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Commit 3c48fbb1 authored by Jon Medhurst's avatar Jon Medhurst Committed by Tixy
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ARM: kprobes: Add new versions of emulate_ldr() and emulate_str() 



These use the register calling conventions required by the new decoding
table framework for calling simulated instructions.

We rename the old versions of these functions to *_old for now.

Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent 12ce5d33

arch/arm/kernel/kprobes-arm.c

+60 −3
Original line number Diff line number Diff line
@@ -502,7 +502,7 @@ static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs) 
		regs->uregs[rn] = rnv_wb;

}



static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs)

static void __kprobes emulate_ldr_old(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;
@@ -535,7 +535,7 @@ static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) 
	regs->uregs[rd] = rdv;

}



static void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs)

static void __kprobes emulate_str_old(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;
@@ -795,7 +795,7 @@ prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi) 
		insn |= 2;	/* Rm = r2 */

	}

	asi->insn[0] = insn;

	asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr : emulate_str;

	asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr_old : emulate_str_old;

	return INSN_GOOD;

}
@@ -922,6 +922,63 @@ emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs) 
		regs->uregs[rn] = rnv;

}



static void __kprobes

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

{

	kprobe_opcode_t insn = p->opcode;

	unsigned long pc = (unsigned long)p->addr + 8;

	int rt = (insn >> 12) & 0xf;

	int rn = (insn >> 16) & 0xf;

	int rm = insn & 0xf;



	register unsigned long rtv asm("r0");

	register unsigned long rnv asm("r2") = (rn == 15) ? pc

							  : regs->uregs[rn];

	register unsigned long rmv asm("r3") = regs->uregs[rm];



	__asm__ __volatile__ (

		BLX("%[fn]")

		: "=r" (rtv), "=r" (rnv)

		: "1" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)

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

	);



	if (rt == 15)

		load_write_pc(rtv, regs);

	else

		regs->uregs[rt] = rtv;



	if (is_writeback(insn))

		regs->uregs[rn] = rnv;

}



static void __kprobes

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

{

	kprobe_opcode_t insn = p->opcode;

	unsigned long rtpc = (unsigned long)p->addr + str_pc_offset;

	unsigned long rnpc = (unsigned long)p->addr + 8;

	int rt = (insn >> 12) & 0xf;

	int rn = (insn >> 16) & 0xf;

	int rm = insn & 0xf;



	register unsigned long rtv asm("r0") = (rt == 15) ? rtpc

							  : regs->uregs[rt];

	register unsigned long rnv asm("r2") = (rn == 15) ? rnpc

							  : regs->uregs[rn];

	register unsigned long rmv asm("r3") = regs->uregs[rm];



	__asm__ __volatile__ (

		BLX("%[fn]")

		: "=r" (rnv)

		: "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)

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

	);



	if (is_writeback(insn))

		regs->uregs[rn] = rnv;

}



static void __kprobes

emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)

{