXYxaK8y1OMwtQvxnU4FUiEdaDe/rPxVsCBNIx++7FtgvIE1DXXU5ejT+mTnEa5Mk=@vger.kernel.org X-Gm-Message-State: AFq9FYLnZ/JqJztsG9ZAuxOP6G5Ywt0sgvQGEL7iel5MCVLnZqQXjLQR b/HDmKUhQIpClpBN1HUjcXs8MlZsgHb4Iz6cIbyt2vGaZ0KyyZE4VK/w X-Gm-Gg: AYBFou2oQzsFs1tRh7vyefubfTUStzPz+TsAcBFh6nts19tEoa/4rlGB8+g5NcORUfl FhI3rmr2Ika5YyhAHVobe2worTO7rgEmUtsnAzBjw1hdvdiwIzUDwZ4KtnTXwuCuOzKpSgq2yNF zw9FUe8Wlvfqq9VcpnVoqZ0+mi6zPsKPzH2x/edmxUNEadoIVja2+a92BiqqjXslQf0PNVVKVmc vDoFBowLzIMaGPgqQ8H+OP6GmOKm15IIP6ZJ5m0dIW2LMOnQ5qNA+Q1fIJei6PLWZUrEllX2BQ6 C1LH/5tQo4fsUPj5FFe63tmrC5IQJfiY8UldTLH/JEWcuafJZUDiUUDykq+XubtVYWOmZP9rCH7 l9QecP3ZVPFHdPJIxByFyJ0HWoi4Z0/6ITrxJ0il5KYQpj46PgyipcYxehJOFmEAaGGFNIh+veq S5p0IDpDkcBJtS6Wl8GYZu9OelFMStPCe0TRbN2xaPeVZ+xL04xqc6vIHy4ruTO6it1EVmdc0Zr /H0M2YwmWV/CrJLNBlVP3T039KibWz+3h9iSacAf8CEBjBZVy6NSoikXkjRIwFexpsJQnQ2tqz5 ib/NSEiwH8XywLG/uSOuEFPaUcI471ZYKTVT8TBTEG/hDiijW1To0Y61 X-Received: by 2002:a05:7301:52ca:b0:369:fc38:6821 with SMTP id 5a478bee46e88-36a423938f2mr10214355eec.12.1793529157617; Sun, 01 Nov 2026 02:32:37 -0800 (PST) Received: from localhost.localdomain ([98.148.34.5]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-36a428c17bdsm25242506eec.6.2026.11.01.02.32.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Nov 2026 02:32:35 -0800 (PST) From: Hungyu Lin To: ast@kernel.org, bpf@vger.kernel.org Cc: andrii@kernel.org, qmo@kernel.org, daniel@iogearbox.net, yonghong.song@linux.dev, eddyz87@gmail.com, ihor.solodrai@linux.dev, shuah@kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Hungyu Lin Subject: [PATCH bpf-next v3 1/3] libbpf: Normalize enum values according to signedness Date: Sun, 1 Nov 2026 10:32:19 +0000 Message-ID: <20261101103221.51534-2-dennylin0707@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261101103221.51534-1-dennylin0707@gmail.com> References: <20261101103221.51534-1-dennylin0707@gmail.com> X-Mailing-List: linux-kernel@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 BTF_KIND_ENUM stores enumerators in a signed 32-bit field even for unsigned enums. btf_dump_enum_data() compares unsigned data against that signed field, so values with bit 31 set fail to match their names. get_map_field_long() also sign-extends the field: for example, __ulong(map_extra, 0x80000000) becomes 0xffffffff80000000 instead of the requested arena mapping address. Add btf_enum_value() to extend an enumerator according to kflag and use it in both places. For data dumps, keep the original comparison as well. Older BTF producers did not record enum signedness; an eight-byte BTF_KIND_ENUM can contain signed data such as -1 with kflag clear. Using only the helper would lose an existing name match. This compatibility comparison does not truncate the data value or change the numeric fallback. For an eight-byte BTF_KIND_ENUM with kflag clear, a negative stored enumerator can therefore match both its sign- and zero-extended values. The record cannot distinguish legacy signed metadata from unsigned metadata with the same bits. Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Fixes: d147357e2e59 ("libbpf: Allow specifying 64-bit integers in map BTF.") Suggested-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/DMJG1R2YIJRK.16CZLV9S5U7Z7@gmail.com/ Signed-off-by: Hungyu Lin --- tools/lib/bpf/btf.h | 6 ++++++ tools/lib/bpf/btf_dump.c | 3 ++- tools/lib/bpf/libbpf.c | 2 +- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 57f12630c5d1..eeb4984d6c57 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -636,6 +636,12 @@ static inline struct btf_enum *btf_enum(const struct btf_type *t) return (struct btf_enum *)(t + 1); } +/* btf_enum->val is signed even for unsigned enums; kflag records the sign. */ +static inline __s64 btf_enum_value(const struct btf_type *t, const struct btf_enum *e) +{ + return btf_kflag(t) ? (__s64)e->val : (__u32)e->val; +} + struct btf_enum64; static inline struct btf_enum64 *btf_enum64(const struct btf_type *t) diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index ea9a34db4c00..b636dc4185a0 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -2373,7 +2373,8 @@ static int btf_dump_enum_data(struct btf_dump *d, const struct btf_enum *e; for (i = 0, e = btf_enum(t); i < btf_vlen(t); i++, e++) { - if (value != e->val) + /* Keep names from legacy signed enums without kflag. */ + if (value != e->val && value != btf_enum_value(t, e)) continue; btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off)); return 0; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 02e75b183ed0..cecd6b5f27de 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2627,7 +2627,7 @@ static bool get_map_field_long(const char *map_name, const struct btf *btf, if (btf_is_enum(t)) { const struct btf_enum *e = btf_enum(t); - *res = e->val; + *res = btf_enum_value(t, e); } else { const struct btf_enum64 *e = btf_enum64(t); -- 2.43.0