| Jan Willeke | 975fab1 | 2014-09-22 16:37:27 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Common helper functions for kprobes and uprobes |
| 3 | * |
| 4 | * Copyright IBM Corp. 2014 |
| 5 | */ |
| 6 | |
| Heiko Carstens | db55947 | 2017-05-02 13:20:11 +0200 | [diff] [blame] | 7 | #include <linux/errno.h> |
| Jan Willeke | d6fe5be | 2014-10-08 10:16:08 +0200 | [diff] [blame] | 8 | #include <asm/kprobes.h> |
| Jan Willeke | 975fab1 | 2014-09-22 16:37:27 +0200 | [diff] [blame] | 9 | #include <asm/dis.h> |
| 10 | |
| 11 | int probe_is_prohibited_opcode(u16 *insn) |
| 12 | { |
| 13 | if (!is_known_insn((unsigned char *)insn)) |
| 14 | return -EINVAL; |
| 15 | switch (insn[0] >> 8) { |
| 16 | case 0x0c: /* bassm */ |
| 17 | case 0x0b: /* bsm */ |
| 18 | case 0x83: /* diag */ |
| 19 | case 0x44: /* ex */ |
| 20 | case 0xac: /* stnsm */ |
| 21 | case 0xad: /* stosm */ |
| 22 | return -EINVAL; |
| 23 | case 0xc6: |
| 24 | switch (insn[0] & 0x0f) { |
| 25 | case 0x00: /* exrl */ |
| 26 | return -EINVAL; |
| 27 | } |
| 28 | } |
| 29 | switch (insn[0]) { |
| 30 | case 0x0101: /* pr */ |
| 31 | case 0xb25a: /* bsa */ |
| 32 | case 0xb240: /* bakr */ |
| 33 | case 0xb258: /* bsg */ |
| 34 | case 0xb218: /* pc */ |
| 35 | case 0xb228: /* pt */ |
| 36 | case 0xb98d: /* epsw */ |
| 37 | case 0xe560: /* tbegin */ |
| 38 | case 0xe561: /* tbeginc */ |
| 39 | case 0xb2f8: /* tend */ |
| 40 | return -EINVAL; |
| 41 | } |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | int probe_get_fixup_type(u16 *insn) |
| 46 | { |
| 47 | /* default fixup method */ |
| 48 | int fixup = FIXUP_PSW_NORMAL; |
| 49 | |
| 50 | switch (insn[0] >> 8) { |
| 51 | case 0x05: /* balr */ |
| 52 | case 0x0d: /* basr */ |
| 53 | fixup = FIXUP_RETURN_REGISTER; |
| 54 | /* if r2 = 0, no branch will be taken */ |
| 55 | if ((insn[0] & 0x0f) == 0) |
| 56 | fixup |= FIXUP_BRANCH_NOT_TAKEN; |
| 57 | break; |
| 58 | case 0x06: /* bctr */ |
| 59 | case 0x07: /* bcr */ |
| 60 | fixup = FIXUP_BRANCH_NOT_TAKEN; |
| 61 | break; |
| 62 | case 0x45: /* bal */ |
| 63 | case 0x4d: /* bas */ |
| 64 | fixup = FIXUP_RETURN_REGISTER; |
| 65 | break; |
| 66 | case 0x47: /* bc */ |
| 67 | case 0x46: /* bct */ |
| 68 | case 0x86: /* bxh */ |
| 69 | case 0x87: /* bxle */ |
| 70 | fixup = FIXUP_BRANCH_NOT_TAKEN; |
| 71 | break; |
| 72 | case 0x82: /* lpsw */ |
| 73 | fixup = FIXUP_NOT_REQUIRED; |
| 74 | break; |
| 75 | case 0xb2: /* lpswe */ |
| 76 | if ((insn[0] & 0xff) == 0xb2) |
| 77 | fixup = FIXUP_NOT_REQUIRED; |
| 78 | break; |
| 79 | case 0xa7: /* bras */ |
| 80 | if ((insn[0] & 0x0f) == 0x05) |
| 81 | fixup |= FIXUP_RETURN_REGISTER; |
| 82 | break; |
| 83 | case 0xc0: |
| 84 | if ((insn[0] & 0x0f) == 0x05) /* brasl */ |
| 85 | fixup |= FIXUP_RETURN_REGISTER; |
| 86 | break; |
| 87 | case 0xeb: |
| 88 | switch (insn[2] & 0xff) { |
| 89 | case 0x44: /* bxhg */ |
| 90 | case 0x45: /* bxleg */ |
| 91 | fixup = FIXUP_BRANCH_NOT_TAKEN; |
| 92 | break; |
| 93 | } |
| 94 | break; |
| 95 | case 0xe3: /* bctg */ |
| 96 | if ((insn[2] & 0xff) == 0x46) |
| 97 | fixup = FIXUP_BRANCH_NOT_TAKEN; |
| 98 | break; |
| 99 | case 0xec: |
| 100 | switch (insn[2] & 0xff) { |
| 101 | case 0xe5: /* clgrb */ |
| 102 | case 0xe6: /* cgrb */ |
| 103 | case 0xf6: /* crb */ |
| 104 | case 0xf7: /* clrb */ |
| 105 | case 0xfc: /* cgib */ |
| 106 | case 0xfd: /* cglib */ |
| 107 | case 0xfe: /* cib */ |
| 108 | case 0xff: /* clib */ |
| 109 | fixup = FIXUP_BRANCH_NOT_TAKEN; |
| 110 | break; |
| 111 | } |
| 112 | break; |
| 113 | } |
| 114 | return fixup; |
| 115 | } |
| 116 | |
| 117 | int probe_is_insn_relative_long(u16 *insn) |
| 118 | { |
| 119 | /* Check if we have a RIL-b or RIL-c format instruction which |
| 120 | * we need to modify in order to avoid instruction emulation. */ |
| 121 | switch (insn[0] >> 8) { |
| 122 | case 0xc0: |
| 123 | if ((insn[0] & 0x0f) == 0x00) /* larl */ |
| 124 | return true; |
| 125 | break; |
| 126 | case 0xc4: |
| 127 | switch (insn[0] & 0x0f) { |
| 128 | case 0x02: /* llhrl */ |
| 129 | case 0x04: /* lghrl */ |
| 130 | case 0x05: /* lhrl */ |
| 131 | case 0x06: /* llghrl */ |
| 132 | case 0x07: /* sthrl */ |
| 133 | case 0x08: /* lgrl */ |
| 134 | case 0x0b: /* stgrl */ |
| 135 | case 0x0c: /* lgfrl */ |
| 136 | case 0x0d: /* lrl */ |
| 137 | case 0x0e: /* llgfrl */ |
| 138 | case 0x0f: /* strl */ |
| 139 | return true; |
| 140 | } |
| 141 | break; |
| 142 | case 0xc6: |
| 143 | switch (insn[0] & 0x0f) { |
| 144 | case 0x02: /* pfdrl */ |
| 145 | case 0x04: /* cghrl */ |
| 146 | case 0x05: /* chrl */ |
| 147 | case 0x06: /* clghrl */ |
| 148 | case 0x07: /* clhrl */ |
| 149 | case 0x08: /* cgrl */ |
| 150 | case 0x0a: /* clgrl */ |
| 151 | case 0x0c: /* cgfrl */ |
| 152 | case 0x0d: /* crl */ |
| 153 | case 0x0e: /* clgfrl */ |
| 154 | case 0x0f: /* clrl */ |
| 155 | return true; |
| 156 | } |
| 157 | break; |
| 158 | } |
| 159 | return false; |
| 160 | } |