1 /* Test program for PKEYS registers. 2 3 Copyright 2015-2019 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include <stddef.h> 21 #include "x86-cpuid.h" 22 23 #ifndef NOINLINE 24 #define NOINLINE __attribute__ ((noinline)) 25 #endif 26 27 unsigned int have_pkru (void) NOINLINE; 28 29 static inline unsigned long 30 rdpkru (void) 31 { 32 unsigned int eax, edx; 33 unsigned int ecx = 0; 34 unsigned int pkru; 35 36 asm volatile (".byte 0x0f,0x01,0xee\n\t" 37 : "=a" (eax), "=d" (edx) 38 : "c" (ecx)); 39 pkru = eax; 40 return pkru; 41 } 42 43 static inline void 44 wrpkru (unsigned int pkru) 45 { 46 unsigned int eax = pkru; 47 unsigned int ecx = 0; 48 unsigned int edx = 0; 49 50 asm volatile (".byte 0x0f,0x01,0xef\n\t" 51 : : "a" (eax), "c" (ecx), "d" (edx)); 52 } 53 54 unsigned int NOINLINE 55 have_pkru (void) 56 { 57 unsigned int eax, ebx, ecx, edx; 58 59 if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx)) 60 return 0; 61 62 if ((ecx & bit_OSXSAVE) == bit_OSXSAVE) 63 { 64 if (__get_cpuid_max (0, NULL) < 7) 65 return 0; 66 67 __cpuid_count (7, 0, eax, ebx, ecx, edx); 68 69 if ((ecx & bit_PKU) == bit_PKU) 70 return 1; 71 } 72 return 0; 73 } 74 75 int 76 main (int argc, char **argv) 77 { 78 unsigned int wr_value = 0x12345678; 79 unsigned int rd_value = 0x0; 80 81 if (have_pkru ()) 82 { 83 wrpkru (wr_value); 84 asm ("nop\n\t"); /* break here 1. */ 85 86 rd_value = rdpkru (); 87 asm ("nop\n\t"); /* break here 2. */ 88 } 89 return 0; 90 } 91