From 41713d1396312a027ec02abc4767041627c178ef Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Mon, 18 Apr 2011 08:53:57 +0100 Subject: [PATCH] ARM: kprobes: Fix emulation of PLD instructions The PLD instructions wasn't being decoded correctly and the emulation code wasn't adjusting PC correctly. As the PLD instruction is only a performance hint we emulate it as a simple nop, and we can broaden the instruction decoding to take into account newer PLI and PLDW instructions. Signed-off-by: Jon Medhurst Signed-off-by: Nicolas Pitre --- arch/arm/kernel/kprobes-decode.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index b81fbfb3315..bddf8d0f3dc 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -657,14 +657,8 @@ static void __kprobes emulate_none(struct kprobe *p, struct pt_regs *regs) insnslot_0arg_rflags(regs->ARM_cpsr, i_fn); } -static void __kprobes emulate_rn16(struct kprobe *p, struct pt_regs *regs) +static void __kprobes emulate_nop(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; - kprobe_opcode_t insn = p->opcode; - int rn = (insn >> 16) & 0xf; - long rnv = regs->uregs[rn]; - - insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); } static void __kprobes emulate_rd12rm0(struct kprobe *p, struct pt_regs *regs) @@ -941,12 +935,13 @@ space_1111(kprobe_opcode_t insn, struct arch_specific_insn *asi) (insn & 0xfe5f0f00) == 0xf84d0500) return INSN_REJECTED; - /* PLD : 1111 01x1 x101 xxxx xxxx xxxx xxxx xxxx : */ - if ((insn & 0xfd700000) == 0xf4500000) { - insn &= 0xfff0ffff; /* Rn = r0 */ - asi->insn[0] = insn; - asi->insn_handler = emulate_rn16; - return INSN_GOOD; + /* memory hint : 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDI : 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDW : 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLD : 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfe300000) == 0xf4100000) { + asi->insn_handler = emulate_nop; + return INSN_GOOD_NO_SLOT; } /* BLX(1) : 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx : */ -- 2.46.0