/*
* Single-step support.
*
* Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/prefetch.h>
#include <asm/sstep.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/cputable.h>
extern char system_call_common[];
#ifdef CONFIG_PPC64
/* Bits in SRR1 that are copied from MSR */
#define MSR_MASK 0xffffffff87c0ffffUL
#else
#define MSR_MASK 0x87c0ffff
#endif
/* Bits in XER */
#define XER_SO 0x80000000U
#define XER_OV 0x40000000U
#define XER_CA 0x20000000U
#ifdef CONFIG_PPC_FPU
/*
* Functions in ldstfp.S
*/
extern int do_lfs(int rn, unsigned long ea);
extern int do_lfd(int rn, unsigned long ea);
extern int do_stfs(int rn, unsigned long ea);
extern int do_stfd(int rn, unsigned long ea);
extern int do_lvx(int rn, unsigned long ea);
extern int do_stvx(int rn, unsigned long ea);
extern int do_lxvd2x(int rn, unsigned long ea);
extern int do_stxvd2x(int rn, unsigned long ea);
#endif
/*
* Emulate the truncation of 64 bit values in 32-bit mode.
*/
static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
{
#ifdef __powerpc64__
if ((msr & MSR_64BIT) == 0)
val &= 0xffffffffUL;
#endif
return val;
}
/*
* Determine whether a conditional branch instruction would branch.
*/
static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
{
unsigned int bo = (instr >> 21) & 0x1f;
unsigned int bi;
if ((bo & 4) == 0) {
/* decrement counter */
--regs->ctr;
if (((bo >> 1) & 1) ^ (regs->ctr == 0))
return 0;
}
if ((bo & 0x10) == 0) {
/* check bit from CR */
bi = (instr >> 16) & 0x1f;
if (((regs->ccr >> (31 - bi)) & 1) != ((bo >> 3) & 1))
return 0;
}
return 1;
}
static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
{
if (!user_mode(regs))
return 1;
return __access_ok(ea, nb, USER_DS);
}
/*
* Calculate effective address for a D-form instruction
*/
static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs)
{
int ra;
unsigned long ea;
ra = (instr >> 16) & 0x1f;
ea = (signed short) instr; /* sign-extend */
if (ra)
ea += regs->gpr[ra];
return truncate_if_32bit(regs->msr, ea);
}
#ifdef __powerpc64__
/*
* Calculate effective address for a DS-form instruction
*/
static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
{
int ra;
unsigned long ea;
ra = (instr >> 16) & 0x1f;
ea = (signed short) (instr & ~3); /* sign-extend */
if (ra)
ea += regs->gpr[ra];
return truncate_if_32bit(regs->msr, ea);
}
#endif /* __powerpc64 */
/*
* Calculate effective address for an X-form instruction
*/
static unsigned long __kprobes xform_ea(unsigned int instr,
struct pt_regs *regs)
{
int ra, rb;
unsigned long ea;
ra = (instr >> 16) & 0x1f;
rb = (instr >> 11) & 0x1f;
ea = regs->gpr[rb];
if (ra)
ea += regs->gpr[ra];
return truncate_if_32bit(regs->msr, ea);
}
/*
* Return the largest power of 2, not greater than sizeof(unsigned long),
* such that x is a multiple of it.
*/
static inline unsigned long max_align(unsigned long x)
{
x |= sizeof(unsigned long);
return x & -x; /* isolates rightmost bit */
}
static inline unsigned long byterev_2(unsigned long x)
{
return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
}
static inline unsigned long byterev_4(unsigned long x)
{
return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
((x & 0xff00) << 8) | ((x & 0xff) << 24);
}
#ifdef __powerpc64__
static inline unsigned long byterev_8(unsigned long x)
{
return (byterev_4(x) << 32) | byterev_4(x >> 32);
}
#endif
static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
int nb)
{
int err = 0;
unsigned long x = 0;
switch (nb) {
case 1:
err = __get_user(x, (unsigned char __user *) ea);
break;
case 2:
err = __get_user(x, (unsigned short __user *) ea);
break;
case 4:
err = __get_user(x, (unsigned int __user *) ea);
break;
#ifdef __powerpc64__
case 8:
err = __get_user(x, (unsigned long __user *) ea);
break;
#endif
}
if (!err)
*dest = x;
return err;
}
static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
int nb, struct pt_regs *regs)
{
int err;
unsigned long x, b, c;
#ifdef __LITTLE_ENDIAN__
int len = nb; /* save a copy of the length for byte reversal */
#endif
/* unaligned, do this in pieces */
x = 0;
for (; nb > 0; nb -= c) {
#ifdef __LITTLE_ENDIAN__
c = 1;
#endif
#ifdef __BIG_ENDIAN__
c = max_align(ea);
#endif
if (c > nb)
c = max_align(nb);
err = read_mem_aligned(&b, ea, c);
if (err)
return err;
x = (x << (8 * c)) + b;
ea += c;
}
#ifdef __LITTLE_ENDIAN__
switch (len) {
case 2:
*dest = byterev_2(x);
break;
case 4:
*dest = byterev_4(x);
break;
#ifdef __powerpc64__
case 8:
*dest = byterev_8(x);
break;
#endif
}
#endif
#ifdef __BIG_ENDIAN__
*dest = x;
#endif
return 0;
}
/*
* Read memory at address ea for nb bytes, return 0 for success
* or -EFAULT if an error occurred.
*/
static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
struct pt_regs *regs)
{
if (!address_ok(regs, ea, nb))
return -EFAULT;
if ((ea & (nb - 1)) == 0)
return read_mem_aligned(dest, ea, nb);
return read_mem_unaligned(dest, ea, nb, regs);
}
static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
int nb)
{
int err = 0;
switch (nb) {
case 1:
err = __put_user(val, (unsigned char __user *) ea);
break;
case 2:
err = __put_user(val, (unsigned short __user *) ea);
break;
case 4:
err = __put_user(val, (unsigned int __user *) ea);
break;
#ifdef __powerpc64__
case 8:
err = __put_user(val, (unsigned long __user *) ea);
break;
#endif
}
return err;
}
static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
int nb, struct pt_regs *regs)
{
int err;
unsigned long c;
#ifdef __LITTLE_ENDIAN__
switch (nb) {
case 2:
val = byterev_2(val);
break;
case 4:
val = byterev_4(val);
break;
#ifdef __powerpc64__
case 8:
val = byterev_8(val);
break;
#endif
}
#endif
/* unaligned or little-endian, do this in pieces */
for (; nb > 0; nb -= c) {
#ifdef __LITTLE_ENDIAN__
c = 1;
#endif
#ifdef __BIG_ENDIAN__
c = max_align(ea);
#endif
if (c > nb)
c = max_align(nb);
err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
if (err)
return err;
ea += c;
}
return 0;
}
/*
* Write memory at address ea for nb bytes, return 0 for success
* or -EFAULT if an error occurred.
*/
static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
struct pt_regs *regs)
{
if (!address_ok(regs, ea, nb))
return -EFAULT;
if ((ea & (nb - 1)) == 0)
return write_mem_aligned(val, ea, nb);
return write_mem_unaligned(val, ea, nb, regs);
}
#ifdef CONFIG_PPC_FPU
/*
* Check the address and alignment, and call func to do the actual
* load or store.
*/
static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, int nb,
struct pt_regs *regs)
{
int err;
union {
double dbl;
unsigned long ul[2];
struct {
#ifdef __BIG_ENDIAN__
unsigned _pad_;
unsigned word;
#endif
#ifdef __LITTLE_ENDIAN__
unsigned word;
unsigned _pad_;
#endif
} single;
} data;
unsigned long ptr;
if (!address_ok(regs, ea, nb))
return -EFAULT;
if ((ea & 3) == 0)
return (*func)(rn, ea);
ptr = (unsigned long) &data.ul;
if (sizeof(unsigned long) == 8 || nb == 4) {
err = read_mem_unaligned(&data.ul[0], ea, nb, regs);
if (nb == 4)
ptr = (unsigned long)&(data.single.word);
} else {
/* reading a double on 32-bit */
err = read_mem_unaligned(&data.ul[0], ea, 4, regs);
if (!err)
err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
}
if (err)
return err;
return (*func)(rn, ptr);
}
static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, int nb,
struct pt_regs *regs)
{
int err;
union {
double dbl;
unsigned long ul[2];
struct {
#ifdef __BIG_ENDIAN__
unsigned _pad_;
unsigned word;
#endif
#ifdef __LITTLE_ENDIAN__
unsigned word;
unsigned _pad_;
#endif
} single;
} data;
unsigned long ptr;
if (!address_ok(regs, ea, nb))
return -EFAULT;
if ((ea & 3) == 0)
return (*func)(rn, ea);
ptr = (unsigned long) &data.ul[0];
if (sizeof(unsigned long) == 8 || nb == 4) {
if (nb == 4)
ptr = (unsigned long)&(data.single.word);
err = (*func)(rn, ptr);
if (err)
return err;
err = write_mem_unaligned(data.ul[0], ea, nb, regs);
} else {
/* writing a double on 32-bit */
err = (*func)(rn, ptr);
if (err)
return err;
err = write_mem_unaligned(data.ul[0], ea, 4, regs);
if (!err)
err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
}
return err;
}
#endif
#ifdef CONFIG_ALTIVEC
/* For Altivec/VMX, no need to worry about alignment */
static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT;
return (*func)(rn, ea);
}
static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT;
return (*func)(rn, ea);
}
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
int err;
unsigned long val[2];
if (!address_ok(regs, ea, 16))
return -EFAULT;
if ((ea & 3) == 0)
return (*func)(rn, ea);
err = read_mem_unaligned(&val[0], ea, 8, regs);
if (!err)
err = read_mem_unaligned(&val[1], ea + 8, 8, regs);
if (!err)
err = (*func)(rn, (unsigned long) &val[0]);
return err;
}
static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
int err;
unsigned long val[2];
if (!address_ok(regs, ea, 16))
return -EFAULT;
if ((ea & 3) == 0)
return (*func)(rn, ea);
err = (*func)(rn, (unsigned long) &val[0]);
if (err)
return err;
err = write_mem_unaligned(val[0], ea, 8, regs);
if (!err)
err = write_mem_unaligned(val[1], ea + 8, 8, regs);
return err;
}
#endif /* CONFIG_VSX */
#define __put_user_asmx(x, addr, err, op, cr) \
__asm__ __volatile__( \
"1: " op " %2,0,%3\n" \
" mfcr %1\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%4\n" \
" b 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
PPC_LONG_ALIGN "\n" \
PPC_LONG "1b,3b\n" \
".previous" \
: "=r" (err), "=r" (cr) \
: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err))
#define __get_user_asmx(x, addr, err, op) \
__asm__ __volatile__( \
"1: "op" %1,0,%2\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" b 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
PPC_LONG_ALIGN "\n" \
PPC_LONG "1b,3b\n" \
".previous" \
: "=r" (err), "=r" (x) \
: "r" (addr), "i" (-EFAULT), "0" (err))
#define __cacheop_user_asmx(addr, err, op) \
__asm__ __volatile__( \
"1: "op" 0,%1\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" b 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
PPC_LONG_ALIGN "\n" \
PPC_LONG "1b,3b\n" \
".previous" \
: "=r" (err) \
: "r" (addr), "i" (-EFAULT), "0" (err))
static void __kprobes set_cr0(struct pt_regs *regs, int rd)
{
long val = regs->gpr[rd];
regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
#ifdef __powerpc64__
if (!(regs->msr & MSR_64BIT))
val = (int) val;
#endif
if (val < 0)
regs->ccr |= 0x80000000;
else if (val > 0)
regs->ccr |= 0x40000000;
else
regs->ccr |= 0x20000000;
}
static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
unsigned long val1, unsigned long val2,
unsigned long carry_in)
{
unsigned long val = val1 + val2;
if (carry_in)
++val;
regs->gpr[rd] = val;
#ifdef __powerpc64__
if (!(regs->msr & MSR_64BIT)) {
val = (unsigned int) val;
val1 = (unsigned int) val1;
}
#endif
if (val < val1 || (carry_in && val == val1))
regs->xer |= XER_CA;
else
regs->xer &= ~XER_CA;
}
static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
int crfld)
{
unsigned int crval, shift;
crval = (regs->xer >> 31) & 1; /* get SO bit */
if (v1 < v2)
crval |= 8;
else if (v1 > v2)
crval |= 4;
else
crval |= 2;
shift = (7 - crfld) * 4;
regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
}
static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
unsigned long v2, int crfld)
{
unsigned int crval, shift;
crval = (regs->xer >> 31) & 1; /* get SO bit */
if (v1 < v2)
crval |= 8;
else if (v1 > v2)
crval |= 4;
else
crval |= 2;
shift = (7 - crfld) * 4;
regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
}
static int __kprobes trap_compare(long v1, long v2)
{
int ret = 0;
if (v1 < v2)
ret |= 0x10;
else if (v1 > v2)
ret |= 0x08;
else
ret |= 0x04;
if ((unsigned long)v1 < (unsigned long)v2)
ret |= 0x02;
else if ((unsigned long)v1 > (unsigned long)v2)
ret |= 0x01;
return ret;
}
/*
* Elements of 32-bit rotate and mask instructions.
*/
#define MASK32(mb, me) ((0xffffffffUL >> (mb)) + \
((signed long)-0x80000000L >> (me)) + ((me) >= (mb)))
#ifdef __powerpc64__
#define MASK64_L(mb) (~0UL >> (mb))
#define MASK64_R(me) ((signed long)-0x8000000000000000L >> (me))
#define MASK64(mb, me) (MASK64_L(mb) + MASK64_R(me) + ((me) >= (mb)))
#define DATA32(x) (((x) & 0xffffffffUL) | (((x) & 0xffffffffUL) << 32))
#else
#define DATA32(x) (x)
#endif
#define ROTATE(x, n) ((n) ? (((x) << (n)) | ((x) >> (8 * sizeof(long) - (n)))) : (x))
/*
* Decode an instruction, and execute it if that can be done just by
* modifying *regs (i.e. integer arithmetic and logical instructions,
* branches, and barrier instructions).
* Returns 1 if the instruction has been executed, or 0 if not.
* Sets *op to indicate what the instruction does.
*/
int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
unsigned int instr)
{
unsigned int opcode, ra, rb, rd, spr, u;
unsigned long int imm;
unsigned long int val, val2;
unsigned int mb, me, sh;
long ival;
op->type = COMPUTE;
opcode = instr >> 26;
switch (opcode) {
case 16: /* bc */
op->type = BRANCH;
imm = (signed short)(instr & 0xfffc);
if ((instr & 2) == 0)
imm += regs->nip;
regs->nip += 4;
regs->nip = truncate_if_32bit(regs->msr, regs->nip);
if (instr & 1)
regs->link = regs->nip;
if (branch_taken(instr, regs))
regs->nip = truncate_if_32bit(regs->msr, imm);
return 1;
#ifdef CONFIG_PPC64
case 17: /* sc */
if ((instr & 0xfe2) == 2)
op->type = SYSCALL;
else
op->type = UNKNOWN;
return 0;
#endif
case 18: /* b */
op->type = BRANCH;
imm = instr & 0x03fffffc;
if (imm & 0x02000000)
imm -= 0x04000000;
if ((instr & 2) == 0)
imm += regs->nip;
if (instr & 1)
regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
imm = truncate_if_32bit(regs->msr, imm);
regs->nip = imm;
return 1;
case 19:
switch ((instr >> 1) & 0x3ff) {
case 0: /* mcrf */
rd = (instr >> 21) & 0x1c;
ra = (instr >> 16) & 0x1c;
val = (regs->ccr >> ra) & 0xf;
regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);
goto instr_done;
case 16: /* bclr */
case 528: /* bcctr */
op->type = BRANCH;
imm = (instr & 0x400)? regs->ctr: regs->link;
regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
imm = truncate_if_32bit(regs->msr, imm);
if (instr & 1)
regs->link = regs->nip;
if (branch_taken(instr, regs))
regs->nip = imm;
return 1;
case 18: /* rfid, scary */
if (regs->msr & MSR_PR)
goto priv;
op->type = RFI;
return 0;
case 150: /* isync */
op->type = BARRIER;
isync();
goto instr_done;
case 33: /* crnor */
case 129: /* crandc */
case 193: /* crxor */
case 225: /* crnand */
case 257: /* crand */
case 289: /* creqv */
case 417: /* crorc */
case 449: /* cror */
ra = (instr >> 16) & 0x1f;
rb = (instr >> 11) & 0x1f;
rd = (instr >> 21) & 0x1f;
ra = (regs->ccr >> (31 - ra)) & 1;
rb = (regs->ccr >> (31 - rb)) & 1;
val = (instr >> (6 + ra * 2 + rb)) & 1;
regs->ccr = (regs->ccr & ~(1UL << (31 - rd))) |
(val << (31 - rd));
goto instr_done;
}
break;
case 31:
switch ((instr >> 1) & 0x3ff) {
case 598: /* sync */
op->type = BARRIER;
#ifdef __powerpc64__
switch ((instr >> 21) & 3) {
case 1: /* lwsync */
asm volatile("lwsync" : : : "memory");
goto instr_done;
case 2: /* ptesync */
asm volatile("ptesync" : : : "memory");
goto instr_done;
}
#endif
mb();
goto instr_done;
case 854: /* eieio */
op->type = BARRIER;
eieio();
goto instr_done;
}
break;
}
/* Following cases refer to regs->gpr[], so we need all regs */
if (!FULL_REGS(regs))
return 0;
rd = (instr >> 21) & 0x1f;
ra = (instr >> 16) & 0x1f;
rb = (instr >> 11) & 0x1f;
switch (opcode) {
#ifdef __powerpc64__
case 2: /* tdi */
if (rd & trap_compare(regs->gpr[ra], (short) instr))
goto trap;
goto instr_done;
#endif
case 3: /* twi */
if (rd & trap_compare((int)regs->gpr[ra], (short) instr))
goto trap;
goto instr_done;
case 7: /* mulli */
regs->gpr[rd] = regs->gpr[ra] * (short) instr;
goto instr_done;
case 8: /* subfic */
imm = (short) instr;
add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1);
goto instr_done;
case 10: /* cmpli */
imm = (unsigned short) instr;
val = regs->gpr[ra];
#ifdef __powerpc64__
if ((rd & 1) == 0)
val = (unsigned int) val;
#endif
do_cmp_unsigned(regs, val, imm, rd >> 2);
goto instr_done;
case 11: /* cmpi */
imm = (short) instr;
val = regs->gpr[ra];
#ifdef __powerpc64__
if ((rd & 1) == 0)
val = (int) val;
#endif
do_cmp_signed(regs, val, imm, rd >> 2);
goto instr_done;
case 12: /* addic */
imm = (short) instr;
add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
goto instr_done;
case 13: /* addic. */
imm = (short) instr;
add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
set_cr0(regs, rd);
goto instr_done;
case 14: /* addi */
imm = (short) instr;
if (ra)
imm += regs->gpr[ra];
regs->gpr[rd] = imm;
goto instr_done;
case 15: /* addis */
imm = ((short) instr) << 16;
if (ra)
imm += regs->gpr[ra];
regs->gpr[rd] = imm;
goto instr_done;
case 20: /* rlwimi */
mb = (instr >> 6) & 0x1f;
me = (instr >> 1) & 0x1f;
val = DATA32(regs->gpr[rd]);
imm = MASK32(mb, me);
regs->gpr[ra] = (regs->gpr[ra] & ~imm) | (ROTATE(val, rb) & imm);
goto logical_done;
case 21: /* rlwinm */
mb = (instr >> 6) & 0x1f;
me = (instr >> 1) & 0x1f;
val = DATA32(regs->gpr[rd]);
regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
goto logical_done;
case 23: /* rlwnm */
mb = (instr >> 6) & 0x1f;
me = (instr >> 1) & 0x1f;
rb = regs->gpr[rb] & 0x1f;
val = DATA32(regs->gpr[rd]);
regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
goto logical_done;
case 24: /* ori */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] | imm;
goto instr_done;
case 25: /* oris */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] | (imm << 16);
goto instr_done;
case 26: /* xori */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] ^ imm;
goto instr_done;
case 27: /* xoris */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16);
goto instr_done;
case 28: /* andi. */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] & imm;
set_cr0(regs, ra);
goto instr_done;
case 29: /* andis. */
imm = (unsigned short) instr;
regs->gpr[ra] = regs->gpr[rd] & (imm << 16);
set_cr0(regs, ra);
goto instr_done;
#ifdef __powerpc64__
case 30: /* rld* */
mb = ((instr >> 6) & 0x1f) | (instr & 0x20);
val = regs->gpr[rd];
if ((instr & 0x10) == 0) {
sh = rb | ((instr & 2) << 4);
val = ROTATE(val, sh);
switch ((instr >> 2) & 3) {
case 0: /* rldicl */
regs->gpr[ra] = val & MASK64_L(mb);
goto logical_done;
case 1: /* rldicr */
regs->gpr[ra] = val & MASK64_R(mb);
goto logical_done;
case 2: /* rldic */
regs->gpr[ra] = val & MASK64(mb, 63 - sh);
goto logical_done;
case 3: /* rldimi */
imm = MASK64(mb, 63 - sh);
regs->gpr[ra] = (regs->gpr[ra] & ~imm) |
(val & imm);
goto logical_done;
}
} else {
sh = regs->gpr[rb] & 0x3f;
val = ROTATE(val, sh);
switch ((instr >> 1) & 7) {
case 0: /* rldcl */
regs->gpr[ra] = val & MASK64_L(mb);
goto logical_done;
case 1: /* rldcr */
regs->gpr[ra] = val & MASK64_R(mb);
goto logical_done;
}
}
#endif
case 31:
switch ((instr >> 1) & 0x3ff) {
case 4: /* tw */
if (rd == 0x1f ||
(rd & trap_compare((int)regs->gpr[ra],
(int)regs->gpr[rb])))
goto trap;
goto instr_done;
#ifdef __powerpc64__
case 68: /* td */
if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))
goto trap;
goto instr_done;
#endif
case 83: /* mfmsr */
if (regs->msr & MSR_PR)
goto priv;
op->type = MFMSR;
op->reg = rd;
return 0;
case 146: /* mtmsr */
if (regs->msr & MSR_PR)
goto priv;
op->type = MTMSR;
op->reg = rd;
op->val = 0xffffffff & ~(MSR_ME | MSR_LE);
return 0;
#ifdef CONFIG_PPC64
case 178: /* mtmsrd */
if (regs->msr & MSR_PR)
goto priv;
op->type = MTMSR;
op->reg = rd;
/* only MSR_EE and MSR_RI get changed if bit 15 set */
/* mtmsrd doesn't change MSR_HV, MSR_ME or MSR_LE */
imm = (instr & 0x10000)? 0x8002: 0xefffffffffffeffeUL;
op->val = imm;
return 0;
#endif
case 19: /* mfcr */
regs->gpr[rd] = regs->ccr;
regs->gpr[rd] &= 0xffffffffUL;
goto instr_done;
case 144: /* mtcrf */
imm = 0xf0000000UL;
val = regs->gpr[rd];
for (sh = 0; sh < 8; ++sh) {
if (instr & (0x80000 >> sh))
regs->ccr = (regs->ccr & ~imm) |
(val & imm);
imm >>= 4;
}
goto instr_done;
case 339: /* mfspr */
spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
switch (spr) {
case SPRN_XER: /* mfxer */
regs->gpr[rd] = regs->xer;
regs->gpr[rd] &= 0xffffffffUL;
goto instr_done;
case SPRN_LR: /* mflr */
regs->gpr[rd] = regs->link;
goto instr_done;
case SPRN_CTR: /* mfctr */
regs->gpr[rd] = regs->ctr;
goto instr_done;
default:
op->type = MFSPR;
op->reg = rd;
op->spr = spr;
return 0;
}
break;
case 467: /* mtspr */
spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
switch (spr) {
case SPRN_XER: /* mtxer */
regs->xer = (regs->gpr[rd] & 0xffffffffUL);
goto instr_done;
case SPRN_LR: /* mtlr */
regs->link = regs->gpr[rd];
goto instr_done;
case SPRN_CTR: /* mtctr */
regs->ctr = regs->gpr[rd];
goto instr_done;
default:
op->type = MTSPR;
op->val = regs->gpr[rd];
op->spr = spr;
return 0;
}
break;
/*
* Compare instructions
*/
case 0: /* cmp */
val = regs->gpr[ra];
val2 = regs->gpr[rb];
#ifdef __powerpc64__
if ((rd & 1) == 0) {
/* word (32-bit) compare */
val = (int) val;
val2 = (int) val2;
}
#endif
do_cmp_signed(regs, val, val2, rd >> 2);
goto instr_done;
case 32: /* cmpl */
val = regs->gpr[ra];
val2 = regs->gpr[rb];
#ifdef __powerpc64__
if ((rd & 1) == 0) {
/* word (32-bit) compare */
val = (unsigned int) val;
val2 = (unsigned int) val2;
}
#endif
do_cmp_unsigned(regs, val, val2, rd >> 2);
goto instr_done;
/*
* Arithmetic instructions
*/
case 8: /* subfc */
add_with_carry(regs, rd, ~regs->gpr[ra],
regs->gpr[rb], 1);
goto arith_done;
#ifdef __powerpc64__
case 9: /* mulhdu */
asm("mulhdu %0,%1,%2" : "=r" (regs->gpr[rd]) :
"r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
goto arith_done;
#endif
case 10: /* addc */
add_with_carry(regs, rd, regs->gpr[ra],
regs->gpr[rb], 0);
goto arith_done;
case 11: /* mulhwu */
asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) :
"r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
goto arith_done;
case 40: /* subf */
regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra];
goto arith_done;
#ifdef __powerpc64__
case 73: /* mulhd */
asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) :
"r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
goto arith_done;
#endif
case 75: /* mulhw */
asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) :
"r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
goto arith_done;
case 104: /* neg */
regs->gpr[rd] = -regs->gpr[ra];
goto arith_done;
case 136: /* subfe */
add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb],
regs->xer & XER_CA);
goto arith_done;
case 138: /* adde */
add_with_carry(regs, rd, regs->gpr[ra], regs->gpr[rb],
regs->xer & XER_CA);
goto arith_done;
case 200: /* subfze */
add_with_carry(regs, rd, ~regs->gpr[ra], 0L,
regs->xer & XER_CA);
goto arith_done;
case 202: /* addze */
add_with_carry(regs, rd, regs->gpr[ra], 0L,
regs->xer & XER_CA);
goto arith_done;
case 232: /* subfme */
add_with_carry(regs, rd, ~regs->gpr[ra], -1L,
regs->xer & XER_CA);
goto arith_done;
#ifdef __powerpc64__
case 233: /* mulld */
regs->gpr[rd] = regs->gpr[ra] * regs->gpr[rb];
goto arith_done;
#endif
case 234: /* addme */
add_with_carry(regs, rd, regs->gpr[ra], -1L,
regs->xer & XER_CA);
goto arith_done;
case 235: /* mullw */
regs->gpr[rd] = (unsigned int) regs->gpr[ra] *
(unsigned int) regs->gpr[rb];
goto arith_done;
case 266: /* add */
regs->gpr[rd] = regs->gpr[ra] + regs->gpr[rb];
goto arith_done;
#ifdef __powerpc64__
case 457: /* divdu */
regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb];
goto arith_done;
#endif
case 459: /* divwu */
regs->gpr[rd] = (unsigned int) regs->gpr[ra] /
(unsigned int) regs->gpr[rb];
goto arith_done;
#ifdef __powerpc64__
case 489: /* divd */
regs->gpr[rd] = (long int) regs->gpr[ra] /
(long int) regs->gpr[rb];
goto arith_done;
#endif
case 491: /* divw */
regs->gpr[rd] = (int) regs->gpr[ra] /
(int) regs->gpr[rb];
goto arith_done;
/*
* Logical instructions
*/
case 26: /* cntlzw */
asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
"r" (regs->gpr[rd]));
goto logical_done;
#ifdef __powerpc64__
case 58: /* cntlzd */
asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) :
"r" (regs->gpr[rd]));
goto logical_done;
#endif
case 28: /* and */
regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb];
goto logical_done;
case 60: /* andc */
regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
goto logical_done;
case 124: /* nor */
regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
goto logical_done;
case 284: /* xor */
regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
goto logical_done;
case 316: /* xor */
regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
goto logical_done;
case 412: /* orc */
regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
goto logical_done;
case 444: /* or */
regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb];
goto logical_done;
case 476: /* nand */
regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
goto logical_done;
case 922: /* extsh */
regs->gpr[ra] = (signed short) regs->gpr[rd];
goto logical_done;
case 954: /* extsb */
regs->gpr[ra] = (signed char) regs->gpr[rd];
goto logical_done;
#ifdef __powerpc64__
case 986: /* extsw */
regs->gpr[ra] = (signed int) regs->gpr[rd];
goto logical_done;
#endif
/*
* Shift instructions
*/
case 24: /* slw */
sh = regs->gpr[rb] & 0x3f;
if (sh < 32)
regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL;
else
regs->gpr[ra] = 0;
goto logical_done;
case 536: /* srw */
sh = regs->gpr[rb] & 0x3f;
if (sh < 32)
regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh;
else
regs->gpr[ra] = 0;
goto logical_done;
case 792: /* sraw */
sh = regs->gpr[rb] & 0x3f;
ival = (signed int) regs->gpr[rd];
regs->gpr[ra] = ival >> (sh < 32 ? sh : 31);
if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0))
regs->xer |= XER_CA;
else
regs->xer &= ~XER_CA;
goto logical_done;
case 824: /* srawi */
sh = rb;
ival = (signed int) regs->gpr[rd];
regs->gpr[ra] = ival >> sh;
if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
regs->xer |= XER_CA;
else
regs->xer &= ~XER_CA;
goto logical_done;
#ifdef __powerpc64__
case 27: /* sld */
sh = regs->gpr[rb] & 0x7f;
if (sh < 64)
regs->gpr[ra] = regs->gpr[rd] << sh;
else
regs->gpr[ra] = 0;
goto logical_done;
case 539: /* srd */
sh = regs->gpr[rb] & 0x7f;
if (sh < 64)
regs->gpr[ra] = regs->gpr[rd] >> sh;
else
regs->gpr[ra] = 0;
goto logical_done;
case 794: /* srad */
sh = regs->gpr[rb] & 0x7f;
ival = (signed long int) regs->gpr[rd];
regs->gpr[ra] = ival >> (sh < 64 ? sh : 63);
if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0))
regs->xer |= XER_CA;
else
regs->xer &= ~XER_CA;
goto logical_done;
case 826: /* sradi with sh_5 = 0 */
case 827: /* sradi with sh_5 = 1 */
sh = rb | ((instr & 2) << 4);
ival = (signed long int) regs->gpr[rd];
regs->gpr[ra] = ival >> sh;
if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
regs->xer |= XER_CA;
else
regs->xer &= ~XER_CA;
goto logical_done;
#endif /* __powerpc64__ */
/*
* Cache instructions
*/
case 54: /* dcbst */
op->type = MKOP(CACHEOP, DCBST, 0);
op->ea = xform_ea(instr, regs);
return 0;
case 86: /* dcbf */
op->type = MKOP(CACHEOP, DCBF, 0);
op->ea = xform_ea(instr, regs);
return 0;
case 246: /* dcbtst */
op->type = MKOP(CACHEOP, DCBTST, 0);
op->ea = xform_ea(instr, regs);
op->reg = rd;
return 0;
case 278: /* dcbt */
op->type = MKOP(CACHEOP, DCBTST, 0);
op->ea = xform_ea(instr, regs);
op->reg = rd;
return 0;
case 982: /* icbi */
op->type = MKOP(CACHEOP, ICBI, 0);
op->ea = xform_ea(instr, regs);
return 0;
}
break;
}
/*
* Loads and stores.
*/
op->type = UNKNOWN;
op->update_reg = ra;
op->reg = rd;
op->val = regs->gpr[rd];
u = (instr >> 20) & UPDATE;
switch (opcode) {
case 31:
u = instr & UPDATE;
op->ea = xform_ea(instr, regs);
switch ((instr >> 1) & 0x3ff) {
case 20: /* lwarx */
op->type = MKOP(LARX, 0, 4);
break;
case 150: /* stwcx. */
op->type = MKOP(STCX, 0, 4);
break;
#ifdef __powerpc64__
case 84: /* ldarx */
op->type = MKOP(LARX, 0, 8);
break;
case 214: /* stdcx. */
op->type = MKOP(STCX, 0, 8);
break;
case 21: /* ldx */
case 53: /* ldux */
op->type = MKOP(LOAD, u, 8);
break;
#endif
case 23: /* lwzx */
case 55: /* lwzux */
op->type = MKOP(LOAD, u, 4);
break;
case 87: /* lbzx */
case 119: /* lbzux */
op->type = MKOP(LOAD, u, 1);
break;
#ifdef CONFIG_ALTIVEC
case 103: /* lvx */
case 359: /* lvxl */
if (!(regs->msr & MSR_VEC))
goto vecunavail;
op->type = MKOP(LOAD_VMX, 0, 16);
break;
case 231: /* stvx */
case 487: /* stvxl */
if (!(regs->msr & MSR_VEC))
goto vecunavail;
op->type = MKOP(STORE_VMX, 0, 16);
break;
#endif /* CONFIG_ALTIVEC */
#ifdef __powerpc64__
case 149: /* stdx */
case 181: /* stdux */
op->type = MKOP(STORE, u, 8);
break;
#endif
case 151: /* stwx */
case 183: /* stwux */
op->type = MKOP(STORE, u, 4);
break;
case 215: /* stbx */
case 247: /* stbux */
op->type = MKOP(STORE, u, 1);
break;
case 279: /* lhzx */
case 311: /* lhzux */
op->type = MKOP(LOAD, u, 2);
break;
#ifdef __powerpc64__
case 341: /* lwax */
case 373: /* lwaux */
op->type = MKOP(LOAD, SIGNEXT | u, 4);
break;
#endif
case 343: /* lhax */
case 375: /* lhaux */
op->type = MKOP(LOAD, SIGNEXT | u, 2);
break;
case 407: /* sthx */
case 439: /* sthux */
op->type = MKOP(STORE, u, 2);
break;
#ifdef __powerpc64__
case 532: /* ldbrx */
op->type = MKOP(LOAD, BYTEREV, 8);
break;
#endif
case 533: /* lswx */
op->type = MKOP(LOAD_MULTI, 0, regs->xer & 0x7f);
break;
case 534: /* lwbrx */
op->type = MKOP(LOAD, BYTEREV, 4);
break;
case 597: /* lswi */
if (rb == 0)
rb = 32; /* # bytes to load */
op->type = MKOP(LOAD_MULTI, 0, rb);
op->ea = 0;
if (ra)
op->ea = truncate_if_32bit(regs->msr,
regs->gpr[ra]);
break;
#ifdef CONFIG_PPC_FPU
case 535: /* lfsx */
case 567: /* lfsux */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(LOAD_FP, u, 4);
break;
case 599: /* lfdx */
case 631: /* lfdux */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(LOAD_FP, u, 8);
break;
case 663: /* stfsx */
case 695: /* stfsux */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(STORE_FP, u, 4);
break;
case 727: /* stfdx */
case 759: /* stfdux */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(STORE_FP, u, 8);
break;
#endif
#ifdef __powerpc64__
case 660: /* stdbrx */
op->type = MKOP(STORE, BYTEREV, 8);
op->val = byterev_8(regs->gpr[rd]);
break;
#endif
case 661: /* stswx */
op->type = MKOP(STORE_MULTI, 0, regs->xer & 0x7f);
break;
case 662: /* stwbrx */
op->type = MKOP(STORE, BYTEREV, 4);
op->val = byterev_4(regs->gpr[rd]);
break;
case 725:
if (rb == 0)
rb = 32; /* # bytes to store */
op->type = MKOP(STORE_MULTI, 0, rb);
op->ea = 0;
if (ra)
op->ea = truncate_if_32bit(regs->msr,
regs->gpr[ra]);
break;
case 790: /* lhbrx */
op->type = MKOP(LOAD, BYTEREV, 2);
break;
case 918: /* sthbrx */
op->type = MKOP(STORE, BYTEREV, 2);
op->val = byterev_2(regs->gpr[rd]);
break;
#ifdef CONFIG_VSX
case 844: /* lxvd2x */
case 876: /* lxvd2ux */
if (!(regs->msr & MSR_VSX))
goto vsxunavail;
op->reg = rd | ((instr & 1) << 5);
op->type = MKOP(LOAD_VSX, u, 16);
break;
case 972: /* stxvd2x */
case 1004: /* stxvd2ux */
if (!(regs->msr & MSR_VSX))
goto vsxunavail;
op->reg = rd | ((instr & 1) << 5);
op->type = MKOP(STORE_VSX, u, 16);
break;
#endif /* CONFIG_VSX */
}
break;
case 32: /* lwz */
case 33: /* lwzu */
op->type = MKOP(LOAD, u, 4);
op->ea = dform_ea(instr, regs);
break;
case 34: /* lbz */
case 35: /* lbzu */
op->type = MKOP(LOAD, u, 1);
op->ea = dform_ea(instr, regs);
break;
case 36: /* stw */
case 37: /* stwu */
op->type = MKOP(STORE, u, 4);
op->ea = dform_ea(instr, regs);
break;
case 38: /* stb */
case 39: /* stbu */
op->type = MKOP(STORE, u, 1);
op->ea = dform_ea(instr, regs);
break;
case 40: /* lhz */
case 41: /* lhzu */
op->type = MKOP(LOAD, u, 2);
op->ea = dform_ea(instr, regs);
break;
case 42: /* lha */
case 43: /* lhau */
op->type = MKOP(LOAD, SIGNEXT | u, 2);
op->ea = dform_ea(instr, regs);
break;
case 44: /* sth */
case 45: /* sthu */
op->type = MKOP(STORE, u, 2);
op->ea = dform_ea(instr, regs);
break;
case 46: /* lmw */
if (ra >= rd)
break; /* invalid form, ra in range to load */
op->type = MKOP(LOAD_MULTI, 0, 4 * (32 - rd));
op->ea = dform_ea(instr, regs);
break;
case 47: /* stmw */
op->type = MKOP(STORE_MULTI, 0, 4 * (32 - rd));
op->ea = dform_ea(instr, regs);
break;
#ifdef CONFIG_PPC_FPU
case 48: /* lfs */
case 49: /* lfsu */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(LOAD_FP, u, 4);
op->ea = dform_ea(instr, regs);
break;
case 50: /* lfd */
case 51: /* lfdu */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(LOAD_FP, u, 8);
op->ea = dform_ea(instr, regs);
break;
case 52: /* stfs */
case 53: /* stfsu */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(STORE_FP, u, 4);
op->ea = dform_ea(instr, regs);
break;
case 54: /* stfd */
case 55: /* stfdu */
if (!(regs->msr & MSR_FP))
goto fpunavail;
op->type = MKOP(STORE_FP, u, 8);
op->ea = dform_ea(instr, regs);
break;
#endif
#ifdef __powerpc64__
case 58: /* ld[u], lwa */
op->ea = dsform_ea(instr, regs);
switch (instr & 3) {
case 0: /* ld */
op->type = MKOP(LOAD, 0, 8);
break;
case 1: /* ldu */
op->type = MKOP(LOAD, UPDATE, 8);
break;
case 2: /* lwa */
op->type = MKOP(LOAD, SIGNEXT, 4);
break;
}
break;
case 62: /* std[u] */
op->ea = dsform_ea(instr, regs);
switch (instr & 3) {
case 0: /* std */
op->type = MKOP(STORE, 0, 8);
break;
case 1: /* stdu */
op->type = MKOP(STORE, UPDATE, 8);
break;
}
break;
#endif /* __powerpc64__ */
}
return 0;
logical_done:
if (instr & 1)
set_cr0(regs, ra);
goto instr_done;
arith_done:
if (instr & 1)
set_cr0(regs, rd);
instr_done:
regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
return 1;
priv:
op->type = INTERRUPT | 0x700;
op->val = SRR1_PROGPRIV;
return 0;
trap:
op->type = INTERRUPT | 0x700;
op->val = SRR1_PROGTRAP;
return 0;
#ifdef CONFIG_PPC_FPU
fpunavail:
op->type = INTERRUPT | 0x800;
return 0;
#endif
#ifdef CONFIG_ALTIVEC
vecunavail:
op->type = INTERRUPT | 0xf20;
return 0;
#endif
#ifdef CONFIG_VSX
vsxunavail:
op->type = INTERRUPT | 0xf40;
return 0;
#endif
}
EXPORT_SYMBOL_GPL(analyse_instr);
/*
* For PPC32 we always use stwu with r1 to change the stack pointer.
* So this emulated store may corrupt the exception frame, now we
* have to provide the exception frame trampoline, which is pushed
* below the kprobed function stack. So we only update gpr[1] but
* don't emulate the real store operation. We will do real store
* operation safely in exception return code by checking this flag.
*/
static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
{
#ifdef CONFIG_PPC32
/*
* Check if we will touch kernel stack overflow
*/
if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
return -EINVAL;
}
#endif /* CONFIG_PPC32 */
/*
* Check if we already set since that means we'll
* lose the previous value.
*/
WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
set_thread_flag(TIF_EMULATE_STACK_STORE);
return 0;
}
static __kprobes void do_signext(unsigned long *valp, int size)
{
switch (size) {
case 2:
*valp = (signed short) *valp;
break;
case 4:
*valp = (signed int) *valp;
break;
}
}
static __kprobes void do_byterev(unsigned long *valp, int size)
{
switch (size) {
case 2:
*valp = byterev_2(*valp);
break;
case 4:
*valp = byterev_4(*valp);
break;
#ifdef __powerpc64__
case 8:
*valp = byterev_8(*valp);
break;
#endif
}
}
/*
* Emulate instructions that cause a transfer of control,
* loads and stores, and a few other instructions.
* Returns 1 if the step was emulated, 0 if not,
* or -1 if the instruction is one that should not be stepped,
* such as an rfid, or a mtmsrd that would clear MSR_RI.
*/
int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
{
struct instruction_op op;
int r, err, size;
unsigned long val;
unsigned int cr;
int i, rd, nb;
r = analyse_instr(&op, regs, instr);
if (r != 0)
return r;
err = 0;
size = GETSIZE(op.type);
switch (op.type & INSTR_TYPE_MASK) {
case CACHEOP:
if (!address_ok(regs, op.ea, 8))
return 0;
switch (op.type & CACHEOP_MASK) {
case DCBST:
__cacheop_user_asmx(op.ea, err, "dcbst");
break;
case DCBF:
__cacheop_user_asmx(op.ea, err, "dcbf");
break;
case DCBTST:
if (op.reg == 0)
prefetchw((void *) op.ea);
break;
case DCBT:
if (op.reg == 0)
prefetch((void *) op.ea);
break;
case ICBI:
__cacheop_user_asmx(op.ea, err, "icbi");
break;
}
if (err)
return 0;
goto instr_done;
case LARX:
if (regs->msr & MSR_LE)
return 0;
if (op.ea & (size - 1))
break; /* can't handle misaligned */
err = -EFAULT;
if (!address_ok(regs, op.ea, size))
goto ldst_done;
err = 0;
switch (size) {
case 4:
__get_user_asmx(val, op.ea, err, "lwarx");
break;
case 8:
__get_user_asmx(val, op.ea, err, "ldarx");
break;
default:
return 0;
}
if (!err)
regs->gpr[op.reg] = val;
goto ldst_done;
case STCX:
if (regs->msr & MSR_LE)
return 0;
if (op.ea & (size - 1))
break; /* can't handle misaligned */
err = -EFAULT;
if (!address_ok(regs, op.ea, size))
goto ldst_done;
err = 0;
switch (size) {
case 4:
__put_user_asmx(op.val, op.ea, err, "stwcx.", cr);
break;
case 8:
__put_user_asmx(op.val, op.ea, err, "stdcx.", cr);
break;
default:
return 0;
}
if (!err)
regs->ccr = (regs->ccr & 0x0fffffff) |
(cr & 0xe0000000) |
((regs->xer >> 3) & 0x10000000);
goto ldst_done;
case LOAD:
if (regs->msr & MSR_LE)
return 0;
err = read_mem(®s->gpr[op.reg], op.ea, size, regs);
if (!err) {
if (op.type & SIGNEXT)
do_signext(®s->gpr[op.reg], size);
if (op.type & BYTEREV)
do_byterev(®s->gpr[op.reg], size);
}
goto ldst_done;
#ifdef CONFIG_PPC_FPU
case LOAD_FP:
if (regs->msr & MSR_LE)
return 0;
if (size == 4)
err = do_fp_load(op.reg, do_lfs, op.ea, size, regs);
else
err = do_fp_load(op.reg, do_lfd, op.ea, size, regs);
goto ldst_done;
#endif
#ifdef CONFIG_ALTIVEC
case LOAD_VMX:
if (regs->msr & MSR_LE)
return 0;
err = do_vec_load(op.reg, do_lvx, op.ea & ~0xfUL, regs);
goto ldst_done;
#endif
#ifdef CONFIG_VSX
case LOAD_VSX:
if (regs->msr & MSR_LE)
return 0;
err = do_vsx_load(op.reg, do_lxvd2x, op.ea, regs);
goto ldst_done;
#endif
case LOAD_MULTI:
if (regs->msr & MSR_LE)
return 0;
rd = op.reg;
for (i = 0; i < size; i += 4) {
nb = size - i;
if (nb > 4)
nb = 4;
err = read_mem(®s->gpr[rd], op.ea, nb, regs);
if (err)
return 0;
if (nb < 4) /* left-justify last bytes */
regs->gpr[rd] <<= 32 - 8 * nb;
op.ea += 4;
++rd;
}
goto instr_done;
case STORE:
if (regs->msr & MSR_LE)
return 0;
if ((op.type & UPDATE) && size == sizeof(long) &&
op.reg == 1 && op.update_reg == 1 &&
!(regs->msr & MSR_PR) &&
op.ea >= regs->gpr[1] - STACK_INT_FRAME_SIZE) {
err = handle_stack_update(op.ea, regs);
goto ldst_done;
}
err = write_mem(op.val, op.ea, size, regs);
goto ldst_done;
#ifdef CONFIG_PPC_FPU
case STORE_FP:
if (regs->msr & MSR_LE)
return 0;
if (size == 4)
err = do_fp_store(op.reg, do_stfs, op.ea, size, regs);
else
err = do_fp_store(op.reg, do_stfd, op.ea, size, regs);
goto ldst_done;
#endif
#ifdef CONFIG_ALTIVEC
case STORE_VMX:
if (regs->msr & MSR_LE)
return 0;
err = do_vec_store(op.reg, do_stvx, op.ea & ~0xfUL, regs);
goto ldst_done;
#endif
#ifdef CONFIG_VSX
case STORE_VSX:
if (regs->msr & MSR_LE)
return 0;
err = do_vsx_store(op.reg, do_stxvd2x, op.ea, regs);
goto ldst_done;
#endif
case STORE_MULTI:
if (regs->msr & MSR_LE)
return 0;
rd = op.reg;
for (i = 0; i < size; i += 4) {
val = regs->gpr[rd];
nb = size - i;
if (nb > 4)
nb = 4;
else
val >>= 32 - 8 * nb;
err = write_mem(val, op.ea, nb, regs);
if (err)
return 0;
op.ea += 4;
++rd;
}
goto instr_done;
case MFMSR:
regs->gpr[op.reg] = regs->msr & MSR_MASK;
goto instr_done;
case MTMSR:
val = regs->gpr[op.reg];
if ((val & MSR_RI) == 0)
/* can't step mtmsr[d] that would clear MSR_RI */
return -1;
/* here op.val is the mask of bits to change */
regs->msr = (regs->msr & ~op.val) | (val & op.val);
goto instr_done;
#ifdef CONFIG_PPC64
case SYSCALL: /* sc */
/*
* N.B. this uses knowledge about how the syscall
* entry code works. If that is changed, this will
* need to be changed also.
*/
if (regs->gpr[0] == 0x1ebe &&
cpu_has_feature(CPU_FTR_REAL_LE)) {
regs->msr ^= MSR_LE;
goto instr_done;
}
regs->gpr[9] = regs->gpr[13];
regs->gpr[10] = MSR_KERNEL;
regs->gpr[11] = regs->nip + 4;
regs->gpr[12] = regs->msr & MSR_MASK;
regs->gpr[13] = (unsigned long) get_paca();
regs->nip = (unsigned long) &system_call_common;
regs->msr = MSR_KERNEL;
return 1;
case RFI:
return -1;
#endif
}
return 0;
ldst_done:
if (err)
return 0;
if (op.type & UPDATE)
regs->gpr[op.update_reg] = op.ea;
instr_done:
regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
return 1;
}