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<h4 class="subsection">22.8.3 Security restriction for auto-loading</h4>

<p><a name="index-auto_002dloading-safe_002dpath-1723"></a>
As the files of inferior can come from untrusted source (such as submitted by
an application user) <span class="sc">gdb</span> does not always load any files automatically. 
<span class="sc">gdb</span> provides the &lsquo;<samp><span class="samp">set auto-load safe-path</span></samp>&rsquo; setting to list
directories trusted for loading files not explicitly requested by user. 
Each directory can also be a shell wildcard pattern.

   <p>If the path is not set properly you will see a warning and the file will not
get loaded:

<pre class="smallexample">     $ ./gdb -q ./gdb
     Reading symbols from /home/user/gdb/gdb...done.
     warning: File "/home/user/gdb/gdb-gdb.gdb" auto-loading has been
              declined by your `auto-load safe-path' set
              to "$debugdir:$datadir/auto-load".
     warning: File "/home/user/gdb/gdb-gdb.py" auto-loading has been
              declined by your `auto-load safe-path' set
              to "$debugdir:$datadir/auto-load".
</pre>
   <p class="noindent">To instruct <span class="sc">gdb</span> to go ahead and use the init files anyway,
invoke <span class="sc">gdb</span> like this:

<pre class="smallexample">     $ gdb -q -iex "set auto-load safe-path /home/user/gdb" ./gdb
</pre>
   <p>The list of trusted directories is controlled by the following commands:

     <dl>
<a name="set-auto_002dload-safe_002dpath"></a><a name="index-set-auto_002dload-safe_002dpath-1724"></a><dt><code>set auto-load safe-path </code><span class="roman">[</span><var>directories</var><span class="roman">]</span><dd>Set the list of directories (and their subdirectories) trusted for automatic
loading and execution of scripts.  You can also enter a specific trusted file. 
Each directory can also be a shell wildcard pattern; wildcards do not match
directory separator - see <code>FNM_PATHNAME</code> for system function <code>fnmatch</code>
(see <a href="../libc/Wildcard-Matching.html#Wildcard-Matching">fnmatch</a>). 
If you omit <var>directories</var>, &lsquo;<samp><span class="samp">auto-load safe-path</span></samp>&rsquo; will be reset to
its default value as specified during <span class="sc">gdb</span> compilation.

     <p>The list of directories uses path separator (&lsquo;<samp><span class="samp">:</span></samp>&rsquo; on GNU and Unix
systems, &lsquo;<samp><span class="samp">;</span></samp>&rsquo; on MS-Windows and MS-DOS) to separate directories, similarly
to the <samp><span class="env">PATH</span></samp> environment variable.

     <p><a name="show-auto_002dload-safe_002dpath"></a><a name="index-show-auto_002dload-safe_002dpath-1725"></a><br><dt><code>show auto-load safe-path</code><dd>Show the list of directories trusted for automatic loading and execution of
scripts.

     <p><a name="add_002dauto_002dload_002dsafe_002dpath"></a><a name="index-add_002dauto_002dload_002dsafe_002dpath-1726"></a><br><dt><code>add-auto-load-safe-path</code><dd>Add an entry (or list of entries) to the list of directories trusted for
automatic loading and execution of scripts.  Multiple entries may be delimited
by the host platform path separator in use. 
</dl>

   <p>This variable defaults to what <code>--with-auto-load-dir</code> has been configured
to (see <a href="with_002dauto_002dload_002ddir.html#with_002dauto_002dload_002ddir">with-auto-load-dir</a>).  <samp><span class="file">$debugdir</span></samp> and <samp><span class="file">$datadir</span></samp>
substitution applies the same as for <a href="set-auto_002dload-scripts_002ddirectory.html#set-auto_002dload-scripts_002ddirectory">set auto-load scripts-directory</a>. 
The default <code>set auto-load safe-path</code> value can be also overriden by
<span class="sc">gdb</span> configuration option <samp><span class="option">--with-auto-load-safe-path</span></samp>.

   <p>Setting this variable to <samp><span class="file">/</span></samp> disables this security protection,
corresponding <span class="sc">gdb</span> configuration option is
<samp><span class="option">--without-auto-load-safe-path</span></samp>. 
This variable is supposed to be set to the system directories writable by the
system superuser only.  Users can add their source directories in init files in
their home directories (see <a href="Home-Directory-Init-File.html#Home-Directory-Init-File">Home Directory Init File</a>).  See also deprecated
init file in the current directory
(see <a href="Init-File-in-the-Current-Directory-during-Startup.html#Init-File-in-the-Current-Directory-during-Startup">Init File in the Current Directory during Startup</a>).

   <p>To force <span class="sc">gdb</span> to load the files it declined to load in the previous
example, you could use one of the following ways:

     <dl>
<dt><samp><span class="file">~/.gdbinit</span></samp>: &lsquo;<samp><span class="samp">add-auto-load-safe-path ~/src/gdb</span></samp>&rsquo;<dd>Specify this trusted directory (or a file) as additional component of the list. 
You have to specify also any existing directories displayed by
by &lsquo;<samp><span class="samp">show auto-load safe-path</span></samp>&rsquo; (such as &lsquo;<samp><span class="samp">/usr:/bin</span></samp>&rsquo; in this example).

     <br><dt><kbd>gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" ...</kbd><dd>Specify this directory as in the previous case but just for a single
<span class="sc">gdb</span> session.

     <br><dt><kbd>gdb -iex "set auto-load safe-path /" ...</kbd><dd>Disable auto-loading safety for a single <span class="sc">gdb</span> session. 
This assumes all the files you debug during this <span class="sc">gdb</span> session will come
from trusted sources.

     <br><dt><kbd>./configure --without-auto-load-safe-path</kbd><dd>During compilation of <span class="sc">gdb</span> you may disable any auto-loading safety. 
This assumes all the files you will ever debug with this <span class="sc">gdb</span> come from
trusted sources. 
</dl>

   <p>On the other hand you can also explicitly forbid automatic files loading which
also suppresses any such warning messages:

     <dl>
<dt><kbd>gdb -iex "set auto-load no" ...</kbd><dd>You can use <span class="sc">gdb</span> command-line option for a single <span class="sc">gdb</span> session.

     <br><dt><samp><span class="file">~/.gdbinit</span></samp>: &lsquo;<samp><span class="samp">set auto-load no</span></samp>&rsquo;<dd>Disable auto-loading globally for the user
(see <a href="Home-Directory-Init-File.html#Home-Directory-Init-File">Home Directory Init File</a>).  While it is improbable, you could also
use system init file instead (see <a href="System_002dwide-configuration.html#System_002dwide-configuration">System-wide configuration</a>). 
</dl>

   <p>This setting applies to the file names as entered by user.  If no entry matches
<span class="sc">gdb</span> tries as a last resort to also resolve all the file names into
their canonical form (typically resolving symbolic links) and compare the
entries again.  <span class="sc">gdb</span> already canonicalizes most of the filenames on its
own before starting the comparison so a canonical form of directories is
recommended to be entered.

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