 888be25402
			
		
	
	
	888be25402
	
	
	
		
			
			If we are running BE8, the data and instruction endianness do not match, so use <asm/opcodes.h> to correctly translate memory accesses into ARM instructions. Acked-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> [taras.kondratiuk@linaro.org: fixed Thumb instruction fetch order] Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
		
			
				
	
	
		
			666 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			666 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * arch/arm/kernel/kprobes-thumb.c
 | |
|  *
 | |
|  * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
 | |
|  *
 | |
|  * 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.
 | |
|  */
 | |
| 
 | |
| #include <linux/types.h>
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/ptrace.h>
 | |
| #include <linux/kprobes.h>
 | |
| 
 | |
| #include "kprobes.h"
 | |
| #include "probes-thumb.h"
 | |
| 
 | |
| /* These emulation encodings are functionally equivalent... */
 | |
| #define t32_emulate_rd8rn16rm0ra12_noflags \
 | |
| 		t32_emulate_rdlo12rdhi8rn16rm0_noflags
 | |
| 
 | |
| /* t32 thumb actions */
 | |
| 
 | |
| static void __kprobes
 | |
| t32_simulate_table_branch(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 	int rm = insn & 0xf;
 | |
| 
 | |
| 	unsigned long rnv = (rn == 15) ? pc : regs->uregs[rn];
 | |
| 	unsigned long rmv = regs->uregs[rm];
 | |
| 	unsigned int halfwords;
 | |
| 
 | |
| 	if (insn & 0x10) /* TBH */
 | |
| 		halfwords = ((u16 *)rnv)[rmv];
 | |
| 	else /* TBB */
 | |
| 		halfwords = ((u8 *)rnv)[rmv];
 | |
| 
 | |
| 	regs->ARM_pc = pc + 2 * halfwords;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_simulate_mrs(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	int rd = (insn >> 8) & 0xf;
 | |
| 	unsigned long mask = 0xf8ff03df; /* Mask out execution state */
 | |
| 	regs->uregs[rd] = regs->ARM_cpsr & mask;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_simulate_cond_branch(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc;
 | |
| 
 | |
| 	long offset = insn & 0x7ff;		/* imm11 */
 | |
| 	offset += (insn & 0x003f0000) >> 5;	/* imm6 */
 | |
| 	offset += (insn & 0x00002000) << 4;	/* J1 */
 | |
| 	offset += (insn & 0x00000800) << 7;	/* J2 */
 | |
| 	offset -= (insn & 0x04000000) >> 7;	/* Apply sign bit */
 | |
| 
 | |
| 	regs->ARM_pc = pc + (offset * 2);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t32_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	int cc = (insn >> 22) & 0xf;
 | |
| 	asi->insn_check_cc = probes_condition_checks[cc];
 | |
| 	asi->insn_handler = t32_simulate_cond_branch;
 | |
| 	return INSN_GOOD_NO_SLOT;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_simulate_branch(probes_opcode_t insn,
 | |
| 		    struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc;
 | |
| 
 | |
| 	long offset = insn & 0x7ff;		/* imm11 */
 | |
| 	offset += (insn & 0x03ff0000) >> 5;	/* imm10 */
 | |
| 	offset += (insn & 0x00002000) << 9;	/* J1 */
 | |
| 	offset += (insn & 0x00000800) << 10;	/* J2 */
 | |
| 	if (insn & 0x04000000)
 | |
| 		offset -= 0x00800000; /* Apply sign bit */
 | |
| 	else
 | |
| 		offset ^= 0x00600000; /* Invert J1 and J2 */
 | |
| 
 | |
| 	if (insn & (1 << 14)) {
 | |
| 		/* BL or BLX */
 | |
| 		regs->ARM_lr = regs->ARM_pc | 1;
 | |
| 		if (!(insn & (1 << 12))) {
 | |
| 			/* BLX so switch to ARM mode */
 | |
| 			regs->ARM_cpsr &= ~PSR_T_BIT;
 | |
| 			pc &= ~3;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	regs->ARM_pc = pc + (offset * 2);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_simulate_ldr_literal(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long addr = regs->ARM_pc & ~3;
 | |
| 	int rt = (insn >> 12) & 0xf;
 | |
| 	unsigned long rtv;
 | |
| 
 | |
| 	long offset = insn & 0xfff;
 | |
| 	if (insn & 0x00800000)
 | |
| 		addr += offset;
 | |
| 	else
 | |
| 		addr -= offset;
 | |
| 
 | |
| 	if (insn & 0x00400000) {
 | |
| 		/* LDR */
 | |
| 		rtv = *(unsigned long *)addr;
 | |
| 		if (rt == 15) {
 | |
| 			bx_write_pc(rtv, regs);
 | |
| 			return;
 | |
| 		}
 | |
| 	} else if (insn & 0x00200000) {
 | |
| 		/* LDRH */
 | |
| 		if (insn & 0x01000000)
 | |
| 			rtv = *(s16 *)addr;
 | |
| 		else
 | |
| 			rtv = *(u16 *)addr;
 | |
| 	} else {
 | |
| 		/* LDRB */
 | |
| 		if (insn & 0x01000000)
 | |
| 			rtv = *(s8 *)addr;
 | |
| 		else
 | |
| 			rtv = *(u8 *)addr;
 | |
| 	}
 | |
| 
 | |
| 	regs->uregs[rt] = rtv;
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t32_decode_ldmstm(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	enum probes_insn ret = kprobe_decode_ldmstm(insn, asi, d);
 | |
| 
 | |
| 	/* Fixup modified instruction to have halfwords in correct order...*/
 | |
| 	insn = __mem_to_opcode_arm(asi->insn[0]);
 | |
| 	((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn >> 16);
 | |
| 	((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0xffff);
 | |
| 
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_ldrdstrd(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc & ~3;
 | |
| 	int rt1 = (insn >> 12) & 0xf;
 | |
| 	int rt2 = (insn >> 8) & 0xf;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 
 | |
| 	register unsigned long rt1v asm("r0") = regs->uregs[rt1];
 | |
| 	register unsigned long rt2v asm("r1") = regs->uregs[rt2];
 | |
| 	register unsigned long rnv asm("r2") = (rn == 15) ? pc
 | |
| 							  : regs->uregs[rn];
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"blx    %[fn]"
 | |
| 		: "=r" (rt1v), "=r" (rt2v), "=r" (rnv)
 | |
| 		: "0" (rt1v), "1" (rt2v), "2" (rnv), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	if (rn != 15)
 | |
| 		regs->uregs[rn] = rnv; /* Writeback base register */
 | |
| 	regs->uregs[rt1] = rt1v;
 | |
| 	regs->uregs[rt2] = rt2v;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_ldrstr(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	int rt = (insn >> 12) & 0xf;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 	int rm = insn & 0xf;
 | |
| 
 | |
| 	register unsigned long rtv asm("r0") = regs->uregs[rt];
 | |
| 	register unsigned long rnv asm("r2") = regs->uregs[rn];
 | |
| 	register unsigned long rmv asm("r3") = regs->uregs[rm];
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"blx    %[fn]"
 | |
| 		: "=r" (rtv), "=r" (rnv)
 | |
| 		: "0" (rtv), "1" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	regs->uregs[rn] = rnv; /* Writeback base register */
 | |
| 	if (rt == 15) /* Can't be true for a STR as they aren't allowed */
 | |
| 		bx_write_pc(rtv, regs);
 | |
| 	else
 | |
| 		regs->uregs[rt] = rtv;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_rd8rn16rm0_rwflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	int rd = (insn >> 8) & 0xf;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 	int rm = insn & 0xf;
 | |
| 
 | |
| 	register unsigned long rdv asm("r1") = regs->uregs[rd];
 | |
| 	register unsigned long rnv asm("r2") = regs->uregs[rn];
 | |
| 	register unsigned long rmv asm("r3") = regs->uregs[rm];
 | |
| 	unsigned long cpsr = regs->ARM_cpsr;
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"msr	cpsr_fs, %[cpsr]	\n\t"
 | |
| 		"blx    %[fn]			\n\t"
 | |
| 		"mrs	%[cpsr], cpsr		\n\t"
 | |
| 		: "=r" (rdv), [cpsr] "=r" (cpsr)
 | |
| 		: "0" (rdv), "r" (rnv), "r" (rmv),
 | |
| 		  "1" (cpsr), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	regs->uregs[rd] = rdv;
 | |
| 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_rd8pc16_noflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc;
 | |
| 	int rd = (insn >> 8) & 0xf;
 | |
| 
 | |
| 	register unsigned long rdv asm("r1") = regs->uregs[rd];
 | |
| 	register unsigned long rnv asm("r2") = pc & ~3;
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"blx    %[fn]"
 | |
| 		: "=r" (rdv)
 | |
| 		: "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	regs->uregs[rd] = rdv;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_rd8rn16_noflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	int rd = (insn >> 8) & 0xf;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 
 | |
| 	register unsigned long rdv asm("r1") = regs->uregs[rd];
 | |
| 	register unsigned long rnv asm("r2") = regs->uregs[rn];
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"blx    %[fn]"
 | |
| 		: "=r" (rdv)
 | |
| 		: "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	regs->uregs[rd] = rdv;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t32_emulate_rdlo12rdhi8rn16rm0_noflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi,
 | |
| 		struct pt_regs *regs)
 | |
| {
 | |
| 	int rdlo = (insn >> 12) & 0xf;
 | |
| 	int rdhi = (insn >> 8) & 0xf;
 | |
| 	int rn = (insn >> 16) & 0xf;
 | |
| 	int rm = insn & 0xf;
 | |
| 
 | |
| 	register unsigned long rdlov asm("r0") = regs->uregs[rdlo];
 | |
| 	register unsigned long rdhiv asm("r1") = regs->uregs[rdhi];
 | |
| 	register unsigned long rnv asm("r2") = regs->uregs[rn];
 | |
| 	register unsigned long rmv asm("r3") = regs->uregs[rm];
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"blx    %[fn]"
 | |
| 		: "=r" (rdlov), "=r" (rdhiv)
 | |
| 		: "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv),
 | |
| 		  [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	regs->uregs[rdlo] = rdlov;
 | |
| 	regs->uregs[rdhi] = rdhiv;
 | |
| }
 | |
| /* t16 thumb actions */
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_bxblx(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc + 2;
 | |
| 	int rm = (insn >> 3) & 0xf;
 | |
| 	unsigned long rmv = (rm == 15) ? pc : regs->uregs[rm];
 | |
| 
 | |
| 	if (insn & (1 << 7)) /* BLX ? */
 | |
| 		regs->ARM_lr = regs->ARM_pc | 1;
 | |
| 
 | |
| 	bx_write_pc(rmv, regs);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_ldr_literal(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long *base = (unsigned long *)((regs->ARM_pc + 2) & ~3);
 | |
| 	long index = insn & 0xff;
 | |
| 	int rt = (insn >> 8) & 0x7;
 | |
| 	regs->uregs[rt] = base[index];
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_ldrstr_sp_relative(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long* base = (unsigned long *)regs->ARM_sp;
 | |
| 	long index = insn & 0xff;
 | |
| 	int rt = (insn >> 8) & 0x7;
 | |
| 	if (insn & 0x800) /* LDR */
 | |
| 		regs->uregs[rt] = base[index];
 | |
| 	else /* STR */
 | |
| 		base[index] = regs->uregs[rt];
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_reladr(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long base = (insn & 0x800) ? regs->ARM_sp
 | |
| 					    : ((regs->ARM_pc + 2) & ~3);
 | |
| 	long offset = insn & 0xff;
 | |
| 	int rt = (insn >> 8) & 0x7;
 | |
| 	regs->uregs[rt] = base + offset * 4;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_add_sp_imm(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	long imm = insn & 0x7f;
 | |
| 	if (insn & 0x80) /* SUB */
 | |
| 		regs->ARM_sp -= imm * 4;
 | |
| 	else /* ADD */
 | |
| 		regs->ARM_sp += imm * 4;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_cbz(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	int rn = insn & 0x7;
 | |
| 	probes_opcode_t nonzero = regs->uregs[rn] ? insn : ~insn;
 | |
| 	if (nonzero & 0x800) {
 | |
| 		long i = insn & 0x200;
 | |
| 		long imm5 = insn & 0xf8;
 | |
| 		unsigned long pc = regs->ARM_pc + 2;
 | |
| 		regs->ARM_pc = pc + (i >> 3) + (imm5 >> 2);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_it(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	/*
 | |
| 	 * The 8 IT state bits are split into two parts in CPSR:
 | |
| 	 *	ITSTATE<1:0> are in CPSR<26:25>
 | |
| 	 *	ITSTATE<7:2> are in CPSR<15:10>
 | |
| 	 * The new IT state is in the lower byte of insn.
 | |
| 	 */
 | |
| 	unsigned long cpsr = regs->ARM_cpsr;
 | |
| 	cpsr &= ~PSR_IT_MASK;
 | |
| 	cpsr |= (insn & 0xfc) << 8;
 | |
| 	cpsr |= (insn & 0x03) << 25;
 | |
| 	regs->ARM_cpsr = cpsr;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_singlestep_it(probes_opcode_t insn,
 | |
| 		  struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	regs->ARM_pc += 2;
 | |
| 	t16_simulate_it(insn, asi, regs);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t16_decode_it(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	asi->insn_singlestep = t16_singlestep_it;
 | |
| 	return INSN_GOOD_NO_SLOT;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_cond_branch(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc + 2;
 | |
| 	long offset = insn & 0x7f;
 | |
| 	offset -= insn & 0x80; /* Apply sign bit */
 | |
| 	regs->ARM_pc = pc + (offset * 2);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t16_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	int cc = (insn >> 8) & 0xf;
 | |
| 	asi->insn_check_cc = probes_condition_checks[cc];
 | |
| 	asi->insn_handler = t16_simulate_cond_branch;
 | |
| 	return INSN_GOOD_NO_SLOT;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_simulate_branch(probes_opcode_t insn,
 | |
| 		   struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc + 2;
 | |
| 	long offset = insn & 0x3ff;
 | |
| 	offset -= insn & 0x400; /* Apply sign bit */
 | |
| 	regs->ARM_pc = pc + (offset * 2);
 | |
| }
 | |
| 
 | |
| static unsigned long __kprobes
 | |
| t16_emulate_loregs(probes_opcode_t insn,
 | |
| 		   struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long oldcpsr = regs->ARM_cpsr;
 | |
| 	unsigned long newcpsr;
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"msr	cpsr_fs, %[oldcpsr]	\n\t"
 | |
| 		"ldmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"blx	%[fn]			\n\t"
 | |
| 		"stmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"mrs	%[newcpsr], cpsr	\n\t"
 | |
| 		: [newcpsr] "=r" (newcpsr)
 | |
| 		: [oldcpsr] "r" (oldcpsr), [regs] "r" (regs),
 | |
| 		  [fn] "r" (asi->insn_fn)
 | |
| 		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
 | |
| 		  "lr", "memory", "cc"
 | |
| 		);
 | |
| 
 | |
| 	return (oldcpsr & ~APSR_MASK) | (newcpsr & APSR_MASK);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_loregs_rwflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	regs->ARM_cpsr = t16_emulate_loregs(insn, asi, regs);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_loregs_noitrwflags(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long cpsr = t16_emulate_loregs(insn, asi, regs);
 | |
| 	if (!in_it_block(cpsr))
 | |
| 		regs->ARM_cpsr = cpsr;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_hiregs(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long pc = regs->ARM_pc + 2;
 | |
| 	int rdn = (insn & 0x7) | ((insn & 0x80) >> 4);
 | |
| 	int rm = (insn >> 3) & 0xf;
 | |
| 
 | |
| 	register unsigned long rdnv asm("r1");
 | |
| 	register unsigned long rmv asm("r0");
 | |
| 	unsigned long cpsr = regs->ARM_cpsr;
 | |
| 
 | |
| 	rdnv = (rdn == 15) ? pc : regs->uregs[rdn];
 | |
| 	rmv = (rm == 15) ? pc : regs->uregs[rm];
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"msr	cpsr_fs, %[cpsr]	\n\t"
 | |
| 		"blx    %[fn]			\n\t"
 | |
| 		"mrs	%[cpsr], cpsr		\n\t"
 | |
| 		: "=r" (rdnv), [cpsr] "=r" (cpsr)
 | |
| 		: "0" (rdnv), "r" (rmv), "1" (cpsr), [fn] "r" (asi->insn_fn)
 | |
| 		: "lr", "memory", "cc"
 | |
| 	);
 | |
| 
 | |
| 	if (rdn == 15)
 | |
| 		rdnv &= ~1;
 | |
| 
 | |
| 	regs->uregs[rdn] = rdnv;
 | |
| 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t16_decode_hiregs(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	insn &= ~0x00ff;
 | |
| 	insn |= 0x001; /* Set Rdn = R1 and Rm = R0 */
 | |
| 	((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn);
 | |
| 	asi->insn_handler = t16_emulate_hiregs;
 | |
| 	return INSN_GOOD;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_push(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	__asm__ __volatile__ (
 | |
| 		"ldr	r9, [%[regs], #13*4]	\n\t"
 | |
| 		"ldr	r8, [%[regs], #14*4]	\n\t"
 | |
| 		"ldmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"blx	%[fn]			\n\t"
 | |
| 		"str	r9, [%[regs], #13*4]	\n\t"
 | |
| 		:
 | |
| 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
 | |
| 		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9",
 | |
| 		  "lr", "memory", "cc"
 | |
| 		);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t16_decode_push(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	/*
 | |
| 	 * To simulate a PUSH we use a Thumb-2 "STMDB R9!, {registers}"
 | |
| 	 * and call it with R9=SP and LR in the register list represented
 | |
| 	 * by R8.
 | |
| 	 */
 | |
| 	/* 1st half STMDB R9!,{} */
 | |
| 	((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe929);
 | |
| 	/* 2nd half (register list) */
 | |
| 	((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
 | |
| 	asi->insn_handler = t16_emulate_push;
 | |
| 	return INSN_GOOD;
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_pop_nopc(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	__asm__ __volatile__ (
 | |
| 		"ldr	r9, [%[regs], #13*4]	\n\t"
 | |
| 		"ldmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"blx	%[fn]			\n\t"
 | |
| 		"stmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"str	r9, [%[regs], #13*4]	\n\t"
 | |
| 		:
 | |
| 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
 | |
| 		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
 | |
| 		  "lr", "memory", "cc"
 | |
| 		);
 | |
| }
 | |
| 
 | |
| static void __kprobes
 | |
| t16_emulate_pop_pc(probes_opcode_t insn,
 | |
| 		struct arch_probes_insn *asi, struct pt_regs *regs)
 | |
| {
 | |
| 	register unsigned long pc asm("r8");
 | |
| 
 | |
| 	__asm__ __volatile__ (
 | |
| 		"ldr	r9, [%[regs], #13*4]	\n\t"
 | |
| 		"ldmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"blx	%[fn]			\n\t"
 | |
| 		"stmia	%[regs], {r0-r7}	\n\t"
 | |
| 		"str	r9, [%[regs], #13*4]	\n\t"
 | |
| 		: "=r" (pc)
 | |
| 		: [regs] "r" (regs), [fn] "r" (asi->insn_fn)
 | |
| 		: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
 | |
| 		  "lr", "memory", "cc"
 | |
| 		);
 | |
| 
 | |
| 	bx_write_pc(pc, regs);
 | |
| }
 | |
| 
 | |
| static enum probes_insn __kprobes
 | |
| t16_decode_pop(probes_opcode_t insn, struct arch_probes_insn *asi,
 | |
| 		const struct decode_header *d)
 | |
| {
 | |
| 	/*
 | |
| 	 * To simulate a POP we use a Thumb-2 "LDMDB R9!, {registers}"
 | |
| 	 * and call it with R9=SP and PC in the register list represented
 | |
| 	 * by R8.
 | |
| 	 */
 | |
| 	/* 1st half LDMIA R9!,{} */
 | |
| 	((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe8b9);
 | |
| 	/* 2nd half (register list) */
 | |
| 	((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
 | |
| 	asi->insn_handler = insn & 0x100 ? t16_emulate_pop_pc
 | |
| 					 : t16_emulate_pop_nopc;
 | |
| 	return INSN_GOOD;
 | |
| }
 | |
| 
 | |
| const union decode_action kprobes_t16_actions[NUM_PROBES_T16_ACTIONS] = {
 | |
| 	[PROBES_T16_ADD_SP] = {.handler = t16_simulate_add_sp_imm},
 | |
| 	[PROBES_T16_CBZ] = {.handler = t16_simulate_cbz},
 | |
| 	[PROBES_T16_SIGN_EXTEND] = {.handler = t16_emulate_loregs_rwflags},
 | |
| 	[PROBES_T16_PUSH] = {.decoder = t16_decode_push},
 | |
| 	[PROBES_T16_POP] = {.decoder = t16_decode_pop},
 | |
| 	[PROBES_T16_SEV] = {.handler = probes_emulate_none},
 | |
| 	[PROBES_T16_WFE] = {.handler = probes_simulate_nop},
 | |
| 	[PROBES_T16_IT] = {.decoder = t16_decode_it},
 | |
| 	[PROBES_T16_CMP] = {.handler = t16_emulate_loregs_rwflags},
 | |
| 	[PROBES_T16_ADDSUB] = {.handler = t16_emulate_loregs_noitrwflags},
 | |
| 	[PROBES_T16_LOGICAL] = {.handler = t16_emulate_loregs_noitrwflags},
 | |
| 	[PROBES_T16_LDR_LIT] = {.handler = t16_simulate_ldr_literal},
 | |
| 	[PROBES_T16_BLX] = {.handler = t16_simulate_bxblx},
 | |
| 	[PROBES_T16_HIREGOPS] = {.decoder = t16_decode_hiregs},
 | |
| 	[PROBES_T16_LDRHSTRH] = {.handler = t16_emulate_loregs_rwflags},
 | |
| 	[PROBES_T16_LDRSTR] = {.handler = t16_simulate_ldrstr_sp_relative},
 | |
| 	[PROBES_T16_ADR] = {.handler = t16_simulate_reladr},
 | |
| 	[PROBES_T16_LDMSTM] = {.handler = t16_emulate_loregs_rwflags},
 | |
| 	[PROBES_T16_BRANCH_COND] = {.decoder = t16_decode_cond_branch},
 | |
| 	[PROBES_T16_BRANCH] = {.handler = t16_simulate_branch},
 | |
| };
 | |
| 
 | |
| const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = {
 | |
| 	[PROBES_T32_LDMSTM] = {.decoder = t32_decode_ldmstm},
 | |
| 	[PROBES_T32_LDRDSTRD] = {.handler = t32_emulate_ldrdstrd},
 | |
| 	[PROBES_T32_TABLE_BRANCH] = {.handler = t32_simulate_table_branch},
 | |
| 	[PROBES_T32_TST] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_MOV] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_ADDSUB] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_LOGICAL] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_CMP] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_ADDWSUBW_PC] = {.handler = t32_emulate_rd8pc16_noflags,},
 | |
| 	[PROBES_T32_ADDWSUBW] = {.handler = t32_emulate_rd8rn16_noflags},
 | |
| 	[PROBES_T32_MOVW] = {.handler = t32_emulate_rd8rn16_noflags},
 | |
| 	[PROBES_T32_SAT] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_BITFIELD] = {.handler = t32_emulate_rd8rn16_noflags},
 | |
| 	[PROBES_T32_SEV] = {.handler = probes_emulate_none},
 | |
| 	[PROBES_T32_WFE] = {.handler = probes_simulate_nop},
 | |
| 	[PROBES_T32_MRS] = {.handler = t32_simulate_mrs},
 | |
| 	[PROBES_T32_BRANCH_COND] = {.decoder = t32_decode_cond_branch},
 | |
| 	[PROBES_T32_BRANCH] = {.handler = t32_simulate_branch},
 | |
| 	[PROBES_T32_PLDI] = {.handler = probes_simulate_nop},
 | |
| 	[PROBES_T32_LDR_LIT] = {.handler = t32_simulate_ldr_literal},
 | |
| 	[PROBES_T32_LDRSTR] = {.handler = t32_emulate_ldrstr},
 | |
| 	[PROBES_T32_SIGN_EXTEND] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_MEDIA] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_REVERSE] = {.handler = t32_emulate_rd8rn16_noflags},
 | |
| 	[PROBES_T32_MUL_ADD] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
 | |
| 	[PROBES_T32_MUL_ADD2] = {.handler = t32_emulate_rd8rn16rm0ra12_noflags},
 | |
| 	[PROBES_T32_MUL_ADD_LONG] = {
 | |
| 		.handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags},
 | |
| };
 |