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Commit 8723942f authored by Jon Medhurst's avatar Jon Medhurst Committed by Tixy
Browse files

ARM: kprobes: Add emulate_ldrdstrd() 



This is an emulation function for the LDRD and STRD instructions.

Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Acked-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent 3535a89a

arch/arm/kernel/kprobes-arm.c

+29 −0
Original line number Diff line number Diff line
@@ -893,6 +893,35 @@ prep_emulate_rdhi16rdlo12rs8rm0_wflags(kprobe_opcode_t insn, 
	return INSN_GOOD;

}



static void __kprobes

emulate_ldrdstrd(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") = regs->uregs[rt];

	register unsigned long rt2v asm("r1") = regs->uregs[rt+1];

	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" (rt2v), "=r" (rnv)

		: "0" (rtv), "1" (rt2v), "2" (rnv), "r" (rmv),

		  [fn] "r" (p->ainsn.insn_fn)

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

	);



	regs->uregs[rt] = rtv;

	regs->uregs[rt+1] = rt2v;

	if (is_writeback(insn))

		regs->uregs[rn] = rnv;

}



static void __kprobes

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

{