From: Jon Medhurst <tixy@yxit.co.uk>
Date: Mon, 18 Apr 2011 07:53:57 +0000 (+0100)
Subject: ARM: kprobes: Fix emulation of PLD instructions
X-Git-Tag: v2.6.39-rc6~9^2~2^2~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=41713d1396312a027ec02abc4767041627c178ef;p=users%2Fjedix%2Flinux-maple.git
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 <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
---
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c
index b81fbfb33151..bddf8d0f3dc1 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 : */