1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  #ifndef _LINUX_UPROBES_H
3  #define _LINUX_UPROBES_H
4  /*
5   * User-space Probes (UProbes)
6   *
7   * Copyright (C) IBM Corporation, 2008-2012
8   * Authors:
9   *	Srikar Dronamraju
10   *	Jim Keniston
11   * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra
12   */
13  
14  #include <linux/errno.h>
15  #include <linux/rbtree.h>
16  #include <linux/types.h>
17  #include <linux/wait.h>
18  
19  struct uprobe;
20  struct vm_area_struct;
21  struct mm_struct;
22  struct inode;
23  struct notifier_block;
24  struct page;
25  
26  #define UPROBE_HANDLER_REMOVE		1
27  #define UPROBE_HANDLER_MASK		1
28  
29  #define MAX_URETPROBE_DEPTH		64
30  
31  struct uprobe_consumer {
32  	/*
33  	 * handler() can return UPROBE_HANDLER_REMOVE to signal the need to
34  	 * unregister uprobe for current process. If UPROBE_HANDLER_REMOVE is
35  	 * returned, filter() callback has to be implemented as well and it
36  	 * should return false to "confirm" the decision to uninstall uprobe
37  	 * for the current process. If filter() is omitted or returns true,
38  	 * UPROBE_HANDLER_REMOVE is effectively ignored.
39  	 */
40  	int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
41  	int (*ret_handler)(struct uprobe_consumer *self,
42  				unsigned long func,
43  				struct pt_regs *regs);
44  	bool (*filter)(struct uprobe_consumer *self, struct mm_struct *mm);
45  
46  	struct list_head cons_node;
47  };
48  
49  #ifdef CONFIG_UPROBES
50  #include <asm/uprobes.h>
51  
52  enum uprobe_task_state {
53  	UTASK_RUNNING,
54  	UTASK_SSTEP,
55  	UTASK_SSTEP_ACK,
56  	UTASK_SSTEP_TRAPPED,
57  };
58  
59  /*
60   * uprobe_task: Metadata of a task while it singlesteps.
61   */
62  struct uprobe_task {
63  	enum uprobe_task_state		state;
64  
65  	union {
66  		struct {
67  			struct arch_uprobe_task	autask;
68  			unsigned long		vaddr;
69  		};
70  
71  		struct {
72  			struct callback_head	dup_xol_work;
73  			unsigned long		dup_xol_addr;
74  		};
75  	};
76  
77  	struct uprobe			*active_uprobe;
78  	unsigned long			xol_vaddr;
79  
80  	struct arch_uprobe              *auprobe;
81  
82  	struct return_instance		*return_instances;
83  	unsigned int			depth;
84  };
85  
86  struct return_instance {
87  	struct uprobe		*uprobe;
88  	unsigned long		func;
89  	unsigned long		stack;		/* stack pointer */
90  	unsigned long		orig_ret_vaddr; /* original return address */
91  	bool			chained;	/* true, if instance is nested */
92  
93  	struct return_instance	*next;		/* keep as stack */
94  };
95  
96  enum rp_check {
97  	RP_CHECK_CALL,
98  	RP_CHECK_CHAIN_CALL,
99  	RP_CHECK_RET,
100  };
101  
102  struct xol_area;
103  
104  struct uprobes_state {
105  	struct xol_area		*xol_area;
106  };
107  
108  extern void __init uprobes_init(void);
109  extern int set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
110  extern int set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
111  extern bool is_swbp_insn(uprobe_opcode_t *insn);
112  extern bool is_trap_insn(uprobe_opcode_t *insn);
113  extern unsigned long uprobe_get_swbp_addr(struct pt_regs *regs);
114  extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs);
115  extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t);
116  extern struct uprobe *uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc);
117  extern int uprobe_apply(struct uprobe *uprobe, struct uprobe_consumer *uc, bool);
118  extern void uprobe_unregister_nosync(struct uprobe *uprobe, struct uprobe_consumer *uc);
119  extern void uprobe_unregister_sync(void);
120  extern int uprobe_mmap(struct vm_area_struct *vma);
121  extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end);
122  extern void uprobe_start_dup_mmap(void);
123  extern void uprobe_end_dup_mmap(void);
124  extern void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm);
125  extern void uprobe_free_utask(struct task_struct *t);
126  extern void uprobe_copy_process(struct task_struct *t, unsigned long flags);
127  extern int uprobe_post_sstep_notifier(struct pt_regs *regs);
128  extern int uprobe_pre_sstep_notifier(struct pt_regs *regs);
129  extern void uprobe_notify_resume(struct pt_regs *regs);
130  extern bool uprobe_deny_signal(void);
131  extern bool arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
132  extern void uprobe_clear_state(struct mm_struct *mm);
133  extern int  arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
134  extern int  arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);
135  extern int  arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
136  extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
137  extern int  arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
138  extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
139  extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs);
140  extern bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, struct pt_regs *regs);
141  extern bool arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs);
142  extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
143  					 void *src, unsigned long len);
144  extern void uprobe_handle_trampoline(struct pt_regs *regs);
145  extern void *arch_uprobe_trampoline(unsigned long *psize);
146  extern unsigned long uprobe_get_trampoline_vaddr(void);
147  #else /* !CONFIG_UPROBES */
148  struct uprobes_state {
149  };
150  
uprobes_init(void)151  static inline void uprobes_init(void)
152  {
153  }
154  
155  #define uprobe_get_trap_addr(regs)	instruction_pointer(regs)
156  
157  static inline struct uprobe *
uprobe_register(struct inode * inode,loff_t offset,loff_t ref_ctr_offset,struct uprobe_consumer * uc)158  uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc)
159  {
160  	return ERR_PTR(-ENOSYS);
161  }
162  static inline int
uprobe_apply(struct uprobe * uprobe,struct uprobe_consumer * uc,bool add)163  uprobe_apply(struct uprobe* uprobe, struct uprobe_consumer *uc, bool add)
164  {
165  	return -ENOSYS;
166  }
167  static inline void
uprobe_unregister_nosync(struct uprobe * uprobe,struct uprobe_consumer * uc)168  uprobe_unregister_nosync(struct uprobe *uprobe, struct uprobe_consumer *uc)
169  {
170  }
uprobe_unregister_sync(void)171  static inline void uprobe_unregister_sync(void)
172  {
173  }
uprobe_mmap(struct vm_area_struct * vma)174  static inline int uprobe_mmap(struct vm_area_struct *vma)
175  {
176  	return 0;
177  }
178  static inline void
uprobe_munmap(struct vm_area_struct * vma,unsigned long start,unsigned long end)179  uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
180  {
181  }
uprobe_start_dup_mmap(void)182  static inline void uprobe_start_dup_mmap(void)
183  {
184  }
uprobe_end_dup_mmap(void)185  static inline void uprobe_end_dup_mmap(void)
186  {
187  }
188  static inline void
uprobe_dup_mmap(struct mm_struct * oldmm,struct mm_struct * newmm)189  uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
190  {
191  }
uprobe_notify_resume(struct pt_regs * regs)192  static inline void uprobe_notify_resume(struct pt_regs *regs)
193  {
194  }
uprobe_deny_signal(void)195  static inline bool uprobe_deny_signal(void)
196  {
197  	return false;
198  }
uprobe_free_utask(struct task_struct * t)199  static inline void uprobe_free_utask(struct task_struct *t)
200  {
201  }
uprobe_copy_process(struct task_struct * t,unsigned long flags)202  static inline void uprobe_copy_process(struct task_struct *t, unsigned long flags)
203  {
204  }
uprobe_clear_state(struct mm_struct * mm)205  static inline void uprobe_clear_state(struct mm_struct *mm)
206  {
207  }
208  #endif /* !CONFIG_UPROBES */
209  #endif	/* _LINUX_UPROBES_H */
210