/* Test program for PKEYS registers. Copyright 2015-2019 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include #include "x86-cpuid.h" #ifndef NOINLINE #define NOINLINE __attribute__ ((noinline)) #endif unsigned int have_pkru (void) NOINLINE; static inline unsigned long rdpkru (void) { unsigned int eax, edx; unsigned int ecx = 0; unsigned int pkru; asm volatile (".byte 0x0f,0x01,0xee\n\t" : "=a" (eax), "=d" (edx) : "c" (ecx)); pkru = eax; return pkru; } static inline void wrpkru (unsigned int pkru) { unsigned int eax = pkru; unsigned int ecx = 0; unsigned int edx = 0; asm volatile (".byte 0x0f,0x01,0xef\n\t" : : "a" (eax), "c" (ecx), "d" (edx)); } unsigned int NOINLINE have_pkru (void) { unsigned int eax, ebx, ecx, edx; if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx)) return 0; if ((ecx & bit_OSXSAVE) == bit_OSXSAVE) { if (__get_cpuid_max (0, NULL) < 7) return 0; __cpuid_count (7, 0, eax, ebx, ecx, edx); if ((ecx & bit_PKU) == bit_PKU) return 1; } return 0; } int main (int argc, char **argv) { unsigned int wr_value = 0x12345678; unsigned int rd_value = 0x0; if (have_pkru ()) { wrpkru (wr_value); asm ("nop\n\t"); /* break here 1. */ rd_value = rdpkru (); asm ("nop\n\t"); /* break here 2. */ } return 0; }