From 3cdfcbfd32b9d1c0d4a6fa80ee9c390927aab948 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 30 Aug 2017 14:12:25 +1000 Subject: [PATCH] powerpc: Change analyse_instr so it doesn't modify *regs The analyse_instr function currently doesn't just work out what an instruction does, it also executes those instructions whose effect is only to update CPU registers that are stored in struct pt_regs. This is undesirable because optprobes uses analyse_instr to work out if an instruction could be successfully emulated in future. This changes analyse_instr so it doesn't modify *regs; instead it stores information in the instruction_op structure to indicate what registers (GPRs, CR, XER, LR) would be set and what value they would be set to. A companion function called emulate_update_regs() can then use that information to update a pt_regs struct appropriately. As a minor cleanup, this replaces inline asm using the cntlzw and cntlzd instructions with calls to __builtin_clz() and __builtin_clzl(). Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/sstep.h | 52 ++- arch/powerpc/lib/sstep.c | 601 ++++++++++++++++++------------- 2 files changed, 396 insertions(+), 257 deletions(-) diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h index d3a42cc45a82..442e6363eb5a 100644 --- a/arch/powerpc/include/asm/sstep.h +++ b/arch/powerpc/include/asm/sstep.h @@ -23,9 +23,6 @@ struct pt_regs; #define IS_RFID(instr) (((instr) & 0xfc0007fe) == 0x4c000024) #define IS_RFI(instr) (((instr) & 0xfc0007fe) == 0x4c000064) -/* Emulate instructions that cause a transfer of control. */ -extern int emulate_step(struct pt_regs *regs, unsigned int instr); - enum instruction_type { COMPUTE, /* arith/logical/CR op, etc. */ LOAD, @@ -55,11 +52,29 @@ enum instruction_type { #define INSTR_TYPE_MASK 0x1f +/* Compute flags, ORed in with type */ +#define SETREG 0x20 +#define SETCC 0x40 +#define SETXER 0x80 + +/* Branch flags, ORed in with type */ +#define SETLK 0x20 +#define BRTAKEN 0x40 +#define DECCTR 0x80 + /* Load/store flags, ORed in with type */ #define SIGNEXT 0x20 #define UPDATE 0x40 /* matches bit in opcode 31 instructions */ #define BYTEREV 0x80 +/* Barrier type field, ORed in with type */ +#define BARRIER_MASK 0xe0 +#define BARRIER_SYNC 0x00 +#define BARRIER_ISYNC 0x20 +#define BARRIER_EIEIO 0x40 +#define BARRIER_LWSYNC 0x60 +#define BARRIER_PTESYNC 0x80 + /* Cacheop values, ORed in with type */ #define CACHEOP_MASK 0x700 #define DCBST 0 @@ -83,7 +98,36 @@ struct instruction_op { int update_reg; /* For MFSPR */ int spr; + u32 ccval; + u32 xerval; }; -extern int analyse_instr(struct instruction_op *op, struct pt_regs *regs, +/* + * Decode an instruction, and return information about it in *op + * without changing *regs. + * + * Return value is 1 if the instruction can be emulated just by + * updating *regs with the information in *op, -1 if we need the + * GPRs but *regs doesn't contain the full register set, or 0 + * otherwise. + */ +extern int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, unsigned int instr); + +/* + * Emulate an instruction that can be executed just by updating + * fields in *regs. + */ +void emulate_update_regs(struct pt_regs *reg, struct instruction_op *op); + +/* + * Emulate instructions that cause a transfer of control, + * arithmetic/logical instructions, loads and stores, + * cache operations and barriers. + * + * Returns 1 if the instruction was emulated successfully, + * 0 if it could not be emulated, or -1 for an instruction that + * should not be emulated (rfid, mtmsrd clearing MSR_RI, etc.). + */ +extern int emulate_step(struct pt_regs *regs, unsigned int instr); + diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index a85b82c0e3f3..e190b8dc11a2 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -62,15 +62,17 @@ static nokprobe_inline unsigned long truncate_if_32bit(unsigned long msr, /* * Determine whether a conditional branch instruction would branch. */ -static nokprobe_inline int branch_taken(unsigned int instr, struct pt_regs *regs) +static nokprobe_inline int branch_taken(unsigned int instr, + const struct pt_regs *regs, + struct instruction_op *op) { unsigned int bo = (instr >> 21) & 0x1f; unsigned int bi; if ((bo & 4) == 0) { /* decrement counter */ - --regs->ctr; - if (((bo >> 1) & 1) ^ (regs->ctr == 0)) + op->type |= DECCTR; + if (((bo >> 1) & 1) ^ (regs->ctr == 1)) return 0; } if ((bo & 0x10) == 0) { @@ -92,7 +94,8 @@ static nokprobe_inline long address_ok(struct pt_regs *regs, unsigned long ea, i /* * Calculate effective address for a D-form instruction */ -static nokprobe_inline unsigned long dform_ea(unsigned int instr, struct pt_regs *regs) +static nokprobe_inline unsigned long dform_ea(unsigned int instr, + const struct pt_regs *regs) { int ra; unsigned long ea; @@ -109,7 +112,8 @@ static nokprobe_inline unsigned long dform_ea(unsigned int instr, struct pt_regs /* * Calculate effective address for a DS-form instruction */ -static nokprobe_inline unsigned long dsform_ea(unsigned int instr, struct pt_regs *regs) +static nokprobe_inline unsigned long dsform_ea(unsigned int instr, + const struct pt_regs *regs) { int ra; unsigned long ea; @@ -127,7 +131,7 @@ static nokprobe_inline unsigned long dsform_ea(unsigned int instr, struct pt_reg * Calculate effective address for an X-form instruction */ static nokprobe_inline unsigned long xform_ea(unsigned int instr, - struct pt_regs *regs) + const struct pt_regs *regs) { int ra, rb; unsigned long ea; @@ -526,24 +530,27 @@ static nokprobe_inline int do_vsx_store(int rn, int (*func)(int, unsigned long), : "=r" (err) \ : "r" (addr), "i" (-EFAULT), "0" (err)) -static nokprobe_inline void set_cr0(struct pt_regs *regs, int rd) +static nokprobe_inline void set_cr0(const struct pt_regs *regs, + struct instruction_op *op, int rd) { long val = regs->gpr[rd]; - regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000); + op->type |= SETCC; + op->ccval = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000); #ifdef __powerpc64__ if (!(regs->msr & MSR_64BIT)) val = (int) val; #endif if (val < 0) - regs->ccr |= 0x80000000; + op->ccval |= 0x80000000; else if (val > 0) - regs->ccr |= 0x40000000; + op->ccval |= 0x40000000; else - regs->ccr |= 0x20000000; + op->ccval |= 0x20000000; } -static nokprobe_inline void add_with_carry(struct pt_regs *regs, int rd, +static nokprobe_inline void add_with_carry(const struct pt_regs *regs, + struct instruction_op *op, int rd, unsigned long val1, unsigned long val2, unsigned long carry_in) { @@ -551,24 +558,29 @@ static nokprobe_inline void add_with_carry(struct pt_regs *regs, int rd, if (carry_in) ++val; - regs->gpr[rd] = val; + op->type = COMPUTE + SETREG + SETXER; + op->reg = rd; + op->val = val; #ifdef __powerpc64__ if (!(regs->msr & MSR_64BIT)) { val = (unsigned int) val; val1 = (unsigned int) val1; } #endif + op->xerval = regs->xer; if (val < val1 || (carry_in && val == val1)) - regs->xer |= XER_CA; + op->xerval |= XER_CA; else - regs->xer &= ~XER_CA; + op->xerval &= ~XER_CA; } -static nokprobe_inline void do_cmp_signed(struct pt_regs *regs, long v1, long v2, - int crfld) +static nokprobe_inline void do_cmp_signed(const struct pt_regs *regs, + struct instruction_op *op, + long v1, long v2, int crfld) { unsigned int crval, shift; + op->type = COMPUTE + SETCC; crval = (regs->xer >> 31) & 1; /* get SO bit */ if (v1 < v2) crval |= 8; @@ -577,14 +589,17 @@ static nokprobe_inline void do_cmp_signed(struct pt_regs *regs, long v1, long v2 else crval |= 2; shift = (7 - crfld) * 4; - regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift); + op->ccval = (regs->ccr & ~(0xf << shift)) | (crval << shift); } -static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long v1, - unsigned long v2, int crfld) +static nokprobe_inline void do_cmp_unsigned(const struct pt_regs *regs, + struct instruction_op *op, + unsigned long v1, + unsigned long v2, int crfld) { unsigned int crval, shift; + op->type = COMPUTE + SETCC; crval = (regs->xer >> 31) & 1; /* get SO bit */ if (v1 < v2) crval |= 8; @@ -593,11 +608,12 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long else crval |= 2; shift = (7 - crfld) * 4; - regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift); + op->ccval = (regs->ccr & ~(0xf << shift)) | (crval << shift); } -static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1, - unsigned long v2, int rd) +static nokprobe_inline void do_cmpb(const struct pt_regs *regs, + struct instruction_op *op, + unsigned long v1, unsigned long v2) { unsigned long long out_val, mask; int i; @@ -608,16 +624,16 @@ static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1, if ((v1 & mask) == (v2 & mask)) out_val |= mask; } - - regs->gpr[rd] = out_val; + op->val = out_val; } /* * The size parameter is used to adjust the equivalent popcnt instruction. * popcntb = 8, popcntw = 32, popcntd = 64 */ -static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1, - int size, int ra) +static nokprobe_inline void do_popcnt(const struct pt_regs *regs, + struct instruction_op *op, + unsigned long v1, int size) { unsigned long long out = v1; @@ -626,23 +642,24 @@ static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1, out = (out + (out >> 4)) & 0x0f0f0f0f0f0f0f0f; if (size == 8) { /* popcntb */ - regs->gpr[ra] = out; + op->val = out; return; } out += out >> 8; out += out >> 16; if (size == 32) { /* popcntw */ - regs->gpr[ra] = out & 0x0000003f0000003f; + op->val = out & 0x0000003f0000003f; return; } out = (out + (out >> 32)) & 0x7f; - regs->gpr[ra] = out; /* popcntd */ + op->val = out; /* popcntd */ } #ifdef CONFIG_PPC64 -static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1, - unsigned long v2, int ra) +static nokprobe_inline void do_bpermd(const struct pt_regs *regs, + struct instruction_op *op, + unsigned long v1, unsigned long v2) { unsigned char perm, idx; unsigned int i; @@ -654,26 +671,27 @@ static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1, if (v2 & PPC_BIT(idx)) perm |= 1 << i; } - regs->gpr[ra] = perm; + op->val = perm; } #endif /* CONFIG_PPC64 */ /* * The size parameter adjusts the equivalent prty instruction. * prtyw = 32, prtyd = 64 */ -static nokprobe_inline void do_prty(struct pt_regs *regs, unsigned long v, - int size, int ra) +static nokprobe_inline void do_prty(const struct pt_regs *regs, + struct instruction_op *op, + unsigned long v, int size) { unsigned long long res = v ^ (v >> 8); res ^= res >> 16; if (size == 32) { /* prtyw */ - regs->gpr[ra] = res & 0x0000000100000001; + op->val = res & 0x0000000100000001; return; } res ^= res >> 32; - regs->gpr[ra] = res & 1; /*prtyd */ + op->val = res & 1; /*prtyd */ } static nokprobe_inline int trap_compare(long v1, long v2) @@ -709,14 +727,18 @@ static nokprobe_inline int trap_compare(long v1, long v2) #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. + * Decode an instruction, and return information about it in *op + * without changing *regs. + * Integer arithmetic and logical instructions, branches, and barrier + * instructions can be emulated just using the information in *op. + * + * Return value is 1 if the instruction can be emulated just by + * updating *regs with the information in *op, -1 if we need the + * GPRs but *regs doesn't contain the full register set, or 0 + * otherwise. */ -int analyse_instr(struct instruction_op *op, struct pt_regs *regs, - unsigned int instr) +int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, + unsigned int instr) { unsigned int opcode, ra, rb, rd, spr, u; unsigned long int imm; @@ -733,12 +755,11 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, imm = (signed short)(instr & 0xfffc); if ((instr & 2) == 0) imm += regs->nip; - regs->nip += 4; - regs->nip = truncate_if_32bit(regs->msr, regs->nip); + op->val = truncate_if_32bit(regs->msr, imm); if (instr & 1) - regs->link = regs->nip; - if (branch_taken(instr, regs)) - regs->nip = truncate_if_32bit(regs->msr, imm); + op->type |= SETLK; + if (branch_taken(instr, regs, op)) + op->type |= BRTAKEN; return 1; #ifdef CONFIG_PPC64 case 17: /* sc */ @@ -749,38 +770,37 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, return 0; #endif case 18: /* b */ - op->type = BRANCH; + op->type = BRANCH | BRTAKEN; imm = instr & 0x03fffffc; if (imm & 0x02000000) imm -= 0x04000000; if ((instr & 2) == 0) imm += regs->nip; + op->val = truncate_if_32bit(regs->msr, imm); if (instr & 1) - regs->link = truncate_if_32bit(regs->msr, regs->nip + 4); - imm = truncate_if_32bit(regs->msr, imm); - regs->nip = imm; + op->type |= SETLK; return 1; case 19: switch ((instr >> 1) & 0x3ff) { case 0: /* mcrf */ + op->type = COMPUTE + SETCC; rd = 7 - ((instr >> 23) & 0x7); ra = 7 - ((instr >> 18) & 0x7); rd *= 4; ra *= 4; val = (regs->ccr >> ra) & 0xf; - regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd); - goto instr_done; + op->ccval = (regs->ccr & ~(0xfUL << rd)) | (val << rd); + return 1; 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); + op->val = truncate_if_32bit(regs->msr, imm); if (instr & 1) - regs->link = regs->nip; - if (branch_taken(instr, regs)) - regs->nip = imm; + op->type |= SETLK; + if (branch_taken(instr, regs, op)) + op->type |= BRTAKEN; return 1; case 18: /* rfid, scary */ @@ -790,9 +810,8 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, return 0; case 150: /* isync */ - op->type = BARRIER; - isync(); - goto instr_done; + op->type = BARRIER | BARRIER_ISYNC; + return 1; case 33: /* crnor */ case 129: /* crandc */ @@ -802,45 +821,47 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, case 289: /* creqv */ case 417: /* crorc */ case 449: /* cror */ + op->type = COMPUTE + SETCC; 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))) | + op->ccval = (regs->ccr & ~(1UL << (31 - rd))) | (val << (31 - rd)); - goto instr_done; + return 1; + default: + op->type = UNKNOWN; + return 0; } break; case 31: switch ((instr >> 1) & 0x3ff) { case 598: /* sync */ - op->type = BARRIER; + op->type = BARRIER + BARRIER_SYNC; #ifdef __powerpc64__ switch ((instr >> 21) & 3) { case 1: /* lwsync */ - asm volatile("lwsync" : : : "memory"); - goto instr_done; + op->type = BARRIER + BARRIER_LWSYNC; + break; case 2: /* ptesync */ - asm volatile("ptesync" : : : "memory"); - goto instr_done; + op->type = BARRIER + BARRIER_PTESYNC; + break; } #endif - mb(); - goto instr_done; + return 1; case 854: /* eieio */ - op->type = BARRIER; - eieio(); - goto instr_done; + op->type = BARRIER + BARRIER_EIEIO; + return 1; } break; } /* Following cases refer to regs->gpr[], so we need all regs */ if (!FULL_REGS(regs)) - return 0; + return -1; rd = (instr >> 21) & 0x1f; ra = (instr >> 16) & 0x1f; @@ -851,21 +872,21 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, case 2: /* tdi */ if (rd & trap_compare(regs->gpr[ra], (short) instr)) goto trap; - goto instr_done; + return 1; #endif case 3: /* twi */ if (rd & trap_compare((int)regs->gpr[ra], (short) instr)) goto trap; - goto instr_done; + return 1; case 7: /* mulli */ - regs->gpr[rd] = regs->gpr[ra] * (short) instr; - goto instr_done; + op->val = regs->gpr[ra] * (short) instr; + goto compute_done; case 8: /* subfic */ imm = (short) instr; - add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1); - goto instr_done; + add_with_carry(regs, op, rd, ~regs->gpr[ra], imm, 1); + return 1; case 10: /* cmpli */ imm = (unsigned short) instr; @@ -874,8 +895,8 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, if ((rd & 1) == 0) val = (unsigned int) val; #endif - do_cmp_unsigned(regs, val, imm, rd >> 2); - goto instr_done; + do_cmp_unsigned(regs, op, val, imm, rd >> 2); + return 1; case 11: /* cmpi */ imm = (short) instr; @@ -884,47 +905,47 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, if ((rd & 1) == 0) val = (int) val; #endif - do_cmp_signed(regs, val, imm, rd >> 2); - goto instr_done; + do_cmp_signed(regs, op, val, imm, rd >> 2); + return 1; case 12: /* addic */ imm = (short) instr; - add_with_carry(regs, rd, regs->gpr[ra], imm, 0); - goto instr_done; + add_with_carry(regs, op, rd, regs->gpr[ra], imm, 0); + return 1; case 13: /* addic. */ imm = (short) instr; - add_with_carry(regs, rd, regs->gpr[ra], imm, 0); - set_cr0(regs, rd); - goto instr_done; + add_with_carry(regs, op, rd, regs->gpr[ra], imm, 0); + set_cr0(regs, op, rd); + return 1; case 14: /* addi */ imm = (short) instr; if (ra) imm += regs->gpr[ra]; - regs->gpr[rd] = imm; - goto instr_done; + op->val = imm; + goto compute_done; case 15: /* addis */ imm = ((short) instr) << 16; if (ra) imm += regs->gpr[ra]; - regs->gpr[rd] = imm; - goto instr_done; + op->val = imm; + goto compute_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); + op->val = (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); + op->val = ROTATE(val, rb) & MASK32(mb, me); goto logical_done; case 23: /* rlwnm */ @@ -932,40 +953,37 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, me = (instr >> 1) & 0x1f; rb = regs->gpr[rb] & 0x1f; val = DATA32(regs->gpr[rd]); - regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me); + op->val = 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; + op->val = regs->gpr[rd] | (unsigned short) instr; + goto logical_done_nocc; case 25: /* oris */ imm = (unsigned short) instr; - regs->gpr[ra] = regs->gpr[rd] | (imm << 16); - goto instr_done; + op->val = regs->gpr[rd] | (imm << 16); + goto logical_done_nocc; case 26: /* xori */ - imm = (unsigned short) instr; - regs->gpr[ra] = regs->gpr[rd] ^ imm; - goto instr_done; + op->val = regs->gpr[rd] ^ (unsigned short) instr; + goto logical_done_nocc; case 27: /* xoris */ imm = (unsigned short) instr; - regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16); - goto instr_done; + op->val = regs->gpr[rd] ^ (imm << 16); + goto logical_done_nocc; case 28: /* andi. */ - imm = (unsigned short) instr; - regs->gpr[ra] = regs->gpr[rd] & imm; - set_cr0(regs, ra); - goto instr_done; + op->val = regs->gpr[rd] & (unsigned short) instr; + set_cr0(regs, op, ra); + goto logical_done_nocc; case 29: /* andis. */ imm = (unsigned short) instr; - regs->gpr[ra] = regs->gpr[rd] & (imm << 16); - set_cr0(regs, ra); - goto instr_done; + op->val = regs->gpr[rd] & (imm << 16); + set_cr0(regs, op, ra); + goto logical_done_nocc; #ifdef __powerpc64__ case 30: /* rld* */ @@ -976,34 +994,36 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, val = ROTATE(val, sh); switch ((instr >> 2) & 3) { case 0: /* rldicl */ - regs->gpr[ra] = val & MASK64_L(mb); - goto logical_done; + val &= MASK64_L(mb); + break; case 1: /* rldicr */ - regs->gpr[ra] = val & MASK64_R(mb); - goto logical_done; + val &= MASK64_R(mb); + break; case 2: /* rldic */ - regs->gpr[ra] = val & MASK64(mb, 63 - sh); - goto logical_done; + val &= MASK64(mb, 63 - sh); + break; case 3: /* rldimi */ imm = MASK64(mb, 63 - sh); - regs->gpr[ra] = (regs->gpr[ra] & ~imm) | + val = (regs->gpr[ra] & ~imm) | (val & imm); - goto logical_done; } + op->val = val; + 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); + op->val = val & MASK64_L(mb); goto logical_done; case 1: /* rldcr */ - regs->gpr[ra] = val & MASK64_R(mb); + op->val = val & MASK64_R(mb); goto logical_done; } } #endif - break; /* illegal instruction */ + op->type = UNKNOWN; /* illegal instruction */ + return 0; case 31: switch ((instr >> 1) & 0x3ff) { @@ -1012,12 +1032,12 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, (rd & trap_compare((int)regs->gpr[ra], (int)regs->gpr[rb]))) goto trap; - goto instr_done; + return 1; #ifdef __powerpc64__ case 68: /* td */ if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb])) goto trap; - goto instr_done; + return 1; #endif case 83: /* mfmsr */ if (regs->msr & MSR_PR) @@ -1046,74 +1066,50 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, #endif case 19: /* mfcr */ + imm = 0xffffffffUL; if ((instr >> 20) & 1) { imm = 0xf0000000UL; for (sh = 0; sh < 8; ++sh) { - if (instr & (0x80000 >> sh)) { - regs->gpr[rd] = regs->ccr & imm; + if (instr & (0x80000 >> sh)) break; - } imm >>= 4; } - - goto instr_done; } - - regs->gpr[rd] = regs->ccr; - regs->gpr[rd] &= 0xffffffffUL; - goto instr_done; + op->val = regs->ccr & imm; + goto compute_done; case 144: /* mtcrf */ + op->type = COMPUTE + SETCC; imm = 0xf0000000UL; val = regs->gpr[rd]; + op->val = regs->ccr; for (sh = 0; sh < 8; ++sh) { if (instr & (0x80000 >> sh)) - regs->ccr = (regs->ccr & ~imm) | + op->val = (op->val & ~imm) | (val & imm); imm >>= 4; } - goto instr_done; + return 1; 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; + op->type = MFSPR; + op->reg = rd; + op->spr = spr; + if (spr == SPRN_XER || spr == SPRN_LR || + spr == SPRN_CTR) + return 1; + return 0; 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; + op->type = MTSPR; + op->val = regs->gpr[rd]; + op->spr = spr; + if (spr == SPRN_XER || spr == SPRN_LR || + spr == SPRN_CTR) + return 1; + return 0; /* * Compare instructions @@ -1128,8 +1124,8 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, val2 = (int) val2; } #endif - do_cmp_signed(regs, val, val2, rd >> 2); - goto instr_done; + do_cmp_signed(regs, op, val, val2, rd >> 2); + return 1; case 32: /* cmpl */ val = regs->gpr[ra]; @@ -1141,113 +1137,113 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, val2 = (unsigned int) val2; } #endif - do_cmp_unsigned(regs, val, val2, rd >> 2); - goto instr_done; + do_cmp_unsigned(regs, op, val, val2, rd >> 2); + return 1; case 508: /* cmpb */ - do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra); - goto instr_done; + do_cmpb(regs, op, regs->gpr[rd], regs->gpr[rb]); + goto logical_done_nocc; /* * Arithmetic instructions */ case 8: /* subfc */ - add_with_carry(regs, rd, ~regs->gpr[ra], + add_with_carry(regs, op, 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]) : + asm("mulhdu %0,%1,%2" : "=r" (op->val) : "r" (regs->gpr[ra]), "r" (regs->gpr[rb])); goto arith_done; #endif case 10: /* addc */ - add_with_carry(regs, rd, regs->gpr[ra], + add_with_carry(regs, op, rd, regs->gpr[ra], regs->gpr[rb], 0); goto arith_done; case 11: /* mulhwu */ - asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) : + asm("mulhwu %0,%1,%2" : "=r" (op->val) : "r" (regs->gpr[ra]), "r" (regs->gpr[rb])); goto arith_done; case 40: /* subf */ - regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra]; + op->val = regs->gpr[rb] - regs->gpr[ra]; goto arith_done; #ifdef __powerpc64__ case 73: /* mulhd */ - asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) : + asm("mulhd %0,%1,%2" : "=r" (op->val) : "r" (regs->gpr[ra]), "r" (regs->gpr[rb])); goto arith_done; #endif case 75: /* mulhw */ - asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) : + asm("mulhw %0,%1,%2" : "=r" (op->val) : "r" (regs->gpr[ra]), "r" (regs->gpr[rb])); goto arith_done; case 104: /* neg */ - regs->gpr[rd] = -regs->gpr[ra]; + op->val = -regs->gpr[ra]; goto arith_done; case 136: /* subfe */ - add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb], - regs->xer & XER_CA); + add_with_carry(regs, op, 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); + add_with_carry(regs, op, 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, + add_with_carry(regs, op, rd, ~regs->gpr[ra], 0L, regs->xer & XER_CA); goto arith_done; case 202: /* addze */ - add_with_carry(regs, rd, regs->gpr[ra], 0L, + add_with_carry(regs, op, rd, regs->gpr[ra], 0L, regs->xer & XER_CA); goto arith_done; case 232: /* subfme */ - add_with_carry(regs, rd, ~regs->gpr[ra], -1L, + add_with_carry(regs, op, 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]; + op->val = regs->gpr[ra] * regs->gpr[rb]; goto arith_done; #endif case 234: /* addme */ - add_with_carry(regs, rd, regs->gpr[ra], -1L, + add_with_carry(regs, op, rd, regs->gpr[ra], -1L, regs->xer & XER_CA); goto arith_done; case 235: /* mullw */ - regs->gpr[rd] = (unsigned int) regs->gpr[ra] * + op->val = (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]; + op->val = regs->gpr[ra] + regs->gpr[rb]; goto arith_done; #ifdef __powerpc64__ case 457: /* divdu */ - regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb]; + op->val = regs->gpr[ra] / regs->gpr[rb]; goto arith_done; #endif case 459: /* divwu */ - regs->gpr[rd] = (unsigned int) regs->gpr[ra] / + op->val = (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] / + op->val = (long int) regs->gpr[ra] / (long int) regs->gpr[rb]; goto arith_done; #endif case 491: /* divw */ - regs->gpr[rd] = (int) regs->gpr[ra] / + op->val = (int) regs->gpr[ra] / (int) regs->gpr[rb]; goto arith_done; @@ -1260,85 +1256,83 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, val = (regs->ccr >> (31 - mb)) & 1; val2 = (ra) ? regs->gpr[ra] : 0; - regs->gpr[rd] = (val) ? val2 : regs->gpr[rb]; - goto logical_done; + op->val = (val) ? val2 : regs->gpr[rb]; + goto compute_done; case 26: /* cntlzw */ - asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) : - "r" (regs->gpr[rd])); + op->val = __builtin_clz((unsigned int) regs->gpr[rd]); goto logical_done; #ifdef __powerpc64__ case 58: /* cntlzd */ - asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) : - "r" (regs->gpr[rd])); + op->val = __builtin_clzl(regs->gpr[rd]); goto logical_done; #endif case 28: /* and */ - regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb]; + op->val = regs->gpr[rd] & regs->gpr[rb]; goto logical_done; case 60: /* andc */ - regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb]; + op->val = regs->gpr[rd] & ~regs->gpr[rb]; goto logical_done; case 122: /* popcntb */ - do_popcnt(regs, regs->gpr[rd], 8, ra); + do_popcnt(regs, op, regs->gpr[rd], 8); goto logical_done; case 124: /* nor */ - regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]); + op->val = ~(regs->gpr[rd] | regs->gpr[rb]); goto logical_done; case 154: /* prtyw */ - do_prty(regs, regs->gpr[rd], 32, ra); + do_prty(regs, op, regs->gpr[rd], 32); goto logical_done; case 186: /* prtyd */ - do_prty(regs, regs->gpr[rd], 64, ra); + do_prty(regs, op, regs->gpr[rd], 64); goto logical_done; #ifdef CONFIG_PPC64 case 252: /* bpermd */ - do_bpermd(regs, regs->gpr[rd], regs->gpr[rb], ra); + do_bpermd(regs, op, regs->gpr[rd], regs->gpr[rb]); goto logical_done; #endif case 284: /* xor */ - regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]); + op->val = ~(regs->gpr[rd] ^ regs->gpr[rb]); goto logical_done; case 316: /* xor */ - regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb]; + op->val = regs->gpr[rd] ^ regs->gpr[rb]; goto logical_done; case 378: /* popcntw */ - do_popcnt(regs, regs->gpr[rd], 32, ra); + do_popcnt(regs, op, regs->gpr[rd], 32); goto logical_done; case 412: /* orc */ - regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb]; + op->val = regs->gpr[rd] | ~regs->gpr[rb]; goto logical_done; case 444: /* or */ - regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb]; + op->val = regs->gpr[rd] | regs->gpr[rb]; goto logical_done; case 476: /* nand */ - regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]); + op->val = ~(regs->gpr[rd] & regs->gpr[rb]); goto logical_done; #ifdef CONFIG_PPC64 case 506: /* popcntd */ - do_popcnt(regs, regs->gpr[rd], 64, ra); + do_popcnt(regs, op, regs->gpr[rd], 64); goto logical_done; #endif case 922: /* extsh */ - regs->gpr[ra] = (signed short) regs->gpr[rd]; + op->val = (signed short) regs->gpr[rd]; goto logical_done; case 954: /* extsb */ - regs->gpr[ra] = (signed char) regs->gpr[rd]; + op->val = (signed char) regs->gpr[rd]; goto logical_done; #ifdef __powerpc64__ case 986: /* extsw */ - regs->gpr[ra] = (signed int) regs->gpr[rd]; + op->val = (signed int) regs->gpr[rd]; goto logical_done; #endif @@ -1348,75 +1342,83 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, case 24: /* slw */ sh = regs->gpr[rb] & 0x3f; if (sh < 32) - regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL; + op->val = (regs->gpr[rd] << sh) & 0xffffffffUL; else - regs->gpr[ra] = 0; + op->val = 0; goto logical_done; case 536: /* srw */ sh = regs->gpr[rb] & 0x3f; if (sh < 32) - regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh; + op->val = (regs->gpr[rd] & 0xffffffffUL) >> sh; else - regs->gpr[ra] = 0; + op->val = 0; goto logical_done; case 792: /* sraw */ + op->type = COMPUTE + SETREG + SETXER; sh = regs->gpr[rb] & 0x3f; ival = (signed int) regs->gpr[rd]; - regs->gpr[ra] = ival >> (sh < 32 ? sh : 31); + op->val = ival >> (sh < 32 ? sh : 31); + op->xerval = regs->xer; if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0)) - regs->xer |= XER_CA; + op->xerval |= XER_CA; else - regs->xer &= ~XER_CA; + op->xerval &= ~XER_CA; goto logical_done; case 824: /* srawi */ + op->type = COMPUTE + SETREG + SETXER; sh = rb; ival = (signed int) regs->gpr[rd]; - regs->gpr[ra] = ival >> sh; + op->val = ival >> sh; + op->xerval = regs->xer; if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0) - regs->xer |= XER_CA; + op->xerval |= XER_CA; else - regs->xer &= ~XER_CA; + op->xerval &= ~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; + op->val = regs->gpr[rd] << sh; else - regs->gpr[ra] = 0; + op->val = 0; goto logical_done; case 539: /* srd */ sh = regs->gpr[rb] & 0x7f; if (sh < 64) - regs->gpr[ra] = regs->gpr[rd] >> sh; + op->val = regs->gpr[rd] >> sh; else - regs->gpr[ra] = 0; + op->val = 0; goto logical_done; case 794: /* srad */ + op->type = COMPUTE + SETREG + SETXER; sh = regs->gpr[rb] & 0x7f; ival = (signed long int) regs->gpr[rd]; - regs->gpr[ra] = ival >> (sh < 64 ? sh : 63); + op->val = ival >> (sh < 64 ? sh : 63); + op->xerval = regs->xer; if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0)) - regs->xer |= XER_CA; + op->xerval |= XER_CA; else - regs->xer &= ~XER_CA; + op->xerval &= ~XER_CA; goto logical_done; case 826: /* sradi with sh_5 = 0 */ case 827: /* sradi with sh_5 = 1 */ + op->type = COMPUTE + SETREG + SETXER; sh = rb | ((instr & 2) << 4); ival = (signed long int) regs->gpr[rd]; - regs->gpr[ra] = ival >> sh; + op->val = ival >> sh; + op->xerval = regs->xer; if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0) - regs->xer |= XER_CA; + op->xerval |= XER_CA; else - regs->xer &= ~XER_CA; + op->xerval &= ~XER_CA; goto logical_done; #endif /* __powerpc64__ */ @@ -1787,15 +1789,18 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, logical_done: if (instr & 1) - set_cr0(regs, ra); - goto instr_done; + set_cr0(regs, op, ra); + logical_done_nocc: + op->reg = ra; + op->type |= SETREG; + return 1; arith_done: if (instr & 1) - set_cr0(regs, rd); - - instr_done: - regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4); + set_cr0(regs, op, rd); + compute_done: + op->reg = rd; + op->type |= SETREG; return 1; priv: @@ -1886,6 +1891,92 @@ static nokprobe_inline void do_byterev(unsigned long *valp, int size) } } +/* + * Emulate an instruction that can be executed just by updating + * fields in *regs. + */ +void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op) +{ + unsigned long next_pc; + + next_pc = truncate_if_32bit(regs->msr, regs->nip + 4); + switch (op->type & INSTR_TYPE_MASK) { + case COMPUTE: + if (op->type & SETREG) + regs->gpr[op->reg] = op->val; + if (op->type & SETCC) + regs->ccr = op->ccval; + if (op->type & SETXER) + regs->xer = op->xerval; + break; + + case BRANCH: + if (op->type & SETLK) + regs->link = next_pc; + if (op->type & BRTAKEN) + next_pc = op->val; + if (op->type & DECCTR) + --regs->ctr; + break; + + case BARRIER: + switch (op->type & BARRIER_MASK) { + case BARRIER_SYNC: + mb(); + break; + case BARRIER_ISYNC: + isync(); + break; + case BARRIER_EIEIO: + eieio(); + break; + case BARRIER_LWSYNC: + asm volatile("lwsync" : : : "memory"); + break; + case BARRIER_PTESYNC: + asm volatile("ptesync" : : : "memory"); + break; + } + break; + + case MFSPR: + switch (op->spr) { + case SPRN_XER: + regs->gpr[op->reg] = regs->xer & 0xffffffffUL; + break; + case SPRN_LR: + regs->gpr[op->reg] = regs->link; + break; + case SPRN_CTR: + regs->gpr[op->reg] = regs->ctr; + break; + default: + WARN_ON_ONCE(1); + } + break; + + case MTSPR: + switch (op->spr) { + case SPRN_XER: + regs->xer = op->val & 0xffffffffUL; + break; + case SPRN_LR: + regs->link = op->val; + break; + case SPRN_CTR: + regs->ctr = op->val; + break; + default: + WARN_ON_ONCE(1); + } + break; + + default: + WARN_ON_ONCE(1); + } + regs->nip = next_pc; +} + /* * Emulate instructions that cause a transfer of control, * loads and stores, and a few other instructions. @@ -1902,8 +1993,12 @@ int emulate_step(struct pt_regs *regs, unsigned int instr) int i, rd, nb; r = analyse_instr(&op, regs, instr); - if (r != 0) + if (r < 0) return r; + if (r > 0) { + emulate_update_regs(regs, &op); + return 1; + } err = 0; size = GETSIZE(op.type); -- 2.20.1