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 C38EF39B946 for ; Sat, 28 Feb 2026 18:15:20 +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=1772302520; cv=none; b=FxGd0OgQqZ87p0nsVLMqRt9z55rR8Uh9u7XGQE3/SFFulnARmIBissV30RljH3RoszpwtpiEJ+ZI1Q4JflGgLGCt9mJn2XlRooJ0jBtiH+/NBB7nBvaMlJHhC+o+vsROQv9FPyzlb4BW3hqzE3HXMs0ZkpQBdHZp2mwERwY5D48= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302520; c=relaxed/simple; bh=zo3zIFH9qrF9J0RpUtvVmckqMGpkYgj99di/zOQHI24=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rcN+WRNVcNwCNyUBSyHSVlmeM2yd1YFUuJkSRVdQEyOWso09y80tULPBfk7lfVY4O8qaS5nwMHoURBRgKboCmoligYTeW2Agz67d3CGKY85tlNmwa7DYOQkEnP0MnNJ1lCNqj3PjGLkC4fiHqwyI+I4JtexRWmJ2w2bN3b/J2B4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hhZAkmeV; 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="hhZAkmeV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3577AC116D0; Sat, 28 Feb 2026 18:15:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302520; bh=zo3zIFH9qrF9J0RpUtvVmckqMGpkYgj99di/zOQHI24=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hhZAkmeVdDX7w5fhRIWiSU9WGkIfNV251PntP+EtjS7lO/kGDtEzc3CmzmdrfTHTu ZB6N2AQcIZxYzsHrOxHMSuWsTIQ3ItRfBrHsxCtW6XBsW8y/Ek/ufre1qpuQ13YqZH OhKIu05uLJjKF5TiZV2iadJBXfLsd5BqAvexlTo0mv9QA3wzVnaE0wyXabu2m4rtDb r4144ZNfo5BJI2ATvbzuxLQ1wKfJGT2d/ePZK51P6pvchus7O3lwBCmFl0+QmUKPE7 2ys4R+85mb/hcD8cGCpeCSucRp2Lau3O1HvYv5EPHcJtLyTsGxKLbT4wqvbTpFjr2w EtCdMj/RDmvMg== From: Sasha Levin To: patches@lists.linux.dev Cc: Ilya Leoshkevich , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.15 018/164] libbpf: Fix dumping big-endian bitfields Date: Sat, 28 Feb 2026 13:12:37 -0500 Message-ID: <20260228181505.1600663-18-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181505.1600663-1-sashal@kernel.org> References: <20260228181505.1600663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Ilya Leoshkevich [ Upstream commit c9e982b879465ca74e3593ce82808aa259265a71 ] On big-endian arches not only bytes, but also bits are numbered in reverse order (see e.g. S/390 ELF ABI Supplement, but this is also true for other big-endian arches as well). Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211013160902.428340-3-iii@linux.ibm.com Stable-dep-of: 5714ca8cba5e ("libbpf: Fix OOB read in btf_dump_get_bitfield_value") Signed-off-by: Sasha Levin --- tools/lib/bpf/btf_dump.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index d62b2d2e8aacb..91ab07901a1bc 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1656,29 +1656,28 @@ static int btf_dump_get_bitfield_value(struct btf_dump *d, __u64 *value) { __u16 left_shift_bits, right_shift_bits; - __u8 nr_copy_bits, nr_copy_bytes; const __u8 *bytes = data; - int sz = t->size; + __u8 nr_copy_bits; __u64 num = 0; int i; /* Maximum supported bitfield size is 64 bits */ - if (sz > 8) { - pr_warn("unexpected bitfield size %d\n", sz); + if (t->size > 8) { + pr_warn("unexpected bitfield size %d\n", t->size); return -EINVAL; } /* Bitfield value retrieval is done in two steps; first relevant bytes are * stored in num, then we left/right shift num to eliminate irrelevant bits. */ - nr_copy_bits = bit_sz + bits_offset; - nr_copy_bytes = t->size; #if __BYTE_ORDER == __LITTLE_ENDIAN - for (i = nr_copy_bytes - 1; i >= 0; i--) + for (i = t->size - 1; i >= 0; i--) num = num * 256 + bytes[i]; + nr_copy_bits = bit_sz + bits_offset; #elif __BYTE_ORDER == __BIG_ENDIAN - for (i = 0; i < nr_copy_bytes; i++) + for (i = 0; i < t->size; i++) num = num * 256 + bytes[i]; + nr_copy_bits = t->size * 8 - bits_offset; #else # error "Unrecognized __BYTE_ORDER__" #endif -- 2.51.0