pkey-x86.h (3293B)
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 51static 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 57static 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 70static 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 87static 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 107static inline u32 pkey_bit_position(int pkey) 108{ 109 return pkey * PKEY_BITS_PER_PKEY; 110} 111 112#define XSTATE_PKEY_BIT (9) 113#define XSTATE_PKEY 0x200 114#define XSTATE_BV_OFFSET 512 115 116int pkey_reg_xstate_offset(void) 117{ 118 unsigned int eax; 119 unsigned int ebx; 120 unsigned int ecx; 121 unsigned int edx; 122 int xstate_offset; 123 int xstate_size; 124 unsigned long XSTATE_CPUID = 0xd; 125 int leaf; 126 127 /* assume that XSTATE_PKEY is set in XCR0 */ 128 leaf = XSTATE_PKEY_BIT; 129 { 130 __cpuid_count(XSTATE_CPUID, leaf, eax, ebx, ecx, edx); 131 132 if (leaf == XSTATE_PKEY_BIT) { 133 xstate_offset = ebx; 134 xstate_size = eax; 135 } 136 } 137 138 if (xstate_size == 0) { 139 printf("could not find size/offset of PKEY in xsave state\n"); 140 return 0; 141 } 142 143 return xstate_offset; 144} 145 146static inline int get_arch_reserved_keys(void) 147{ 148 return NR_RESERVED_PKEYS; 149} 150 151void expect_fault_on_read_execonly_key(void *p1, int pkey) 152{ 153 int ptr_contents; 154 155 ptr_contents = read_ptr(p1); 156 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); 157 expected_pkey_fault(pkey); 158} 159 160void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey) 161{ 162 return PTR_ERR_ENOTSUP; 163} 164 165#endif /* _PKEYS_X86_H */