huangmeng
/
asj_pe_project


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419
							<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This file documents the GNU Assembler "as".

Copyright (C) 1991-2020 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts.  A copy of the license is included in the
section entitled "GNU Free Documentation License".
 -->
<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Using as: BPF Opcodes</title>

<meta name="description" content="Using as: BPF Opcodes">
<meta name="keywords" content="Using as: BPF Opcodes">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="BPF_002dDependent.html#BPF_002dDependent" rel="up" title="BPF-Dependent">
<link href="CR16_002dDependent.html#CR16_002dDependent" rel="next" title="CR16-Dependent">
<link href="BPF-Directives.html#BPF-Directives" rel="previous" title="BPF Directives">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="BPF-Opcodes"></a>
<div class="header">
<p>
Previous: <a href="BPF-Directives.html#BPF-Directives" accesskey="p" rel="previous">BPF Directives</a>, Up: <a href="BPF_002dDependent.html#BPF_002dDependent" accesskey="u" rel="up">BPF-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Opcodes-5"></a>
<h4 class="subsection">9.7.4 Opcodes</h4>

<a name="index-BPF-opcodes"></a>
<a name="index-opcodes-for-BPF"></a>
<p>In the instruction descriptions below the following field descriptors
are used:
</p>
<dl compact="compact">
<dt><code>%d</code></dt>
<dd><p>Destination general-purpose register whose role is to be destination
of an operation.
</p></dd>
<dt><code>%s</code></dt>
<dd><p>Source general-purpose register whose role is to be the source of an
operation.
</p></dd>
<dt><code>disp16</code></dt>
<dd><p>16-bit signed PC-relative offset, measured in number of 64-bit words,
minus one.
</p></dd>
<dt><code>disp32</code></dt>
<dd><p>32-bit signed PC-relative offset, measured in number of 64-bit words,
minus one.
</p></dd>
<dt><code>offset16</code></dt>
<dd><p>Signed 16-bit immediate.
</p></dd>
<dt><code>imm32</code></dt>
<dd><p>Signed 32-bit immediate.
</p></dd>
<dt><code>imm64</code></dt>
<dd><p>Signed 64-bit immediate.
</p></dd>
</dl>

<a name="Arithmetic-instructions"></a>
<h4 class="subsubsection">9.7.4.1 Arithmetic instructions</h4>

<p>The destination register in these instructions act like an
accumulator.
</p>
<dl compact="compact">
<dt><code>add %d, (%s|imm32)</code></dt>
<dd><p>64-bit arithmetic addition.
</p></dd>
<dt><code>sub %d, (%s|imm32)</code></dt>
<dd><p>64-bit arithmetic subtraction.
</p></dd>
<dt><code>mul %d, (%s|imm32)</code></dt>
<dd><p>64-bit arithmetic multiplication.
</p></dd>
<dt><code>div %d, (%s|imm32)</code></dt>
<dd><p>64-bit arithmetic integer division.
</p></dd>
<dt><code>mod %d, (%s|imm32)</code></dt>
<dd><p>64-bit integer remainder.
</p></dd>
<dt><code>and %d, (%s|imm32)</code></dt>
<dd><p>64-bit bit-wise &ldquo;and&rdquo; operation.
</p></dd>
<dt><code>or %d, (%s|imm32)</code></dt>
<dd><p>64-bit bit-wise &ldquo;or&rdquo; operation.
</p></dd>
<dt><code>xor %d, (%s|imm32)</code></dt>
<dd><p>64-bit bit-wise exclusive-or operation.
</p></dd>
<dt><code>lsh %d, (%s|imm32)</code></dt>
<dd><p>64-bit left shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>rsh %d, (%s|imm32)</code></dt>
<dd><p>64-bit right logical shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>arsh %d, (%s|imm32)</code></dt>
<dd><p>64-bit right arithmetic shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>neg %d</code></dt>
<dd><p>64-bit arithmetic negation.
</p></dd>
<dt><code>mov %d, (%s|imm32)</code></dt>
<dd><p>Move the 64-bit value of <code>%s</code> in <code>%d</code>, or load <code>imm32</code>
in <code>%d</code>.
</p></dd>
</dl>

<a name="g_t32_002dbit-arithmetic-instructions"></a>
<h4 class="subsubsection">9.7.4.2 32-bit arithmetic instructions</h4>

<p>The destination register in these instructions act as an accumulator.
</p>
<dl compact="compact">
<dt><code>add32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit arithmetic addition.
</p></dd>
<dt><code>sub32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit arithmetic subtraction.
</p></dd>
<dt><code>mul32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit arithmetic multiplication.
</p></dd>
<dt><code>div32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit arithmetic integer division.
</p></dd>
<dt><code>mod32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit integer remainder.
</p></dd>
<dt><code>and32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit bit-wise &ldquo;and&rdquo; operation.
</p></dd>
<dt><code>or32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit bit-wise &ldquo;or&rdquo; operation.
</p></dd>
<dt><code>xor32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit bit-wise exclusive-or operation.
</p></dd>
<dt><code>lsh32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit left shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>rsh32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit right logical shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>arsh32 %d, (%s|imm32)</code></dt>
<dd><p>32-bit right arithmetic shift, by <code>%s</code> or <code>imm32</code> bits.
</p></dd>
<dt><code>neg32 %d</code></dt>
<dd><p>32-bit arithmetic negation.
</p></dd>
<dt><code>mov32 %d, (%s|imm32)</code></dt>
<dd><p>Move the 32-bit value of <code>%s</code> in <code>%d</code>, or load <code>imm32</code>
in <code>%d</code>.
</p></dd>
</dl>

<a name="Endianness-conversion-instructions"></a>
<h4 class="subsubsection">9.7.4.3 Endianness conversion instructions</h4>

<dl compact="compact">
<dt><code>endle %d, (8|16|32)</code></dt>
<dd><p>Convert the 8-bit, 16-bit or 32-bit value in <code>%d</code> to
little-endian.
</p></dd>
<dt><code>endbe %d, (8|16|32)</code></dt>
<dd><p>Convert the 8-bit, 16-bit or 32-bit value in <code>%d</code> to big-endian.
</p></dd>
</dl>

<a name="g_t64_002dbit-load-and-pseudo-maps"></a>
<h4 class="subsubsection">9.7.4.4 64-bit load and pseudo maps</h4>

<dl compact="compact">
<dt><code>lddw %d, imm64</code></dt>
<dd><p>Load the given signed 64-bit immediate, or pseudo map descriptor, to
the destination register <code>%d</code>.
</p></dd>
<dt><code>lddw %d, %map_fd(N)</code></dt>
<dd><p>Load the address of the given pseudo map fd <em>N</em> to the
destination register <code>%d</code>.
</p></dd>
</dl>

<a name="Load-instructions-for-socket-filters"></a>
<h4 class="subsubsection">9.7.4.5 Load instructions for socket filters</h4>

<p>The following instructions are intended to be used in socket filters,
and are therefore not general-purpose: they make assumptions on the
contents of several registers.  See the file
<samp>Documentation/networking/filter.txt</samp> in the Linux kernel source
tree for more information.
</p>
<p>Absolute loads:
</p>
<dl compact="compact">
<dt><code>ldabsdw imm32</code></dt>
<dd><p>Absolute 64-bit load.
</p></dd>
<dt><code>ldabsw imm32</code></dt>
<dd><p>Absolute 32-bit load.
</p></dd>
<dt><code>ldabsh imm32</code></dt>
<dd><p>Absolute 16-bit load.
</p></dd>
<dt><code>ldabsb imm32</code></dt>
<dd><p>Absolute 8-bit load.
</p></dd>
</dl>

<p>Indirect loads:
</p>
<dl compact="compact">
<dt><code>ldinddw %s, imm32</code></dt>
<dd><p>Indirect 64-bit load.
</p></dd>
<dt><code>ldindw %s, imm32</code></dt>
<dd><p>Indirect 32-bit load.
</p></dd>
<dt><code>ldindh %s, imm32</code></dt>
<dd><p>Indirect 16-bit load.
</p></dd>
<dt><code>ldindb %s, imm32</code></dt>
<dd><p>Indirect 8-bit load.
</p></dd>
</dl>

<a name="Generic-load_002fstore-instructions"></a>
<h4 class="subsubsection">9.7.4.6 Generic load/store instructions</h4>

<p>General-purpose load and store instructions are provided for several
word sizes.
</p>
<p>Load to register instructions:
</p>
<dl compact="compact">
<dt><code>ldxdw %d, [%s+offset16]</code></dt>
<dd><p>Generic 64-bit load.
</p></dd>
<dt><code>ldxw %d, [%s+offset16]</code></dt>
<dd><p>Generic 32-bit load.
</p></dd>
<dt><code>ldxh %d, [%s+offset16]</code></dt>
<dd><p>Generic 16-bit load.
</p></dd>
<dt><code>ldxb %d, [%s+offset16]</code></dt>
<dd><p>Generic 8-bit load.
</p></dd>
</dl>

<p>Store from register instructions:
</p>
<dl compact="compact">
<dt><code>stxdw [%d+offset16], %s</code></dt>
<dd><p>Generic 64-bit store.
</p></dd>
<dt><code>stxw [%d+offset16], %s</code></dt>
<dd><p>Generic 32-bit store.
</p></dd>
<dt><code>stxh [%d+offset16], %s</code></dt>
<dd><p>Generic 16-bit store.
</p></dd>
<dt><code>stxb [%d+offset16], %s</code></dt>
<dd><p>Generic 8-bit store.
</p></dd>
</dl>

<p>Store from immediates instructions:
</p>
<dl compact="compact">
<dt><code>stddw [%d+offset16], imm32</code></dt>
<dd><p>Store immediate as 64-bit.
</p></dd>
<dt><code>stdw [%d+offset16], imm32</code></dt>
<dd><p>Store immediate as 32-bit.
</p></dd>
<dt><code>stdh [%d+offset16], imm32</code></dt>
<dd><p>Store immediate as 16-bit.
</p></dd>
<dt><code>stdb [%d+offset16], imm32</code></dt>
<dd><p>Store immediate as 8-bit.
</p></dd>
</dl>

<a name="Jump-instructions"></a>
<h4 class="subsubsection">9.7.4.7 Jump instructions</h4>

<p>eBPF provides the following compare-and-jump instructions, which
compare the values of the two given registers, or the values of a
register and an immediate, and perform a branch in case the comparison
holds true.
</p>
<dl compact="compact">
<dt><code>ja %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump-always.
</p></dd>
<dt><code>jeq %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if equal.
</p></dd>
<dt><code>jgt %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if greater.
</p></dd>
<dt><code>jge %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if greater or equal.
</p></dd>
<dt><code>jlt %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if lesser.
</p></dd>
<dt><code>jle %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if lesser or equal.
</p></dd>
<dt><code>jset %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if signed equal.
</p></dd>
<dt><code>jne %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if not equal.
</p></dd>
<dt><code>jsgt %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if signed greater.
</p></dd>
<dt><code>jsge %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if signed greater or equal.
</p></dd>
<dt><code>jslt %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if signed lesser.
</p></dd>
<dt><code>jsle %d,(%s|imm32),disp16</code></dt>
<dd><p>Jump if signed lesser or equal.
</p></dd>
</dl>

<p>A call instruction is provided in order to perform calls to other eBPF
functions, or to external kernel helpers:
</p>
<dl compact="compact">
<dt><code>call (disp32|imm32)</code></dt>
<dd><p>Jump and link to the offset <em>disp32</em>, or to the kernel helper
function identified by <em>imm32</em>.
</p></dd>
</dl>

<p>Finally:
</p>
<dl compact="compact">
<dt><code>exit</code></dt>
<dd><p>Terminate the eBPF program.
</p></dd>
</dl>

<a name="Atomic-instructions"></a>
<h4 class="subsubsection">9.7.4.8 Atomic instructions</h4>

<p>Atomic exchange-and-add instructions are provided in two flavors: one
for swapping 64-bit quantities and another for 32-bit quantities.
</p>
<dl compact="compact">
<dt><code>xadddw [%d+offset16],%s</code></dt>
<dd><p>Exchange-and-add a 64-bit value at the specified location.
</p></dd>
<dt><code>xaddw [%d+offset16],%s</code></dt>
<dd><p>Exchange-and-add a 32-bit value at the specified location.
</p></dd>
</dl>


<hr>
<div class="header">
<p>
Previous: <a href="BPF-Directives.html#BPF-Directives" accesskey="p" rel="previous">BPF Directives</a>, Up: <a href="BPF_002dDependent.html#BPF_002dDependent" accesskey="u" rel="up">BPF-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
</div>


</body>
</html>