From 6823fc85fcfba11675f2027aadf2d5291c6f351b Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Fri, 8 Apr 2011 15:32:54 +0100 Subject: [PATCH] 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: Jon Medhurst Signed-off-by: Nicolas Pitre --- arch/arm/kernel/kprobes-decode.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index c24e21ec427f..348ff47acd06 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -883,11 +883,12 @@ emulate_alu_tests(struct kprobe *p, struct pt_regs *regs) static enum kprobe_insn __kprobes 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 |= 0x00001000; /* Rn = r0, Rd = r1 */ - if (insn & (1 << ibit)) { + if (not_imm) { insn &= ~0xf; insn |= 2; /* Rm = r2 */ } -- 2.20.1