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161 lines
3.4 KiB
161 lines
3.4 KiB
// SPDX-License-Identifier: GPL-2.0
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/*
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* Common helper functions for kprobes and uprobes
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*
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* Copyright IBM Corp. 2014
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*/
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#include <linux/errno.h>
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#include <asm/kprobes.h>
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#include <asm/dis.h>
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int probe_is_prohibited_opcode(u16 *insn)
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{
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if (!is_known_insn((unsigned char *)insn))
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return -EINVAL;
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switch (insn[0] >> 8) {
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case 0x0c: /* bassm */
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case 0x0b: /* bsm */
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case 0x83: /* diag */
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case 0x44: /* ex */
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case 0xac: /* stnsm */
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case 0xad: /* stosm */
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return -EINVAL;
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case 0xc6:
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switch (insn[0] & 0x0f) {
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case 0x00: /* exrl */
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return -EINVAL;
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}
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}
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switch (insn[0]) {
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case 0x0101: /* pr */
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case 0xb25a: /* bsa */
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case 0xb240: /* bakr */
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case 0xb258: /* bsg */
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case 0xb218: /* pc */
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case 0xb228: /* pt */
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case 0xb98d: /* epsw */
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case 0xe560: /* tbegin */
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case 0xe561: /* tbeginc */
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case 0xb2f8: /* tend */
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return -EINVAL;
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}
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return 0;
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}
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int probe_get_fixup_type(u16 *insn)
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{
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/* default fixup method */
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int fixup = FIXUP_PSW_NORMAL;
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switch (insn[0] >> 8) {
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case 0x05: /* balr */
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case 0x0d: /* basr */
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fixup = FIXUP_RETURN_REGISTER;
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/* if r2 = 0, no branch will be taken */
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if ((insn[0] & 0x0f) == 0)
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fixup |= FIXUP_BRANCH_NOT_TAKEN;
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break;
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case 0x06: /* bctr */
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case 0x07: /* bcr */
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fixup = FIXUP_BRANCH_NOT_TAKEN;
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break;
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case 0x45: /* bal */
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case 0x4d: /* bas */
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fixup = FIXUP_RETURN_REGISTER;
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break;
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case 0x47: /* bc */
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case 0x46: /* bct */
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case 0x86: /* bxh */
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case 0x87: /* bxle */
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fixup = FIXUP_BRANCH_NOT_TAKEN;
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break;
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case 0x82: /* lpsw */
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fixup = FIXUP_NOT_REQUIRED;
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break;
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case 0xb2: /* lpswe */
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if ((insn[0] & 0xff) == 0xb2)
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fixup = FIXUP_NOT_REQUIRED;
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break;
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case 0xa7: /* bras */
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if ((insn[0] & 0x0f) == 0x05)
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fixup |= FIXUP_RETURN_REGISTER;
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break;
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case 0xc0:
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if ((insn[0] & 0x0f) == 0x05) /* brasl */
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fixup |= FIXUP_RETURN_REGISTER;
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break;
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case 0xeb:
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switch (insn[2] & 0xff) {
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case 0x44: /* bxhg */
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case 0x45: /* bxleg */
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fixup = FIXUP_BRANCH_NOT_TAKEN;
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break;
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}
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break;
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case 0xe3: /* bctg */
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if ((insn[2] & 0xff) == 0x46)
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fixup = FIXUP_BRANCH_NOT_TAKEN;
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break;
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case 0xec:
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switch (insn[2] & 0xff) {
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case 0xe5: /* clgrb */
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case 0xe6: /* cgrb */
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case 0xf6: /* crb */
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case 0xf7: /* clrb */
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case 0xfc: /* cgib */
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case 0xfd: /* cglib */
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case 0xfe: /* cib */
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case 0xff: /* clib */
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fixup = FIXUP_BRANCH_NOT_TAKEN;
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break;
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}
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break;
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}
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return fixup;
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}
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int probe_is_insn_relative_long(u16 *insn)
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{
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/* Check if we have a RIL-b or RIL-c format instruction which
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* we need to modify in order to avoid instruction emulation. */
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switch (insn[0] >> 8) {
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case 0xc0:
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if ((insn[0] & 0x0f) == 0x00) /* larl */
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return true;
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break;
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case 0xc4:
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switch (insn[0] & 0x0f) {
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case 0x02: /* llhrl */
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case 0x04: /* lghrl */
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case 0x05: /* lhrl */
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case 0x06: /* llghrl */
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case 0x07: /* sthrl */
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case 0x08: /* lgrl */
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case 0x0b: /* stgrl */
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case 0x0c: /* lgfrl */
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case 0x0d: /* lrl */
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case 0x0e: /* llgfrl */
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case 0x0f: /* strl */
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return true;
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}
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break;
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case 0xc6:
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switch (insn[0] & 0x0f) {
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case 0x02: /* pfdrl */
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case 0x04: /* cghrl */
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case 0x05: /* chrl */
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case 0x06: /* clghrl */
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case 0x07: /* clhrl */
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case 0x08: /* cgrl */
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case 0x0a: /* clgrl */
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case 0x0c: /* cgfrl */
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case 0x0d: /* crl */
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case 0x0e: /* clgfrl */
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case 0x0f: /* clrl */
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return true;
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}
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break;
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}
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return false;
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}
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