path: root/doc/rfc/rfc9669.txt

Internet Engineering Task Force (IETF)                    D. Thaler, Ed.
Request for Comments: 9669                                  October 2024
Category: Standards Track                                               
ISSN: 2070-1721


                 BPF Instruction Set Architecture (ISA)

Abstract

   eBPF (which is no longer an acronym for anything), also commonly
   referred to as BPF, is a technology with origins in the Linux kernel
   that can run untrusted programs in a privileged context such as an
   operating system kernel.  This document specifies the BPF instruction
   set architecture (ISA).

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc9669.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Revised BSD License text as described in Section 4.e of the
   Trust Legal Provisions and are provided without warranty as described
   in the Revised BSD License.

Table of Contents

   1.  Introduction
   2.  Documentation Conventions
     2.1.  Types
     2.2.  Functions
     2.3.  Definitions
     2.4.  Conformance Groups
   3.  Instruction Encoding
     3.1.  Basic Instruction Encoding
     3.2.  Wide Instruction Encoding
     3.3.  Instruction Classes
   4.  Arithmetic and Jump Instructions
     4.1.  Arithmetic Instructions
     4.2.  Byte Swap Instructions
     4.3.  Jump Instructions
       4.3.1.  Helper Functions
       4.3.2.  Program-Local Functions
   5.  Load and Store Instructions
     5.1.  Regular Load and Store Operations
     5.2.  Sign-Extension Load Operations
     5.3.  Atomic Operations
     5.4.  64-bit Immediate Instructions
       5.4.1.  Maps
       5.4.2.  Platform Variables
     5.5.  Legacy BPF Packet Access Instructions
   6.  Security Considerations
   7.  IANA Considerations
     7.1.  BPF Instruction Conformance Groups Registry
       7.1.1.  BPF Instruction Conformance Groups Registration
               Template
     7.2.  BPF Instruction Set Registry
       7.2.1.  BPF Instruction Registration Template
     7.3.  Adding Instructions
     7.4.  Deprecating Instructions
     7.5.  Change Control
     7.6.  Expert Review Instructions
   8.  References
     8.1.  Normative References
     8.2.  Informative References
   Appendix A.  Initial BPF Instruction Set Values
   Acknowledgements
   Author's Address

1.  Introduction

   eBPF, also commonly referred to as BPF, is a technology with origins
   in the Linux kernel that can run untrusted programs in a privileged
   context such as an operating system kernel.  This document specifies
   the BPF instruction set architecture (ISA).

   As a historical note, BPF originally stood for Berkeley Packet
   Filter, but now that it can do so much more than packet filtering,
   the acronym no longer makes sense.  BPF is now considered a
   standalone term that does not stand for anything.  The original BPF
   is sometimes referred to as cBPF (classic BPF) to distinguish it from
   the now widely deployed eBPF (extended BPF).

2.  Documentation Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   For brevity and consistency, this document refers to families of
   types using a shorthand syntax and refers to several expository,
   mnemonic functions when describing the semantics of instructions.
   The range of valid values for those types and the semantics of those
   functions are defined in the following subsections.

2.1.  Types

   This document refers to integer types with the notation SN to specify
   a type's signedness (S) and bit width (N), respectively.

                               +===+==========+
                               | S | Meaning  |
                               +===+==========+
                               | u | unsigned |
                               +---+----------+
                               | s | signed   |
                               +---+----------+

                             Table 1: Meaning of
                             Signedness Notation

                             +=====+===========+
                             | N   | Bit Width |
                             +=====+===========+
                             | 8   | 8 bits    |
                             +-----+-----------+
                             | 16  | 16 bits   |
                             +-----+-----------+
                             | 32  | 32 bits   |
                             +-----+-----------+
                             | 64  | 64 bits   |
                             +-----+-----------+
                             | 128 | 128 bits  |
                             +-----+-----------+

                             Table 2: Meaning of
                              Bit-Width Notation

   For example, _u32_ is a type whose valid values are all the 32-bit
   unsigned numbers and _s16_ is a type whose valid values are all the
   16-bit signed numbers.

2.2.  Functions

   The following byte swap functions are direction agnostic.  That is,
   the same function is used for conversion in either direction
   discussed below.

   *  be16: Takes an unsigned 16-bit number and converts it between host
      byte order and big-endian byte order [IEN137].

   *  be32: Takes an unsigned 32-bit number and converts it between host
      byte order and big-endian byte order.

   *  be64: Takes an unsigned 64-bit number and converts it between host
      byte order and big-endian byte order.

   *  bswap16: Takes an unsigned 16-bit number in either big- or little-
      endian format and returns the equivalent number with the same bit
      width but opposite endianness.

   *  bswap32: Takes an unsigned 32-bit number in either big- or little-
      endian format and returns the equivalent number with the same bit
      width but opposite endianness.

   *  bswap64: Takes an unsigned 64-bit number in either big- or little-
      endian format and returns the equivalent number with the same bit
      width but opposite endianness.

   *  le16: Takes an unsigned 16-bit number and converts it between host
      byte order and little-endian byte order.

   *  le32: Takes an unsigned 32-bit number and converts it between host
      byte order and little-endian byte order.

   *  le64: Takes an unsigned 64-bit number and converts it between host
      byte order and little-endian byte order.

2.3.  Definitions

   Sign Extend:  To sign extend an X-bit number, A, to a Y-bit number,
      B, means to

      1.  Copy all X bits from A to the lower X bits of B.

      2.  Set the value of the remaining Y - X bits of B to the value of
          the most significant bit of A.

      |  *Example*
      |  
      |  Sign extend an 8-bit number A to a 16-bit number B on a big-
      |  endian platform:
      |  
      |     A:          10000110
      |     B: 11111111 10000110

2.4.  Conformance Groups

   An implementation does not need to support all instructions specified
   in this document (e.g., deprecated instructions).  Instead, a number
   of conformance groups are specified.  An implementation MUST support
   the base32 conformance group and MAY support additional conformance
   groups, where supporting a conformance group means it MUST support
   all instructions in that conformance group.

   The use of named conformance groups enables interoperability between
   a runtime that executes instructions, and tools such as compilers
   that generate instructions for the runtime.  Thus, capability
   discovery in terms of conformance groups might be done manually by
   users or automatically by tools.

   Each conformance group has a short ASCII label (e.g., "base32") that
   corresponds to a set of instructions that are mandatory.  That is,
   each instruction has one or more conformance groups of which it is a
   member.

   This document defines the following conformance groups:

   base32:  includes all instructions defined in this specification
      unless otherwise noted.

   base64:  includes base32, plus instructions explicitly noted as being
      in the base64 conformance group.

   atomic32:  includes 32-bit atomic operation instructions (see
      Section 5.3).

   atomic64:  includes atomic32, plus 64-bit atomic operation
      instructions.

   divmul32:  includes 32-bit division, multiplication, and modulo
      instructions.

   divmul64:  includes divmul32, plus 64-bit division, multiplication,
      and modulo instructions.

   packet:  deprecated packet access instructions.

3.  Instruction Encoding

   BPF has two instruction encodings:

   *  the basic instruction encoding, which uses 64 bits to encode an
      instruction

   *  the wide instruction encoding, which appends a second 64 bits
      after the basic instruction for a total of 128 bits.

3.1.  Basic Instruction Encoding

   A basic instruction is encoded as follows:

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    opcode     |     regs      |            offset             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                              imm                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   *opcode:*  operation to perform, encoded as follows:

      +-+-+-+-+-+-+-+-+
      |specific |class|
      +-+-+-+-+-+-+-+-+

      *specific:*  The format of these bits varies by instruction class

      *class:*  the instruction class (see Section 3.3)

   *regs:*  the source and destination register numbers, encoded as
      follows on a little-endian host:

      +-+-+-+-+-+-+-+-+
      |src_reg|dst_reg|
      +-+-+-+-+-+-+-+-+

      and as follows on a big-endian host:

      +-+-+-+-+-+-+-+-+
      |dst_reg|src_reg|
      +-+-+-+-+-+-+-+-+

      *src_reg:*  the source register number (0-10), except where
         otherwise specified (64-bit immediate instructions (see
         Section 5.4) reuse this field for other purposes)

      *dst_reg:*  the destination register number (0-10), unless
         otherwise specified (future instructions might reuse this field
         for other purposes)

   *offset:*  signed integer offset used with pointer arithmetic, except
      where otherwise specified (some arithmetic instructions reuse this
      field for other purposes)

   *imm:*  signed integer immediate value

   Note that the contents of multi-byte fields ('offset' and 'imm') are
   stored using big-endian byte ordering on big-endian hosts and little-
   endian byte ordering on little-endian hosts.

   For example:

  opcode                  offset imm          assembly
         src_reg dst_reg
  07     0       1        00 00  44 33 22 11  r1 += 0x11223344 // little
         dst_reg src_reg
  07     1       0        00 00  11 22 33 44  r1 += 0x11223344 // big

   Note that most instructions do not use all of the fields.  Unused
   fields SHALL be cleared to zero.

3.2.  Wide Instruction Encoding

   Some instructions are defined to use the wide instruction encoding,
   which uses two 32-bit immediate values.  The 64 bits following the
   basic instruction format contain a pseudo instruction with 'opcode',
   'dst_reg', 'src_reg', and 'offset' all set to zero.

   This is depicted in the following figure:

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    opcode     |     regs      |            offset             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                              imm                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           reserved                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           next_imm                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   *opcode:*  operation to perform, encoded as explained above

   *regs:*  the source and destination register numbers (unless
      otherwise specified), encoded as explained above

   *offset:*  signed integer offset used with pointer arithmetic, unless
      otherwise specified

   *imm:*  signed integer immediate value

   *reserved:*  unused, set to zero

   *next_imm:*  second signed integer immediate value

3.3.  Instruction Classes

   The three least significant bits of the 'opcode' field store the
   instruction class:

      +=======+=======+=================================+===========+
      | class | Value | Description                     | Reference |
      +=======+=======+=================================+===========+
      | LD    | 0x0   | non-standard load operations    | Section 5 |
      +-------+-------+---------------------------------+-----------+
      | LDX   | 0x1   | load into register operations   | Section 5 |
      +-------+-------+---------------------------------+-----------+
      | ST    | 0x2   | store from immediate operations | Section 5 |
      +-------+-------+---------------------------------+-----------+
      | STX   | 0x3   | store from register operations  | Section 5 |
      +-------+-------+---------------------------------+-----------+
      | ALU   | 0x4   | 32-bit arithmetic operations    | Section 4 |
      +-------+-------+---------------------------------+-----------+
      | JMP   | 0x5   | 64-bit jump operations          | Section 4 |
      +-------+-------+---------------------------------+-----------+
      | JMP32 | 0x6   | 32-bit jump operations          | Section 4 |
      +-------+-------+---------------------------------+-----------+
      | ALU64 | 0x7   | 64-bit arithmetic operations    | Section 4 |
      +-------+-------+---------------------------------+-----------+

                         Table 3: Instruction Class

4.  Arithmetic and Jump Instructions

   For arithmetic and jump instructions (ALU, ALU64, JMP, and JMP32),
   the 8-bit 'opcode' field is divided into three parts:

   +-+-+-+-+-+-+-+-+
   |  code |s|class|
   +-+-+-+-+-+-+-+-+

   *code:*  the operation code, whose meaning varies by instruction
      class

   *s (source):*  the source operand location, which unless otherwise
      specified is one of:

        +========+=======+==========================================+
        | source | Value | Description                              |
        +========+=======+==========================================+
        | K      | 0     | use 32-bit 'imm' value as source operand |
        +--------+-------+------------------------------------------+
        | X      | 1     | use 'src_reg' register value as source   |
        |        |       | operand                                  |
        +--------+-------+------------------------------------------+

                       Table 4: Source Operand Location

   *class:*  the instruction class (see Section 3.3)

4.1.  Arithmetic Instructions

   ALU uses 32-bit wide operands while ALU64 uses 64-bit wide operands
   for otherwise identical operations.  ALU64 instructions belong to the
   base64 conformance group unless noted otherwise.  The 'code' field
   encodes the operation as below, where 'src' refers to the source
   operand and 'dst' refers to the value of the destination register.

    +=======+======+=========+=======================================+
    | Name  | code | offset  | Description                           |
    +=======+======+=========+=======================================+
    | ADD   | 0x0  | 0       | dst += src                            |
    +-------+------+---------+---------------------------------------+
    | SUB   | 0x1  | 0       | dst -= src                            |
    +-------+------+---------+---------------------------------------+
    | MUL   | 0x2  | 0       | dst *= src                            |
    +-------+------+---------+---------------------------------------+
    | DIV   | 0x3  | 0       | dst = (src != 0) ? (dst / src) : 0    |
    +-------+------+---------+---------------------------------------+
    | SDIV  | 0x3  | 1       | dst = (src != 0) ? (dst s/ src) : 0   |
    +-------+------+---------+---------------------------------------+
    | OR    | 0x4  | 0       | dst |= src                            |
    +-------+------+---------+---------------------------------------+
    | AND   | 0x5  | 0       | dst &= src                            |
    +-------+------+---------+---------------------------------------+
    | LSH   | 0x6  | 0       | dst <<= (src & mask)                  |
    +-------+------+---------+---------------------------------------+
    | RSH   | 0x7  | 0       | dst >>= (src & mask)                  |
    +-------+------+---------+---------------------------------------+
    | NEG   | 0x8  | 0       | dst = -dst                            |
    +-------+------+---------+---------------------------------------+
    | MOD   | 0x9  | 0       | dst = (src != 0) ? (dst % src) : dst  |
    +-------+------+---------+---------------------------------------+
    | SMOD  | 0x9  | 1       | dst = (src != 0) ? (dst s% src) : dst |
    +-------+------+---------+---------------------------------------+
    | XOR   | 0xa  | 0       | dst ^= src                            |
    +-------+------+---------+---------------------------------------+
    | MOV   | 0xb  | 0       | dst = src                             |
    +-------+------+---------+---------------------------------------+
    | MOVSX | 0xb  | 8/16/32 | dst = (s8,s16,s32)src                 |
    +-------+------+---------+---------------------------------------+
    | ARSH  | 0xc  | 0       | sign extending (Section 2.3) dst >>=  |
    |       |      |         | (src & mask)                          |
    +-------+------+---------+---------------------------------------+
    | END   | 0xd  | 0       | byte swap operations (see             |
    |       |      |         | Section 4.2)                          |
    +-------+------+---------+---------------------------------------+

                     Table 5: Arithmetic Instructions

   Underflow and overflow are allowed during arithmetic operations,
   meaning the 64-bit or 32-bit value will wrap.  If BPF program
   execution would result in division by zero, the destination register
   is instead set to zero.  If execution would result in modulo by zero,
   for ALU64 the value of the destination register is unchanged whereas
   for ALU the upper 32 bits of the destination register are zeroed.

   {ADD, X, ALU}, where 'code' = ADD, 'source' = X, and 'class' = ALU,
   means:

      dst = (u32) ((u32) dst + (u32) src)

   where '(u32)' indicates that the upper 32 bits are zeroed.

   {ADD, X, ALU64} means:

      dst = dst + src

   {XOR, K, ALU} means:

      dst = (u32) dst ^ (u32) imm

   {XOR, K, ALU64} means:

      dst = dst ^ imm

   Note that most arithmetic instructions have 'offset' set to 0.  Only
   three instructions (SDIV, SMOD, MOVSX) have a non-zero 'offset'.

   Division, multiplication, and modulo operations for ALU are part of
   the "divmul32" conformance group, and division, multiplication, and
   modulo operations for ALU64 are part of the "divmul64" conformance
   group.  The division and modulo operations support both unsigned and
   signed flavors.

   For unsigned operations (DIV and MOD), for ALU, 'imm' is interpreted
   as a 32-bit unsigned value.  For ALU64, 'imm' is first sign extended
   (Section 2.3) from 32 to 64 bits, and then interpreted as a 64-bit
   unsigned value.

   For signed operations (SDIV and SMOD), for ALU, 'imm' is interpreted
   as a 32-bit signed value.  For ALU64, 'imm' is first sign extended
   (Section 2.3) from 32 to 64 bits, and then interpreted as a 64-bit
   signed value.

   Note that there are varying definitions of the signed modulo
   operation when the dividend or divisor are negative, where
   implementations often vary by language such that Python, Ruby, etc.
   differ from C, Go, Java, etc.  This specification requires that
   signed modulo MUST use truncated division (where -13 % 3 == -1) as
   implemented in C, Go, etc.:

      a % n = a - n * trunc(a / n)

   The MOVSX instruction does a move operation with sign extension.
   {MOVSX, X, ALU} sign extends (Section 2.3) 8-bit and 16-bit operands
   into 32-bit operands, and zeroes the remaining upper 32 bits.
   {MOVSX, X, ALU64} sign extends (Section 2.3) 8-bit, 16-bit, and
   32-bit operands into 64-bit operands.  Unlike other arithmetic
   instructions, MOVSX is only defined for register source operands (X).

   {MOV, K, ALU64} means:

      dst = (s64)imm

   {MOV, X, ALU} means:

      dst = (u32)src

   {MOVSX, X, ALU} with 'offset' 8 means:

      dst = (u32)(s32)(s8)src

   The NEG instruction is only defined when the source bit is clear (K).

   Shift operations use a mask of 0x3F (63) for 64-bit operations and
   0x1F (31) for 32-bit operations.

4.2.  Byte Swap Instructions

   The byte swap instructions use instruction classes of ALU and ALU64
   and a 4-bit 'code' field of END.

   The byte swap instructions operate on the destination register only
   and do not use a separate source register or immediate value.

   For ALU, the 1-bit source operand field in the opcode is used to
   select what byte order the operation converts from or to.  For ALU64,
   the 1-bit source operand field in the opcode is reserved and MUST be
   set to 0.

         +=======+==========+=======+===========================+
         | class | source   | Value | Description               |
         +=======+==========+=======+===========================+
         | ALU   | LE       | 0     | convert between host byte |
         |       |          |       | order and little endian   |
         +-------+----------+-------+---------------------------+
         | ALU   | BE       | 1     | convert between host byte |
         |       |          |       | order and big endian      |
         +-------+----------+-------+---------------------------+
         | ALU64 | Reserved | 0     | do byte swap              |
         |       |          |       | unconditionally           |
         +-------+----------+-------+---------------------------+

                     Table 6: Byte Swap Instructions

   The 'imm' field encodes the width of the swap operations.  The
   following widths are supported: 16, 32, and 64.  Width 64 operations
   belong to the base64 conformance group and other swap operations
   belong to the base32 conformance group.

   Examples:

   {END, LE, ALU} with 'imm' = 16/32/64 means:

      dst = le16(dst)
      dst = le32(dst)
      dst = le64(dst)

   {END, BE, ALU} with 'imm' = 16/32/64 means:

      dst = be16(dst)
      dst = be32(dst)
      dst = be64(dst)

   {END, TO, ALU64} with 'imm' = 16/32/64 means:

      dst = bswap16(dst)
      dst = bswap32(dst)
      dst = bswap64(dst)

4.3.  Jump Instructions

   JMP32 uses 32-bit wide operands and indicates the base32 conformance
   group; JMP uses 64-bit wide operands for otherwise identical
   operations and indicates the base64 conformance group unless
   otherwise specified.  The 'code' field encodes the operation as
   below:

    +======+=======+=========+======================+================+
    | code | Value | src_reg | Description          | Notes          |
    +======+=======+=========+======================+================+
    | JA   | 0x0   | 0x0     | PC += offset         | {JA, K, JMP}   |
    |      |       |         |                      | only           |
    +------+-------+---------+----------------------+----------------+
    | JA   | 0x0   | 0x0     | PC += imm            | {JA, K, JMP32} |
    |      |       |         |                      | only           |
    +------+-------+---------+----------------------+----------------+
    | JEQ  | 0x1   | any     | PC += offset if dst  |                |
    |      |       |         | == src               |                |
    +------+-------+---------+----------------------+----------------+
    | JGT  | 0x2   | any     | PC += offset if dst  | unsigned       |
    |      |       |         | > src                |                |
    +------+-------+---------+----------------------+----------------+
    | JGE  | 0x3   | any     | PC += offset if dst  | unsigned       |
    |      |       |         | >= src               |                |
    +------+-------+---------+----------------------+----------------+
    | JSET | 0x4   | any     | PC += offset if dst  |                |
    |      |       |         | & src                |                |
    +------+-------+---------+----------------------+----------------+
    | JNE  | 0x5   | any     | PC += offset if dst  |                |
    |      |       |         | != src               |                |
    +------+-------+---------+----------------------+----------------+
    | JSGT | 0x6   | any     | PC += offset if dst  | signed         |
    |      |       |         | > src                |                |
    +------+-------+---------+----------------------+----------------+
    | JSGE | 0x7   | any     | PC += offset if dst  | signed         |
    |      |       |         | >= src               |                |
    +------+-------+---------+----------------------+----------------+
    | CALL | 0x8   | 0x0     | call helper function | {CALL, K, JMP} |
    |      |       |         | by static ID         | only, see      |
    |      |       |         |                      | Section 4.3.1  |
    +------+-------+---------+----------------------+----------------+
    | CALL | 0x8   | 0x1     | call PC += imm       | {CALL, K, JMP} |
    |      |       |         |                      | only, see      |
    |      |       |         |                      | Section 4.3.2  |
    +------+-------+---------+----------------------+----------------+
    | CALL | 0x8   | 0x2     | call helper function | {CALL, K, JMP} |
    |      |       |         | by BTF ID            | only, see      |
    |      |       |         |                      | Section 4.3.1  |
    +------+-------+---------+----------------------+----------------+
    | EXIT | 0x9   | 0x0     | return               | {CALL, K, JMP} |
    |      |       |         |                      | only           |
    +------+-------+---------+----------------------+----------------+
    | JLT  | 0xa   | any     | PC += offset if dst  | unsigned       |
    |      |       |         | < src                |                |
    +------+-------+---------+----------------------+----------------+
    | JLE  | 0xb   | any     | PC += offset if dst  | unsigned       |
    |      |       |         | <= src               |                |
    +------+-------+---------+----------------------+----------------+
    | JSLT | 0xc   | any     | PC += offset if dst  | signed         |
    |      |       |         | < src                |                |
    +------+-------+---------+----------------------+----------------+
    | JSLE | 0xd   | any     | PC += offset if dst  | signed         |
    |      |       |         | <= src               |                |
    +------+-------+---------+----------------------+----------------+

                        Table 7: Jump Instructions

   where 'PC' denotes the program counter, and the offset to increment
   by is in units of 64-bit instructions relative to the instruction
   following the jump instruction.  Thus 'PC += 1' skips execution of
   the next instruction if it's a basic instruction or results in
   undefined behavior if the next instruction is a 128-bit wide
   instruction.

   Example:

   {JSGE, X, JMP32} means:

      if (s32)dst s>= (s32)src goto +offset

   where 's>=' indicates a signed '>=' comparison.

   {JLE, K, JMP} means:

      if dst <= (u64)(s64)imm goto +offset

   {JA, K, JMP32} means:

      gotol +imm

   where 'imm' means the branch offset comes from the 'imm' field.

   Note that there are two flavors of JA instructions.  The JMP class
   permits a 16-bit jump offset specified by the 'offset' field, whereas
   the JMP32 class permits a 32-bit jump offset specified by the 'imm'
   field.  A conditional jump greater than 16 bits may be converted to a
   conditional jump less than 16 bits plus a 32-bit unconditional jump.

   All CALL and JA instructions belong to the base32 conformance group.

4.3.1.  Helper Functions

   Helper functions are a concept whereby BPF programs can call into a
   set of function calls exposed by the underlying platform.

   Historically, each helper function was identified by a static ID
   encoded in the 'imm' field.  Further documentation of helper
   functions is outside the scope of this document and standardization
   is left for future work, but use is widely deployed and more
   information can be found in platform-specific documentation (e.g.,
   Linux kernel documentation).

   Platforms that support the BPF Type Format (BTF) support identifying
   a helper function by a BTF ID encoded in the 'imm' field, where the
   BTF ID identifies the helper name and type.  Further documentation of
   BTF is outside the scope of this document and standardization is left
   for future work, but use is widely deployed and more information can
   be found in platform-specific documentation (e.g., Linux kernel
   documentation).

4.3.2.  Program-Local Functions

   Program-local functions are functions exposed by the same BPF program
   as the caller, and are referenced by offset from the instruction
   following the call instruction, similar to JA.  The offset is encoded
   in the 'imm' field of the call instruction.  An EXIT within the
   program-local function will return to the caller.

5.  Load and Store Instructions

   For load and store instructions (LD, LDX, ST, and STX), the 8-bit
   'opcode' field is divided as follows:

   +-+-+-+-+-+-+-+-+
   |mode |sz |class|
   +-+-+-+-+-+-+-+-+

   *mode:*  The mode modifier is one of:

       +========+=======+===============================+=============+
       | mode   | Value | Description                   | Reference   |
       +========+=======+===============================+=============+
       | IMM    | 0     | 64-bit immediate instructions | Section 5.4 |
       +--------+-------+-------------------------------+-------------+
       | ABS    | 1     | legacy BPF packet access      | Section 5.5 |
       |        |       | (absolute)                    |             |
       +--------+-------+-------------------------------+-------------+
       | IND    | 2     | legacy BPF packet access      | Section 5.5 |
       |        |       | (indirect)                    |             |
       +--------+-------+-------------------------------+-------------+
       | MEM    | 3     | regular load and store        | Section 5.1 |
       |        |       | operations                    |             |
       +--------+-------+-------------------------------+-------------+
       | MEMSX  | 4     | sign-extension load           | Section 5.2 |
       |        |       | operations                    |             |
       +--------+-------+-------------------------------+-------------+
       | ATOMIC | 6     | atomic operations             | Section 5.3 |
       +--------+-------+-------------------------------+-------------+

                            Table 8: Mode Modifier

   *sz (size):*  The size modifier is one of:

                   +======+=======+=======================+
                   | size | Value | Description           |
                   +======+=======+=======================+
                   | W    | 0     | word (4 bytes)        |
                   +------+-------+-----------------------+
                   | H    | 1     | half word (2 bytes)   |
                   +------+-------+-----------------------+
                   | B    | 2     | byte                  |
                   +------+-------+-----------------------+
                   | DW   | 3     | double word (8 bytes) |
                   +------+-------+-----------------------+

                            Table 9: Size Modifier

      Instructions using DW belong to the base64 conformance group.

   *class:*  The instruction class (see Section 3.3)

5.1.  Regular Load and Store Operations

   The MEM mode modifier is used to encode regular load and store
   instructions that transfer data between a register and memory.

   {MEM, <size>, STX} means:

      *(size *) (dst + offset) = src

   {MEM, <size>, ST} means:

      *(size *) (dst + offset) = imm

   {MEM, <size>, LDX} means:

      dst = *(unsigned size *) (src + offset)

   Where '<size>' is one of: B, H, W, or DW, and 'unsigned size' is one
   of: u8, u16, u32, or u64.

5.2.  Sign-Extension Load Operations

   The MEMSX mode modifier is used to encode sign-extension load
   instructions (Section 2.3) that transfer data between a register and
   memory.

   {MEMSX, <size>, LDX} means:

      dst = *(signed size *) (src + offset)

   Where '<size>' is one of: B, H, or W, and 'signed size' is one of:
   s8, s16, or s32.

5.3.  Atomic Operations

   Atomic operations operate on memory and cannot be interrupted or
   corrupted by other access to the same memory region by other BPF
   programs or means outside of this specification.

   All atomic operations supported by BPF are encoded as store
   operations that use the ATOMIC mode modifier as follows:

   *  {ATOMIC, W, STX} for 32-bit operations, which are part of the
      "atomic32" conformance group.

   *  {ATOMIC, DW, STX} for 64-bit operations, which are part of the
      "atomic64" conformance group.

   *  8-bit and 16-bit wide atomic operations are not supported.

   The 'imm' field is used to encode the actual atomic operation.
   Simple atomic operations use a subset of the values defined to encode
   arithmetic operations in the 'imm' field to encode the atomic
   operation:

                       +=====+=======+=============+
                       | imm | Value | Description |
                       +=====+=======+=============+
                       | ADD | 0x00  | atomic add  |
                       +-----+-------+-------------+
                       | OR  | 0x40  | atomic or   |
                       +-----+-------+-------------+
                       | AND | 0x50  | atomic and  |
                       +-----+-------+-------------+
                       | XOR | 0xa0  | atomic xor  |
                       +-----+-------+-------------+

                          Table 10: Simple Atomic
                                 Operations

   {ATOMIC, W, STX} with 'imm' = ADD means:

      *(u32 *)(dst + offset) += src

   {ATOMIC, DW, STX} with 'imm' = ADD means:

      *(u64 *)(dst + offset) += src

   In addition to the simple atomic operations, there is also a modifier
   and two complex atomic operations:

         +=========+==============+=============================+
         | imm     | Value        | Description                 |
         +=========+==============+=============================+
         | FETCH   | 0x01         | modifier: return old value  |
         +---------+--------------+-----------------------------+
         | XCHG    | 0xe0 | FETCH | atomic exchange             |
         +---------+--------------+-----------------------------+
         | CMPXCHG | 0xf0 | FETCH | atomic compare and exchange |
         +---------+--------------+-----------------------------+

            Table 11: Complex Atomic Operations and a Modifier

   The FETCH modifier is optional for simple atomic operations and is
   always set for the complex atomic operations.  If the FETCH flag is
   set, then the operation also overwrites src with the value that was
   in memory before it was modified.

   The XCHG operation atomically exchanges src with the value addressed
   by dst + offset.

   The CMPXCHG operation atomically compares the value addressed by dst
   + offset with R0.  If they match, the value addressed by dst + offset
   is replaced with src.  In either case, the value that was at dst +
   offset before the operation is zero-extended and loaded back to R0.

5.4.  64-bit Immediate Instructions

   Instructions with the IMM 'mode' modifier use the wide instruction
   encoding defined in Section 3, and use the 'src_reg' field of the
   basic instruction to hold an opcode subtype.

   The following table defines a set of {IMM, DW, LD} instructions with
   opcode subtypes in the 'src_reg' field, using new terms such as "map"
   defined further below:

    +=========+================================+==========+==========+
    | src_reg | Pseudocode                     | imm Type | dst Type |
    +=========+================================+==========+==========+
    | 0x0     | dst = (next_imm << 32) | imm   | integer  | integer  |
    +---------+--------------------------------+----------+----------+
    | 0x1     | dst = map_by_fd(imm)           | map fd   | map      |
    +---------+--------------------------------+----------+----------+
    | 0x2     | dst = map_val(map_by_fd(imm))  | map fd   | data     |
    |         | + next_imm                     |          | address  |
    +---------+--------------------------------+----------+----------+
    | 0x3     | dst = var_addr(imm)            | variable | data     |
    |         |                                | id       | address  |
    +---------+--------------------------------+----------+----------+
    | 0x4     | dst = code_addr(imm)           | integer  | code     |
    |         |                                |          | address  |
    +---------+--------------------------------+----------+----------+
    | 0x5     | dst = map_by_idx(imm)          | map      | map      |
    |         |                                | index    |          |
    +---------+--------------------------------+----------+----------+
    | 0x6     | dst = map_val(map_by_idx(imm)) | map      | data     |
    |         | + next_imm                     | index    | address  |
    +---------+--------------------------------+----------+----------+

                 Table 12: 64-bit Immediate Instructions

   where

   *  map_by_fd(imm) means to convert a 32-bit file descriptor into an
      address of a map (see Section 5.4.1)

   *  map_by_idx(imm) means to convert a 32-bit index into an address of
      a map

   *  map_val(map) gets the address of the first value in a given map

   *  var_addr(imm) gets the address of a platform variable (see
      Section 5.4.2) with a given id

   *  code_addr(imm) gets the address of the instruction at a specified
      relative offset in number of (64-bit) instructions

   *  the 'imm type' can be used by disassemblers for display

   *  the 'dst type' can be used for verification and just-in-time
      compilation purposes

5.4.1.  Maps

   Maps are shared memory regions accessible by BPF programs on some
   platforms.  A map can have various semantics as defined in a separate
   document, and may or may not have a single contiguous memory region,
   but the 'map_val(map)' is currently only defined for maps that do
   have a single contiguous memory region.

   Each map can have a file descriptor (fd) if supported by the
   platform, where 'map_by_fd(imm)' means to get the map with the
   specified file descriptor.  Each BPF program can also be defined to
   use a set of maps associated with the program at load time, and
   'map_by_idx(imm)' means to get the map with the given index in the
   set associated with the BPF program containing the instruction.

5.4.2.  Platform Variables

   Platform variables are memory regions, identified by integer ids,
   exposed by the runtime, and accessible by BPF programs on some
   platforms.  The 'var_addr(imm)' operation means to get the address of
   the memory region identified by the given id.

5.5.  Legacy BPF Packet Access Instructions

   BPF previously introduced special instructions for access to packet
   data that were carried over from classic BPF.  These instructions
   used an instruction class of LD, a size modifier of W, H, or B, and a
   mode modifier of ABS or IND.  The 'dst_reg' and 'offset' fields were
   set to zero, and 'src_reg' was set to zero for ABS.  However, these
   instructions are deprecated and SHOULD no longer be used.  All legacy
   packet access instructions belong to the "packet" conformance group.

6.  Security Considerations

   BPF programs could use BPF instructions to do malicious things with
   memory, CPU, networking, or other system resources.  This is not
   fundamentally different from any other type of software that may run
   on a device.  Execution environments should be carefully designed to
   only run BPF programs that are trusted and verified, and sandboxing
   and privilege level separation are key strategies for limiting
   security and abuse impact.  For example, BPF verifiers are well-known
   and widely deployed and are responsible for ensuring that BPF
   programs will terminate within a reasonable time, only interact with
   memory in safe ways, adhere to platform-specified API contracts, and
   don't use instructions with undefined behavior.  This level of
   verification can often provide a stronger level of security assurance
   than for other software and operating system code.  While the details
   are out of scope of this document, Linux [LINUX] and PREVAIL
   [PREVAIL] provide many details.  Future IETF work will document
   verifier expectations and building blocks for allowing safe execution
   of untrusted BPF programs.

   Executing programs using the BPF instruction set also requires either
   an interpreter or a compiler to translate them to built-in hardware
   processor instructions.  In general, interpreters are considered a
   source of insecurity (e.g., gadgets susceptible to side-channel
   attacks due to speculative execution) whenever one is used in the
   same memory address space as data with confidentiality concerns.  As
   such, use of a compiler is recommended instead.  Compilers should be
   audited carefully for vulnerabilities to ensure that compilation of a
   trusted and verified BPF program to built-in processor instructions
   does not introduce vulnerabilities.

   Exposing functionality via BPF extends the interface between the
   component executing the BPF program and the component submitting it.
   Careful consideration of what functionality is exposed and how that
   impacts the security properties desired is required.

7.  IANA Considerations

   This document defines two registries.

7.1.  BPF Instruction Conformance Groups Registry

   This document defines an IANA registry for BPF instruction
   conformance groups, as follows:

   *  Name of the registry: BPF Instruction Conformance Groups

   *  Name of the registry group: BPF Instructions

   *  Required information for registrations: See the BPF Instruction
      Conformance Groups Registration Template (Section 7.1.1)

   *  Syntax of registry entries: Each entry has the following fields:
      name, description, includes, excludes, status, change controller,
      and reference.  See Section 7.1.1 for more details.

   *  Registration policy (see Section 4 of [RFC8126] for details):

      -  Permanent: Standards Action or IESG Approval

      -  Provisional: Specification Required

      -  Historical: Specification Required

   *  Contact: BPF Working Group

   *  Change Controller: IETF

   Initial entries in this registry are as follows:

   +========+===============+========+========+============+===========+
   |Name    | Description   |Includes|Excludes| Status     | Reference |
   +========+===============+========+========+============+===========+
   |atomic32| 32-bit        |-       |-       | Permanent  | RFC 9669, |
   |        | atomic        |        |        |            | Section   |
   |        | instructions  |        |        |            | 5.3       |
   +--------+---------------+--------+--------+------------+-----------+
   |atomic64| 64-bit        |atomic32|-       | Permanent  | RFC 9669, |
   |        | atomic        |        |        |            | Section   |
   |        | instructions  |        |        |            | 5.3       |
   +--------+---------------+--------+--------+------------+-----------+
   |base32  | 32-bit base   |-       |-       | Permanent  | RFC 9669  |
   |        | instructions  |        |        |            |           |
   +--------+---------------+--------+--------+------------+-----------+
   |base64  | 64-bit base   |base32  |-       | Permanent  | RFC 9669  |
   |        | instructions  |        |        |            |           |
   +--------+---------------+--------+--------+------------+-----------+
   |divmul32| 32-bit        |-       |-       | Permanent  | RFC 9669, |
   |        | division and  |        |        |            | Section   |
   |        | modulo        |        |        |            | 4.1       |
   +--------+---------------+--------+--------+------------+-----------+
   |divmul64| 64-bit        |divmul32|-       | Permanent  | RFC 9669, |
   |        | division and  |        |        |            | Section   |
   |        | modulo        |        |        |            | 4.1       |
   +--------+---------------+--------+--------+------------+-----------+
   |packet  | Legacy        |-       |-       | Historical | RFC 9669, |
   |        | packet        |        |        |            | Section   |
   |        | instructions  |        |        |            | 5.5       |
   +--------+---------------+--------+--------+------------+-----------+

                    Table 13: Initial Conformance Groups

7.1.1.  BPF Instruction Conformance Groups Registration Template

   This template describes the fields that must be supplied in a
   registration request:

   Name:  Alphanumeric label indicating the name of the conformance
      group.

   Description:  Brief description of the conformance group.

   Includes:  Any other conformance groups that are included by this
      group.

   Excludes:  Any other conformance groups that are excluded by this
      group.

   Status:  This reflects the status requested and must be one of
      'Permanent', 'Provisional', or 'Historical'.

   Contact:  Person (including contact information) to contact for
      further information.

   Change Controller:  Organization or person (often the author of the
      defining specification), including contact information, authorized
      to change this.

   Reference:  A reference to the defining specification.  Include full
      citations for all referenced documents.  Registration requests for
      'Provisional' registration can be included in an Internet-Draft;
      when the documents are approved for publication as an RFC, the
      registration will be updated to 'Permanent'.

7.2.  BPF Instruction Set Registry

   This document defines an IANA registry for BPF instructions, as
   follows:

   *  Name of the registry: BPF Instruction Set

   *  Name of the registry group: BPF Instructions

   *  Required information for registrations: See the BPF Instruction
      Registration Template (Section 7.2.1)

   *  Syntax of registry entries: Each entry has the following fields:
      opcode, src, offset, imm, description, groups, change controller,
      and reference.  See Section 7.2.1 for more details.

   *  Registration policy: New instructions require a new entry in the
      conformance group registry and the same registration policies
      apply.

   *  Contact: BPF Working Group

   *  Change Controller: IETF

   *  Initial registrations: See Appendix A.  Instructions other than
      those listed as deprecated are Permanent.  Any listed as
      deprecated are Historical.

7.2.1.  BPF Instruction Registration Template

   This template describes the fields that must be supplied in a
   registration request:

   Opcode:  A 1-byte value in hex format indicating the value of the
      opcode field.

   Src_reg:  Either a numeric value indicating the value of the src_reg
      field, or "any".

   Offset:  Either a numeric value indicating the value of the offset
      field, or "any".

   Imm:  Either a value indicating the value of the imm field, or "any".

   Description:  Description of what the instruction does, typically in
      pseudocode.

   Groups:  A list of one or more comma-separated conformance groups to
      which the instruction belongs.

   Contact:  Person (including contact information) to contact for
      further information.

   Change Controller:  Organization or person (often the author),
      including contact information, authorized to change this.

   Reference:  A reference to the defining specification.  Include full
      citations for all referenced documents.  Registration requests for
      'Provisional' registration can be included in an Internet-Draft;
      when the documents are approved for publication as an RFC, the
      registration will be updated to 'Permanent'.

7.3.  Adding Instructions

   A specification may add additional instructions to the BPF
   Instruction Set registry.  Once a conformance group is registered
   with a set of instructions, no further instructions can be added to
   that conformance group.  A specification should instead create a new
   conformance group that includes the original conformance group, plus
   any newly added instructions.  Inclusion of the original conformance
   group is done via the "includes" column of the BPF Instruction
   Conformance Groups registry, and inclusion of newly added
   instructions is done via the "groups" column of the BPF Instruction
   Set registry.

   For example, consider an existing hypothetical group called "example"
   with two instructions in it.  One might add two more instructions by
   first adding an "examplev2" group to the BPF Instruction Conformance
   Groups registry as follows:

    +===========+==================+==========+==========+===========+
    | Name      | Description      | Includes | Excludes | Status    |
    +===========+==================+==========+==========+===========+
    | example   | Original example | -        | -        | Permanent |
    |           | instructions     |          |          |           |
    +-----------+------------------+----------+----------+-----------+
    | examplev2 | Newer set of     | example  | -        | Permanent |
    |           | example          |          |          |           |
    |           | instructions     |          |          |           |
    +-----------+------------------+----------+----------+-----------+

             Table 14: Conformance Group Example for Addition

   And then adding the new instructions into the BPF Instruction Set
   registry as follows:

       +========+=====+================================+===========+
       | opcode | ... | Description                    | Groups    |
       +========+=====+================================+===========+
       | aaa    | ... | Original example instruction 1 | example   |
       +--------+-----+--------------------------------+-----------+
       | bbb    | ... | Original example instruction 2 | example   |
       +--------+-----+--------------------------------+-----------+
       | ccc    | ... | Added example instruction 3    | examplev2 |
       +--------+-----+--------------------------------+-----------+
       | ddd    | ... | Added example instruction 4    | examplev2 |
       +--------+-----+--------------------------------+-----------+

                   Table 15: Instruction Addition Example

   Supporting the "examplev2" group thus requires supporting all four
   example instructions.

7.4.  Deprecating Instructions

   Deprecating instructions that are part of an existing conformance
   group can be done by defining a new conformance group for the newly
   deprecated instructions, and defining a new conformance group that
   supersedes the existing conformance group containing the
   instructions, where the new conformance group includes the existing
   one and excludes the deprecated instruction group.

   For example, if deprecating an instruction in an existing
   hypothetical group called "example", two new groups ("legacyexample"
   and "examplev2") might be registered in the BPF Instruction
   Conformance Groups registry as follows:

   +===============+==============+========+===============+==========+
   | Name          | Description  |Includes| Excludes      |Status    |
   +===============+==============+========+===============+==========+
   | example       | Original     |-       | -             |Permanent |
   |               | example      |        |               |          |
   |               | instructions |        |               |          |
   +---------------+--------------+--------+---------------+----------+
   | legacyexample | Legacy       |-       | -             |Historical|
   |               | example      |        |               |          |
   |               | instructions |        |               |          |
   +---------------+--------------+--------+---------------+----------+
   | examplev2     | Example      |example | legacyexample |Permanent |
   |               | instructions |        |               |          |
   +---------------+--------------+--------+---------------+----------+

           Table 16: Conformance Group Example for Deprecation

   The BPF Instruction Set registry entries for the deprecated
   instructions would then be updated to add "legacyexample" to the set
   of groups for those instructions, as follows:

      +========+=====+=============================+===============+
      | opcode | ... | Description                 | Groups        |
      +========+=====+=============================+===============+
      | aaa    | ... | Good original instruction 1 | example       |
      +--------+-----+-----------------------------+---------------+
      | bbb    | ... | Good original instruction 2 | example       |
      +--------+-----+-----------------------------+---------------+
      | ccc    | ... | Bad original instruction 3  | example,      |
      |        |     |                             | legacyexample |
      +--------+-----+-----------------------------+---------------+
      | ddd    | ... | Bad original instruction 4  | example,      |
      |        |     |                             | legacyexample |
      +--------+-----+-----------------------------+---------------+

                Table 17: Instruction Deprecation Example

   Finally, updated implementations that dropped support for the
   deprecated instructions would then be able to claim conformance to
   "examplev2" rather than "example".

7.5.  Change Control

   Registrations can be updated in a registry by the same mechanism as
   required for an initial registration.  In cases where the original
   definition of an entry is contained in an IESG-approved document, in
   which case the IETF would be the change controller, update of the
   specification also requires IESG approval.

   'Provisional' registrations can be updated by the change controller
   designated in the existing registration.  In addition, the IESG can
   reassign responsibility for a 'Provisional' registration or can
   request specific changes to an entry.  This will enable changes to be
   made to entries where the original registrant is out of contact or
   unwilling or unable to make changes.

   Transition from 'Provisional' to 'Permanent' status can be requested
   and approved in the same manner as a new 'Permanent' registration.
   Transition from 'Permanent' to 'Historical' status requires IESG
   approval.  Transition from 'Provisional' to 'Historical' can be
   requested by anyone authorized to update the 'Provisional'
   registration.

7.6.  Expert Review Instructions

   The IANA registries established by this document are informed by
   written specifications, which themselves are facilitated and approved
   by an Expert Review process (see Section 5.3 of [RFC8126]).

   Designated experts are expected to consult with the active BPF
   working group (e.g., via email to the working group's mailing list)
   if it exists, as well as other interested parties (e.g., via email to
   one or more active mailing list(s) for relevant BPF communities and
   platforms).  The designated expert is expected to verify that the
   encoding and semantics for any new instructions are properly
   documented in a public-facing specification.  In the event of future
   RFC documents for ISA extensions, experts may permit early assignment
   before the RFC document is available, as long as a specification that
   satisfies the above requirements exists.

8.  References

8.1.  Normative References

   [IEN137]   Cohen, D., "ON HOLY WARS AND A PLEA FOR PEACE", IEN 137, 1
              April 1980, <https://www.rfc-editor.org/ien/ien137.txt>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

8.2.  Informative References

   [LINUX]    "eBPF verifier",
              <https://www.kernel.org/doc/html/latest/bpf/
              verifier.html>.

   [PREVAIL]  Gershuni, E., Amit, N., Gurfinkel, A., Narodytska, N.,
              Navas, J., Rinetzky, N., Ryzhyk, L., and M. Sagiv, "Simple
              and Precise Static Analysis of Untrusted Linux Kernel
              Extensions", DOI 10.1145/3314221.3314590, June 2019,
              <https://doi.org/10.1145/3314221.3314590>.

Appendix A.  Initial BPF Instruction Set Values

   Initial values for the BPF Instruction Set registry are given below.
   The descriptions in this table are informative.  In case of any
   discrepancy, the reference is authoritative.

   +======+=======+====+====+========================+========+=======+
   |opcode|src_reg|off-|imm |Description             |Groups  |Ref    |
   |      |       |set |    |                        |        |       |
   +======+=======+====+====+========================+========+=======+
   |0x00  |0x0    |0   |any |(additional immediate   |base64  |RFC    |
   |      |       |    |    |value)                  |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x04  |0x0    |0   |any |dst = (u32)((u32)dst +  |base32  |RFC    |
   |      |       |    |    |(u32)imm)               |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x05  |0x0    |any |0x00|goto +offset            |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x06  |0x0    |0   |any |goto +imm               |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x07  |0x0    |0   |any |dst += imm              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x0c  |any    |0   |0x00|dst = (u32)((u32)dst +  |base32  |RFC    |
   |      |       |    |    |(u32)src)               |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x0f  |any    |0   |0x00|dst += src              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x14  |0x0    |0   |any |dst = (u32)((u32)dst -  |base32  |RFC    |
   |      |       |    |    |(u32)imm)               |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x15  |0x0    |any |any |if dst == imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x16  |0x0    |any |any |if (u32)dst == imm goto |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x17  |0x0    |0   |any |dst -= imm              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x0    |0   |any |dst = (next_imm << 32) ||base64  |RFC    |
   |      |       |    |    |imm                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x1    |0   |any |dst = map_by_fd(imm)    |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x2    |0   |any |dst =                   |base64  |RFC    |
   |      |       |    |    |map_val(map_by_fd(imm)) |        |9669,  |
   |      |       |    |    |+ next_imm              |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x3    |0   |any |dst = var_addr(imm)     |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x4    |0   |any |dst = code_addr(imm)    |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x5    |0   |any |dst = map_by_idx(imm)   |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x18  |0x6    |0   |any |dst =                   |base64  |RFC    |
   |      |       |    |    |map_val(map_by_idx(imm))|        |9669,  |
   |      |       |    |    |+ next_imm              |        |Section|
   |      |       |    |    |                        |        |5.4    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x1c  |any    |0   |0x00|dst = (u32)((u32)dst -  |base32  |RFC    |
   |      |       |    |    |(u32)src)               |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x1d  |any    |any |0x00|if dst == src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x1e  |any    |any |0x00|if (u32)dst == (u32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x1f  |any    |0   |0x00|dst -= src              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x20  |0x0    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x24  |0x0    |0   |any |dst = (u32)(dst * imm)  |divmul32|RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x25  |0x0    |any |any |if dst > imm goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x26  |0x0    |any |any |if (u32)dst > imm goto  |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x27  |0x0    |0   |any |dst *= imm              |divmul64|RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x28  |0x0    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x2c  |any    |0   |0x00|dst = (u32)(dst * src)  |divmul32|RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x2d  |any    |any |0x00|if dst > src goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x2e  |any    |any |0x00|if (u32)dst > (u32)src  |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x2f  |any    |0   |0x00|dst *= src              |divmul64|RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x30  |0x0    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x34  |0x0    |0   |any |dst = (u32)((imm != 0) ?|divmul32|RFC    |
   |      |       |    |    |((u32)dst / (u32)imm) : |        |9669,  |
   |      |       |    |    |0)                      |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x34  |0x0    |1   |any |dst = (u32)((imm != 0) ?|divmul32|RFC    |
   |      |       |    |    |((s32)dst s/ imm) : 0)  |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x35  |0x0    |any |any |if dst >= imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x36  |0x0    |any |any |if (u32)dst >= imm goto |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x37  |0x0    |0   |any |dst = (imm != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |/ (u32)imm) : 0         |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x37  |0x0    |1   |any |dst = (imm != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |s/ imm) : 0             |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3c  |any    |0   |0x00|dst = (u32)((src != 0) ?|divmul32|RFC    |
   |      |       |    |    |((u32)dst / (u32)src) : |        |9669,  |
   |      |       |    |    |0)                      |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3c  |any    |1   |0x00|dst = (u32)((src != 0) ?|divmul32|RFC    |
   |      |       |    |    |((s32)dst s/(s32)src) : |        |9669,  |
   |      |       |    |    |0)                      |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3d  |any    |any |0x00|if dst >= src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3e  |any    |any |0x00|if (u32)dst >= (u32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3f  |any    |0   |0x00|dst = (src != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |/ src) : 0              |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x3f  |any    |1   |0x00|dst = (src != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |s/ src) : 0             |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x40  |any    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x44  |0x0    |0   |any |dst = (u32)(dst | imm)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x45  |0x0    |any |any |if dst & imm goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x46  |0x0    |any |any |if (u32)dst & imm goto  |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x47  |0x0    |0   |any |dst |= imm              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x48  |any    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x4c  |any    |0   |0x00|dst = (u32)(dst | src)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x4d  |any    |any |0x00|if dst & src goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x4e  |any    |any |0x00|if (u32)dst & (u32)src  |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x4f  |any    |0   |0x00|dst |= src              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x50  |any    |0   |any |(deprecated,            |packet  |RFC    |
   |      |       |    |    |implementation-specific)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.5    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x54  |0x0    |0   |any |dst = (u32)(dst & imm)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x55  |0x0    |any |any |if dst != imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x56  |0x0    |any |any |if (u32)dst != imm goto |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x57  |0x0    |0   |any |dst &= imm              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x5c  |any    |0   |0x00|dst = (u32)(dst & src)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x5d  |any    |any |0x00|if dst != src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x5e  |any    |any |0x00|if (u32)dst != (u32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x5f  |any    |0   |0x00|dst &= src              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x61  |any    |any |0x00|dst = *(u32 *)(src +    |base32  |RFC    |
   |      |       |    |    |offset)                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x62  |0x0    |any |any |*(u32 *)(dst + offset) =|base32  |RFC    |
   |      |       |    |    |imm                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x63  |any    |any |0x00|*(u32 *)(dst + offset) =|base32  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x64  |0x0    |0   |any |dst = (u32)(dst << imm) |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x65  |0x0    |any |any |if dst s> imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x66  |0x0    |any |any |if (s32)dst s> (s32)imm |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x67  |0x0    |0   |any |dst <<= imm             |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x69  |any    |any |0x00|dst = *(u16 *)(src +    |base32  |RFC    |
   |      |       |    |    |offset)                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6a  |0x0    |any |any |*(u16 *)(dst + offset) =|base32  |RFC    |
   |      |       |    |    |imm                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6b  |any    |any |0x00|*(u16 *)(dst + offset) =|base32  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6c  |any    |0   |0x00|dst = (u32)(dst << src) |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6d  |any    |any |0x00|if dst s> src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6e  |any    |any |0x00|if (s32)dst s> (s32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x6f  |any    |0   |0x00|dst <<= src             |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x71  |any    |any |0x00|dst = *(u8 *)(src +     |base32  |RFC    |
   |      |       |    |    |offset)                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x72  |0x0    |any |any |*(u8 *)(dst + offset) = |base32  |RFC    |
   |      |       |    |    |imm                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x73  |any    |any |0x00|*(u8 *)(dst + offset) = |base32  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x74  |0x0    |0   |any |dst = (u32)(dst >> imm) |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x75  |0x0    |any |any |if dst s>= imm goto     |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x76  |0x0    |any |any |if (s32)dst s>= (s32)imm|base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x77  |0x0    |0   |any |dst >>= imm             |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x79  |any    |any |0x00|dst = *(u64 *)(src +    |base64  |RFC    |
   |      |       |    |    |offset)                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7a  |0x0    |any |any |*(u64 *)(dst + offset) =|base64  |RFC    |
   |      |       |    |    |imm                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7b  |any    |any |0x00|*(u64 *)(dst + offset) =|base64  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5      |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7c  |any    |0   |0x00|dst = (u32)(dst >> src) |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7d  |any    |any |0x00|if dst s>= src goto     |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7e  |any    |any |0x00|if (s32)dst s>= (s32)src|base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x7f  |any    |0   |0x00|dst >>= src             |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x84  |0x0    |0   |0x00|dst = (u32)-dst         |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x85  |0x0    |0   |any |call helper function by |base32  |RFC    |
   |      |       |    |    |static ID               |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3.1  |
   +------+-------+----+----+------------------------+--------+-------+
   |0x85  |0x1    |0   |any |call PC += imm          |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3.2  |
   +------+-------+----+----+------------------------+--------+-------+
   |0x85  |0x2    |0   |any |call helper function by |base32  |RFC    |
   |      |       |    |    |BTF ID                  |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3.1  |
   +------+-------+----+----+------------------------+--------+-------+
   |0x87  |0x0    |0   |0x00|dst = -dst              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x94  |0x0    |0   |any |dst = (u32)((imm !=     |divmul32|RFC    |
   |      |       |    |    |0)?((u32)dst % (u32)imm)|        |9669,  |
   |      |       |    |    |: dst)                  |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x94  |0x0    |1   |any |dst = (u32)((imm != 0) ?|divmul32|RFC    |
   |      |       |    |    |((s32)dst s% imm) : dst)|        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x95  |0x0    |0   |0x00|return                  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x97  |0x0    |0   |any |dst = (imm != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |% (u32)imm) : dst       |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x97  |0x0    |1   |any |dst = (imm != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |s% imm) : dst           |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x9c  |any    |0   |0x00|dst = (u32)((src !=     |divmul32|RFC    |
   |      |       |    |    |0)?((u32)dst % (u32)src)|        |9669,  |
   |      |       |    |    |: dst)                  |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x9c  |any    |1   |0x00|dst = (u32)((src !=     |divmul32|RFC    |
   |      |       |    |    |0)?((s32)dst s%         |        |9669,  |
   |      |       |    |    |(s32)src) :dst)         |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x9f  |any    |0   |0x00|dst = (src != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |% src) : dst            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0x9f  |any    |1   |0x00|dst = (src != 0) ? (dst |divmul64|RFC    |
   |      |       |    |    |s% src) : dst           |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xa4  |0x0    |0   |any |dst = (u32)(dst ^ imm)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xa5  |0x0    |any |any |if dst < imm goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xa6  |0x0    |any |any |if (u32)dst < imm goto  |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xa7  |0x0    |0   |any |dst ^= imm              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xac  |any    |0   |0x00|dst = (u32)(dst ^ src)  |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xad  |any    |any |0x00|if dst < src goto       |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xae  |any    |any |0x00|if (u32)dst < (u32)src  |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xaf  |any    |0   |0x00|dst ^= src              |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xb4  |0x0    |0   |any |dst = (u32) imm         |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xb5  |0x0    |any |any |if dst <= imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xb6  |0x0    |any |any |if (u32)dst <= imm goto |base32  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xb7  |0x0    |0   |any |dst = imm               |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbc  |any    |0   |0x00|dst = (u32) src         |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbc  |any    |8   |0x00|dst = (u32) (s32) (s8)  |base32  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbc  |any    |16  |0x00|dst = (u32) (s32) (s16) |base32  |RFC    |
   |      |       |    |    |src                     |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbd  |any    |any |0x00|if dst <= src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbe  |any    |any |0x00|if (u32)dst <= (u32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbf  |any    |0   |0x00|dst = src               |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbf  |any    |8   |0x00|dst = (s64) (s8) src    |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbf  |any    |16  |0x00|dst = (s64) (s16) src   |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xbf  |any    |32  |0x00|dst = (s64) (s32) src   |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x00|lock *(u32 *)(dst +     |atomic32|RFC    |
   |      |       |    |    |offset) += src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x01|src =                   |atomic32|RFC    |
   |      |       |    |    |atomic_fetch_add_32((u32|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x40|lock *(u32 *)(dst +     |atomic32|RFC    |
   |      |       |    |    |offset) |= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x41|src =                   |atomic32|RFC    |
   |      |       |    |    |atomic_fetch_or_32((u32 |        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x50|lock *(u32 *)(dst +     |atomic32|RFC    |
   |      |       |    |    |offset) &= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0x51|src =                   |atomic32|RFC    |
   |      |       |    |    |atomic_fetch_and_32((u32|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0xa0|lock *(u32 *)(dst +     |atomic32|RFC    |
   |      |       |    |    |offset) ^= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0xa1|src =                   |atomic32|RFC    |
   |      |       |    |    |atomic_fetch_xor_32((u32|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0xe1|src = xchg_32((u32      |atomic32|RFC    |
   |      |       |    |    |*)(dst + offset), src)  |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc3  |any    |any |0xf1|r0 = cmpxchg_32((u32    |atomic32|RFC    |
   |      |       |    |    |*)(dst + offset), r0,   |        |9669,  |
   |      |       |    |    |src)                    |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc4  |0x0    |0   |any |dst = (u32)(dst s>> imm)|base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc5  |0x0    |any |any |if dst s< imm goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc6  |0x0    |any |any |if (s32)dst s< (s32)imm |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xc7  |0x0    |0   |any |dst s>>= imm            |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xcc  |any    |0   |0x00|dst = (u32)(dst s>> src)|base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xcd  |any    |any |0x00|if dst s< src goto      |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xce  |any    |any |0x00|if (s32)dst s< (s32)src |base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xcf  |any    |0   |0x00|dst s>>= src            |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.1    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd4  |0x0    |0   |0x10|dst = htole16(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd4  |0x0    |0   |0x20|dst = htole32(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd4  |0x0    |0   |0x40|dst = htole64(dst)      |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd5  |0x0    |any |any |if dst s<= imm goto     |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd6  |0x0    |any |any |if (s32)dst s<= (s32)imm|base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd7  |0x0    |0   |0x10|dst = bswap16(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd7  |0x0    |0   |0x20|dst = bswap32(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xd7  |0x0    |0   |0x40|dst = bswap64(dst)      |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x00|lock *(u64 *)(dst +     |atomic64|RFC    |
   |      |       |    |    |offset) += src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x01|src =                   |atomic64|RFC    |
   |      |       |    |    |atomic_fetch_add_64((u64|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x40|lock *(u64 *)(dst +     |atomic64|RFC    |
   |      |       |    |    |offset) |= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x41|src =                   |atomic64|RFC    |
   |      |       |    |    |atomic_fetch_or_64((u64 |        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x50|lock *(u64 *)(dst +     |atomic64|RFC    |
   |      |       |    |    |offset) &= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0x51|src =                   |atomic64|RFC    |
   |      |       |    |    |atomic_fetch_and_64((u64|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0xa0|lock *(u64 *)(dst +     |atomic64|RFC    |
   |      |       |    |    |offset) ^= src          |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0xa1|src =                   |atomic64|RFC    |
   |      |       |    |    |atomic_fetch_xor_64((u64|        |9669,  |
   |      |       |    |    |*)(dst + offset), src)  |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0xe1|src = xchg_64((u64      |atomic64|RFC    |
   |      |       |    |    |*)(dst + offset), src)  |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdb  |any    |any |0xf1|r0 = cmpxchg_64((u64    |atomic64|RFC    |
   |      |       |    |    |*)(dst + offset), r0,   |        |9669,  |
   |      |       |    |    |src)                    |        |Section|
   |      |       |    |    |                        |        |5.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdc  |0x0    |0   |0x10|dst = htobe16(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdc  |0x0    |0   |0x20|dst = htobe32(dst)      |base32  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdc  |0x0    |0   |0x40|dst = htobe64(dst)      |base64  |RFC    |
   |      |       |    |    |                        |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.2    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xdd  |any    |any |0x00|if dst s<= src goto     |base64  |RFC    |
   |      |       |    |    |+offset                 |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+
   |0xde  |any    |any |0x00|if (s32)dst s<= (s32)src|base32  |RFC    |
   |      |       |    |    |goto +offset            |        |9669,  |
   |      |       |    |    |                        |        |Section|
   |      |       |    |    |                        |        |4.3    |
   +------+-------+----+----+------------------------+--------+-------+

               Table 18: Initial BPF Instruction Set Values

Acknowledgements

   This document was generated from instruction-set.rst in the Linux
   kernel repository, to which a number of other individuals have
   authored contributions over time, including Akhil Raj, Alexei
   Starovoitov, Brendan Jackman, Christoph Hellwig, Daniel Borkmann,
   Ilya Leoshkevich, Jiong Wang, Jose E. Marchesi, Kosuke Fujimoto,
   Shahab Vahedi, Tiezhu Yang, Will Hawkins, and Zheng Yejian, with
   review and suggestions by many others including Alan Jowett, Andrii
   Nakryiko, David Vernet, Jim Harris, Quentin Monnet, Song Liu, Shung-
   Hsi Yu, Stanislav Fomichev, Watson Ladd, and Yonghong Song.

Author's Address

   Dave Thaler (editor)
   Redmond, WA 98052
   United States of America
   Email: dave.thaler.ietf@gmail.com