From patchwork Thu Aug 22 09:24:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Ambardar X-Patchwork-Id: 13773108 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) (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 B478417BB2A; Thu, 22 Aug 2024 09:25:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.49 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724318706; cv=none; b=SLLJJqZTpqWgzQ8jH/ky9OTHTYSKJkyN9rbohIg9N8Ev0dABFFBY1EUuk5jj0B1TuTEjVQKVbGommSutr66HN0uNkjDWm609vKfXS8jOkpsCLYWb7xVe1AvbAvvWeAqM7v2PFlJYeIZEwk55cgyP3oLHTZ/QvMCZPgltSN1tt6Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724318706; c=relaxed/simple; bh=TxA2C+GdCqOmHIAvvr4Uuh0LZXojsqIzQodG1UXIbJw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Zpgg5jBp0qRQss59/qiuKMkSdXpPE3yc4NlL5MJgm94AZChgqJQtLwMJ+iB19qTHWMz8JJYt3cikG7olDSeDjMcMsPSBOSnRKqdF/p6BP1MgmuV8xfpzI0jNkTQAdP5+38f+6tqCGeN453Ip6CdHcN+6zIRuNZkrvMBVcRDwnko= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=YSWxAXgK; arc=none smtp.client-ip=209.85.216.49 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) header.d=gmail.com header.i=@gmail.com header.b="YSWxAXgK" Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-2d3bc043e81so451990a91.2; Thu, 22 Aug 2024 02:25:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1724318704; x=1724923504; 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; bh=hIq9mb8QDFOrDtUTONaareYk+pebO6PU/g3DNG9tstM=; b=YSWxAXgKa4b1YmvvacKbsFSjJzbV4LxDZ855qoIEk2W7HlJMEeLtAeUHxkNcihM+iC MNBVQW+c/3PX8kpU1807UXoTeivfohDBtoS5CmnWXuHCmssnBZxYMN9OXGfV4i0OQCd1 SchQqOvPK6zmEJdQ8C+qf+H1OlVOan0q3ZJRyL2cFVZe6Z1CyYBEbkEoEpOzRxESps4t S8wuHVNuhTi3BpP+qgUPH7xYbaIqUFRzF3qKJ+VduPh3xH9g0Iu8zcVIpr3Dilw/c/O5 o45QkPHRaSQBsF7yiL/9CLxi5zfewj/B7LFfDlmhkoGwrW/tq+QVdxYsL6CaBjXmpf3C BDDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724318704; x=1724923504; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hIq9mb8QDFOrDtUTONaareYk+pebO6PU/g3DNG9tstM=; b=CWKXMcQ/+iq32K3OAba6t57TT++2l6Nd6ZAZ1brmDkxyKyTcUzFOPiFMC9tAGb/fbl CEXb8dpPAziE9Ws6ekwHJC6IjJc2c+bH0AcmuT1ndtbwnQ6fhYPqgy6HIcOfsMhX2Rdd +fwVgJIEUutiTRfODH26M2USmd3tUqDEuvKU7w6fmPrO51NWdYbO46RcaDRuhky6Zoim 6ic6HyGp501vGFDkBF+BXvAqOoVblVCh6ttwaz+n6G+eoyJCKKHCp6BFTOZLn8dKiqPs n7D+Iq9XrRKec1u59UiKznOJBDRL00NVlFhQzYPAYIaoOZEzWxmfiGm6NLBBsWWRGNbA 6/kg== X-Forwarded-Encrypted: i=1; AJvYcCUNyXNhy2Y2F0dSDMLbK1aOjKrhaLALeal3ASF4+AZJEN+HDhig036XJQ7V7tBYMfD22VCuSBQA79MVoBuRAnI=@vger.kernel.org X-Gm-Message-State: AOJu0Yw0c5R85chF/LdXpFHQrogOe70llJJJ8RVsQcBK4XBZVdDW3KfI apXYTTzTb71zN7x9HT4rWS38S18fPgB5O4OXWSJk2YswVOjVjiiuDnvGyuxz X-Google-Smtp-Source: AGHT+IF4NbmvsWWc8JOu4qe9+WWagOMF5F5qnjixbQqeDaZwde0vuaZs3+C9Rzt6XrfJQ25OqL30oA== X-Received: by 2002:a17:90a:6fc1:b0:2cf:c9df:4cc8 with SMTP id 98e67ed59e1d1-2d61728e621mr1501220a91.38.1724318703682; Thu, 22 Aug 2024 02:25:03 -0700 (PDT) Received: from localhost.localdomain (69-172-146-21.cable.teksavvy.com. [69.172.146.21]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2d5eb90decasm3548820a91.23.2024.08.22.02.25.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Aug 2024 02:25:03 -0700 (PDT) From: Tony Ambardar X-Google-Original-From: Tony Ambardar To: bpf@vger.kernel.org Cc: Tony Ambardar , linux-kselftest@vger.kernel.org, Andrii Nakryiko , Eduard Zingerman , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , Ilya Leoshkevich , Quentin Monnet Subject: [PATCH bpf-next v2 5/8] libbpf: Support opening bpf objects of either endianness Date: Thu, 22 Aug 2024 02:24:28 -0700 Message-Id: <3b65982b50a9ca77a13d7a5a07b8b5d37abc477f.1724313164.git.tony.ambardar@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Tony Ambardar Allow bpf_object__open() to access files of either endianness, and convert included BPF programs to native byte-order in-memory for introspection. Signed-off-by: Tony Ambardar --- tools/lib/bpf/libbpf.c | 21 +++++++++++++++++++-- tools/lib/bpf/libbpf_internal.h | 11 +++++++++++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8a0a0c1e37e1..a542031f4f73 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -940,6 +940,21 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data, return 0; } +static void bpf_object_bswap_progs(struct bpf_object *obj) +{ + struct bpf_program *prog = obj->programs; + struct bpf_insn *insn; + int p, i; + + for (p = 0; p < obj->nr_programs; p++, prog++) { + insn = prog->insns; + for (i = 0; i < prog->insns_cnt; i++, insn++) + bpf_insn_bswap(insn); + pr_debug("prog '%s': converted %zu insns to native byteorder\n", + prog->name, prog->insns_cnt); + } +} + static const struct btf_member * find_member_by_offset(const struct btf_type *t, __u32 bit_offset) { @@ -1610,7 +1625,6 @@ static int bpf_object__check_endianness(struct bpf_object *obj) #else # error "Unrecognized __BYTE_ORDER__" #endif - pr_warn("elf: endianness mismatch in %s.\n", obj->path); return -LIBBPF_ERRNO__ENDIAN; } @@ -3953,6 +3967,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj) return -LIBBPF_ERRNO__FORMAT; } + /* change BPF program insns to native endianness for introspection */ + if (bpf_object__check_endianness(obj)) + bpf_object_bswap_progs(obj); + /* sort BPF programs by section name and in-section instruction offset * for faster search */ @@ -7993,7 +8011,6 @@ static struct bpf_object *bpf_object_open(const char *path, const void *obj_buf, } err = bpf_object__elf_init(obj); - err = err ? : bpf_object__check_endianness(obj); err = err ? : bpf_object__elf_collect(obj); err = err ? : bpf_object__collect_externs(obj); err = err ? : bpf_object_fixup_btf(obj); diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 6b0270c83537..f53daa601c6f 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -590,6 +591,16 @@ static inline bool is_ldimm64_insn(struct bpf_insn *insn) return insn->code == (BPF_LD | BPF_IMM | BPF_DW); } +static inline void bpf_insn_bswap(struct bpf_insn *insn) +{ + /* dst_reg & src_reg nibbles */ + __u8 *regs = (__u8 *)insn + offsetofend(struct bpf_insn, code); + + *regs = (*regs >> 4) | (*regs << 4); + insn->off = bswap_16(insn->off); + insn->imm = bswap_32(insn->imm); +} + /* Unconditionally dup FD, ensuring it doesn't use [0, 2] range. * Original FD is not closed or altered in any other way. * Preserves original FD value, if it's invalid (negative).