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<section id="s390-debug-feature">
<h1>S390 Debug Feature<a class="headerlink" href="#s390-debug-feature" title="Link to this heading">¶</a></h1>
<dl class="simple">
<dt>files:</dt><dd><ul class="simple">
<li><p>arch/s390/kernel/debug.c</p></li>
<li><p>arch/s390/include/asm/debug.h</p></li>
</ul>
</dd>
</dl>
<section id="description">
<h2>Description:<a class="headerlink" href="#description" title="Link to this heading">¶</a></h2>
<p>The goal of this feature is to provide a kernel debug logging API
where log records can be stored efficiently in memory, where each component
(e.g. device drivers) can have one separate debug log.
One purpose of this is to inspect the debug logs after a production system crash
in order to analyze the reason for the crash.</p>
<p>If the system still runs but only a subcomponent which uses dbf fails,
it is possible to look at the debug logs on a live system via the Linux
debugfs filesystem.</p>
<p>The debug feature may also very useful for kernel and driver development.</p>
</section>
<section id="design">
<h2>Design:<a class="headerlink" href="#design" title="Link to this heading">¶</a></h2>
<p>Kernel components (e.g. device drivers) can register themselves at the debug
feature with the function call <a class="reference internal" href="#c.debug_register" title="debug_register"><code class="xref c c-func docutils literal notranslate"><span class="pre">debug_register()</span></code></a>.
This function initializes a
debug log for the caller. For each debug log exists a number of debug areas
where exactly one is active at one time. Each debug area consists of contiguous
pages in memory. In the debug areas there are stored debug entries (log records)
which are written by event- and exception-calls.</p>
<p>An event-call writes the specified debug entry to the active debug
area and updates the log pointer for the active area. If the end
of the active debug area is reached, a wrap around is done (ring buffer)
and the next debug entry will be written at the beginning of the active
debug area.</p>
<p>An exception-call writes the specified debug entry to the log and
switches to the next debug area. This is done in order to be sure
that the records which describe the origin of the exception are not
overwritten when a wrap around for the current area occurs.</p>
<p>The debug areas themselves are also ordered in form of a ring buffer.
When an exception is thrown in the last debug area, the following debug
entries are then written again in the very first area.</p>
<p>There are four versions for the event- and exception-calls: One for
logging raw data, one for text, one for numbers (unsigned int and long),
and one for sprintf-like formatted strings.</p>
<p>Each debug entry contains the following data:</p>
<ul class="simple">
<li><p>Timestamp</p></li>
<li><p>Cpu-Number of calling task</p></li>
<li><p>Level of debug entry (0...6)</p></li>
<li><p>Return Address to caller</p></li>
<li><p>Flag, if entry is an exception or not</p></li>
</ul>
<p>The debug logs can be inspected in a live system through entries in
the debugfs-filesystem. Under the toplevel directory “<code class="docutils literal notranslate"><span class="pre">s390dbf</span></code>” there is
a directory for each registered component, which is named like the
corresponding component. The debugfs normally should be mounted to
<code class="docutils literal notranslate"><span class="pre">/sys/kernel/debug</span></code> therefore the debug feature can be accessed under
<code class="docutils literal notranslate"><span class="pre">/sys/kernel/debug/s390dbf</span></code>.</p>
<p>The content of the directories are files which represent different views
to the debug log. Each component can decide which views should be
used through registering them with the function <a class="reference internal" href="#c.debug_register_view" title="debug_register_view"><code class="xref c c-func docutils literal notranslate"><span class="pre">debug_register_view()</span></code></a>.
Predefined views for hex/ascii and sprintf data are provided.
It is also possible to define other views. The content of
a view can be inspected simply by reading the corresponding debugfs file.</p>
<p>All debug logs have an actual debug level (range from 0 to 6).
The default level is 3. Event and Exception functions have a <code class="xref c c-data docutils literal notranslate"><span class="pre">level</span></code>
parameter. Only debug entries with a level that is lower or equal
than the actual level are written to the log. This means, when
writing events, high priority log entries should have a low level
value whereas low priority entries should have a high one.
The actual debug level can be changed with the help of the debugfs-filesystem
through writing a number string “x” to the <code class="docutils literal notranslate"><span class="pre">level</span></code> debugfs file which is
provided for every debug log. Debugging can be switched off completely
by using “-” on the <code class="docutils literal notranslate"><span class="pre">level</span></code> debugfs file.</p>
<p>Example:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> echo "-" > /sys/kernel/debug/s390dbf/dasd/level
</pre></div>
</div>
<p>It is also possible to deactivate the debug feature globally for every
debug log. You can change the behavior using 2 sysctl parameters in
<code class="docutils literal notranslate"><span class="pre">/proc/sys/s390dbf</span></code>:</p>
<p>There are currently 2 possible triggers, which stop the debug feature
globally. The first possibility is to use the <code class="docutils literal notranslate"><span class="pre">debug_active</span></code> sysctl. If
set to 1 the debug feature is running. If <code class="docutils literal notranslate"><span class="pre">debug_active</span></code> is set to 0 the
debug feature is turned off.</p>
<p>The second trigger which stops the debug feature is a kernel oops.
That prevents the debug feature from overwriting debug information that
happened before the oops. After an oops you can reactivate the debug feature
by piping 1 to <code class="docutils literal notranslate"><span class="pre">/proc/sys/s390dbf/debug_active</span></code>. Nevertheless, it’s not
suggested to use an oopsed kernel in a production environment.</p>
<p>If you want to disallow the deactivation of the debug feature, you can use
the <code class="docutils literal notranslate"><span class="pre">debug_stoppable</span></code> sysctl. If you set <code class="docutils literal notranslate"><span class="pre">debug_stoppable</span></code> to 0 the debug
feature cannot be stopped. If the debug feature is already stopped, it
will stay deactivated.</p>
</section>
<section id="kernel-interfaces">
<h2>Kernel Interfaces:<a class="headerlink" href="#kernel-interfaces" title="Link to this heading">¶</a></h2>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_next_entry">
<span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_next_entry</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">file_private_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">p_info</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_next_entry" title="Link to this definition">¶</a><br /></dt>
<dd><p>Go to the next entry</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">file_private_info_t</span> <span class="pre">*p_info</span></code></dt><dd><p>Private info that is manipulated</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Sets the current position in <strong>p_info</strong> to the next entry. If no further entry
exists the current position is set to one after the end the return value
indicates that no further entries exist.</p>
<p><strong>Return</strong></p>
<p>True if there are more following entries, false otherwise</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_to_act_entry">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_to_act_entry</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">file_private_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">p_info</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_to_act_entry" title="Link to this definition">¶</a><br /></dt>
<dd><p>Go to the currently active entry</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">file_private_info_t</span> <span class="pre">*p_info</span></code></dt><dd><p>Private info that is manipulated</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Sets the current position in <strong>p_info</strong> to the currently active
entry of <strong>p_info->debug_info_snap</strong></p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_prev_entry">
<span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_prev_entry</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">file_private_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">p_info</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_prev_entry" title="Link to this definition">¶</a><br /></dt>
<dd><p>Go to the previous entry</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">file_private_info_t</span> <span class="pre">*p_info</span></code></dt><dd><p>Private info that is manipulated</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Sets the current position in <strong>p_info</strong> to the previous entry. If no previous entry
exists the current position is set left as DEBUG_PROLOG_ENTRY and the return value
indicates that no previous entries exist.</p>
<p><strong>Return</strong></p>
<p>True if there are more previous entries, false otherwise</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_move_entry">
<span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_move_entry</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">file_private_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">p_info</span></span>, <span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="n"><span class="pre">reverse</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_move_entry" title="Link to this definition">¶</a><br /></dt>
<dd><p>Go to next entry in either the forward or backward direction</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">file_private_info_t</span> <span class="pre">*p_info</span></code></dt><dd><p>Private info that is manipulated</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">bool</span> <span class="pre">reverse</span></code></dt><dd><p>If true go to the next entry in reverse i.e. previous</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Sets the current position in <strong>p_info</strong> to the next (<strong>reverse</strong> == false) or
previous (<strong>reverse</strong> == true) entry.</p>
<p><strong>Return</strong></p>
<p>True if there are further entries in that direction,
false otherwise.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_dump">
<span class="n"><span class="pre">ssize_t</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_dump</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="k"><span class="pre">struct</span></span><span class="w"> </span><span class="n"><span class="pre">debug_view</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">view</span></span>, <span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">buf</span></span>, <span class="n"><span class="pre">size_t</span></span><span class="w"> </span><span class="n"><span class="pre">buf_size</span></span>, <span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="n"><span class="pre">reverse</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_dump" title="Link to this definition">¶</a><br /></dt>
<dd><p>Get a textual representation of debug info, or as much as fits</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>Debug information to use</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">struct</span> <span class="pre">debug_view</span> <span class="pre">*view</span></code></dt><dd><p>View with which to dump the debug information</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">char</span> <span class="pre">*buf</span></code></dt><dd><p>Buffer the textual debug data representation is written to</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">size_t</span> <span class="pre">buf_size</span></code></dt><dd><p>Size of the buffer, including the trailing ‘0’ byte</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">bool</span> <span class="pre">reverse</span></code></dt><dd><p>Go backwards from the last written entry</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>This function may be used whenever a textual representation of the debug
information is required without using an s390dbf file.</p>
<p><strong>Note</strong></p>
<p>It is the callers responsibility to supply a view that is compatible
with the debug information data.</p>
<p><strong>Return</strong></p>
<p>On success returns the number of bytes written to the buffer not
including the trailing ‘0’ byte. If bug_size == 0 the function returns 0.
On failure an error code less than 0 is returned.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_register_mode">
<span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_register_mode</span></span></span><span class="sig-paren">(</span><span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">name</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">pages_per_area</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">nr_areas</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">buf_size</span></span>, <span class="n"><span class="pre">umode_t</span></span><span class="w"> </span><span class="n"><span class="pre">mode</span></span>, <span class="n"><span class="pre">uid_t</span></span><span class="w"> </span><span class="n"><span class="pre">uid</span></span>, <span class="n"><span class="pre">gid_t</span></span><span class="w"> </span><span class="n"><span class="pre">gid</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_register_mode" title="Link to this definition">¶</a><br /></dt>
<dd><p>creates and initializes debug area.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">const</span> <span class="pre">char</span> <span class="pre">*name</span></code></dt><dd><p>Name of debug log (e.g. used for debugfs entry)</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">pages_per_area</span></code></dt><dd><p>Number of pages, which will be allocated per area</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">nr_areas</span></code></dt><dd><p>Number of debug areas</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">buf_size</span></code></dt><dd><p>Size of data area in each debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">umode_t</span> <span class="pre">mode</span></code></dt><dd><p>File mode for debugfs files. E.g. S_IRWXUGO</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">uid_t</span> <span class="pre">uid</span></code></dt><dd><p>User ID for debugfs files. Currently only 0 is supported.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">gid_t</span> <span class="pre">gid</span></code></dt><dd><p>Group ID for debugfs files. Currently only 0 is supported.</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Handle for generated debug area</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if register failed</p></li>
</ul>
<p><strong>Description</strong></p>
<p>Allocates memory for a debug log.
Must not be called within an interrupt handler.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_register">
<span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_register</span></span></span><span class="sig-paren">(</span><span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">name</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">pages_per_area</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">nr_areas</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">buf_size</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_register" title="Link to this definition">¶</a><br /></dt>
<dd><p>creates and initializes debug area with default file mode.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">const</span> <span class="pre">char</span> <span class="pre">*name</span></code></dt><dd><p>Name of debug log (e.g. used for debugfs entry)</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">pages_per_area</span></code></dt><dd><p>Number of pages, which will be allocated per area</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">nr_areas</span></code></dt><dd><p>Number of debug areas</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">buf_size</span></code></dt><dd><p>Size of data area in each debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Handle for generated debug area</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if register failed</p></li>
</ul>
<p><strong>Description</strong></p>
<p>Allocates memory for a debug log.
The debugfs file mode access permissions are read and write for user.
Must not be called within an interrupt handler.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_register_static">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_register_static</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">pages_per_area</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">nr_areas</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_register_static" title="Link to this definition">¶</a><br /></dt>
<dd><p>registers a static debug area</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>Handle for static debug area</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">pages_per_area</span></code></dt><dd><p>Number of pages per area</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">nr_areas</span></code></dt><dd><p>Number of debug areas</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Register debug_info_t defined using DEFINE_STATIC_DEBUG_INFO.</p>
<p><strong>Note</strong></p>
<dl class="simple">
<dt>This function is called automatically via an initcall generated by</dt><dd><p>DEFINE_STATIC_DEBUG_INFO.</p>
</dd>
</dl>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_unregister">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_unregister</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_unregister" title="Link to this definition">¶</a><br /></dt>
<dd><p>give back debug area.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<p>none</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_set_level">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_set_level</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">new_level</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_set_level" title="Link to this definition">¶</a><br /></dt>
<dd><p>Sets new actual debug level if new_level is valid.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">new_level</span></code></dt><dd><p>new debug level</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<p>none</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_stop_all">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_stop_all</span></span></span><span class="sig-paren">(</span><span class="kt"><span class="pre">void</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_stop_all" title="Link to this definition">¶</a><br /></dt>
<dd><p>stops the debug feature if stopping is allowed.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">void</span></code></dt><dd><p>no arguments</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>none</p></li>
</ul>
<p><strong>Description</strong></p>
<p>Currently used in case of a kernel oops.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_set_critical">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_set_critical</span></span></span><span class="sig-paren">(</span><span class="kt"><span class="pre">void</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_set_critical" title="Link to this definition">¶</a><br /></dt>
<dd><p>event/exception functions try lock instead of spin.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">void</span></code></dt><dd><p>no arguments</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>none</p></li>
</ul>
<p><strong>Description</strong></p>
<p>Currently used in case of stopping all CPUs but the current one.
Once in this state, functions to write a debug entry for an
event or exception no longer spin on the debug area lock,
but only try to get it and fail if they do not get the lock.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_register_view">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_register_view</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="k"><span class="pre">struct</span></span><span class="w"> </span><span class="n"><span class="pre">debug_view</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">view</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_register_view" title="Link to this definition">¶</a><br /></dt>
<dd><p>registers new debug view and creates debugfs dir entry</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">struct</span> <span class="pre">debug_view</span> <span class="pre">*view</span></code></dt><dd><p>pointer to debug view struct</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>0 : ok</p></li>
<li><p>< 0: Error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_unregister_view">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_unregister_view</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="k"><span class="pre">struct</span></span><span class="w"> </span><span class="n"><span class="pre">debug_view</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">view</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_unregister_view" title="Link to this definition">¶</a><br /></dt>
<dd><p>unregisters debug view and removes debugfs dir entry</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">struct</span> <span class="pre">debug_view</span> <span class="pre">*view</span></code></dt><dd><p>pointer to debug view struct</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>0 : ok</p></li>
<li><p>< 0: Error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_level_enabled">
<span class="kt"><span class="pre">bool</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">debug_level_enabled</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_level_enabled" title="Link to this definition">¶</a><br /></dt>
<dd><p>Returns true if debug events for the specified level would be logged. Otherwise returns false.</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">true</span></code> if level is less or equal to the current debug level.</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_event">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_event</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">data</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">length</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_event" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes binary debug entry to active debug area (if level <= actual debug level)</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">void</span> <span class="pre">*data</span></code></dt><dd><p>pointer to data for debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">length</span></code></dt><dd><p>length of data in bytes</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_int_event">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_int_event</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">tag</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_int_event" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes unsigned integer debug entry to active debug area (if level <= actual debug level)</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">unsigned</span> <span class="pre">int</span> <span class="pre">tag</span></code></dt><dd><p>integer value for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_long_event">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_long_event</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">long</span></span><span class="w"> </span><span class="n"><span class="pre">tag</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_long_event" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes unsigned long debug entry to active debug area (if level <= actual debug level)</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">unsigned</span> <span class="pre">long</span> <span class="pre">tag</span></code></dt><dd><p>long integer value for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_text_event">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_text_event</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">txt</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_text_event" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes string debug entry in ascii format to active debug area (if level <= actual debug level)</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">const</span> <span class="pre">char</span> <span class="pre">*txt</span></code></dt><dd><p>string for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c macro">
<dt class="sig sig-object c" id="c.debug_sprintf_event">
<span class="sig-name descname"><span class="n"><span class="pre">debug_sprintf_event</span></span></span><a class="headerlink" href="#c.debug_sprintf_event" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>
<p><code class="docutils literal notranslate"><span class="pre">debug_sprintf_event</span> <span class="pre">(_id,</span> <span class="pre">_level,</span> <span class="pre">_fmt,</span> <span class="pre">...)</span></code></p>
<blockquote>
<div><p>writes debug entry with format string and varargs (longs) to active debug area (if level $<=$ actual debug level).</p>
</div></blockquote>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">_id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">_level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">_fmt</span></code></dt><dd><p>format string for debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">...</span></code></dt><dd><p>varargs used as in <a class="reference internal" href="../../core-api/kernel-api.html#c.sprintf" title="sprintf"><code class="xref c c-func docutils literal notranslate"><span class="pre">sprintf()</span></code></a></p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
<p><strong>Description</strong></p>
<p>floats and long long datatypes cannot be used as varargs.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_exception">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_exception</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">data</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">length</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_exception" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes binary debug entry to active debug area (if level <= actual debug level) and switches to next debug area</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">void</span> <span class="pre">*data</span></code></dt><dd><p>pointer to data for debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">length</span></code></dt><dd><p>length of data in bytes</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_int_exception">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_int_exception</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">tag</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_int_exception" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes unsigned int debug entry to active debug area (if level <= actual debug level) and switches to next debug area</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">unsigned</span> <span class="pre">int</span> <span class="pre">tag</span></code></dt><dd><p>integer value for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_long_exception">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_long_exception</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">long</span></span><span class="w"> </span><span class="n"><span class="pre">tag</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_long_exception" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes long debug entry to active debug area (if level <= actual debug level) and switches to next debug area</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">unsigned</span> <span class="pre">long</span> <span class="pre">tag</span></code></dt><dd><p>long integer value for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.debug_text_exception">
<span class="n"><span class="pre">debug_entry_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">debug_text_exception</span></span></span><span class="sig-paren">(</span><span class="n"><span class="pre">debug_info_t</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">id</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">level</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">txt</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.debug_text_exception" title="Link to this definition">¶</a><br /></dt>
<dd><p>writes string debug entry in ascii format to active debug area (if level <= actual debug level) and switches to next debug area area</p>
</dd></dl>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">debug_info_t</span> <span class="pre">*id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">int</span> <span class="pre">level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">const</span> <span class="pre">char</span> <span class="pre">*txt</span></code></dt><dd><p>string for debug entry</p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
</div>
<dl class="c macro">
<dt class="sig sig-object c" id="c.debug_sprintf_exception">
<span class="sig-name descname"><span class="n"><span class="pre">debug_sprintf_exception</span></span></span><a class="headerlink" href="#c.debug_sprintf_exception" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>
<p><code class="docutils literal notranslate"><span class="pre">debug_sprintf_exception</span> <span class="pre">(_id,</span> <span class="pre">_level,</span> <span class="pre">_fmt,</span> <span class="pre">...)</span></code></p>
<blockquote>
<div><p>writes debug entry with format string and varargs (longs) to active debug area (if level <= actual debug level) and switches to next debug area.</p>
</div></blockquote>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">_id</span></code></dt><dd><p>handle for debug log</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">_level</span></code></dt><dd><p>debug level</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">_fmt</span></code></dt><dd><p>format string for debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">...</span></code></dt><dd><p>varargs used as in <a class="reference internal" href="../../core-api/kernel-api.html#c.sprintf" title="sprintf"><code class="xref c c-func docutils literal notranslate"><span class="pre">sprintf()</span></code></a></p>
</dd>
</dl>
<p><strong>Return</strong></p>
<ul class="simple">
<li><p>Address of written debug entry</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">NULL</span></code> if error</p></li>
</ul>
<p><strong>Description</strong></p>
<p>floats and long long datatypes cannot be used as varargs.</p>
</div>
<dl class="c macro">
<dt class="sig sig-object c" id="c.DEFINE_STATIC_DEBUG_INFO">
<span class="sig-name descname"><span class="n"><span class="pre">DEFINE_STATIC_DEBUG_INFO</span></span></span><a class="headerlink" href="#c.DEFINE_STATIC_DEBUG_INFO" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>
<p><code class="docutils literal notranslate"><span class="pre">DEFINE_STATIC_DEBUG_INFO</span> <span class="pre">(var,</span> <span class="pre">name,</span> <span class="pre">pages,</span> <span class="pre">nr_areas,</span> <span class="pre">buf_size,</span> <span class="pre">view)</span></code></p>
<blockquote>
<div><p>Define static debug_info_t</p>
</div></blockquote>
<div class="kernelindent docutils container">
<p><strong>Parameters</strong></p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">var</span></code></dt><dd><p>Name of debug_info_t variable</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">name</span></code></dt><dd><p>Name of debug log (e.g. used for debugfs entry)</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">pages</span></code></dt><dd><p>Number of pages per area</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">nr_areas</span></code></dt><dd><p>Number of debug areas</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">buf_size</span></code></dt><dd><p>Size of data area in each debug entry</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">view</span></code></dt><dd><p>Pointer to debug view struct</p>
</dd>
</dl>
<p><strong>Description</strong></p>
<p>Define a static debug_info_t for early tracing. The associated debugfs log
is automatically registered with the specified debug view.</p>
<p>Important: Users of this macro must not call any of the
debug_register/<code class="xref c c-func broken_xref docutils literal notranslate"><span class="pre">_unregister()</span></code> functions for this debug_info_t!</p>
<p><strong>Note</strong></p>
<p>Tracing will start with a fixed number of initial pages and areas.
The debug area will be changed to use the specified numbers during
arch_initcall.</p>
</div>
</section>
<section id="predefined-views">
<h2>Predefined views:<a class="headerlink" href="#predefined-views" title="Link to this heading">¶</a></h2>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">extern</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="w"> </span><span class="n">debug_hex_ascii_view</span><span class="p">;</span>
<span class="k">extern</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="w"> </span><span class="n">debug_sprintf_view</span><span class="p">;</span>
</pre></div>
</div>
</section>
<section id="examples">
<h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">¶</a></h2>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cm">/*</span>
<span class="cm"> * hex_ascii-view Example</span>
<span class="cm"> */</span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><linux/init.h></span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><asm/debug.h></span>
<span class="k">static</span><span class="w"> </span><span class="n">debug_info_t</span><span class="w"> </span><span class="o">*</span><span class="n">debug_info</span><span class="p">;</span>
<span class="k">static</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">init</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="cm">/* register 4 debug areas with one page each and 4 byte data field */</span>
<span class="w"> </span><span class="n">debug_info</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">debug_register</span><span class="p">(</span><span class="s">"test"</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="w"> </span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_register_view</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">debug_hex_ascii_view</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_text_event</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="w"> </span><span class="p">,</span><span class="w"> </span><span class="s">"one "</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_int_exception</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">,</span><span class="w"> </span><span class="mi">4711</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_event</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">);</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">static</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">cleanup</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="n">debug_unregister</span><span class="p">(</span><span class="n">debug_info</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">module_init</span><span class="p">(</span><span class="n">init</span><span class="p">);</span>
<span class="n">module_exit</span><span class="p">(</span><span class="n">cleanup</span><span class="p">);</span>
</pre></div>
</div>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cm">/*</span>
<span class="cm"> * sprintf-view Example</span>
<span class="cm"> */</span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><linux/init.h></span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><asm/debug.h></span>
<span class="k">static</span><span class="w"> </span><span class="n">debug_info_t</span><span class="w"> </span><span class="o">*</span><span class="n">debug_info</span><span class="p">;</span>
<span class="k">static</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">init</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="cm">/* register 4 debug areas with one page each and data field for */</span>
<span class="w"> </span><span class="cm">/* format string pointer + 2 varargs (= 3 * sizeof(long)) */</span>
<span class="w"> </span><span class="n">debug_info</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">debug_register</span><span class="p">(</span><span class="s">"test"</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">,</span><span class="w"> </span><span class="k">sizeof</span><span class="p">(</span><span class="kt">long</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mi">3</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_register_view</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">debug_sprintf_view</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_sprintf_event</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="p">,</span><span class="w"> </span><span class="s">"first event in %s:%i</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="n">__FILE__</span><span class="p">,</span><span class="n">__LINE__</span><span class="p">);</span>
<span class="w"> </span><span class="n">debug_sprintf_exception</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s">"pointer to debug info: %p</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="o">&</span><span class="n">debug_info</span><span class="p">);</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">static</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">cleanup</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="n">debug_unregister</span><span class="p">(</span><span class="n">debug_info</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">module_init</span><span class="p">(</span><span class="n">init</span><span class="p">);</span>
<span class="n">module_exit</span><span class="p">(</span><span class="n">cleanup</span><span class="p">);</span>
</pre></div>
</div>
</section>
<section id="debugfs-interface">
<h2>Debugfs Interface<a class="headerlink" href="#debugfs-interface" title="Link to this heading">¶</a></h2>
<p>Views to the debug logs can be investigated through reading the corresponding
debugfs-files:</p>
<p>Example:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> ls /sys/kernel/debug/s390dbf/dasd
flush hex_ascii level pages
> cat /sys/kernel/debug/s390dbf/dasd/hex_ascii | sort -k2,2 -s
00 00974733272:680099 2 - 02 0006ad7e 07 ea 4a 90 | ....
00 00974733272:682210 2 - 02 0006ade6 46 52 45 45 | FREE
00 00974733272:682213 2 - 02 0006adf6 07 ea 4a 90 | ....
00 00974733272:682281 1 * 02 0006ab08 41 4c 4c 43 | EXCP
01 00974733272:682284 2 - 02 0006ab16 45 43 4b 44 | ECKD
01 00974733272:682287 2 - 02 0006ab28 00 00 00 04 | ....
01 00974733272:682289 2 - 02 0006ab3e 00 00 00 20 | ...
01 00974733272:682297 2 - 02 0006ad7e 07 ea 4a 90 | ....
01 00974733272:684384 2 - 00 0006ade6 46 52 45 45 | FREE
01 00974733272:684388 2 - 00 0006adf6 07 ea 4a 90 | ....
</pre></div>
</div>
<p>See section about predefined views for explanation of the above output!</p>
</section>
<section id="changing-the-debug-level">
<h2>Changing the debug level<a class="headerlink" href="#changing-the-debug-level" title="Link to this heading">¶</a></h2>
<p>Example:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> cat /sys/kernel/debug/s390dbf/dasd/level
3
> echo "5" > /sys/kernel/debug/s390dbf/dasd/level
> cat /sys/kernel/debug/s390dbf/dasd/level
5
</pre></div>
</div>
</section>
<section id="flushing-debug-areas">
<h2>Flushing debug areas<a class="headerlink" href="#flushing-debug-areas" title="Link to this heading">¶</a></h2>
<p>Debug areas can be flushed with piping the number of the desired
area (0...n) to the debugfs file “flush”. When using “-” all debug areas
are flushed.</p>
<p>Examples:</p>
<ol class="arabic">
<li><p>Flush debug area 0:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> echo "0" > /sys/kernel/debug/s390dbf/dasd/flush
</pre></div>
</div>
</li>
<li><p>Flush all debug areas:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> echo "-" > /sys/kernel/debug/s390dbf/dasd/flush
</pre></div>
</div>
</li>
</ol>
</section>
<section id="changing-the-size-of-debug-areas">
<h2>Changing the size of debug areas<a class="headerlink" href="#changing-the-size-of-debug-areas" title="Link to this heading">¶</a></h2>
<p>It is possible the change the size of debug areas through piping
the number of pages to the debugfs file “pages”. The resize request will
also flush the debug areas.</p>
<p>Example:</p>
<p>Define 4 pages for the debug areas of debug feature “dasd”:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> echo "4" > /sys/kernel/debug/s390dbf/dasd/pages
</pre></div>
</div>
</section>
<section id="stopping-the-debug-feature">
<h2>Stopping the debug feature<a class="headerlink" href="#stopping-the-debug-feature" title="Link to this heading">¶</a></h2>
<p>Example:</p>
<ol class="arabic">
<li><p>Check if stopping is allowed:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> cat /proc/sys/s390dbf/debug_stoppable
</pre></div>
</div>
</li>
<li><p>Stop debug feature:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> echo 0 > /proc/sys/s390dbf/debug_active
</pre></div>
</div>
</li>
</ol>
</section>
<section id="crash-interface">
<h2>crash Interface<a class="headerlink" href="#crash-interface" title="Link to this heading">¶</a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">crash</span></code> tool since v5.1.0 has a built-in command
<code class="docutils literal notranslate"><span class="pre">s390dbf</span></code> to display all the debug logs or export them to the file system.
With this tool it is possible
to investigate the debug logs on a live system and with a memory dump after
a system crash.</p>
</section>
<section id="investigating-raw-memory">
<h2>Investigating raw memory<a class="headerlink" href="#investigating-raw-memory" title="Link to this heading">¶</a></h2>
<p>One last possibility to investigate the debug logs at a live
system and after a system crash is to look at the raw memory
under VM or at the Service Element.
It is possible to find the anchor of the debug-logs through
the <code class="docutils literal notranslate"><span class="pre">debug_area_first</span></code> symbol in the System map. Then one has
to follow the correct pointers of the data-structures defined
in debug.h and find the debug-areas in memory.
Normally modules which use the debug feature will also have
a global variable with the pointer to the debug-logs. Following
this pointer it will also be possible to find the debug logs in
memory.</p>
<p>For this method it is recommended to use ‘16 * x + 4’ byte (x = 0..n)
for the length of the data field in <a class="reference internal" href="#c.debug_register" title="debug_register"><code class="xref c c-func docutils literal notranslate"><span class="pre">debug_register()</span></code></a> in
order to see the debug entries well formatted.</p>
</section>
<section id="id1">
<h2>Predefined Views<a class="headerlink" href="#id1" title="Link to this heading">¶</a></h2>
<p>There are two predefined views: hex_ascii and sprintf.
The hex_ascii view shows the data field in hex and ascii representation
(e.g. <code class="docutils literal notranslate"><span class="pre">45</span> <span class="pre">43</span> <span class="pre">4b</span> <span class="pre">44</span> <span class="pre">|</span> <span class="pre">ECKD</span></code>).</p>
<p>The sprintf view formats the debug entries in the same way as the sprintf
function would do. The sprintf event/exception functions write to the
debug entry a pointer to the format string (size = sizeof(long))
and for each vararg a long value. So e.g. for a debug entry with a format
string plus two varargs one would need to allocate a (3 * sizeof(long))
byte data area in the <a class="reference internal" href="#c.debug_register" title="debug_register"><code class="xref c c-func docutils literal notranslate"><span class="pre">debug_register()</span></code></a> function.</p>
<dl class="simple">
<dt>IMPORTANT:</dt><dd><p>Using “%s” in sprintf event functions is dangerous. You can only
use “%s” in the sprintf event functions, if the memory for the passed string
is available as long as the debug feature exists. The reason behind this is
that due to performance considerations only a pointer to the string is stored
in the debug feature. If you log a string that is freed afterwards, you will
get an OOPS when inspecting the debug feature, because then the debug feature
will access the already freed memory.</p>
</dd>
<dt>NOTE:</dt><dd><p>If using the sprintf view do NOT use other event/exception functions
than the sprintf-event and -exception functions.</p>
</dd>
</dl>
<p>The format of the hex_ascii and sprintf view is as follows:</p>
<ul class="simple">
<li><p>Number of area</p></li>
<li><p>Timestamp (formatted as seconds and microseconds since 00:00:00 Coordinated
Universal Time (UTC), January 1, 1970)</p></li>
<li><p>level of debug entry</p></li>
<li><p>Exception flag (* = Exception)</p></li>
<li><p>Cpu-Number of calling task</p></li>
<li><p>Return Address to caller</p></li>
<li><p>data field</p></li>
</ul>
<p>A typical line of the hex_ascii view will look like the following (first line
is only for explanation and will not be displayed when ‘cating’ the view):</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>area time level exception cpu caller data (hex + ascii)
--------------------------------------------------------------------------
00 00964419409:440690 1 - 00 88023fe
</pre></div>
</div>
</section>
<section id="defining-views">
<h2>Defining views<a class="headerlink" href="#defining-views" title="Link to this heading">¶</a></h2>
<p>Views are specified with the ‘debug_view’ structure. There are defined
callback functions which are used for reading and writing the debugfs files:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">name</span><span class="p">[</span><span class="n">DEBUG_MAX_PROCF_LEN</span><span class="p">];</span>
<span class="w"> </span><span class="n">debug_prolog_proc_t</span><span class="o">*</span><span class="w"> </span><span class="n">prolog_proc</span><span class="p">;</span>
<span class="w"> </span><span class="n">debug_header_proc_t</span><span class="o">*</span><span class="w"> </span><span class="n">header_proc</span><span class="p">;</span>
<span class="w"> </span><span class="n">debug_format_proc_t</span><span class="o">*</span><span class="w"> </span><span class="n">format_proc</span><span class="p">;</span>
<span class="w"> </span><span class="n">debug_input_proc_t</span><span class="o">*</span><span class="w"> </span><span class="n">input_proc</span><span class="p">;</span>
<span class="w"> </span><span class="kt">void</span><span class="o">*</span><span class="w"> </span><span class="n">private_data</span><span class="p">;</span>
<span class="p">};</span>
</pre></div>
</div>
<p>where:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">typedef</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">(</span><span class="n">debug_header_proc_t</span><span class="p">)</span><span class="w"> </span><span class="p">(</span><span class="n">debug_info_t</span><span class="o">*</span><span class="w"> </span><span class="n">id</span><span class="p">,</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="o">*</span><span class="w"> </span><span class="n">view</span><span class="p">,</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">area</span><span class="p">,</span>
<span class="w"> </span><span class="n">debug_entry_t</span><span class="o">*</span><span class="w"> </span><span class="n">entry</span><span class="p">,</span>
<span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">out_buf</span><span class="p">);</span>
<span class="k">typedef</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">(</span><span class="n">debug_format_proc_t</span><span class="p">)</span><span class="w"> </span><span class="p">(</span><span class="n">debug_info_t</span><span class="o">*</span><span class="w"> </span><span class="n">id</span><span class="p">,</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="o">*</span><span class="w"> </span><span class="n">view</span><span class="p">,</span><span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">out_buf</span><span class="p">,</span>
<span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">in_buf</span><span class="p">);</span>
<span class="k">typedef</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">(</span><span class="n">debug_prolog_proc_t</span><span class="p">)</span><span class="w"> </span><span class="p">(</span><span class="n">debug_info_t</span><span class="o">*</span><span class="w"> </span><span class="n">id</span><span class="p">,</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="o">*</span><span class="w"> </span><span class="n">view</span><span class="p">,</span>
<span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">out_buf</span><span class="p">);</span>
<span class="k">typedef</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">(</span><span class="n">debug_input_proc_t</span><span class="p">)</span><span class="w"> </span><span class="p">(</span><span class="n">debug_info_t</span><span class="o">*</span><span class="w"> </span><span class="n">id</span><span class="p">,</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="o">*</span><span class="w"> </span><span class="n">view</span><span class="p">,</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">file</span><span class="o">*</span><span class="w"> </span><span class="n">file</span><span class="p">,</span><span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">user_buf</span><span class="p">,</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">in_buf_size</span><span class="p">,</span><span class="w"> </span><span class="n">loff_t</span><span class="o">*</span><span class="w"> </span><span class="n">offset</span><span class="p">);</span>
</pre></div>
</div>
<p>The “private_data” member can be used as pointer to view specific data.
It is not used by the debug feature itself.</p>
<p>The output when reading a debugfs file is structured like this:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>"prolog_proc output"
"header_proc output 1" "format_proc output 1"
"header_proc output 2" "format_proc output 2"
"header_proc output 3" "format_proc output 3"
...
</pre></div>
</div>
<p>When a view is read from the debugfs, the Debug Feature calls the
‘prolog_proc’ once for writing the prolog.
Then ‘header_proc’ and ‘format_proc’ are called for each
existing debug entry.</p>
<p>The input_proc can be used to implement functionality when it is written to
the view (e.g. like with <code class="docutils literal notranslate"><span class="pre">echo</span> <span class="pre">"0"</span> <span class="pre">></span> <span class="pre">/sys/kernel/debug/s390dbf/dasd/level</span></code>).</p>
<p>For header_proc there can be used the default function
<code class="xref c c-func docutils literal notranslate"><span class="pre">debug_dflt_header_fn()</span></code> which is defined in debug.h.
and which produces the same header output as the predefined views.
E.g:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>00 00964419409:440761 2 - 00 88023ec
</pre></div>
</div>
<p>In order to see how to use the callback functions check the implementation
of the default views!</p>
<p>Example:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#include</span><span class="w"> </span><span class="cpf"><asm/debug.h></span>
<span class="cp">#define UNKNOWNSTR "data: %08x"</span>
<span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="o">*</span><span class="w"> </span><span class="n">messages</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span>
<span class="p">{</span><span class="s">"This error...........</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="w"> </span><span class="s">"That error...........</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="w"> </span><span class="s">"Problem..............</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="w"> </span><span class="s">"Something went wrong.</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="w"> </span><span class="s">"Everything ok........</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="w"> </span><span class="nb">NULL</span>
<span class="p">};</span>
<span class="k">static</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">debug_test_format_fn</span><span class="p">(</span>
<span class="w"> </span><span class="n">debug_info_t</span><span class="w"> </span><span class="o">*</span><span class="n">id</span><span class="p">,</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="w"> </span><span class="o">*</span><span class="n">view</span><span class="p">,</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">out_buf</span><span class="p">,</span><span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">in_buf</span>
<span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">rc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">id</span><span class="o">-></span><span class="n">buf_size</span><span class="w"> </span><span class="o">>=</span><span class="w"> </span><span class="mi">4</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">msg_nr</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">*</span><span class="p">((</span><span class="kt">int</span><span class="o">*</span><span class="p">)</span><span class="n">in_buf</span><span class="p">);</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">msg_nr</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="k">sizeof</span><span class="p">(</span><span class="n">messages</span><span class="p">)</span><span class="w"> </span><span class="o">/</span><span class="w"> </span><span class="k">sizeof</span><span class="p">(</span><span class="kt">char</span><span class="o">*</span><span class="p">)</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<span class="w"> </span><span class="n">rc</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="n">sprintf</span><span class="p">(</span><span class="n">out_buf</span><span class="p">,</span><span class="w"> </span><span class="s">"%s"</span><span class="p">,</span><span class="w"> </span><span class="n">messages</span><span class="p">[</span><span class="n">msg_nr</span><span class="p">]);</span>
<span class="w"> </span><span class="k">else</span>
<span class="w"> </span><span class="n">rc</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="n">sprintf</span><span class="p">(</span><span class="n">out_buf</span><span class="p">,</span><span class="w"> </span><span class="n">UNKNOWNSTR</span><span class="p">,</span><span class="w"> </span><span class="n">msg_nr</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">rc</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">struct</span><span class="w"> </span><span class="nc">debug_view</span><span class="w"> </span><span class="n">debug_test_view</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="s">"myview"</span><span class="p">,</span><span class="w"> </span><span class="cm">/* name of view */</span>
<span class="w"> </span><span class="nb">NULL</span><span class="p">,</span><span class="w"> </span><span class="cm">/* no prolog */</span>
<span class="w"> </span><span class="o">&</span><span class="n">debug_dflt_header_fn</span><span class="p">,</span><span class="w"> </span><span class="cm">/* default header for each entry */</span>
<span class="w"> </span><span class="o">&</span><span class="n">debug_test_format_fn</span><span class="p">,</span><span class="w"> </span><span class="cm">/* our own format function */</span>
<span class="w"> </span><span class="nb">NULL</span><span class="p">,</span><span class="w"> </span><span class="cm">/* no input function */</span>
<span class="w"> </span><span class="nb">NULL</span><span class="w"> </span><span class="cm">/* no private data */</span>
<span class="p">};</span>
</pre></div>
</div>
<section id="test">
<h3>test:<a class="headerlink" href="#test" title="Link to this heading">¶</a></h3>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="n">debug_info_t</span><span class="w"> </span><span class="o">*</span><span class="n">debug_info</span><span class="p">;</span>
<span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<span class="p">...</span>
<span class="n">debug_info</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">debug_register</span><span class="p">(</span><span class="s">"test"</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">);</span>
<span class="n">debug_register_view</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">debug_test_view</span><span class="p">);</span>
<span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="mi">10</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">++</span><span class="p">)</span>
<span class="w"> </span><span class="n">debug_int_event</span><span class="p">(</span><span class="n">debug_info</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="n">i</span><span class="p">);</span>
</pre></div>
</div>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>> cat /sys/kernel/debug/s390dbf/test/myview
00 00964419734:611402 1 - 00 88042ca This error...........
00 00964419734:611405 1 - 00 88042ca That error...........
00 00964419734:611408 1 - 00 88042ca Problem..............
00 00964419734:611411 1 - 00 88042ca Something went wrong.
00 00964419734:611414 1 - 00 88042ca Everything ok........
00 00964419734:611417 1 - 00 88042ca data: 00000005
00 00964419734:611419 1 - 00 88042ca data: 00000006
00 00964419734:611422 1 - 00 88042ca data: 00000007
00 00964419734:611425 1 - 00 88042ca data: 00000008
00 00964419734:611428 1 - 00 88042ca data: 00000009
</pre></div>
</div>
</section>
</section>
</section>
</div>
</div>
</div>
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