1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Chapter 9. Symbols</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Unreliable Guide To Hacking The Linux Kernel"><link rel="up" href="index.html" title="Unreliable Guide To Hacking The Linux Kernel"><link rel="prev" href="atomic-ops.html" title="Chapter 8. Atomic Operations"><link rel="next" href="sym-exportsymbols-gpl.html" title="EXPORT_SYMBOL_GPL() include/linux/export.h"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 9. Symbols</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="atomic-ops.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="sym-exportsymbols-gpl.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="symbols"></a>Chapter 9. Symbols</h1></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="sect1"><a href="symbols.html#sym-exportsymbols"><code class="function">EXPORT_SYMBOL()</code> 2 <code class="filename">include/linux/export.h</code></a></span></dt><dt><span class="sect1"><a href="sym-exportsymbols-gpl.html"><code class="function">EXPORT_SYMBOL_GPL()</code> 3 <code class="filename">include/linux/export.h</code></a></span></dt></dl></div><p> 4 Within the kernel proper, the normal linking rules apply 5 (ie. unless a symbol is declared to be file scope with the 6 <span class="type">static</span> keyword, it can be used anywhere in the 7 kernel). However, for modules, a special exported symbol table is 8 kept which limits the entry points to the kernel proper. Modules 9 can also export symbols. 10 </p><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sym-exportsymbols"></a><code class="function">EXPORT_SYMBOL()</code> 11 <code class="filename">include/linux/export.h</code></h2></div></div></div><p> 12 This is the classic method of exporting a symbol: dynamically 13 loaded modules will be able to use the symbol as normal. 14 </p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="atomic-ops.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="sym-exportsymbols-gpl.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 8. Atomic Operations </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <code class="function">EXPORT_SYMBOL_GPL()</code> 15 <code class="filename">include/linux/export.h</code></td></tr></table></div></body></html> 16