1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #ifndef _PKEYS_X86_H 4 #define _PKEYS_X86_H 5 6 #ifdef __i386__ 7 8 #ifndef SYS_mprotect_key 9 # define SYS_mprotect_key 380 10 #endif 11 12 #ifndef SYS_pkey_alloc 13 # define SYS_pkey_alloc 381 14 # define SYS_pkey_free 382 15 #endif 16 17 #define REG_IP_IDX REG_EIP 18 #define si_pkey_offset 0x14 19 20 #else 21 22 #ifndef SYS_mprotect_key 23 # define SYS_mprotect_key 329 24 #endif 25 26 #ifndef SYS_pkey_alloc 27 # define SYS_pkey_alloc 330 28 # define SYS_pkey_free 331 29 #endif 30 31 #define REG_IP_IDX REG_RIP 32 #define si_pkey_offset 0x20 33 34 #endif 35 36 #ifndef PKEY_DISABLE_ACCESS 37 # define PKEY_DISABLE_ACCESS 0x1 38 #endif 39 40 #ifndef PKEY_DISABLE_WRITE 41 # define PKEY_DISABLE_WRITE 0x2 42 #endif 43 44 #define NR_PKEYS 16 45 #define NR_RESERVED_PKEYS 2 /* pkey-0 and exec-only-pkey */ 46 #define PKEY_BITS_PER_PKEY 2 47 #define HPAGE_SIZE (1UL<<21) 48 #define PAGE_SIZE 4096 49 #define MB (1<<20) 50 51 static inline void __page_o_noops(void) 52 { 53 /* 8-bytes of instruction * 512 bytes = 1 page */ 54 asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr"); 55 } 56 57 static inline u64 __read_pkey_reg(void) 58 { 59 unsigned int eax, edx; 60 unsigned int ecx = 0; 61 unsigned pkey_reg; 62 63 asm volatile(".byte 0x0f,0x01,0xee\n\t" 64 : "=a" (eax), "=d" (edx) 65 : "c" (ecx)); 66 pkey_reg = eax; 67 return pkey_reg; 68 } 69 70 static inline void __write_pkey_reg(u64 pkey_reg) 71 { 72 unsigned int eax = pkey_reg; 73 unsigned int ecx = 0; 74 unsigned int edx = 0; 75 76 dprintf4("%s() changing %016llx to %016llx\n", __func__, 77 __read_pkey_reg(), pkey_reg); 78 asm volatile(".byte 0x0f,0x01,0xef\n\t" 79 : : "a" (eax), "c" (ecx), "d" (edx)); 80 assert(pkey_reg == __read_pkey_reg()); 81 } 82 83 /* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */ 84 #define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */ 85 #define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */ 86 87 static inline int cpu_has_pkeys(void) 88 { 89 unsigned int eax; 90 unsigned int ebx; 91 unsigned int ecx; 92 unsigned int edx; 93 94 __cpuid_count(0x7, 0x0, eax, ebx, ecx, edx); 95 96 if (!(ecx & X86_FEATURE_PKU)) { 97 dprintf2("cpu does not have PKU\n"); 98 return 0; 99 } 100 if (!(ecx & X86_FEATURE_OSPKE)) { 101 dprintf2("cpu does not have OSPKE\n"); 102 return 0; 103 } 104 return 1; 105 } 106 107 static inline int cpu_max_xsave_size(void) 108 { 109 unsigned long XSTATE_CPUID = 0xd; 110 unsigned int eax; 111 unsigned int ebx; 112 unsigned int ecx; 113 unsigned int edx; 114 115 __cpuid_count(XSTATE_CPUID, 0, eax, ebx, ecx, edx); 116 return ecx; 117 } 118 119 static inline u32 pkey_bit_position(int pkey) 120 { 121 return pkey * PKEY_BITS_PER_PKEY; 122 } 123 124 #define XSTATE_PKEY_BIT (9) 125 #define XSTATE_PKEY 0x200 126 #define XSTATE_BV_OFFSET 512 127 128 int pkey_reg_xstate_offset(void) 129 { 130 unsigned int eax; 131 unsigned int ebx; 132 unsigned int ecx; 133 unsigned int edx; 134 int xstate_offset; 135 int xstate_size; 136 unsigned long XSTATE_CPUID = 0xd; 137 int leaf; 138 139 /* assume that XSTATE_PKEY is set in XCR0 */ 140 leaf = XSTATE_PKEY_BIT; 141 { 142 __cpuid_count(XSTATE_CPUID, leaf, eax, ebx, ecx, edx); 143 144 if (leaf == XSTATE_PKEY_BIT) { 145 xstate_offset = ebx; 146 xstate_size = eax; 147 } 148 } 149 150 if (xstate_size == 0) { 151 printf("could not find size/offset of PKEY in xsave state\n"); 152 return 0; 153 } 154 155 return xstate_offset; 156 } 157 158 static inline int get_arch_reserved_keys(void) 159 { 160 return NR_RESERVED_PKEYS; 161 } 162 163 void expect_fault_on_read_execonly_key(void *p1, int pkey) 164 { 165 int ptr_contents; 166 167 ptr_contents = read_ptr(p1); 168 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); 169 expected_pkey_fault(pkey); 170 } 171 172 void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey) 173 { 174 return PTR_ERR_ENOTSUP; 175 } 176 177 #endif /* _PKEYS_X86_H */ 178