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

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef _PKEYS_POWERPC_H
   4 #define _PKEYS_POWERPC_H
   5
   6 #ifndef SYS_mprotect_key
   7 # define SYS_mprotect_key       386
   8 #endif
   9 #ifndef SYS_pkey_alloc
  10 # define SYS_pkey_alloc         384
  11 # define SYS_pkey_free          385
  12 #endif
  13 #define REG_IP_IDX              PT_NIP
  14 #define REG_TRAPNO              PT_TRAP
  15 #define gregs                   gp_regs
  16 #define fpregs                  fp_regs
  17 #define si_pkey_offset          0x20
  18
  19 #undef PKEY_DISABLE_ACCESS
  20 #define PKEY_DISABLE_ACCESS     0x3  /* disable read and write */
  21
  22 #undef PKEY_DISABLE_WRITE
  23 #define PKEY_DISABLE_WRITE      0x2
  24
  25 #define NR_PKEYS                32
  26 #define NR_RESERVED_PKEYS_4K    27 /* pkey-0, pkey-1, exec-only-pkey
  27                                       and 24 other keys that cannot be
  28                                       represented in the PTE */
  29 #define NR_RESERVED_PKEYS_64K_3KEYS     3 /* PowerNV and KVM: pkey-0,
  30                                              pkey-1 and exec-only key */
  31 #define NR_RESERVED_PKEYS_64K_4KEYS     4 /* PowerVM: pkey-0, pkey-1,
  32                                              pkey-31 and exec-only key */
  33 #define PKEY_BITS_PER_PKEY      2
  34 #define HPAGE_SIZE              (1UL << 24)
  35 #define PAGE_SIZE               sysconf(_SC_PAGESIZE)
  36
  37 static inline u32 pkey_bit_position(int pkey)
  38 {
  39         return (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY;
  40 }
  41
  42 static inline u64 __read_pkey_reg(void)
  43 {
  44         u64 pkey_reg;
  45
  46         asm volatile("mfspr %0, 0xd" : "=r" (pkey_reg));
  47
  48         return pkey_reg;
  49 }
  50
  51 static inline void __write_pkey_reg(u64 pkey_reg)
  52 {
  53         u64 amr = pkey_reg;
  54
  55         dprintf4("%s() changing %016llx to %016llx\n",
  56                          __func__, __read_pkey_reg(), pkey_reg);
  57
  58         asm volatile("isync; mtspr 0xd, %0; isync"
  59                      : : "r" ((unsigned long)(amr)) : "memory");
  60
  61         dprintf4("%s() pkey register after changing %016llx to %016llx\n",
  62                         __func__, __read_pkey_reg(), pkey_reg);
  63 }
  64
  65 static inline int cpu_has_pkeys(void)
  66 {
  67         /* No simple way to determine this */
  68         return 1;
  69 }
  70
  71 static inline bool arch_is_powervm()
  72 {
  73         struct stat buf;
  74
  75         if ((stat("/sys/firmware/devicetree/base/ibm,partition-name", &buf) == 0) &&
  76             (stat("/sys/firmware/devicetree/base/hmc-managed?", &buf) == 0) &&
  77             (stat("/sys/firmware/devicetree/base/chosen/qemu,graphic-width", &buf) == -1) )
  78                 return true;
  79
  80         return false;
  81 }
  82
  83 static inline int get_arch_reserved_keys(void)
  84 {
  85         if (sysconf(_SC_PAGESIZE) == 4096)
  86                 return NR_RESERVED_PKEYS_4K;
  87         else
  88                 if (arch_is_powervm())
  89                         return NR_RESERVED_PKEYS_64K_4KEYS;
  90                 else
  91                         return NR_RESERVED_PKEYS_64K_3KEYS;
  92 }
  93
  94 void expect_fault_on_read_execonly_key(void *p1, int pkey)
  95 {
  96         /*
  97          * powerpc does not allow userspace to change permissions of exec-only
  98          * keys since those keys are not allocated by userspace. The signal
  99          * handler wont be able to reset the permissions, which means the code
 100          * will infinitely continue to segfault here.
 101          */
 102         return;
 103 }
 104
 105 /* 4-byte instructions * 16384 = 64K page */
 106 #define __page_o_noops() asm(".rept 16384 ; nop; .endr")
 107
 108 void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
 109 {
 110         void *ptr;
 111         int ret;
 112
 113         dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
 114                         size, prot, pkey);
 115         pkey_assert(pkey < NR_PKEYS);
 116         ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
 117         pkey_assert(ptr != (void *)-1);
 118
 119         ret = syscall(__NR_subpage_prot, ptr, size, NULL);
 120         if (ret) {
 121                 perror("subpage_perm");
 122                 return PTR_ERR_ENOTSUP;
 123         }
 124
 125         ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
 126         pkey_assert(!ret);
 127         record_pkey_malloc(ptr, size, prot);
 128
 129         dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
 130         return ptr;
 131 }
 132
 133 #endif /* _PKEYS_POWERPC_H */