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Commit 3535a89a authored by Jon Medhurst's avatar Jon Medhurst Committed by Tixy
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ARM: kprobes: Migrate ARM data-processing (register) instructions to decoding tables 



Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent 9f596e51

arch/arm/kernel/kprobes-arm.c

+63 −48
Original line number Diff line number Diff line
@@ -968,6 +968,68 @@ static const union decode_item arm_1111_table[] = { 
	DECODE_END

};



static const union decode_item arm_cccc_000x_table[] = {

	/* Data-processing (register)					*/



	/* <op>S PC, ...	cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx */

	DECODE_REJECT	(0x0e10f000, 0x0010f000),



	/* MOV IP, SP		1110 0001 1010 0000 1100 0000 0000 1101 */

	DECODE_SIMULATE	(0xffffffff, 0xe1a0c00d, simulate_mov_ipsp),



	/* TST (register)	cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */

	/* TEQ (register)	cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */

	/* CMP (register)	cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */

	/* CMN (register)	cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */

	DECODE_EMULATEX	(0x0f900010, 0x01100000, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(ANY, 0, 0, 0, ANY)),



	/* MOV (register)	cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */

	/* MVN (register)	cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */

	DECODE_EMULATEX	(0x0fa00010, 0x01a00000, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(0, ANY, 0, 0, ANY)),



	/* AND (register)	cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */

	/* EOR (register)	cccc 0000 001x xxxx xxxx xxxx xxx0 xxxx */

	/* SUB (register)	cccc 0000 010x xxxx xxxx xxxx xxx0 xxxx */

	/* RSB (register)	cccc 0000 011x xxxx xxxx xxxx xxx0 xxxx */

	/* ADD (register)	cccc 0000 100x xxxx xxxx xxxx xxx0 xxxx */

	/* ADC (register)	cccc 0000 101x xxxx xxxx xxxx xxx0 xxxx */

	/* SBC (register)	cccc 0000 110x xxxx xxxx xxxx xxx0 xxxx */

	/* RSC (register)	cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */

	/* ORR (register)	cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */

	/* BIC (register)	cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */

	DECODE_EMULATEX	(0x0e000010, 0x00000000, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(ANY, ANY, 0, 0, ANY)),



	/* TST (reg-shift reg)	cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */

	/* TEQ (reg-shift reg)	cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */

	/* CMP (reg-shift reg)	cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */

	/* CMN (reg-shift reg)	cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */

	DECODE_EMULATEX	(0x0f900090, 0x01100010, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(ANY, 0, NOPC, 0, ANY)),



	/* MOV (reg-shift reg)	cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */

	/* MVN (reg-shift reg)	cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */

	DECODE_EMULATEX	(0x0fa00090, 0x01a00010, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(0, ANY, NOPC, 0, ANY)),



	/* AND (reg-shift reg)	cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */

	/* EOR (reg-shift reg)	cccc 0000 001x xxxx xxxx xxxx 0xx1 xxxx */

	/* SUB (reg-shift reg)	cccc 0000 010x xxxx xxxx xxxx 0xx1 xxxx */

	/* RSB (reg-shift reg)	cccc 0000 011x xxxx xxxx xxxx 0xx1 xxxx */

	/* ADD (reg-shift reg)	cccc 0000 100x xxxx xxxx xxxx 0xx1 xxxx */

	/* ADC (reg-shift reg)	cccc 0000 101x xxxx xxxx xxxx 0xx1 xxxx */

	/* SBC (reg-shift reg)	cccc 0000 110x xxxx xxxx xxxx 0xx1 xxxx */

	/* RSC (reg-shift reg)	cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */

	/* ORR (reg-shift reg)	cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */

	/* BIC (reg-shift reg)	cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */

	DECODE_EMULATEX	(0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags,

						 REGS(ANY, ANY, NOPC, 0, ANY)),



	DECODE_END

};



static enum kprobe_insn __kprobes

space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi)

{
@@ -1126,54 +1188,7 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) 
		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;

	return kprobe_decode_insn(insn, asi, arm_cccc_000x_table, false);

}



static enum kprobe_insn __kprobes