Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7848786a authored by Jon Medhurst's avatar Jon Medhurst Committed by Tixy
Browse files

ARM: kprobes: Decode 32-bit Thumb data-processing (plain binary immediate) instructions 



Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent 2fcaf7e7

arch/arm/kernel/kprobes-thumb.c

+95 −0
Original line number Diff line number Diff line
@@ -124,6 +124,46 @@ t32_emulate_rd8rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs) 
	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);

}



static void __kprobes

t32_emulate_rd8pc16_noflags(struct kprobe *p, struct pt_regs *regs)

{

	kprobe_opcode_t insn = p->opcode;

	unsigned long pc = thumb_probe_pc(p);

	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" (p->ainsn.insn_fn)

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

	);



	regs->uregs[rd] = rdv;

}



static void __kprobes

t32_emulate_rd8rn16_noflags(struct kprobe *p, struct pt_regs *regs)

{

	kprobe_opcode_t insn = p->opcode;

	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" (p->ainsn.insn_fn)

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

	);



	regs->uregs[rd] = rdv;

}



static const union decode_item t32_table_1110_100x_x0xx[] = {

	/* Load/store multiple instructions */
@@ -293,6 +333,55 @@ static const union decode_item t32_table_1111_0x0x___0[] = { 
	DECODE_END

};



static const union decode_item t32_table_1111_0x1x___0[] = {

	/* Data-processing (plain binary immediate)			*/



	/* ADDW Rd, PC, #imm	1111 0x10 0000 1111 0xxx xxxx xxxx xxxx */

	DECODE_OR	(0xfbff8000, 0xf20f0000),

	/* SUBW	Rd, PC, #imm	1111 0x10 1010 1111 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfbff8000, 0xf2af0000, t32_emulate_rd8pc16_noflags,

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



	/* ADDW SP, SP, #imm	1111 0x10 0000 1101 0xxx 1101 xxxx xxxx */

	DECODE_OR	(0xfbff8f00, 0xf20d0d00),

	/* SUBW	SP, SP, #imm	1111 0x10 1010 1101 0xxx 1101 xxxx xxxx */

	DECODE_EMULATEX	(0xfbff8f00, 0xf2ad0d00, t32_emulate_rd8rn16_noflags,

						 REGS(SP, 0, SP, 0, 0)),



	/* ADDW			1111 0x10 0000 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_OR	(0xfbf08000, 0xf2000000),

	/* SUBW			1111 0x10 1010 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfbf08000, 0xf2a00000, t32_emulate_rd8rn16_noflags,

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



	/* MOVW			1111 0x10 0100 xxxx 0xxx xxxx xxxx xxxx */

	/* MOVT			1111 0x10 1100 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfb708000, 0xf2400000, t32_emulate_rd8rn16_noflags,

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



	/* SSAT16		1111 0x11 0010 xxxx 0000 xxxx 00xx xxxx */

	/* SSAT			1111 0x11 00x0 xxxx 0xxx xxxx xxxx xxxx */

	/* USAT16		1111 0x11 1010 xxxx 0000 xxxx 00xx xxxx */

	/* USAT			1111 0x11 10x0 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfb508000, 0xf3000000, t32_emulate_rd8rn16rm0_rwflags,

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



	/* SFBX			1111 0x11 0100 xxxx 0xxx xxxx xxxx xxxx */

	/* UFBX			1111 0x11 1100 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfb708000, 0xf3400000, t32_emulate_rd8rn16_noflags,

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



	/* BFC			1111 0x11 0110 1111 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfbff8000, 0xf36f0000, t32_emulate_rd8rn16_noflags,

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



	/* BFI			1111 0x11 0110 xxxx 0xxx xxxx xxxx xxxx */

	DECODE_EMULATEX	(0xfbf08000, 0xf3600000, t32_emulate_rd8rn16_noflags,

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



	DECODE_END

};



static const union decode_item t32_table_1111_0xxx___1[] = {

	/* Branches and miscellaneous control				*/
@@ -334,6 +423,12 @@ const union decode_item kprobe_decode_thumb32_table[] = { 
	 */

	DECODE_TABLE	(0xfa008000, 0xf0000000, t32_table_1111_0x0x___0),



	/*

	 * Data-processing (plain binary immediate)

	 *			1111 0x1x xxxx xxxx 0xxx xxxx xxxx xxxx

	 */

	DECODE_TABLE	(0xfa008000, 0xf2000000, t32_table_1111_0x1x___0),



	/*

	 * Branches and miscellaneous control

	 *			1111 0xxx xxxx xxxx 1xxx xxxx xxxx xxxx