|
- <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- <html>
- <!-- Copyright (C) 1988-2020 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 the
- Invariant Sections being "Free Software" and "Free Software Needs
- Free Documentation", with the Front-Cover Texts being "A GNU Manual,"
- and with the Back-Cover Texts as in (a) below.
-
- (a) The FSF's Back-Cover Text is: "You are free to copy and modify
- this GNU Manual. Buying copies from GNU Press supports the FSF in
- developing GNU and promoting software freedom." -->
- <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
- <title>Patching (Debugging with GDB)</title>
-
- <meta name="description" content="Patching (Debugging with GDB)">
- <meta name="keywords" content="Patching (Debugging with GDB)">
- <meta name="resource-type" content="document">
- <meta name="distribution" content="global">
- <meta name="Generator" content="makeinfo">
- <link href="index.html#Top" rel="start" title="Top">
- <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
- <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
- <link href="Altering.html#Altering" rel="up" title="Altering">
- <link href="Compiling-and-Injecting-Code.html#Compiling-and-Injecting-Code" rel="next" title="Compiling and Injecting Code">
- <link href="Calling.html#Calling" rel="prev" title="Calling">
- <style type="text/css">
- <!--
- a.summary-letter {text-decoration: none}
- blockquote.indentedblock {margin-right: 0em}
- blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
- blockquote.smallquotation {font-size: smaller}
- div.display {margin-left: 3.2em}
- div.example {margin-left: 3.2em}
- div.lisp {margin-left: 3.2em}
- div.smalldisplay {margin-left: 3.2em}
- div.smallexample {margin-left: 3.2em}
- 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.nolinebreak {white-space: nowrap}
- span.roman {font-family: initial; font-weight: normal}
- span.sansserif {font-family: sans-serif; font-weight: normal}
- ul.no-bullet {list-style: none}
- -->
- </style>
-
-
- </head>
-
- <body lang="en">
- <a name="Patching"></a>
- <div class="header">
- <p>
- Next: <a href="Compiling-and-Injecting-Code.html#Compiling-and-Injecting-Code" accesskey="n" rel="next">Compiling and Injecting Code</a>, Previous: <a href="Calling.html#Calling" accesskey="p" rel="prev">Calling</a>, Up: <a href="Altering.html#Altering" accesskey="u" rel="up">Altering</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
- </div>
- <hr>
- <a name="Patching-Programs"></a>
- <h3 class="section">17.6 Patching Programs</h3>
-
- <a name="index-patching-binaries"></a>
- <a name="index-writing-into-executables"></a>
- <a name="index-writing-into-corefiles"></a>
-
- <p>By default, <small>GDB</small> opens the file containing your program’s
- executable code (or the corefile) read-only. This prevents accidental
- alterations to machine code; but it also prevents you from intentionally
- patching your program’s binary.
- </p>
- <p>If you’d like to be able to patch the binary, you can specify that
- explicitly with the <code>set write</code> command. For example, you might
- want to turn on internal debugging flags, or even to make emergency
- repairs.
- </p>
- <dl compact="compact">
- <dd><a name="index-set-write"></a>
- </dd>
- <dt><code>set write on</code></dt>
- <dt><code>set write off</code></dt>
- <dd><p>If you specify ‘<samp>set write on</samp>’, <small>GDB</small> opens executable and
- core files for both reading and writing; if you specify <kbd>set write
- off</kbd> (the default), <small>GDB</small> opens them read-only.
- </p>
- <p>If you have already loaded a file, you must load it again (using the
- <code>exec-file</code> or <code>core-file</code> command) after changing <code>set
- write</code>, for your new setting to take effect.
- </p>
- </dd>
- <dt><code>show write</code></dt>
- <dd><a name="index-show-write"></a>
- <p>Display whether executable files and core files are opened for writing
- as well as reading.
- </p></dd>
- </dl>
-
-
-
-
- </body>
- </html>
|