ARC: kprobes support

Origin port done by Rajeshwar Ranga

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>

arch/arc/include/asm/kprobes.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ARC_KPROBES_H
+#define _ARC_KPROBES_H
+
+#ifdef CONFIG_KPROBES
+
+typedef u16 kprobe_opcode_t;
+
+#define UNIMP_S_INSTRUCTION 0x79e0
+#define TRAP_S_2_INSTRUCTION 0x785e
+
+#define MAX_INSN_SIZE   8
+#define MAX_STACK_SIZE  64
+
+struct arch_specific_insn {
+	int is_short;
+	kprobe_opcode_t *t1_addr, *t2_addr;
+	kprobe_opcode_t t1_opcode, t2_opcode;
+};
+
+#define flush_insn_slot(p)  do {  } while (0)
+
+#define kretprobe_blacklist_size    0
+
+struct kprobe;
+
+void arch_remove_kprobe(struct kprobe *p);
+
+int kprobe_exceptions_notify(struct notifier_block *self,
+			     unsigned long val, void *data);
+
+struct prev_kprobe {
+	struct kprobe *kp;
+	unsigned long status;
+};
+
+struct kprobe_ctlblk {
+	unsigned int kprobe_status;
+	struct pt_regs jprobe_saved_regs;
+	char jprobes_stack[MAX_STACK_SIZE];
+	struct prev_kprobe prev_kprobe;
+};
+
+int kprobe_fault_handler(struct pt_regs *regs, unsigned long cause);
+void kretprobe_trampoline(void);
+void trap_is_kprobe(unsigned long cause, unsigned long address,
+			   struct pt_regs *regs);
+#else
+static void trap_is_kprobe(unsigned long cause, unsigned long address,
+			   struct pt_regs *regs)
+{
+}
+#endif
+
+#endif

arch/arc/include/asm/ptrace.h

@@ -111,6 +111,11 @@ struct callee_regs {
 	(struct pt_regs *)(pg_start + THREAD_SIZE - 4) - 1;	\
 })
 
+static inline long regs_return_value(struct pt_regs *regs)
+{
+	return regs->r0;
+}
+
 #endif /* !__ASSEMBLY__ */
 
 #define orig_r8_IS_SCALL		0x0001