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Commit 6823fc85 authored by Jon Medhurst's avatar Jon Medhurst Committed by Nicolas Pitre
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ARM: kprobes: Fix emulation of LDRH, STRH, LDRSB and LDRSH instructions 



The decoding of these instructions got the register indexed and
immediate indexed forms the wrong way around, causing incorrect
emulation.

Signed-off-by: default avatarJon Medhurst <tixy@yxit.co.uk>
Signed-off-by: default avatarNicolas Pitre <nicolas.pitre@linaro.org>
parent ec58d7f2

arch/arm/kernel/kprobes-decode.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -883,11 +883,12 @@ emulate_alu_tests(struct kprobe *p, struct pt_regs *regs) 
static enum kprobe_insn __kprobes

static enum kprobe_insn __kprobes

prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi)

prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi)

{

{

	int ibit = (insn & (1 << 26)) ? 25 : 22;

	int not_imm = (insn & (1 << 26)) ? (insn & (1 << 25))

					 : (~insn & (1 << 22));





	insn &= 0xfff00fff;

	insn &= 0xfff00fff;

	insn |= 0x00001000;	/* Rn = r0, Rd = r1 */

	insn |= 0x00001000;	/* Rn = r0, Rd = r1 */

	if (insn & (1 << ibit)) {

	if (not_imm) {

		insn &= ~0xf;

		insn &= ~0xf;

		insn |= 2;	/* Rm = r2 */

		insn |= 2;	/* Rm = r2 */

	}

	}