ia32-64/x86/rdpkru.html
2025-07-08 02:23:29 -03:00

93 lines
3.8 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg" xmlns:x86="http://www.felixcloutier.com/x86"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><link rel="stylesheet" type="text/css" href="style.css"></link><title>RDPKRU
— Read Protection Key Rights for User Pages</title></head><body><header><nav><ul><li><a href='index.html'>Index</a></li><li>December 2023</li></ul></nav></header><h1>RDPKRU
— Read Protection Key Rights for User Pages</h1>
<table>
<tr>
<th>Opcode*</th>
<th>Instruction</th>
<th>Op/En</th>
<th>64/32bit Mode Support</th>
<th>CPUID Feature Flag</th>
<th>Description</th></tr>
<tr>
<td>NP 0F 01 EE</td>
<td>RDPKRU</td>
<td>ZO</td>
<td>V/V</td>
<td>OSPKE</td>
<td>Reads PKRU into EAX.</td></tr></table>
<h2 id="instruction-operand-encoding">Instruction Operand Encoding<a class="anchor" href="#instruction-operand-encoding">
</a></h2>
<table>
<tr>
<th>Op/En</th>
<th>Operand 1</th>
<th>Operand 2</th>
<th>Operand 3</th>
<th>Operand 4</th></tr>
<tr>
<td>ZO</td>
<td>N/A</td>
<td>N/A</td>
<td>N/A</td>
<td>N/A</td></tr></table>
<h2 id="description">Description<a class="anchor" href="#description">
</a></h2>
<p>Reads the value of PKRU into EAX and clears EDX. ECX must be 0 when RDPKRU is executed; otherwise, a general-protection exception (#GP) occurs.</p>
<p>RDPKRU can be executed only if CR4.PKE = 1; otherwise, an invalid-opcode exception (#UD) occurs. Software can discover the value of CR4.PKE by examining CPUID.(EAX=07H,ECX=0H):ECX.OSPKE [bit 4].</p>
<p>On processors that support the Intel 64 Architecture, the high-order 32-bits of RCX are ignored and the high-order 32-bits of RDX and RAX are cleared.</p>
<h2 id="operation">Operation<a class="anchor" href="#operation">
</a></h2>
<pre>IF (ECX = 0)
THEN
EAX := PKRU;
EDX := 0;
ELSE #GP(0);
FI;
</pre>
<h2 id="flags-affected">Flags Affected<a class="anchor" href="#flags-affected">
</a></h2>
<p>None.</p>
<h2 id="c-c++-compiler-intrinsic-equivalent">C/C++ Compiler Intrinsic Equivalent<a class="anchor" href="#c-c++-compiler-intrinsic-equivalent">
</a></h2>
<pre>RDPKRU uint32_t _rdpkru_u32(void);
</pre>
<h2 class="exceptions" id="protected-mode-exceptions">Protected Mode Exceptions<a class="anchor" href="#protected-mode-exceptions">
</a></h2>
<table>
<tr>
<td>#GP(0)</td>
<td>If ECX ≠ 0.</td></tr>
<tr>
<td rowspan="2">#UD</td>
<td>If the LOCK prefix is used.</td></tr>
<tr>
<td>If CR4.PKE = 0.</td></tr></table>
<h2 class="exceptions" id="real-address-mode-exceptions">Real-Address Mode Exceptions<a class="anchor" href="#real-address-mode-exceptions">
</a></h2>
<p>Same exceptions as in protected mode.</p>
<h2 class="exceptions" id="virtual-8086-mode-exceptions">Virtual-8086 Mode Exceptions<a class="anchor" href="#virtual-8086-mode-exceptions">
</a></h2>
<p>Same exceptions as in protected mode.</p>
<h2 class="exceptions" id="compatibility-mode-exceptions">Compatibility Mode Exceptions<a class="anchor" href="#compatibility-mode-exceptions">
</a></h2>
<p>Same exceptions as in protected mode.</p>
<h2 class="exceptions" id="64-bit-mode-exceptions">64-Bit Mode Exceptions<a class="anchor" href="#64-bit-mode-exceptions">
</a></h2>
<p>Same exceptions as in protected mode.</p><footer><p>
This UNOFFICIAL, mechanically-separated, non-verified reference is provided for convenience, but it may be
inc<span style="opacity: 0.2">omp</span>lete or b<sub>r</sub>oke<sub>n</sub> in various obvious or non-obvious
ways. Refer to <a href="https://software.intel.com/en-us/download/intel-64-and-ia-32-architectures-sdm-combined-volumes-1-2a-2b-2c-2d-3a-3b-3c-3d-and-4">Intel® 64 and IA-32 Architectures Software Developers Manual</a> for anything serious.
</p></footer></body></html>