/* * Common helper functions for kprobes and uprobes * * Copyright IBM Corp. 2014 */ #include <asm/kprobes.h> #include <asm/dis.h> int probe_is_prohibited_opcode(u16 *insn) { if (!is_known_insn((unsigned char *)insn)) return -EINVAL; switch (insn[0] >> 8) { case 0x0c: /* bassm */ case 0x0b: /* bsm */ case 0x83: /* diag */ case 0x44: /* ex */ case 0xac: /* stnsm */ case 0xad: /* stosm */ return -EINVAL; case 0xc6: switch (insn[0] & 0x0f) { case 0x00: /* exrl */ return -EINVAL; } } switch (insn[0]) { case 0x0101: /* pr */ case 0xb25a: /* bsa */ case 0xb240: /* bakr */ case 0xb258: /* bsg */ case 0xb218: /* pc */ case 0xb228: /* pt */ case 0xb98d: /* epsw */ case 0xe560: /* tbegin */ case 0xe561: /* tbeginc */ case 0xb2f8: /* tend */ return -EINVAL; } return 0; } int probe_get_fixup_type(u16 *insn) { /* default fixup method */ int fixup = FIXUP_PSW_NORMAL; switch (insn[0] >> 8) { case 0x05: /* balr */ case 0x0d: /* basr */ fixup = FIXUP_RETURN_REGISTER; /* if r2 = 0, no branch will be taken */ if ((insn[0] & 0x0f) == 0) fixup |= FIXUP_BRANCH_NOT_TAKEN; break; case 0x06: /* bctr */ case 0x07: /* bcr */ fixup = FIXUP_BRANCH_NOT_TAKEN; break; case 0x45: /* bal */ case 0x4d: /* bas */ fixup = FIXUP_RETURN_REGISTER; break; case 0x47: /* bc */ case 0x46: /* bct */ case 0x86: /* bxh */ case 0x87: /* bxle */ fixup = FIXUP_BRANCH_NOT_TAKEN; break; case 0x82: /* lpsw */ fixup = FIXUP_NOT_REQUIRED; break; case 0xb2: /* lpswe */ if ((insn[0] & 0xff) == 0xb2) fixup = FIXUP_NOT_REQUIRED; break; case 0xa7: /* bras */ if ((insn[0] & 0x0f) == 0x05) fixup |= FIXUP_RETURN_REGISTER; break; case 0xc0: if ((insn[0] & 0x0f) == 0x05) /* brasl */ fixup |= FIXUP_RETURN_REGISTER; break; case 0xeb: switch (insn[2] & 0xff) { case 0x44: /* bxhg */ case 0x45: /* bxleg */ fixup = FIXUP_BRANCH_NOT_TAKEN; break; } break; case 0xe3: /* bctg */ if ((insn[2] & 0xff) == 0x46) fixup = FIXUP_BRANCH_NOT_TAKEN; break; case 0xec: switch (insn[2] & 0xff) { case 0xe5: /* clgrb */ case 0xe6: /* cgrb */ case 0xf6: /* crb */ case 0xf7: /* clrb */ case 0xfc: /* cgib */ case 0xfd: /* cglib */ case 0xfe: /* cib */ case 0xff: /* clib */ fixup = FIXUP_BRANCH_NOT_TAKEN; break; } break; } return fixup; } int probe_is_insn_relative_long(u16 *insn) { /* Check if we have a RIL-b or RIL-c format instruction which * we need to modify in order to avoid instruction emulation. */ switch (insn[0] >> 8) { case 0xc0: if ((insn[0] & 0x0f) == 0x00) /* larl */ return true; break; case 0xc4: switch (insn[0] & 0x0f) { case 0x02: /* llhrl */ case 0x04: /* lghrl */ case 0x05: /* lhrl */ case 0x06: /* llghrl */ case 0x07: /* sthrl */ case 0x08: /* lgrl */ case 0x0b: /* stgrl */ case 0x0c: /* lgfrl */ case 0x0d: /* lrl */ case 0x0e: /* llgfrl */ case 0x0f: /* strl */ return true; } break; case 0xc6: switch (insn[0] & 0x0f) { case 0x02: /* pfdrl */ case 0x04: /* cghrl */ case 0x05: /* chrl */ case 0x06: /* clghrl */ case 0x07: /* clhrl */ case 0x08: /* cgrl */ case 0x0a: /* clgrl */ case 0x0c: /* cgfrl */ case 0x0d: /* crl */ case 0x0e: /* clgfrl */ case 0x0f: /* clrl */ return true; } break; } return false; }