1 /*- 2 * Copyright (c) 2019 The FreeBSD Foundation 3 * 4 * Portions of this software were developed by Konstantin Belousov 5 * under sponsorship from the FreeBSD Foundation. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/param.h> 30 #include <machine/cpufunc.h> 31 #include <machine/specialreg.h> 32 #include <machine/sysarch.h> 33 #include <x86/ifunc.h> 34 #include <errno.h> 35 #include <string.h> 36 37 #define MAX_PKRU_IDX 0xf 38 #ifdef __i386__ 39 #define X86_SET_PKRU I386_SET_PKRU 40 #define X86_CLEAR_PKRU I386_CLEAR_PKRU 41 #else 42 #define X86_SET_PKRU AMD64_SET_PKRU 43 #define X86_CLEAR_PKRU AMD64_CLEAR_PKRU 44 #endif 45 46 static int 47 x86_pkru_get_perm_unsup(u_int keyidx, int *access, int *modify) 48 { 49 50 errno = EOPNOTSUPP; 51 return (-1); 52 } 53 54 static int 55 x86_pkru_get_perm_hw(u_int keyidx, int *access, int *modify) 56 { 57 uint32_t pkru; 58 59 if (keyidx > MAX_PKRU_IDX) { 60 errno = EINVAL; 61 return (-1); 62 } 63 keyidx *= 2; 64 pkru = rdpkru(); 65 *access = (pkru & (1 << keyidx)) == 0; 66 *modify = (pkru & (2 << keyidx)) == 0; 67 return (0); 68 } 69 70 DEFINE_UIFUNC(, int, x86_pkru_get_perm, (u_int, int *, int *)) 71 { 72 73 return ((cpu_stdext_feature2 & CPUID_STDEXT2_OSPKE) == 0 ? 74 x86_pkru_get_perm_unsup : x86_pkru_get_perm_hw); 75 } 76 77 static int 78 x86_pkru_set_perm_unsup(u_int keyidx, int access, int modify) 79 { 80 81 errno = EOPNOTSUPP; 82 return (-1); 83 } 84 85 static int 86 x86_pkru_set_perm_hw(u_int keyidx, int access, int modify) 87 { 88 uint32_t pkru; 89 90 if (keyidx > MAX_PKRU_IDX) { 91 errno = EINVAL; 92 return (-1); 93 } 94 keyidx *= 2; 95 pkru = rdpkru(); 96 pkru &= ~(3 << keyidx); 97 if (!access) 98 pkru |= 1 << keyidx; 99 if (!modify) 100 pkru |= 2 << keyidx; 101 wrpkru(pkru); 102 return (0); 103 } 104 105 DEFINE_UIFUNC(, int, x86_pkru_set_perm, (u_int, int, int)) 106 { 107 108 return ((cpu_stdext_feature2 & CPUID_STDEXT2_OSPKE) == 0 ? 109 x86_pkru_set_perm_unsup : x86_pkru_set_perm_hw); 110 } 111 112 int 113 x86_pkru_protect_range(void *addr, unsigned long len, u_int keyidx, int flags) 114 { 115 struct amd64_set_pkru a64pkru; 116 117 memset(&a64pkru, 0, sizeof(a64pkru)); 118 a64pkru.addr = addr; 119 a64pkru.len = len; 120 a64pkru.keyidx = keyidx; 121 a64pkru.flags = flags; 122 return (sysarch(X86_SET_PKRU, &a64pkru)); 123 } 124 125 int 126 x86_pkru_unprotect_range(void *addr, unsigned long len) 127 { 128 struct amd64_set_pkru a64pkru; 129 130 memset(&a64pkru, 0, sizeof(a64pkru)); 131 a64pkru.addr = addr; 132 a64pkru.len = len; 133 return (sysarch(X86_CLEAR_PKRU, &a64pkru)); 134 } 135