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From: Christoph Hellwig <hch@lst.de>
To: Jonathan Corbet <corbet@lwn.net>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	linux-doc@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org
Subject: [PATCH 4/6] bpf, docs: Fully document the ALU opcodes
Date: Mon,  3 Jan 2022 19:35:54 +0100	[thread overview]
Message-ID: <20220103183556.41040-5-hch@lst.de> (raw)
In-Reply-To: <20220103183556.41040-1-hch@lst.de>

Add pseudo-code to document all the different BPF_ALU / BPF_ALU64
opcodes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/bpf/instruction-set.rst | 30 +++++++++++++--------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
index 2987cbb07f7f6..efba4d1931853 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -82,24 +82,24 @@ BPF_ALU uses 32-bit wide operands while BPF_ALU64 uses 64-bit wide operands for
 otherwise identical operations.
 The code field encodes the operation as below:
 
-  ========  =====  =========================
+  ========  =====  ==========================
   code      value  description
-  ========  =====  =========================
-  BPF_ADD   0x00
-  BPF_SUB   0x10
-  BPF_MUL   0x20
-  BPF_DIV   0x30
-  BPF_OR    0x40
-  BPF_AND   0x50
-  BPF_LSH   0x60
-  BPF_RSH   0x70
-  BPF_NEG   0x80
-  BPF_MOD   0x90
-  BPF_XOR   0xa0
-  BPF_MOV   0xb0   mov reg to reg
+  ========  =====  ==========================
+  BPF_ADD   0x00   dst += src
+  BPF_SUB   0x10   dst -= src
+  BPF_MUL   0x20   dst \*= src
+  BPF_DIV   0x30   dst /= src
+  BPF_OR    0x40   dst \|= src
+  BPF_AND   0x50   dst &= src
+  BPF_LSH   0x60   dst <<= src
+  BPF_RSH   0x70   dst >>= src
+  BPF_NEG   0x80   dst = ~src
+  BPF_MOD   0x90   dst %= src
+  BPF_XOR   0xa0   dst ^= src
+  BPF_MOV   0xb0   dst = src
   BPF_ARSH  0xc0   sign extending shift right
   BPF_END   0xd0   endianness conversion
-  ========  =====  =========================
+  ========  =====  ==========================
 
 BPF_ADD | BPF_X | BPF_ALU means::
 
-- 
2.30.2


  parent reply	other threads:[~2022-01-03 18:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-03 18:35 more eBPF instruction set documentation improvements Christoph Hellwig
2022-01-03 18:35 ` [PATCH 1/6] bpf, docs: Add a setion to explain the basic instruction encoding Christoph Hellwig
2022-01-03 18:35 ` [PATCH 2/6] bpf, docs: Add subsections for ALU and JMP instructions Christoph Hellwig
2022-01-03 18:35 ` [PATCH 3/6] bpf, docs: Document the opcode classes Christoph Hellwig
2022-01-03 18:35 ` Christoph Hellwig [this message]
2022-01-03 18:35 ` [PATCH 5/6] bpf, docs: Fully document the JMP opcodes Christoph Hellwig
2022-01-03 18:35 ` [PATCH 6/6] bpf, docs: Fully document the JMP mode modifiers Christoph Hellwig
2022-01-05 21:14 ` more eBPF instruction set documentation improvements Alexei Starovoitov

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