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Commit 231fb150 authored by Jon Medhurst's avatar Jon Medhurst Committed by Tixy
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ARM: kprobes: Decode 32-bit Thumb long multiply and divide instructions 



Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent 31656c1a

arch/arm/kernel/kprobes-thumb.c

+55 −0
Original line number Diff line number Diff line
@@ -289,6 +289,32 @@ t32_emulate_rd8rn16_noflags(struct kprobe *p, struct pt_regs *regs) 
	regs->uregs[rd] = rdv;

}



static void __kprobes

t32_emulate_rdlo12rdhi8rn16rm0_noflags(struct kprobe *p, struct pt_regs *regs)

{

	kprobe_opcode_t insn = p->opcode;

	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" (p->ainsn.insn_fn)

		: "lr", "memory", "cc"

	);



	regs->uregs[rdlo] = rdlov;

	regs->uregs[rdhi] = rdhiv;

}



static const union decode_item t32_table_1110_100x_x0xx[] = {

	/* Load/store multiple instructions */
@@ -763,6 +789,29 @@ static const union decode_item t32_table_1111_1010___1111[] = { 
	DECODE_END

};



static const union decode_item t32_table_1111_1011_1[] = {

	/* Long multiply, long multiply accumulate, and divide		*/



	/* UMAAL		1111 1011 1110 xxxx xxxx xxxx 0110 xxxx */

	DECODE_OR	(0xfff000f0, 0xfbe00060),

	/* SMLALxy		1111 1011 1100 xxxx xxxx xxxx 10xx xxxx */

	DECODE_OR	(0xfff000c0, 0xfbc00080),

	/* SMLALD{X}		1111 1011 1100 xxxx xxxx xxxx 110x xxxx */

	/* SMLSLD{X}		1111 1011 1101 xxxx xxxx xxxx 110x xxxx */

	DECODE_OR	(0xffe000e0, 0xfbc000c0),

	/* SMULL		1111 1011 1000 xxxx xxxx xxxx 0000 xxxx */

	/* UMULL		1111 1011 1010 xxxx xxxx xxxx 0000 xxxx */

	/* SMLAL		1111 1011 1100 xxxx xxxx xxxx 0000 xxxx */

	/* UMLAL		1111 1011 1110 xxxx xxxx xxxx 0000 xxxx */

	DECODE_EMULATEX	(0xff9000f0, 0xfb800000, t32_emulate_rdlo12rdhi8rn16rm0_noflags,

						 REGS(NOSPPC, NOSPPC, NOSPPC, 0, NOSPPC)),



	/* SDIV			1111 1011 1001 xxxx xxxx xxxx 1111 xxxx */

	/* UDIV			1111 1011 1011 xxxx xxxx xxxx 1111 xxxx */

	/* Other unallocated instructions...				*/

	DECODE_END

};



const union decode_item kprobe_decode_thumb32_table[] = {



	/*
@@ -833,6 +882,12 @@ const union decode_item kprobe_decode_thumb32_table[] = { 
	 */

	DECODE_TABLE	(0xff00f000, 0xfa00f000, t32_table_1111_1010___1111),



	/*

	 * Long multiply, long multiply accumulate, and divide

	 *			1111 1011 1xxx xxxx xxxx xxxx xxxx xxxx

	 */

	DECODE_TABLE	(0xff800000, 0xfb800000, t32_table_1111_1011_1),



	/*

	 * Coprocessor instructions

	 *			1111 11xx xxxx xxxx xxxx xxxx xxxx xxxx