kprobes.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2#ifndef _ASM_X86_KPROBES_H
  3#define _ASM_X86_KPROBES_H
  4/*
  5 *  Kernel Probes (KProbes)
  6 *
  7 * Copyright (C) IBM Corporation, 2002, 2004
  8 *
  9 * See arch/x86/kernel/kprobes.c for x86 kprobes history.
 10 */
 11
 12#include <asm-generic/kprobes.h>
 13
 14#ifdef CONFIG_KPROBES
 15#include <linux/types.h>
 16#include <linux/ptrace.h>
 17#include <linux/percpu.h>
 18#include <asm/text-patching.h>
 19#include <asm/insn.h>
 20
 21#define  __ARCH_WANT_KPROBES_INSN_SLOT
 22
 23struct pt_regs;
 24struct kprobe;
 25
 26typedef u8 kprobe_opcode_t;
 27
 28#define MAX_STACK_SIZE 64
 29#define CUR_STACK_SIZE(ADDR) \
 30	(current_top_of_stack() - (unsigned long)(ADDR))
 31#define MIN_STACK_SIZE(ADDR)				\
 32	(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?	\
 33	 MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
 34
 35#define flush_insn_slot(p)	do { } while (0)
 36
 37/* optinsn template addresses */
 38extern __visible kprobe_opcode_t optprobe_template_entry[];
 39extern __visible kprobe_opcode_t optprobe_template_clac[];
 40extern __visible kprobe_opcode_t optprobe_template_val[];
 41extern __visible kprobe_opcode_t optprobe_template_call[];
 42extern __visible kprobe_opcode_t optprobe_template_end[];
 43#define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + DISP32_SIZE)
 44#define MAX_OPTINSN_SIZE 				\
 45	(((unsigned long)optprobe_template_end -	\
 46	  (unsigned long)optprobe_template_entry) +	\
 47	 MAX_OPTIMIZED_LENGTH + JMP32_INSN_SIZE)
 48
 49extern const int kretprobe_blacklist_size;
 50
 51void arch_remove_kprobe(struct kprobe *p);
 52
 53/* Architecture specific copy of original instruction*/
 54struct arch_specific_insn {
 55	/* copy of the original instruction */
 56	kprobe_opcode_t *insn;
 57	/*
 58	 * boostable = 0: This instruction type is not boostable.
 59	 * boostable = 1: This instruction has been boosted: we have
 60	 * added a relative jump after the instruction copy in insn,
 61	 * so no single-step and fixup are needed (unless there's
 62	 * a post_handler).
 63	 */
 64	unsigned boostable:1;
 65	unsigned char size;	/* The size of insn */
 66	union {
 67		unsigned char opcode;
 68		struct {
 69			unsigned char type;
 70		} jcc;
 71		struct {
 72			unsigned char type;
 73			unsigned char asize;
 74		} loop;
 75		struct {
 76			unsigned char reg;
 77		} indirect;
 78	};
 79	s32 rel32;	/* relative offset must be s32, s16, or s8 */
 80	void (*emulate_op)(struct kprobe *p, struct pt_regs *regs);
 81	/* Number of bytes of text poked */
 82	int tp_len;
 83};
 84
 85struct arch_optimized_insn {
 86	/* copy of the original instructions */
 87	kprobe_opcode_t copied_insn[DISP32_SIZE];
 88	/* detour code buffer */
 89	kprobe_opcode_t *insn;
 90	/* the size of instructions copied to detour code buffer */
 91	size_t size;
 92};
 93
 94/* Return true (!0) if optinsn is prepared for optimization. */
 95static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
 96{
 97	return optinsn->size;
 98}
 99
100struct prev_kprobe {
101	struct kprobe *kp;
102	unsigned long status;
103	unsigned long old_flags;
104	unsigned long saved_flags;
105};
106
107/* per-cpu kprobe control block */
108struct kprobe_ctlblk {
109	unsigned long kprobe_status;
110	unsigned long kprobe_old_flags;
111	unsigned long kprobe_saved_flags;
112	struct prev_kprobe prev_kprobe;
113};
114
115extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
116extern int kprobe_int3_handler(struct pt_regs *regs);
117
118#else
119
120static inline int kprobe_debug_handler(struct pt_regs *regs) { return 0; }
121
122#endif /* CONFIG_KPROBES */
123#endif /* _ASM_X86_KPROBES_H */