tools/testing/selftests/vm/pkey-x86.h

   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 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
  84                 unsigned int *ecx, unsigned int *edx)
  85 {
  86         /* ecx is often an input as well as an output. */
  87         asm volatile(
  88                 "cpuid;"
  89                 : "=a" (*eax),
  90                   "=b" (*ebx),
  91                   "=c" (*ecx),
  92                   "=d" (*edx)
  93                 : "0" (*eax), "2" (*ecx));
  94 }
  95
  96 /* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
  97 #define X86_FEATURE_PKU        (1<<3) /* Protection Keys for Userspace */
  98 #define X86_FEATURE_OSPKE      (1<<4) /* OS Protection Keys Enable */
  99
 100 static inline int cpu_has_pkeys(void)
 101 {
 102         unsigned int eax;
 103         unsigned int ebx;
 104         unsigned int ecx;
 105         unsigned int edx;
 106
 107         eax = 0x7;
 108         ecx = 0x0;
 109         __cpuid(&eax, &ebx, &ecx, &edx);
 110
 111         if (!(ecx & X86_FEATURE_PKU)) {
 112                 dprintf2("cpu does not have PKU\n");
 113                 return 0;
 114         }
 115         if (!(ecx & X86_FEATURE_OSPKE)) {
 116                 dprintf2("cpu does not have OSPKE\n");
 117                 return 0;
 118         }
 119         return 1;
 120 }
 121
 122 static inline u32 pkey_bit_position(int pkey)
 123 {
 124         return pkey * PKEY_BITS_PER_PKEY;
 125 }
 126
 127 #define XSTATE_PKEY_BIT (9)
 128 #define XSTATE_PKEY     0x200
 129
 130 int pkey_reg_xstate_offset(void)
 131 {
 132         unsigned int eax;
 133         unsigned int ebx;
 134         unsigned int ecx;
 135         unsigned int edx;
 136         int xstate_offset;
 137         int xstate_size;
 138         unsigned long XSTATE_CPUID = 0xd;
 139         int leaf;
 140
 141         /* assume that XSTATE_PKEY is set in XCR0 */
 142         leaf = XSTATE_PKEY_BIT;
 143         {
 144                 eax = XSTATE_CPUID;
 145                 ecx = leaf;
 146                 __cpuid(&eax, &ebx, &ecx, &edx);
 147
 148                 if (leaf == XSTATE_PKEY_BIT) {
 149                         xstate_offset = ebx;
 150                         xstate_size = eax;
 151                 }
 152         }
 153
 154         if (xstate_size == 0) {
 155                 printf("could not find size/offset of PKEY in xsave state\n");
 156                 return 0;
 157         }
 158
 159         return xstate_offset;
 160 }
 161
 162 static inline int get_arch_reserved_keys(void)
 163 {
 164         return NR_RESERVED_PKEYS;
 165 }
 166
 167 void expect_fault_on_read_execonly_key(void *p1, int pkey)
 168 {
 169         int ptr_contents;
 170
 171         ptr_contents = read_ptr(p1);
 172         dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
 173         expected_pkey_fault(pkey);
 174 }
 175
 176 void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
 177 {
 178         return PTR_ERR_ENOTSUP;
 179 }
 180
 181 #endif /* _PKEYS_X86_H */