tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1#ifndef _LINUX_KPROBES_H
2#define _LINUX_KPROBES_H
3/*
4 * Kernel Probes (KProbes)
5 * include/linux/kprobes.h
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 * Copyright (C) IBM Corporation, 2002, 2004
22 *
23 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24 * Probes initial implementation ( includes suggestions from
25 * Rusty Russell).
26 * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
27 * interface to access function arguments.
28 */
29#include <linux/config.h>
30#include <linux/list.h>
31#include <linux/notifier.h>
32#include <linux/smp.h>
33#include <asm/kprobes.h>
34
35struct kprobe;
36struct pt_regs;
37typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
38typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
39typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
40 unsigned long flags);
41typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
42 int trapnr);
43struct kprobe {
44 struct hlist_node hlist;
45
46 /* location of the probe point */
47 kprobe_opcode_t *addr;
48
49 /* Called before addr is executed. */
50 kprobe_pre_handler_t pre_handler;
51
52 /* Called after addr is executed, unless... */
53 kprobe_post_handler_t post_handler;
54
55 /* ... called if executing addr causes a fault (eg. page fault).
56 * Return 1 if it handled fault, otherwise kernel will see it. */
57 kprobe_fault_handler_t fault_handler;
58
59 /* ... called if breakpoint trap occurs in probe handler.
60 * Return 1 if it handled break, otherwise kernel will see it. */
61 kprobe_break_handler_t break_handler;
62
63 /* Saved opcode (which has been replaced with breakpoint) */
64 kprobe_opcode_t opcode;
65
66 /* copy of the original instruction */
67 struct arch_specific_insn ainsn;
68};
69
70/*
71 * Special probe type that uses setjmp-longjmp type tricks to resume
72 * execution at a specified entry with a matching prototype corresponding
73 * to the probed function - a trick to enable arguments to become
74 * accessible seamlessly by probe handling logic.
75 * Note:
76 * Because of the way compilers allocate stack space for local variables
77 * etc upfront, regardless of sub-scopes within a function, this mirroring
78 * principle currently works only for probes placed on function entry points.
79 */
80struct jprobe {
81 struct kprobe kp;
82 kprobe_opcode_t *entry; /* probe handling code to jump to */
83};
84
85#ifdef CONFIG_KPROBES
86/* Locks kprobe: irq must be disabled */
87void lock_kprobes(void);
88void unlock_kprobes(void);
89
90/* kprobe running now on this CPU? */
91static inline int kprobe_running(void)
92{
93 extern unsigned int kprobe_cpu;
94 return kprobe_cpu == smp_processor_id();
95}
96
97extern int arch_prepare_kprobe(struct kprobe *p);
98extern void arch_copy_kprobe(struct kprobe *p);
99extern void arch_remove_kprobe(struct kprobe *p);
100extern void show_registers(struct pt_regs *regs);
101
102/* Get the kprobe at this addr (if any). Must have called lock_kprobes */
103struct kprobe *get_kprobe(void *addr);
104
105int register_kprobe(struct kprobe *p);
106void unregister_kprobe(struct kprobe *p);
107int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
108int longjmp_break_handler(struct kprobe *, struct pt_regs *);
109int register_jprobe(struct jprobe *p);
110void unregister_jprobe(struct jprobe *p);
111void jprobe_return(void);
112
113#else
114static inline int kprobe_running(void)
115{
116 return 0;
117}
118static inline int register_kprobe(struct kprobe *p)
119{
120 return -ENOSYS;
121}
122static inline void unregister_kprobe(struct kprobe *p)
123{
124}
125static inline int register_jprobe(struct jprobe *p)
126{
127 return -ENOSYS;
128}
129static inline void unregister_jprobe(struct jprobe *p)
130{
131}
132static inline void jprobe_return(void)
133{
134}
135#endif
136#endif /* _LINUX_KPROBES_H */