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