| 1 | #ifndef _LINUX_KPROBES_H |
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| 2 | #define _LINUX_KPROBES_H |
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| 3 | /* |
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| 4 | * Kernel Probes (KProbes) |
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| 5 | * include/linux/kprobes.h |
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| 6 | * |
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| 7 | * This program is free software; you can redistribute it and/or modify |
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| 8 | * it under the terms of the GNU General Public License as published by |
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| 9 | * the Free Software Foundation; either version 2 of the License, or |
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| 10 | * (at your option) any later version. |
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| 11 | * |
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| 12 | * This program is distributed in the hope that it will be useful, |
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 15 | * GNU General Public License for more details. |
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| 16 | * |
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| 17 | * You should have received a copy of the GNU General Public License |
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| 18 | * along with this program; if not, write to the Free Software |
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| 19 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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| 20 | * |
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| 21 | * Copyright (C) IBM Corporation, 2002, 2004 |
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| 22 | * |
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| 23 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel |
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| 24 | * Probes initial implementation ( includes suggestions from |
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| 25 | * Rusty Russell). |
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| 26 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes |
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| 27 | * interface to access function arguments. |
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| 28 | */ |
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| 29 | #include <linux/list.h> |
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| 30 | #include <linux/notifier.h> |
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| 31 | #include <linux/smp.h> |
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| 32 | #include <asm/kprobes.h> |
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| 33 | |
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| 34 | struct kprobe; |
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| 35 | struct pt_regs; |
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| 36 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
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| 37 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); |
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| 38 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, |
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| 39 | unsigned long flags); |
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| 40 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, |
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| 41 | int trapnr); |
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| 42 | struct kprobe { |
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| 43 | struct hlist_node hlist; |
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| 44 | |
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| 45 | /* list of kprobes for multi-handler support */ |
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| 46 | struct list_head list; |
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| 47 | |
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| 48 | /* location of the probe point */ |
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| 49 | kprobe_opcode_t *addr; |
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| 50 | |
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| 51 | /* Called before addr is executed. */ |
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| 52 | kprobe_pre_handler_t pre_handler; |
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| 53 | |
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| 54 | /* Called after addr is executed, unless... */ |
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| 55 | kprobe_post_handler_t post_handler; |
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| 56 | |
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| 57 | /* ... called if executing addr causes a fault (eg. page fault). |
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| 58 | * Return 1 if it handled fault, otherwise kernel will see it. */ |
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| 59 | kprobe_fault_handler_t fault_handler; |
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| 60 | |
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| 61 | /* ... called if breakpoint trap occurs in probe handler. |
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| 62 | * Return 1 if it handled break, otherwise kernel will see it. */ |
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| 63 | kprobe_break_handler_t break_handler; |
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| 64 | |
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| 65 | /* Saved opcode (which has been replaced with breakpoint) */ |
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| 66 | kprobe_opcode_t opcode; |
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| 67 | |
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| 68 | /* copy of the original instruction */ |
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| 69 | struct arch_specific_insn ainsn; |
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| 70 | }; |
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| 71 | |
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| 72 | /* |
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| 73 | * Special probe type that uses setjmp-longjmp type tricks to resume |
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| 74 | * execution at a specified entry with a matching prototype corresponding |
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| 75 | * to the probed function - a trick to enable arguments to become |
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| 76 | * accessible seamlessly by probe handling logic. |
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| 77 | * Note: |
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| 78 | * Because of the way compilers allocate stack space for local variables |
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| 79 | * etc upfront, regardless of sub-scopes within a function, this mirroring |
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| 80 | * principle currently works only for probes placed on function entry points. |
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| 81 | */ |
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| 82 | struct jprobe { |
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| 83 | struct kprobe kp; |
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| 84 | kprobe_opcode_t *entry; /* probe handling code to jump to */ |
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| 85 | }; |
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| 86 | |
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| 87 | #ifdef CONFIG_KPROBES |
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| 88 | /* Locks kprobe: irq must be disabled */ |
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| 89 | void lock_kprobes(void); |
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| 90 | void unlock_kprobes(void); |
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| 91 | |
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| 92 | /* kprobe running now on this CPU? */ |
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| 93 | static inline int kprobe_running(void) |
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| 94 | { |
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| 95 | extern unsigned int kprobe_cpu; |
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| 96 | return kprobe_cpu == smp_processor_id(); |
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| 97 | } |
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| 98 | |
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| 99 | extern int arch_prepare_kprobe(struct kprobe *p); |
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| 100 | extern void arch_copy_kprobe(struct kprobe *p); |
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| 101 | extern void arch_remove_kprobe(struct kprobe *p); |
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| 102 | extern void show_registers(struct pt_regs *regs); |
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| 103 | |
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| 104 | /* Get the kprobe at this addr (if any). Must have called lock_kprobes */ |
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| 105 | struct kprobe *get_kprobe(void *addr); |
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| 106 | |
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| 107 | int register_kprobe(struct kprobe *p); |
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| 108 | void unregister_kprobe(struct kprobe *p); |
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| 109 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
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| 110 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); |
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| 111 | int register_jprobe(struct jprobe *p); |
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| 112 | void unregister_jprobe(struct jprobe *p); |
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| 113 | void jprobe_return(void); |
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| 114 | |
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| 115 | #else |
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| 116 | static inline int kprobe_running(void) |
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| 117 | { |
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| 118 | return 0; |
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| 119 | } |
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| 120 | static inline int register_kprobe(struct kprobe *p) |
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| 121 | { |
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| 122 | return -ENOSYS; |
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| 123 | } |
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| 124 | static inline void unregister_kprobe(struct kprobe *p) |
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| 125 | { |
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| 126 | } |
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| 127 | static inline int register_jprobe(struct jprobe *p) |
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| 128 | { |
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| 129 | return -ENOSYS; |
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| 130 | } |
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| 131 | static inline void unregister_jprobe(struct jprobe *p) |
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| 132 | { |
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| 133 | } |
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| 134 | static inline void jprobe_return(void) |
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| 135 | { |
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| 136 | } |
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| 137 | #endif |
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| 138 | #endif /* _LINUX_KPROBES_H */ |
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