x86/kprobes: Split out optprobe related code to kprobes-opt.c

Split out optprobe related code to arch/x86/kernel/kprobes-opt.c
for maintenanceability.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: systemtap@sourceware.org
Cc: anderson@redhat.com
Link: http://lkml.kernel.org/r/20120305133222.5982.54794.stgit@localhost.localdomain
[ Tidied up the code a tiny bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/Makefile

@@ -69,6 +69,7 @@ obj-$(CONFIG_KEXEC)		+= machine_kexec_$(BITS).o
 obj-$(CONFIG_KEXEC)		+= relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump_$(BITS).o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
+obj-$(CONFIG_OPTPROBES)		+= kprobes-opt.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault_32.o
 obj-$(CONFIG_KGDB)		+= kgdb.o

arch/x86/kernel/kprobes-common.h

@@ -0,0 +1,102 @@
+#ifndef __X86_KERNEL_KPROBES_COMMON_H
+#define __X86_KERNEL_KPROBES_COMMON_H
+
+/* Kprobes and Optprobes common header */
+
+#ifdef CONFIG_X86_64
+#define SAVE_REGS_STRING			\
+	/* Skip cs, ip, orig_ax. */		\
+	"	subq $24, %rsp\n"		\
+	"	pushq %rdi\n"			\
+	"	pushq %rsi\n"			\
+	"	pushq %rdx\n"			\
+	"	pushq %rcx\n"			\
+	"	pushq %rax\n"			\
+	"	pushq %r8\n"			\
+	"	pushq %r9\n"			\
+	"	pushq %r10\n"			\
+	"	pushq %r11\n"			\
+	"	pushq %rbx\n"			\
+	"	pushq %rbp\n"			\
+	"	pushq %r12\n"			\
+	"	pushq %r13\n"			\
+	"	pushq %r14\n"			\
+	"	pushq %r15\n"
+#define RESTORE_REGS_STRING			\
+	"	popq %r15\n"			\
+	"	popq %r14\n"			\
+	"	popq %r13\n"			\
+	"	popq %r12\n"			\
+	"	popq %rbp\n"			\
+	"	popq %rbx\n"			\
+	"	popq %r11\n"			\
+	"	popq %r10\n"			\
+	"	popq %r9\n"			\
+	"	popq %r8\n"			\
+	"	popq %rax\n"			\
+	"	popq %rcx\n"			\
+	"	popq %rdx\n"			\
+	"	popq %rsi\n"			\
+	"	popq %rdi\n"			\
+	/* Skip orig_ax, ip, cs */		\
+	"	addq $24, %rsp\n"
+#else
+#define SAVE_REGS_STRING			\
+	/* Skip cs, ip, orig_ax and gs. */	\
+	"	subl $16, %esp\n"		\
+	"	pushl %fs\n"			\
+	"	pushl %es\n"			\
+	"	pushl %ds\n"			\
+	"	pushl %eax\n"			\
+	"	pushl %ebp\n"			\
+	"	pushl %edi\n"			\
+	"	pushl %esi\n"			\
+	"	pushl %edx\n"			\
+	"	pushl %ecx\n"			\
+	"	pushl %ebx\n"
+#define RESTORE_REGS_STRING			\
+	"	popl %ebx\n"			\
+	"	popl %ecx\n"			\
+	"	popl %edx\n"			\
+	"	popl %esi\n"			\
+	"	popl %edi\n"			\
+	"	popl %ebp\n"			\
+	"	popl %eax\n"			\
+	/* Skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/\
+	"	addl $24, %esp\n"
+#endif
+
+/* Ensure if the instruction can be boostable */
+extern int can_boost(kprobe_opcode_t *instruction);
+/* Recover instruction if given address is probed */
+extern unsigned long recover_probed_instruction(kprobe_opcode_t *buf,
+					 unsigned long addr);
+/*
+ * Copy an instruction and adjust the displacement if the instruction
+ * uses the %rip-relative addressing mode.
+ */
+extern int __copy_instruction(u8 *dest, u8 *src);
+
+/* Generate a relative-jump/call instruction */
+extern void synthesize_reljump(void *from, void *to);
+extern void synthesize_relcall(void *from, void *to);
+
+#ifdef	CONFIG_OPTPROBES
+extern int arch_init_optprobes(void);
+extern int setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter);
+extern unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr);
+#else	/* !CONFIG_OPTPROBES */
+static inline int arch_init_optprobes(void)
+{
+	return 0;
+}
+static inline int setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter)
+{
+	return 0;
+}
+static inline unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr)
+{
+	return addr;
+}
+#endif
+#endif