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author | Jon Medhurst <tixy@yxit.co.uk> | 2011-07-06 10:49:07 +0100 |
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committer | Tixy <tixy@medhuaa1.miniserver.com> | 2011-07-13 17:32:40 +0000 |
commit | 691b2ff294a4787f3e54f5bb541570ac74bcb6f4 (patch) | |
tree | 77f3452cbd7c20f6bf69ab9c8759720740933b5c /arch/arm/kernel/kprobes-arm.c | |
parent | 592201a9f154cdd5db59304d1369e94d8b551803 (diff) | |
download | linux-691b2ff294a4787f3e54f5bb541570ac74bcb6f4.tar.bz2 |
ARM: kprobes: Rename kprobes-decode.c to kprobes-arm.c
This file contains decoding and emulation functions for the ARM
instruction set. As we will later be adding a file for Thumb and a
file with common decoding functions, this renaming makes things clearer.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel/kprobes-arm.c')
-rw-r--r-- | arch/arm/kernel/kprobes-arm.c | 1670 |
1 files changed, 1670 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c new file mode 100644 index 000000000000..15eeff6aea0e --- /dev/null +++ b/arch/arm/kernel/kprobes-arm.c @@ -0,0 +1,1670 @@ +/* + * arch/arm/kernel/kprobes-decode.c + * + * Copyright (C) 2006, 2007 Motorola Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +/* + * We do not have hardware single-stepping on ARM, This + * effort is further complicated by the ARM not having a + * "next PC" register. Instructions that change the PC + * can't be safely single-stepped in a MP environment, so + * we have a lot of work to do: + * + * In the prepare phase: + * *) If it is an instruction that does anything + * with the CPU mode, we reject it for a kprobe. + * (This is out of laziness rather than need. The + * instructions could be simulated.) + * + * *) Otherwise, decode the instruction rewriting its + * registers to take fixed, ordered registers and + * setting a handler for it to run the instruction. + * + * In the execution phase by an instruction's handler: + * + * *) If the PC is written to by the instruction, the + * instruction must be fully simulated in software. + * + * *) Otherwise, a modified form of the instruction is + * directly executed. Its handler calls the + * instruction in insn[0]. In insn[1] is a + * "mov pc, lr" to return. + * + * Before calling, load up the reordered registers + * from the original instruction's registers. If one + * of the original input registers is the PC, compute + * and adjust the appropriate input register. + * + * After call completes, copy the output registers to + * the original instruction's original registers. + * + * We don't use a real breakpoint instruction since that + * would have us in the kernel go from SVC mode to SVC + * mode losing the link register. Instead we use an + * undefined instruction. To simplify processing, the + * undefined instruction used for kprobes must be reserved + * exclusively for kprobes use. + * + * TODO: ifdef out some instruction decoding based on architecture. + */ + +#include <linux/kernel.h> +#include <linux/kprobes.h> + +#define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit))))) + +#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25) + +#define is_r15(insn, bitpos) (((insn) & (0xf << bitpos)) == (0xf << bitpos)) + +/* + * Test if load/store instructions writeback the address register. + * if P (bit 24) == 0 or W (bit 21) == 1 + */ +#define is_writeback(insn) ((insn ^ 0x01000000) & 0x01200000) + +#define PSR_fs (PSR_f|PSR_s) + +#define KPROBE_RETURN_INSTRUCTION 0xe1a0f00e /* mov pc, lr */ + +typedef long (insn_0arg_fn_t)(void); +typedef long (insn_1arg_fn_t)(long); +typedef long (insn_2arg_fn_t)(long, long); +typedef long (insn_3arg_fn_t)(long, long, long); +typedef long (insn_4arg_fn_t)(long, long, long, long); +typedef long long (insn_llret_0arg_fn_t)(void); +typedef long long (insn_llret_3arg_fn_t)(long, long, long); +typedef long long (insn_llret_4arg_fn_t)(long, long, long, long); + +union reg_pair { + long long dr; +#ifdef __LITTLE_ENDIAN + struct { long r0, r1; }; +#else + struct { long r1, r0; }; +#endif +}; + +/* + * For STR and STM instructions, an ARM core may choose to use either + * a +8 or a +12 displacement from the current instruction's address. + * Whichever value is chosen for a given core, it must be the same for + * both instructions and may not change. This function measures it. + */ + +static int str_pc_offset; + +static void __init find_str_pc_offset(void) +{ + int addr, scratch, ret; + + __asm__ ( + "sub %[ret], pc, #4 \n\t" + "str pc, %[addr] \n\t" + "ldr %[scr], %[addr] \n\t" + "sub %[ret], %[scr], %[ret] \n\t" + : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr)); + + str_pc_offset = ret; +} + +/* + * The insnslot_?arg_r[w]flags() functions below are to keep the + * msr -> *fn -> mrs instruction sequences indivisible so that + * the state of the CPSR flags aren't inadvertently modified + * just before or just after the call. + */ + +static inline long __kprobes +insnslot_0arg_rflags(long cpsr, insn_0arg_fn_t *fn) +{ + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long long __kprobes +insnslot_llret_0arg_rflags(long cpsr, insn_llret_0arg_fn_t *fn) +{ + register long ret0 asm("r0"); + register long ret1 asm("r1"); + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret0), "=r" (ret1) + : [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +static inline long __kprobes +insnslot_1arg_rflags(long r0, long cpsr, insn_1arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_2arg_rflags(long r0, long r1, long cpsr, insn_2arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_3arg_rflags(long r0, long r1, long r2, long cpsr, insn_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), "r" (rr2), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long long __kprobes +insnslot_llret_3arg_rflags(long r0, long r1, long r2, long cpsr, + insn_llret_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret0 asm("r0"); + register long ret1 asm("r1"); + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret0), "=r" (ret1) + : "0" (rr0), "r" (rr1), "r" (rr2), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +static inline long __kprobes +insnslot_4arg_rflags(long r0, long r1, long r2, long r3, long cpsr, + insn_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret asm("r0"); + + __asm__ __volatile__ ( + "msr cpsr_fs, %[cpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + : "=r" (ret) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [cpsr] "r" (cpsr), [fn] "r" (fn) + : "lr", "cc" + ); + return ret; +} + +static inline long __kprobes +insnslot_1arg_rwflags(long r0, long *cpsr, insn_1arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_2arg_rwflags(long r0, long r1, long *cpsr, insn_2arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_3arg_rwflags(long r0, long r1, long r2, long *cpsr, + insn_3arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long __kprobes +insnslot_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr, + insn_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret asm("r0"); + long oldcpsr = *cpsr; + long newcpsr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + return ret; +} + +static inline long long __kprobes +insnslot_llret_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr, + insn_llret_4arg_fn_t *fn) +{ + register long rr0 asm("r0") = r0; + register long rr1 asm("r1") = r1; + register long rr2 asm("r2") = r2; + register long rr3 asm("r3") = r3; + register long ret0 asm("r0"); + register long ret1 asm("r1"); + long oldcpsr = *cpsr; + long newcpsr; + union reg_pair fnr; + + __asm__ __volatile__ ( + "msr cpsr_fs, %[oldcpsr] \n\t" + "mov lr, pc \n\t" + "mov pc, %[fn] \n\t" + "mrs %[newcpsr], cpsr \n\t" + : "=r" (ret0), "=r" (ret1), [newcpsr] "=r" (newcpsr) + : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3), + [oldcpsr] "r" (oldcpsr), [fn] "r" (fn) + : "lr", "cc" + ); + *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs); + fnr.r0 = ret0; + fnr.r1 = ret1; + return fnr.dr; +} + +/* + * To avoid the complications of mimicing single-stepping on a + * processor without a Next-PC or a single-step mode, and to + * avoid having to deal with the side-effects of boosting, we + * simulate or emulate (almost) all ARM instructions. + * + * "Simulation" is where the instruction's behavior is duplicated in + * C code. "Emulation" is where the original instruction is rewritten + * and executed, often by altering its registers. + * + * By having all behavior of the kprobe'd instruction completed before + * returning from the kprobe_handler(), all locks (scheduler and + * interrupt) can safely be released. There is no need for secondary + * breakpoints, no race with MP or preemptable kernels, nor having to + * clean up resources counts at a later time impacting overall system + * performance. By rewriting the instruction, only the minimum registers + * need to be loaded and saved back optimizing performance. + * + * Calling the insnslot_*_rwflags version of a function doesn't hurt + * anything even when the CPSR flags aren't updated by the + * instruction. It's just a little slower in return for saving + * a little space by not having a duplicate function that doesn't + * update the flags. (The same optimization can be said for + * instructions that do or don't perform register writeback) + * Also, instructions can either read the flags, only write the + * flags, or read and write the flags. To save combinations + * rather than for sheer performance, flag functions just assume + * read and write of flags. + */ + +static void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + int disp = branch_displacement(insn); + + if (insn & (1 << 24)) + regs->ARM_lr = iaddr + 4; + + regs->ARM_pc = iaddr + 8 + disp; +} + +static void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + int disp = branch_displacement(insn); + + regs->ARM_lr = iaddr + 4; + regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2); + regs->ARM_cpsr |= PSR_T_BIT; +} + +static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + if (insn & (1 << 5)) + regs->ARM_lr = (long)p->addr + 4; + + regs->ARM_pc = rmv & ~0x1; + regs->ARM_cpsr &= ~PSR_T_BIT; + if (rmv & 0x1) + regs->ARM_cpsr |= PSR_T_BIT; +} + +static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + unsigned long mask = 0xf8ff03df; /* Mask out execution state */ + regs->uregs[rd] = regs->ARM_cpsr & mask; +} + +static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + int rn = (insn >> 16) & 0xf; + int lbit = insn & (1 << 20); + int wbit = insn & (1 << 21); + int ubit = insn & (1 << 23); + int pbit = insn & (1 << 24); + long *addr = (long *)regs->uregs[rn]; + int reg_bit_vector; + int reg_count; + + reg_count = 0; + reg_bit_vector = insn & 0xffff; + while (reg_bit_vector) { + reg_bit_vector &= (reg_bit_vector - 1); + ++reg_count; + } + + if (!ubit) + addr -= reg_count; + addr += (!pbit == !ubit); + + reg_bit_vector = insn & 0xffff; + while (reg_bit_vector) { + int reg = __ffs(reg_bit_vector); + reg_bit_vector &= (reg_bit_vector - 1); + if (lbit) + regs->uregs[reg] = *addr++; + else + *addr++ = regs->uregs[reg]; + } + + if (wbit) { + if (!ubit) + addr -= reg_count; + addr -= (!pbit == !ubit); + regs->uregs[rn] = (long)addr; + } +} + +static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs) +{ + regs->ARM_pc = (long)p->addr + str_pc_offset; + simulate_ldm1stm1(p, regs); + regs->ARM_pc = (long)p->addr + 4; +} + +static void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs) +{ + regs->uregs[12] = regs->uregs[13]; +} + +static void __kprobes emulate_ldrd(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; /* rm may be invalid, don't care. */ + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + + /* Not following the C calling convention here, so need asm(). */ + __asm__ __volatile__ ( + "ldr r0, %[rn] \n\t" + "ldr r1, %[rm] \n\t" + "msr cpsr_fs, %[cpsr]\n\t" + "mov lr, pc \n\t" + "mov pc, %[i_fn] \n\t" + "str r0, %[rn] \n\t" /* in case of writeback */ + "str r2, %[rd0] \n\t" + "str r3, %[rd1] \n\t" + : [rn] "+m" (rnv), + [rd0] "=m" (regs->uregs[rd]), + [rd1] "=m" (regs->uregs[rd+1]) + : [rm] "m" (rmv), + [cpsr] "r" (regs->ARM_cpsr), + [i_fn] "r" (i_fn) + : "r0", "r1", "r2", "r3", "lr", "cc" + ); + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + +static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs) +{ + insn_4arg_fn_t *i_fn = (insn_4arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + /* rm/rmv may be invalid, don't care. */ + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rnv_wb; + + rnv_wb = insnslot_4arg_rflags(rnv, rmv, regs->uregs[rd], + regs->uregs[rd+1], + regs->ARM_cpsr, i_fn); + if (is_writeback(insn)) + regs->uregs[rn] = rnv_wb; +} + +static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) +{ + insn_llret_3arg_fn_t *i_fn = (insn_llret_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + union reg_pair fnr; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rdv; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long cpsr = regs->ARM_cpsr; + + fnr.dr = insnslot_llret_3arg_rflags(rnv, 0, rmv, cpsr, i_fn); + if (rn != 15) + regs->uregs[rn] = fnr.r0; /* Save Rn in case of writeback. */ + rdv = fnr.r1; + + if (rd == 15) { +#if __LINUX_ARM_ARCH__ >= 5 + cpsr &= ~PSR_T_BIT; + if (rdv & 0x1) + cpsr |= PSR_T_BIT; + regs->ARM_cpsr = cpsr; + rdv &= ~0x1; +#else + rdv &= ~0x2; +#endif + } + regs->uregs[rd] = rdv; +} + +static void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long iaddr = (long)p->addr; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rdv = (rd == 15) ? iaddr + str_pc_offset : regs->uregs[rd]; + long rnv = (rn == 15) ? iaddr + 8 : regs->uregs[rn]; + long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */ + long rnv_wb; + + rnv_wb = insnslot_3arg_rflags(rnv, rdv, rmv, regs->ARM_cpsr, i_fn); + if (rn != 15) + regs->uregs[rn] = rnv_wb; /* Save Rn in case of writeback. */ +} + +static void __kprobes emulate_sat(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + /* Writes Q flag */ + regs->uregs[rd] = insnslot_1arg_rwflags(rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_sel(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; + + /* Reads GE bits */ + regs->uregs[rd] = insnslot_2arg_rflags(rnv, rmv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_none(struct kprobe *p, struct pt_regs *regs) +{ + insn_0arg_fn_t *i_fn = (insn_0arg_fn_t *)&p->ainsn.insn[0]; + + insnslot_0arg_rflags(regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_nop(struct kprobe *p, struct pt_regs *regs) +{ +} + +static void __kprobes +emulate_rd12_modify(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + long rdv = regs->uregs[rd]; + + regs->uregs[rd] = insnslot_1arg_rflags(rdv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd12rn0_modify(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = insn & 0xf; + long rdv = regs->uregs[rd]; + long rnv = regs->uregs[rn]; + + regs->uregs[rd] = insnslot_2arg_rflags(rdv, rnv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes emulate_rd12rm0(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rm = insn & 0xf; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = insnslot_1arg_rflags(rmv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd12rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_2arg_rwflags(rnv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd16rn12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 16) & 0xf; + int rn = (insn >> 12) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rnv = regs->uregs[rn]; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_3arg_rwflags(rnv, rsv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rd16rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 16) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + regs->uregs[rd] = + insnslot_2arg_rwflags(rsv, rmv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_rdhi16rdlo12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_llret_4arg_fn_t *i_fn = (insn_llret_4arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + union reg_pair fnr; + int rdhi = (insn >> 16) & 0xf; + int rdlo = (insn >> 12) & 0xf; + int rs = (insn >> 8) & 0xf; + int rm = insn & 0xf; + long rsv = regs->uregs[rs]; + long rmv = regs->uregs[rm]; + + fnr.dr = insnslot_llret_4arg_rwflags(regs->uregs[rdhi], + regs->uregs[rdlo], rsv, rmv, + ®s->ARM_cpsr, i_fn); + regs->uregs[rdhi] = fnr.r0; + regs->uregs[rdlo] = fnr.r1; +} + +static void __kprobes +emulate_alu_imm_rflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn]; + + regs->uregs[rd] = insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_imm_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn]; + + regs->uregs[rd] = insnslot_1arg_rwflags(rnv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_tests_imm(struct kprobe *p, struct pt_regs *regs) +{ + insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + int rn = (insn >> 16) & 0xf; + long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn]; + + insnslot_1arg_rwflags(rnv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_rflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */ + int rs = (insn >> 8) & 0xf; /* invalid, don't care. */ + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rsv = regs->uregs[rs]; + + regs->uregs[rd] = + insnslot_3arg_rflags(rnv, rmv, rsv, regs->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_rwflags(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rd = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */ + int rs = (insn >> 8) & 0xf; /* invalid, don't care. */ + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rsv = regs->uregs[rs]; + + regs->uregs[rd] = + insnslot_3arg_rwflags(rnv, rmv, rsv, ®s->ARM_cpsr, i_fn); +} + +static void __kprobes +emulate_alu_tests(struct kprobe *p, struct pt_regs *regs) +{ + insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; + kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; + int rn = (insn >> 16) & 0xf; + int rs = (insn >> 8) & 0xf; /* rs/rsv may be invalid, don't care. */ + int rm = insn & 0xf; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rsv = regs->uregs[rs]; + + insnslot_3arg_rwflags(rnv, rmv, rsv, ®s->ARM_cpsr, i_fn); +} + +static enum kprobe_insn __kprobes +prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + int not_imm = (insn & (1 << 26)) ? (insn & (1 << 25)) + : (~insn & (1 << 22)); + + if (is_writeback(insn) && is_r15(insn, 16)) + return INSN_REJECTED; /* Writeback to PC */ + + insn &= 0xfff00fff; + insn |= 0x00001000; /* Rn = r0, Rd = r1 */ + if (not_imm) { + insn &= ~0xf; + insn |= 2; /* Rm = r2 */ + } + asi->insn[0] = insn; + asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr : emulate_str; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12_modify(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xffff0fff; /* Rd = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12_modify; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12rn0_modify(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xffff0ff0; /* Rd = r0 */ + insn |= 0x00000001; /* Rn = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12rn0_modify; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12rm0; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd12rn16rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd16rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + if (is_r15(insn, 16)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xfff0f0f0; /* Rd = r0, Rs = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd16rs8rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rd16rn12rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + if (is_r15(insn, 16)) + return INSN_REJECTED; /* Rd is PC */ + + insn &= 0xfff000f0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000102; /* Rs = r1, Rm = r2 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rd16rn12rs8rm0_rwflags; + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +prep_emulate_rdhi16rdlo12rs8rm0_wflags(kprobe_opcode_t insn, + struct arch_specific_insn *asi) +{ + if (is_r15(insn, 16) || is_r15(insn, 12)) + return INSN_REJECTED; /* RdHi or RdLo is PC */ + + insn &= 0xfff000f0; /* RdHi = r0, RdLo = r1 */ + insn |= 0x00001203; /* Rs = r2, Rm = r3 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_rdhi16rdlo12rs8rm0_rwflags; + return INSN_GOOD; +} + +/* + * For the instruction masking and comparisons in all the "space_*" + * functions below, Do _not_ rearrange the order of tests unless + * you're very, very sure of what you are doing. For the sake of + * efficiency, the masks for some tests sometimes assume other test + * have been done prior to them so the number of patterns to test + * for an instruction set can be as broad as possible to reduce the + * number of tests needed. + */ + +static enum kprobe_insn __kprobes +space_1111(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* memory hint : 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDI : 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDW : 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLD : 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfe300000) == 0xf4100000) { + asi->insn_handler = emulate_nop; + return INSN_GOOD_NO_SLOT; + } + + /* BLX(1) : 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfe000000) == 0xfa000000) { + asi->insn_handler = simulate_blx1; + return INSN_GOOD_NO_SLOT; + } + + /* CPS : 1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */ + /* SETEND: 1111 0001 0000 0001 xxxx xxxx 0000 xxxx */ + + /* SRS : 1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* RFE : 1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ + + /* Coprocessor instructions... */ + /* MCRR2 : 1111 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */ + /* MRRC2 : 1111 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */ + /* LDC2 : 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC2 : 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + /* CDP2 : 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + /* MCR2 : 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC2 : 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + + return INSN_REJECTED; +} + +static enum kprobe_insn __kprobes +space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx xxx0 xxxx */ + if ((insn & 0x0f900010) == 0x01000000) { + + /* MRS cpsr : cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */ + if ((insn & 0x0ff000f0) == 0x01000000) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + asi->insn_handler = simulate_mrs; + return INSN_GOOD_NO_SLOT; + } + + /* SMLALxy : cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */ + if ((insn & 0x0ff00090) == 0x01400080) + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, + asi); + + /* SMULWy : cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */ + /* SMULxy : cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */ + if ((insn & 0x0ff000b0) == 0x012000a0 || + (insn & 0x0ff00090) == 0x01600080) + return prep_emulate_rd16rs8rm0_wflags(insn, asi); + + /* SMLAxy : cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx : Q */ + /* SMLAWy : cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx : Q */ + if ((insn & 0x0ff00090) == 0x01000080 || + (insn & 0x0ff000b0) == 0x01200080) + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + + /* BXJ : cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */ + /* MSR : cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */ + /* MRS spsr : cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */ + + /* Other instruction encodings aren't yet defined */ + return INSN_REJECTED; + } + + /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx 0xx1 xxxx */ + else if ((insn & 0x0f900090) == 0x01000010) { + + /* BLX(2) : cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */ + /* BX : cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */ + if ((insn & 0x0ff000d0) == 0x01200010) { + if ((insn & 0x0ff000ff) == 0x0120003f) + return INSN_REJECTED; /* BLX pc */ + asi->insn_handler = simulate_blx2bx; + return INSN_GOOD_NO_SLOT; + } + + /* CLZ : cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */ + if ((insn & 0x0ff000f0) == 0x01600010) + return prep_emulate_rd12rm0(insn, asi); + + /* QADD : cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QSUB : cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QDADD : cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx :Q */ + /* QDSUB : cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx :Q */ + if ((insn & 0x0f9000f0) == 0x01000050) + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + + /* BKPT : 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */ + /* SMC : cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */ + + /* Other instruction encodings aren't yet defined */ + return INSN_REJECTED; + } + + /* cccc 0000 xxxx xxxx xxxx xxxx xxxx 1001 xxxx */ + else if ((insn & 0x0f0000f0) == 0x00000090) { + + /* MUL : cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx : */ + /* MULS : cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx :cc */ + /* MLA : cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx : */ + /* MLAS : cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx :cc */ + /* UMAAL : cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx : */ + /* undef : cccc 0000 0101 xxxx xxxx xxxx 1001 xxxx : */ + /* MLS : cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx : */ + /* undef : cccc 0000 0111 xxxx xxxx xxxx 1001 xxxx : */ + /* UMULL : cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx : */ + /* UMULLS : cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx :cc */ + /* UMLAL : cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx : */ + /* UMLALS : cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx :cc */ + /* SMULL : cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx : */ + /* SMULLS : cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx :cc */ + /* SMLAL : cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx : */ + /* SMLALS : cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx :cc */ + if ((insn & 0x00d00000) == 0x00500000) + return INSN_REJECTED; + else if ((insn & 0x00e00000) == 0x00000000) + return prep_emulate_rd16rs8rm0_wflags(insn, asi); + else if ((insn & 0x00a00000) == 0x00200000) + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + else + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, + asi); + } + + /* cccc 000x xxxx xxxx xxxx xxxx xxxx 1xx1 xxxx */ + else if ((insn & 0x0e000090) == 0x00000090) { + + /* SWP : cccc 0001 0000 xxxx xxxx xxxx 1001 xxxx */ + /* SWPB : cccc 0001 0100 xxxx xxxx xxxx 1001 xxxx */ + /* ??? : cccc 0001 0x01 xxxx xxxx xxxx 1001 xxxx */ + /* ??? : cccc 0001 0x10 xxxx xxxx xxxx 1001 xxxx */ + /* ??? : cccc 0001 0x11 xxxx xxxx xxxx 1001 xxxx */ + /* STREX : cccc 0001 1000 xxxx xxxx xxxx 1001 xxxx */ + /* LDREX : cccc 0001 1001 xxxx xxxx xxxx 1001 xxxx */ + /* STREXD: cccc 0001 1010 xxxx xxxx xxxx 1001 xxxx */ + /* LDREXD: cccc 0001 1011 xxxx xxxx xxxx 1001 xxxx */ + /* STREXB: cccc 0001 1100 xxxx xxxx xxxx 1001 xxxx */ + /* LDREXB: cccc 0001 1101 xxxx xxxx xxxx 1001 xxxx */ + /* STREXH: cccc 0001 1110 xxxx xxxx xxxx 1001 xxxx */ + /* LDREXH: cccc 0001 1111 xxxx xxxx xxxx 1001 xxxx */ + + /* LDRD : cccc 000x xxx0 xxxx xxxx xxxx 1101 xxxx */ + /* STRD : cccc 000x xxx0 xxxx xxxx xxxx 1111 xxxx */ + /* LDRH : cccc 000x xxx1 xxxx xxxx xxxx 1011 xxxx */ + /* STRH : cccc 000x xxx0 xxxx xxxx xxxx 1011 xxxx */ + /* LDRSB : cccc 000x xxx1 xxxx xxxx xxxx 1101 xxxx */ + /* LDRSH : cccc 000x xxx1 xxxx xxxx xxxx 1111 xxxx */ + if ((insn & 0x0f0000f0) == 0x01000090) { + if ((insn & 0x0fb000f0) == 0x01000090) { + /* SWP/SWPB */ + return prep_emulate_rd12rn16rm0_wflags(insn, + asi); + } else { + /* STREX/LDREX variants and unallocaed space */ + return INSN_REJECTED; + } + + } else if ((insn & 0x0e1000d0) == 0x00000d0) { + /* STRD/LDRD */ + if ((insn & 0x0000e000) == 0x0000e000) + return INSN_REJECTED; /* Rd is LR or PC */ + if (is_writeback(insn) && is_r15(insn, 16)) + return INSN_REJECTED; /* Writeback to PC */ + + insn &= 0xfff00fff; + insn |= 0x00002000; /* Rn = r0, Rd = r2 */ + if (!(insn & (1 << 22))) { + /* Register index */ + insn &= ~0xf; + insn |= 1; /* Rm = r1 */ + } + asi->insn[0] = insn; + asi->insn_handler = + (insn & (1 << 5)) ? emulate_strd : emulate_ldrd; + return INSN_GOOD; + } + + /* LDRH/STRH/LDRSB/LDRSH */ + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + return prep_emulate_ldr_str(insn, asi); + } + + /* cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx */ + + /* + * ALU op with S bit and Rd == 15 : + * cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx + */ + if ((insn & 0x0e10f000) == 0x0010f000) + return INSN_REJECTED; + + /* + * "mov ip, sp" is the most common kprobe'd instruction by far. + * Check and optimize for it explicitly. + */ + if (insn == 0xe1a0c00d) { + asi->insn_handler = simulate_mov_ipsp; + return INSN_GOOD_NO_SLOT; + } + + /* + * Data processing: Immediate-shift / Register-shift + * ALU op : cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx + * CPY : cccc 0001 1010 xxxx xxxx 0000 0000 xxxx + * MOV : cccc 0001 101x xxxx xxxx xxxx xxxx xxxx + * *S (bit 20) updates condition codes + * ADC/SBC/RSC reads the C flag + */ + insn &= 0xfff00ff0; /* Rn = r0, Rd = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + if (insn & 0x010) { + insn &= 0xfffff0ff; /* register shift */ + insn |= 0x00000200; /* Rs = r2 */ + } + asi->insn[0] = insn; + + if ((insn & 0x0f900000) == 0x01100000) { + /* + * TST : cccc 0001 0001 xxxx xxxx xxxx xxxx xxxx + * TEQ : cccc 0001 0011 xxxx xxxx xxxx xxxx xxxx + * CMP : cccc 0001 0101 xxxx xxxx xxxx xxxx xxxx + * CMN : cccc 0001 0111 xxxx xxxx xxxx xxxx xxxx + */ + asi->insn_handler = emulate_alu_tests; + } else { + /* ALU ops which write to Rd */ + asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */ + emulate_alu_rwflags : emulate_alu_rflags; + } + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_001x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* MOVW : cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */ + /* MOVT : cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */ + if ((insn & 0x0fb00000) == 0x03000000) + return prep_emulate_rd12_modify(insn, asi); + + /* hints : cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */ + if ((insn & 0x0fff0000) == 0x03200000) { + unsigned op2 = insn & 0x000000ff; + if (op2 == 0x01 || op2 == 0x04) { + /* YIELD : cccc 0011 0010 0000 xxxx xxxx 0000 0001 */ + /* SEV : cccc 0011 0010 0000 xxxx xxxx 0000 0100 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_none; + return INSN_GOOD; + } else if (op2 <= 0x03) { + /* NOP : cccc 0011 0010 0000 xxxx xxxx 0000 0000 */ + /* WFE : cccc 0011 0010 0000 xxxx xxxx 0000 0010 */ + /* WFI : cccc 0011 0010 0000 xxxx xxxx 0000 0011 */ + /* + * We make WFE and WFI true NOPs to avoid stalls due + * to missing events whilst processing the probe. + */ + asi->insn_handler = emulate_nop; + return INSN_GOOD_NO_SLOT; + } + /* For DBG and unallocated hints it's safest to reject them */ + return INSN_REJECTED; + } + + /* + * MSR : cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx + * ALU op with S bit and Rd == 15 : + * cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx + */ + if ((insn & 0x0fb00000) == 0x03200000 || /* MSR */ + (insn & 0x0e10f000) == 0x0210f000) /* ALU s-bit, R15 */ + return INSN_REJECTED; + + /* + * Data processing: 32-bit Immediate + * ALU op : cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx + * MOV : cccc 0011 101x xxxx xxxx xxxx xxxx xxxx + * *S (bit 20) updates condition codes + * ADC/SBC/RSC reads the C flag + */ + insn &= 0xfff00fff; /* Rn = r0 and Rd = r0 */ + asi->insn[0] = insn; + + if ((insn & 0x0f900000) == 0x03100000) { + /* + * TST : cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx + * TEQ : cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx + * CMP : cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx + * CMN : cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx + */ + asi->insn_handler = emulate_alu_tests_imm; + } else { + /* ALU ops which write to Rd */ + asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */ + emulate_alu_imm_rwflags : emulate_alu_imm_rflags; + } + return INSN_GOOD; +} + +static enum kprobe_insn __kprobes +space_cccc_0110__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* SEL : cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx GE: !!! */ + if ((insn & 0x0ff000f0) == 0x068000b0) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ + insn |= 0x00000001; /* Rm = r1 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_sel; + return INSN_GOOD; + } + + /* SSAT : cccc 0110 101x xxxx xxxx xxxx xx01 xxxx :Q */ + /* USAT : cccc 0110 111x xxxx xxxx xxxx xx01 xxxx :Q */ + /* SSAT16 : cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx :Q */ + /* USAT16 : cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx :Q */ + if ((insn & 0x0fa00030) == 0x06a00010 || + (insn & 0x0fb000f0) == 0x06a00030) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ + asi->insn[0] = insn; + asi->insn_handler = emulate_sat; + return INSN_GOOD; + } + + /* REV : cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */ + /* REV16 : cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */ + /* RBIT : cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */ + /* REVSH : cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */ + if ((insn & 0x0ff00070) == 0x06b00030 || + (insn & 0x0ff00070) == 0x06f00030) + return prep_emulate_rd12rm0(insn, asi); + + /* ??? : cccc 0110 0000 xxxx xxxx xxxx xxx1 xxxx : */ + /* SADD16 : cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx :GE */ + /* SADDSUBX : cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx :GE */ + /* SSUBADDX : cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx :GE */ + /* SSUB16 : cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx :GE */ + /* SADD8 : cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx :GE */ + /* ??? : cccc 0110 0001 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0001 xxxx xxxx xxxx 1101 xxxx : */ + /* SSUB8 : cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx :GE */ + /* QADD16 : cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx : */ + /* QADDSUBX : cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx : */ + /* QSUBADDX : cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx : */ + /* QSUB16 : cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx : */ + /* QADD8 : cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx : */ + /* ??? : cccc 0110 0010 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0010 xxxx xxxx xxxx 1101 xxxx : */ + /* QSUB8 : cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx : */ + /* SHADD16 : cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx : */ + /* SHADDSUBX : cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx : */ + /* SHSUBADDX : cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx : */ + /* SHSUB16 : cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx : */ + /* SHADD8 : cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx : */ + /* ??? : cccc 0110 0011 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0011 xxxx xxxx xxxx 1101 xxxx : */ + /* SHSUB8 : cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx : */ + /* ??? : cccc 0110 0100 xxxx xxxx xxxx xxx1 xxxx : */ + /* UADD16 : cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx :GE */ + /* UADDSUBX : cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx :GE */ + /* USUBADDX : cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx :GE */ + /* USUB16 : cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx :GE */ + /* UADD8 : cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx :GE */ + /* ??? : cccc 0110 0101 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0101 xxxx xxxx xxxx 1101 xxxx : */ + /* USUB8 : cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx :GE */ + /* UQADD16 : cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx : */ + /* UQADDSUBX : cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx : */ + /* UQSUBADDX : cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx : */ + /* UQSUB16 : cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx : */ + /* UQADD8 : cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx : */ + /* ??? : cccc 0110 0110 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0110 xxxx xxxx xxxx 1101 xxxx : */ + /* UQSUB8 : cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx : */ + /* UHADD16 : cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx : */ + /* UHADDSUBX : cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx : */ + /* UHSUBADDX : cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx : */ + /* UHSUB16 : cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx : */ + /* UHADD8 : cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx : */ + /* ??? : cccc 0110 0111 xxxx xxxx xxxx 1011 xxxx : */ + /* ??? : cccc 0110 0111 xxxx xxxx xxxx 1101 xxxx : */ + /* UHSUB8 : cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx : */ + if ((insn & 0x0f800010) == 0x06000010) { + if ((insn & 0x00300000) == 0x00000000 || + (insn & 0x000000e0) == 0x000000a0 || + (insn & 0x000000e0) == 0x000000c0) + return INSN_REJECTED; /* Unallocated space */ + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + } + + /* PKHBT : cccc 0110 1000 xxxx xxxx xxxx x001 xxxx : */ + /* PKHTB : cccc 0110 1000 xxxx xxxx xxxx x101 xxxx : */ + if ((insn & 0x0ff00030) == 0x06800010) + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + + /* SXTAB16 : cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx : */ + /* SXTB16 : cccc 0110 1000 1111 xxxx xxxx 0111 xxxx : */ + /* ??? : cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx : */ + /* SXTAB : cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx : */ + /* SXTB : cccc 0110 1010 1111 xxxx xxxx 0111 xxxx : */ + /* SXTAH : cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx : */ + /* SXTH : cccc 0110 1011 1111 xxxx xxxx 0111 xxxx : */ + /* UXTAB16 : cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx : */ + /* UXTB16 : cccc 0110 1100 1111 xxxx xxxx 0111 xxxx : */ + /* ??? : cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx : */ + /* UXTAB : cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx : */ + /* UXTB : cccc 0110 1110 1111 xxxx xxxx 0111 xxxx : */ + /* UXTAH : cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx : */ + /* UXTH : cccc 0110 1111 1111 xxxx xxxx 0111 xxxx : */ + if ((insn & 0x0f8000f0) == 0x06800070) { + if ((insn & 0x00300000) == 0x00100000) + return INSN_REJECTED; /* Unallocated space */ + + if ((insn & 0x000f0000) == 0x000f0000) + return prep_emulate_rd12rm0(insn, asi); + else + return prep_emulate_rd12rn16rm0_wflags(insn, asi); + } + + /* Other instruction encodings aren't yet defined */ + return INSN_REJECTED; +} + +static enum kprobe_insn __kprobes +space_cccc_0111__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* Undef : cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */ + if ((insn & 0x0ff000f0) == 0x03f000f0) + return INSN_REJECTED; + + /* SMLALD : cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */ + /* SMLSLD : cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */ + if ((insn & 0x0ff00090) == 0x07400010) + return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi); + + /* SMLAD : cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx :Q */ + /* SMUAD : cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx :Q */ + /* SMLSD : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx :Q */ + /* SMUSD : cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx : */ + /* SMMLA : cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx : */ + /* SMMUL : cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx : */ + /* USADA8 : cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx : */ + /* USAD8 : cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx : */ + if ((insn & 0x0ff00090) == 0x07000010 || + (insn & 0x0ff000d0) == 0x07500010 || + (insn & 0x0ff000f0) == 0x07800010) { + + if ((insn & 0x0000f000) == 0x0000f000) + return prep_emulate_rd16rs8rm0_wflags(insn, asi); + else + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + } + + /* SMMLS : cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx : */ + if ((insn & 0x0ff000d0) == 0x075000d0) + return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi); + + /* SBFX : cccc 0111 101x xxxx xxxx xxxx x101 xxxx : */ + /* UBFX : cccc 0111 111x xxxx xxxx xxxx x101 xxxx : */ + if ((insn & 0x0fa00070) == 0x07a00050) + return prep_emulate_rd12rm0(insn, asi); + + /* BFI : cccc 0111 110x xxxx xxxx xxxx x001 xxxx : */ + /* BFC : cccc 0111 110x xxxx xxxx xxxx x001 1111 : */ + if ((insn & 0x0fe00070) == 0x07c00010) { + + if ((insn & 0x0000000f) == 0x0000000f) + return prep_emulate_rd12_modify(insn, asi); + else + return prep_emulate_rd12rn0_modify(insn, asi); + } + + return INSN_REJECTED; +} + +static enum kprobe_insn __kprobes +space_cccc_01xx(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* LDR : cccc 01xx x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRB : cccc 01xx x1x1 xxxx xxxx xxxx xxxx xxxx */ + /* LDRBT : cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */ + /* LDRT : cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */ + /* STR : cccc 01xx x0x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRB : cccc 01xx x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* STRBT : cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */ + /* STRT : cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */ + + if ((insn & 0x00500000) == 0x00500000 && is_r15(insn, 12)) + return INSN_REJECTED; /* LDRB into PC */ + + return prep_emulate_ldr_str(insn, asi); +} + +static enum kprobe_insn __kprobes +space_cccc_100x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* LDM(2) : cccc 100x x101 xxxx 0xxx xxxx xxxx xxxx */ + /* LDM(3) : cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */ + if ((insn & 0x0e708000) == 0x85000000 || + (insn & 0x0e508000) == 0x85010000) + return INSN_REJECTED; + + /* LDM(1) : cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ + /* STM(1) : cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */ + asi->insn_handler = ((insn & 0x108000) == 0x008000) ? /* STM & R15 */ + simulate_stm1_pc : simulate_ldm1stm1; + return INSN_GOOD_NO_SLOT; +} + +static enum kprobe_insn __kprobes +space_cccc_101x(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* B : cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */ + /* BL : cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */ + asi->insn_handler = simulate_bbl; + return INSN_GOOD_NO_SLOT; +} + +static enum kprobe_insn __kprobes +space_cccc_11xx(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + /* Coprocessor instructions... */ + /* MCRR : cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ + /* MRRC : cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ + /* LDC : cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */ + /* STC : cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */ + /* CDP : cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */ + /* MCR : cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */ + /* MRC : cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */ + + /* SVC : cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */ + + return INSN_REJECTED; +} + +static unsigned long __kprobes __check_eq(unsigned long cpsr) +{ + return cpsr & PSR_Z_BIT; +} + +static unsigned long __kprobes __check_ne(unsigned long cpsr) +{ + return (~cpsr) & PSR_Z_BIT; +} + +static unsigned long __kprobes __check_cs(unsigned long cpsr) +{ + return cpsr & PSR_C_BIT; +} + +static unsigned long __kprobes __check_cc(unsigned long cpsr) +{ + return (~cpsr) & PSR_C_BIT; +} + +static unsigned long __kprobes __check_mi(unsigned long cpsr) +{ + return cpsr & PSR_N_BIT; +} + +static unsigned long __kprobes __check_pl(unsigned long cpsr) +{ + return (~cpsr) & PSR_N_BIT; +} + +static unsigned long __kprobes __check_vs(unsigned long cpsr) +{ + return cpsr & PSR_V_BIT; +} + +static unsigned long __kprobes __check_vc(unsigned long cpsr) +{ + return (~cpsr) & PSR_V_BIT; +} + +static unsigned long __kprobes __check_hi(unsigned long cpsr) +{ + cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return cpsr & PSR_C_BIT; +} + +static unsigned long __kprobes __check_ls(unsigned long cpsr) +{ + cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */ + return (~cpsr) & PSR_C_BIT; +} + +static unsigned long __kprobes __check_ge(unsigned long cpsr) +{ + cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return (~cpsr) & PSR_N_BIT; +} + +static unsigned long __kprobes __check_lt(unsigned long cpsr) +{ + cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + return cpsr & PSR_N_BIT; +} + +static unsigned long __kprobes __check_gt(unsigned long cpsr) +{ + unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */ + return (~temp) & PSR_N_BIT; +} + +static unsigned long __kprobes __check_le(unsigned long cpsr) +{ + unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */ + temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */ + return temp & PSR_N_BIT; +} + +static unsigned long __kprobes __check_al(unsigned long cpsr) +{ + return true; +} + +static kprobe_check_cc * const condition_checks[16] = { + &__check_eq, &__check_ne, &__check_cs, &__check_cc, + &__check_mi, &__check_pl, &__check_vs, &__check_vc, + &__check_hi, &__check_ls, &__check_ge, &__check_lt, + &__check_gt, &__check_le, &__check_al, &__check_al +}; + +/* Return: + * INSN_REJECTED If instruction is one not allowed to kprobe, + * INSN_GOOD If instruction is supported and uses instruction slot, + * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot. + * + * For instructions we don't want to kprobe (INSN_REJECTED return result): + * These are generally ones that modify the processor state making + * them "hard" to simulate such as switches processor modes or + * make accesses in alternate modes. Any of these could be simulated + * if the work was put into it, but low return considering they + * should also be very rare. + */ +enum kprobe_insn __kprobes +arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) +{ + asi->insn_check_cc = condition_checks[insn>>28]; + asi->insn[1] = KPROBE_RETURN_INSTRUCTION; + + if ((insn & 0xf0000000) == 0xf0000000) + + return space_1111(insn, asi); + + else if ((insn & 0x0e000000) == 0x00000000) + + return space_cccc_000x(insn, asi); + + else if ((insn & 0x0e000000) == 0x02000000) + + return space_cccc_001x(insn, asi); + + else if ((insn & 0x0f000010) == 0x06000010) + + return space_cccc_0110__1(insn, asi); + + else if ((insn & 0x0f000010) == 0x07000010) + + return space_cccc_0111__1(insn, asi); + + else if ((insn & 0x0c000000) == 0x04000000) + + return space_cccc_01xx(insn, asi); + + else if ((insn & 0x0e000000) == 0x08000000) + + return space_cccc_100x(insn, asi); + + else if ((insn & 0x0e000000) == 0x0a000000) + + return space_cccc_101x(insn, asi); + + return space_cccc_11xx(insn, asi); +} + +void __init arm_kprobe_decode_init(void) +{ + find_str_pc_offset(); +} |