blob: ae90e1ae3607052c6ac4403f815d33061fcaf604 [file] [log] [blame]
/*
* 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;
}