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