/* * 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]; if (instr & 0x04000000) { /* update forms */ if ((instr>>26) != 47) /* stmw is not an update form */ regs->gpr[ra] = ea; } } 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]; if ((instr & 3) == 1) /* update forms */ regs->gpr[ra] = ea; } 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 do_update) { int ra, rb; unsigned long ea; ra = (instr >> 16) & 0x1f; rb = (instr >> 11) & 0x1f; ea = regs->gpr[rb]; if (ra) { ea += regs->gpr[ra]; if (do_update) /* update forms */ regs->gpr[ra] = ea; } 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); } /* * 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)) /* * 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) { unsigned int opcode, ra, rb, rd, spr, u; unsigned long int imm; unsigned long int val, val2; unsigned long int ea; unsigned int cr, mb, me, sh; int err; unsigned long old_ra, val3; long ival; opcode = instr >> 26; switch (opcode) { case 16: /* bc */ 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 */ /* * 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; #endif case 18: /* b */ 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 16: /* bclr */ case 528: /* bcctr */ 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 */ return -1; case 150: /* isync */ 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 */ #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 */ 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) { 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 83: /* mfmsr */ if (regs->msr & MSR_PR) break; regs->gpr[rd] = regs->msr & MSR_MASK; goto instr_done; case 146: /* mtmsr */ if (regs->msr & MSR_PR) break; imm = regs->gpr[rd]; if ((imm & MSR_RI) == 0) /* can't step mtmsr that would clear MSR_RI */ return -1; regs->msr = imm; goto instr_done; #ifdef CONFIG_PPC64 case 178: /* mtmsrd */ /* only MSR_EE and MSR_RI get changed if bit 15 set */ /* mtmsrd doesn't change MSR_HV and MSR_ME */ if (regs->msr & MSR_PR) break; imm = (instr & 0x10000)? 0x8002: 0xefffffffffffefffUL; imm = (regs->msr & MSR_MASK & ~imm) | (regs->gpr[rd] & imm); if ((imm & MSR_RI) == 0) /* can't step mtmsrd that would clear MSR_RI */ return -1; regs->msr = imm; goto instr_done; #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 >> 11) & 0x3ff; switch (spr) { case 0x20: /* mfxer */ regs->gpr[rd] = regs->xer; regs->gpr[rd] &= 0xffffffffUL; goto instr_done; case 0x100: /* mflr */ regs->gpr[rd] = regs->link; goto instr_done; case 0x120: /* mfctr */ regs->gpr[rd] = regs->ctr; goto instr_done; } break; case 467: /* mtspr */ spr = (instr >> 11) & 0x3ff; switch (spr) { case 0x20: /* mtxer */ regs->xer = (regs->gpr[rd] & 0xffffffffUL); goto instr_done; case 0x100: /* mtlr */ regs->link = regs->gpr[rd]; goto instr_done; case 0x120: /* mtctr */ regs->ctr = regs->gpr[rd]; goto instr_done; } 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 & ((1 << 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 & ((1 << sh) - 1)) != 0) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; goto logical_done; #ifdef __powerpc64__ case 27: /* sld */ sh = regs->gpr[rd] & 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 & ((1 << 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 & ((1 << sh) - 1)) != 0) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; goto logical_done; #endif /* __powerpc64__ */ /* * Cache instructions */ case 54: /* dcbst */ ea = xform_ea(instr, regs, 0); if (!address_ok(regs, ea, 8)) return 0; err = 0; __cacheop_user_asmx(ea, err, "dcbst"); if (err) return 0; goto instr_done; case 86: /* dcbf */ ea = xform_ea(instr, regs, 0); if (!address_ok(regs, ea, 8)) return 0; err = 0; __cacheop_user_asmx(ea, err, "dcbf"); if (err) return 0; goto instr_done; case 246: /* dcbtst */ if (rd == 0) { ea = xform_ea(instr, regs, 0); prefetchw((void *) ea); } goto instr_done; case 278: /* dcbt */ if (rd == 0) { ea = xform_ea(instr, regs, 0); prefetch((void *) ea); } goto instr_done; } break; } /* * Following cases are for loads and stores, so bail out * if we're in little-endian mode. */ if (regs->msr & MSR_LE) return 0; /* * Save register RA in case it's an update form load or store * and the access faults. */ old_ra = regs->gpr[ra]; switch (opcode) { case 31: u = instr & 0x40; switch ((instr >> 1) & 0x3ff) { case 20: /* lwarx */ ea = xform_ea(instr, regs, 0); if (ea & 3) break; /* can't handle misaligned */ err = -EFAULT; if (!address_ok(regs, ea, 4)) goto ldst_done; err = 0; __get_user_asmx(val, ea, err, "lwarx"); if (!err) regs->gpr[rd] = val; goto ldst_done; case 150: /* stwcx. */ ea = xform_ea(instr, regs, 0); if (ea & 3) break; /* can't handle misaligned */ err = -EFAULT; if (!address_ok(regs, ea, 4)) goto ldst_done; err = 0; __put_user_asmx(regs->gpr[rd], ea, err, "stwcx.", cr); if (!err) regs->ccr = (regs->ccr & 0x0fffffff) | (cr & 0xe0000000) | ((regs->xer >> 3) & 0x10000000); goto ldst_done; #ifdef __powerpc64__ case 84: /* ldarx */ ea = xform_ea(instr, regs, 0); if (ea & 7) break; /* can't handle misaligned */ err = -EFAULT; if (!address_ok(regs, ea, 8)) goto ldst_done; err = 0; __get_user_asmx(val, ea, err, "ldarx"); if (!err) regs->gpr[rd] = val; goto ldst_done; case 214: /* stdcx. */ ea = xform_ea(instr, regs, 0); if (ea & 7) break; /* can't handle misaligned */ err = -EFAULT; if (!address_ok(regs, ea, 8)) goto ldst_done; err = 0; __put_user_asmx(regs->gpr[rd], ea, err, "stdcx.", cr); if (!err) regs->ccr = (regs->ccr & 0x0fffffff) | (cr & 0xe0000000) | ((regs->xer >> 3) & 0x10000000); goto ldst_done; case 21: /* ldx */ case 53: /* ldux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 8, regs); goto ldst_done; #endif case 23: /* lwzx */ case 55: /* lwzux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 4, regs); goto ldst_done; case 87: /* lbzx */ case 119: /* lbzux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 1, regs); goto ldst_done; #ifdef CONFIG_ALTIVEC case 103: /* lvx */ case 359: /* lvxl */ if (!(regs->msr & MSR_VEC)) break; ea = xform_ea(instr, regs, 0); err = do_vec_load(rd, do_lvx, ea, regs); goto ldst_done; case 231: /* stvx */ case 487: /* stvxl */ if (!(regs->msr & MSR_VEC)) break; ea = xform_ea(instr, regs, 0); err = do_vec_store(rd, do_stvx, ea, regs); goto ldst_done; #endif /* CONFIG_ALTIVEC */ #ifdef __powerpc64__ case 149: /* stdx */ case 181: /* stdux */ val = regs->gpr[rd]; err = write_mem(val, xform_ea(instr, regs, u), 8, regs); goto ldst_done; #endif case 151: /* stwx */ case 183: /* stwux */ val = regs->gpr[rd]; err = write_mem(val, xform_ea(instr, regs, u), 4, regs); goto ldst_done; case 215: /* stbx */ case 247: /* stbux */ val = regs->gpr[rd]; err = write_mem(val, xform_ea(instr, regs, u), 1, regs); goto ldst_done; case 279: /* lhzx */ case 311: /* lhzux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 2, regs); goto ldst_done; #ifdef __powerpc64__ case 341: /* lwax */ case 373: /* lwaux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 4, regs); if (!err) regs->gpr[rd] = (signed int) regs->gpr[rd]; goto ldst_done; #endif case 343: /* lhax */ case 375: /* lhaux */ err = read_mem(®s->gpr[rd], xform_ea(instr, regs, u), 2, regs); if (!err) regs->gpr[rd] = (signed short) regs->gpr[rd]; goto ldst_done; case 407: /* sthx */ case 439: /* sthux */ val = regs->gpr[rd]; err = write_mem(val, xform_ea(instr, regs, u), 2, regs); goto ldst_done; #ifdef __powerpc64__ case 532: /* ldbrx */ err = read_mem(&val, xform_ea(instr, regs, 0), 8, regs); if (!err) regs->gpr[rd] = byterev_8(val); goto ldst_done; #endif case 534: /* lwbrx */ err = read_mem(&val, xform_ea(instr, regs, 0), 4, regs); if (!err) regs->gpr[rd] = byterev_4(val); goto ldst_done; #ifdef CONFIG_PPC_CPU case 535: /* lfsx */ case 567: /* lfsux */ if (!(regs->msr & MSR_FP)) break; ea = xform_ea(instr, regs, u); err = do_fp_load(rd, do_lfs, ea, 4, regs); goto ldst_done; case 599: /* lfdx */ case 631: /* lfdux */ if (!(regs->msr & MSR_FP)) break; ea = xform_ea(instr, regs, u); err = do_fp_load(rd, do_lfd, ea, 8, regs); goto ldst_done; case 663: /* stfsx */ case 695: /* stfsux */ if (!(regs->msr & MSR_FP)) break; ea = xform_ea(instr, regs, u); err = do_fp_store(rd, do_stfs, ea, 4, regs); goto ldst_done; case 727: /* stfdx */ case 759: /* stfdux */ if (!(regs->msr & MSR_FP)) break; ea = xform_ea(instr, regs, u); err = do_fp_store(rd, do_stfd, ea, 8, regs); goto ldst_done; #endif #ifdef __powerpc64__ case 660: /* stdbrx */ val = byterev_8(regs->gpr[rd]); err = write_mem(val, xform_ea(instr, regs, 0), 8, regs); goto ldst_done; #endif case 662: /* stwbrx */ val = byterev_4(regs->gpr[rd]); err = write_mem(val, xform_ea(instr, regs, 0), 4, regs); goto ldst_done; case 790: /* lhbrx */ err = read_mem(&val, xform_ea(instr, regs, 0), 2, regs); if (!err) regs->gpr[rd] = byterev_2(val); goto ldst_done; case 918: /* sthbrx */ val = byterev_2(regs->gpr[rd]); err = write_mem(val, xform_ea(instr, regs, 0), 2, regs); goto ldst_done; #ifdef CONFIG_VSX case 844: /* lxvd2x */ case 876: /* lxvd2ux */ if (!(regs->msr & MSR_VSX)) break; rd |= (instr & 1) << 5; ea = xform_ea(instr, regs, u); err = do_vsx_load(rd, do_lxvd2x, ea, regs); goto ldst_done; case 972: /* stxvd2x */ case 1004: /* stxvd2ux */ if (!(regs->msr & MSR_VSX)) break; rd |= (instr & 1) << 5; ea = xform_ea(instr, regs, u); err = do_vsx_store(rd, do_stxvd2x, ea, regs); goto ldst_done; #endif /* CONFIG_VSX */ } break; case 32: /* lwz */ case 33: /* lwzu */ err = read_mem(®s->gpr[rd], dform_ea(instr, regs), 4, regs); goto ldst_done; case 34: /* lbz */ case 35: /* lbzu */ err = read_mem(®s->gpr[rd], dform_ea(instr, regs), 1, regs); goto ldst_done; case 36: /* stw */ val = regs->gpr[rd]; err = write_mem(val, dform_ea(instr, regs), 4, regs); goto ldst_done; case 37: /* stwu */ val = regs->gpr[rd]; val3 = dform_ea(instr, regs); /* * For PPC32 we always use stwu to change stack point with r1. 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. */ if ((ra == 1) && !(regs->msr & MSR_PR) \ && (val3 >= (regs->gpr[1] - STACK_INT_FRAME_SIZE))) { #ifdef CONFIG_PPC32 /* * Check if we will touch kernel sack overflow */ if (val3 - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) { printk(KERN_CRIT "Can't kprobe this since Kernel stack overflow.\n"); err = -EINVAL; break; } #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); err = 0; } else err = write_mem(val, val3, 4, regs); goto ldst_done; case 38: /* stb */ case 39: /* stbu */ val = regs->gpr[rd]; err = write_mem(val, dform_ea(instr, regs), 1, regs); goto ldst_done; case 40: /* lhz */ case 41: /* lhzu */ err = read_mem(®s->gpr[rd], dform_ea(instr, regs), 2, regs); goto ldst_done; case 42: /* lha */ case 43: /* lhau */ err = read_mem(®s->gpr[rd], dform_ea(instr, regs), 2, regs); if (!err) regs->gpr[rd] = (signed short) regs->gpr[rd]; goto ldst_done; case 44: /* sth */ case 45: /* sthu */ val = regs->gpr[rd]; err = write_mem(val, dform_ea(instr, regs), 2, regs); goto ldst_done; case 46: /* lmw */ ra = (instr >> 16) & 0x1f; if (ra >= rd) break; /* invalid form, ra in range to load */ ea = dform_ea(instr, regs); do { err = read_mem(®s->gpr[rd], ea, 4, regs); if (err) return 0; ea += 4; } while (++rd < 32); goto instr_done; case 47: /* stmw */ ea = dform_ea(instr, regs); do { err = write_mem(regs->gpr[rd], ea, 4, regs); if (err) return 0; ea += 4; } while (++rd < 32); goto instr_done; #ifdef CONFIG_PPC_FPU case 48: /* lfs */ case 49: /* lfsu */ if (!(regs->msr & MSR_FP)) break; ea = dform_ea(instr, regs); err = do_fp_load(rd, do_lfs, ea, 4, regs); goto ldst_done; case 50: /* lfd */ case 51: /* lfdu */ if (!(regs->msr & MSR_FP)) break; ea = dform_ea(instr, regs); err = do_fp_load(rd, do_lfd, ea, 8, regs); goto ldst_done; case 52: /* stfs */ case 53: /* stfsu */ if (!(regs->msr & MSR_FP)) break; ea = dform_ea(instr, regs); err = do_fp_store(rd, do_stfs, ea, 4, regs); goto ldst_done; case 54: /* stfd */ case 55: /* stfdu */ if (!(regs->msr & MSR_FP)) break; ea = dform_ea(instr, regs); err = do_fp_store(rd, do_stfd, ea, 8, regs); goto ldst_done; #endif #ifdef __powerpc64__ case 58: /* ld[u], lwa */ switch (instr & 3) { case 0: /* ld */ err = read_mem(®s->gpr[rd], dsform_ea(instr, regs), 8, regs); goto ldst_done; case 1: /* ldu */ err = read_mem(®s->gpr[rd], dsform_ea(instr, regs), 8, regs); goto ldst_done; case 2: /* lwa */ err = read_mem(®s->gpr[rd], dsform_ea(instr, regs), 4, regs); if (!err) regs->gpr[rd] = (signed int) regs->gpr[rd]; goto ldst_done; } break; case 62: /* std[u] */ val = regs->gpr[rd]; switch (instr & 3) { case 0: /* std */ err = write_mem(val, dsform_ea(instr, regs), 8, regs); goto ldst_done; case 1: /* stdu */ err = write_mem(val, dsform_ea(instr, regs), 8, regs); goto ldst_done; } break; #endif /* __powerpc64__ */ } err = -EINVAL; ldst_done: if (err) { regs->gpr[ra] = old_ra; return 0; /* invoke DSI if -EFAULT? */ } instr_done: regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4); return 1; logical_done: if (instr & 1) set_cr0(regs, ra); goto instr_done; arith_done: if (instr & 1) set_cr0(regs, rd); goto instr_done; }