From f248da70ef7a22076d31fac1693bdb1698463ec2 Mon Sep 17 00:00:00 2001
From: Jon Medhurst <tixy@yxit.co.uk>
Date: Sat, 2 Jul 2011 16:30:43 +0100
Subject: [PATCH] --- yaml --- r: 258351 b: refs/heads/master c:
 396b41f68d937a0c48ba624186ed06288b35bb4e h: refs/heads/master i:   258349:
 d55f1b782f3ae7ca336c008a771caf947d0f67ae   258347:
 28db7dc9bb489c0fe285857ac4ecdb752e2c52bb   258343:
 809120663f9526aaea0f3345039f40bcdedf9873   258335:
 ad50c0ac3b9d6008411b2dff1b0a022bc57d4004 v: v3

---
 [refs]                                |  2 +-
 trunk/arch/arm/kernel/kprobes-thumb.c | 38 +++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index e7272ff6910c..20e138059703 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 444956677eccfcdfe05de761e1286f62c423ce88
+refs/heads/master: 396b41f68d937a0c48ba624186ed06288b35bb4e
diff --git a/trunk/arch/arm/kernel/kprobes-thumb.c b/trunk/arch/arm/kernel/kprobes-thumb.c
index 997fc6d59a40..d3133fd2d4e8 100644
--- a/trunk/arch/arm/kernel/kprobes-thumb.c
+++ b/trunk/arch/arm/kernel/kprobes-thumb.c
@@ -141,6 +141,35 @@ t16_decode_it(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD_NO_SLOT;
 }
 
+static void __kprobes
+t16_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs)
+{
+	kprobe_opcode_t insn = p->opcode;
+	unsigned long pc = thumb_probe_pc(p);
+	long offset = insn & 0x7f;
+	offset -= insn & 0x80; /* Apply sign bit */
+	regs->ARM_pc = pc + (offset * 2);
+}
+
+static enum kprobe_insn __kprobes
+t16_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+{
+	int cc = (insn >> 8) & 0xf;
+	asi->insn_check_cc = kprobe_condition_checks[cc];
+	asi->insn_handler = t16_simulate_cond_branch;
+	return INSN_GOOD_NO_SLOT;
+}
+
+static void __kprobes
+t16_simulate_branch(struct kprobe *p, struct pt_regs *regs)
+{
+	kprobe_opcode_t insn = p->opcode;
+	unsigned long pc = thumb_probe_pc(p);
+	long offset = insn & 0x3ff;
+	offset -= insn & 0x400; /* Apply sign bit */
+	regs->ARM_pc = pc + (offset * 2);
+}
+
 static unsigned long __kprobes
 t16_emulate_loregs(struct kprobe *p, struct pt_regs *regs)
 {
@@ -472,6 +501,15 @@ const union decode_item kprobe_decode_thumb16_table[] = {
 	/* SVC				1101 1111 xxxx xxxx */
 	DECODE_REJECT	(0xfe00, 0xde00),
 
+	/* Conditional branch		1101 xxxx xxxx xxxx */
+	DECODE_CUSTOM	(0xf000, 0xd000, t16_decode_cond_branch),
+
+	/*
+	 * Unconditional branch
+	 * B				1110 0xxx xxxx xxxx
+	 */
+	DECODE_SIMULATE	(0xf800, 0xe000, t16_simulate_branch),
+
 	DECODE_END
 };