Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 28 | * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston |
| 29 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| 30 | * <prasanna@in.ibm.com> added function-return probes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | */ |
| 32 | #include <linux/config.h> |
| 33 | #include <linux/list.h> |
| 34 | #include <linux/notifier.h> |
| 35 | #include <linux/smp.h> |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 36 | #include <linux/percpu.h> |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 37 | #include <linux/spinlock.h> |
| 38 | #include <linux/rcupdate.h> |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 39 | |
Keshavamurthy Anil S | 00d7c05 | 2005-12-12 00:37:33 -0800 | [diff] [blame] | 40 | #ifdef CONFIG_KPROBES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <asm/kprobes.h> |
| 42 | |
Prasanna S Panchamukhi | ea32c65 | 2005-06-23 00:09:36 -0700 | [diff] [blame] | 43 | /* kprobe_status settings */ |
| 44 | #define KPROBE_HIT_ACTIVE 0x00000001 |
| 45 | #define KPROBE_HIT_SS 0x00000002 |
| 46 | #define KPROBE_REENTER 0x00000004 |
| 47 | #define KPROBE_HIT_SSDONE 0x00000008 |
| 48 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 49 | /* Attach to insert probes on any functions which should be ignored*/ |
| 50 | #define __kprobes __attribute__((__section__(".kprobes.text"))) |
| 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | struct kprobe; |
| 53 | struct pt_regs; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 54 | struct kretprobe; |
| 55 | struct kretprobe_instance; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
| 57 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); |
| 58 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, |
| 59 | unsigned long flags); |
| 60 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, |
| 61 | int trapnr); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 62 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
| 63 | struct pt_regs *); |
| 64 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | struct kprobe { |
| 66 | struct hlist_node hlist; |
| 67 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 68 | /* list of kprobes for multi-handler support */ |
| 69 | struct list_head list; |
| 70 | |
Prasanna S Panchamukhi | ea32c65 | 2005-06-23 00:09:36 -0700 | [diff] [blame] | 71 | /*count the number of times this probe was temporarily disarmed */ |
| 72 | unsigned long nmissed; |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | /* location of the probe point */ |
| 75 | kprobe_opcode_t *addr; |
| 76 | |
| 77 | /* Called before addr is executed. */ |
| 78 | kprobe_pre_handler_t pre_handler; |
| 79 | |
| 80 | /* Called after addr is executed, unless... */ |
| 81 | kprobe_post_handler_t post_handler; |
| 82 | |
| 83 | /* ... called if executing addr causes a fault (eg. page fault). |
| 84 | * Return 1 if it handled fault, otherwise kernel will see it. */ |
| 85 | kprobe_fault_handler_t fault_handler; |
| 86 | |
| 87 | /* ... called if breakpoint trap occurs in probe handler. |
| 88 | * Return 1 if it handled break, otherwise kernel will see it. */ |
| 89 | kprobe_break_handler_t break_handler; |
| 90 | |
| 91 | /* Saved opcode (which has been replaced with breakpoint) */ |
| 92 | kprobe_opcode_t opcode; |
| 93 | |
| 94 | /* copy of the original instruction */ |
| 95 | struct arch_specific_insn ainsn; |
| 96 | }; |
| 97 | |
| 98 | /* |
| 99 | * Special probe type that uses setjmp-longjmp type tricks to resume |
| 100 | * execution at a specified entry with a matching prototype corresponding |
| 101 | * to the probed function - a trick to enable arguments to become |
| 102 | * accessible seamlessly by probe handling logic. |
| 103 | * Note: |
| 104 | * Because of the way compilers allocate stack space for local variables |
| 105 | * etc upfront, regardless of sub-scopes within a function, this mirroring |
| 106 | * principle currently works only for probes placed on function entry points. |
| 107 | */ |
| 108 | struct jprobe { |
| 109 | struct kprobe kp; |
| 110 | kprobe_opcode_t *entry; /* probe handling code to jump to */ |
| 111 | }; |
| 112 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 113 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
| 114 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); |
| 115 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 116 | #ifdef ARCH_SUPPORTS_KRETPROBES |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 117 | extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 118 | #else /* ARCH_SUPPORTS_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 119 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
| 120 | struct pt_regs *regs) |
| 121 | { |
| 122 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 123 | #endif /* ARCH_SUPPORTS_KRETPROBES */ |
| 124 | /* |
| 125 | * Function-return probe - |
| 126 | * Note: |
| 127 | * User needs to provide a handler function, and initialize maxactive. |
| 128 | * maxactive - The maximum number of instances of the probed function that |
| 129 | * can be active concurrently. |
| 130 | * nmissed - tracks the number of times the probed function's return was |
| 131 | * ignored, due to maxactive being too low. |
| 132 | * |
| 133 | */ |
| 134 | struct kretprobe { |
| 135 | struct kprobe kp; |
| 136 | kretprobe_handler_t handler; |
| 137 | int maxactive; |
| 138 | int nmissed; |
| 139 | struct hlist_head free_instances; |
| 140 | struct hlist_head used_instances; |
| 141 | }; |
| 142 | |
| 143 | struct kretprobe_instance { |
| 144 | struct hlist_node uflist; /* either on free list or used list */ |
| 145 | struct hlist_node hlist; |
| 146 | struct kretprobe *rp; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 147 | kprobe_opcode_t *ret_addr; |
| 148 | struct task_struct *task; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 149 | }; |
| 150 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 151 | extern spinlock_t kretprobe_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | extern int arch_prepare_kprobe(struct kprobe *p); |
| 153 | extern void arch_copy_kprobe(struct kprobe *p); |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame] | 154 | extern void arch_arm_kprobe(struct kprobe *p); |
| 155 | extern void arch_disarm_kprobe(struct kprobe *p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | extern void arch_remove_kprobe(struct kprobe *p); |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 157 | extern int arch_init_kprobes(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | extern void show_registers(struct pt_regs *regs); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 159 | extern kprobe_opcode_t *get_insn_slot(void); |
| 160 | extern void free_insn_slot(kprobe_opcode_t *slot); |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 161 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 163 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | struct kprobe *get_kprobe(void *addr); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 165 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 167 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
| 168 | static inline struct kprobe *kprobe_running(void) |
| 169 | { |
| 170 | return (__get_cpu_var(current_kprobe)); |
| 171 | } |
| 172 | |
| 173 | static inline void reset_current_kprobe(void) |
| 174 | { |
| 175 | __get_cpu_var(current_kprobe) = NULL; |
| 176 | } |
| 177 | |
| 178 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) |
| 179 | { |
| 180 | return (&__get_cpu_var(kprobe_ctlblk)); |
| 181 | } |
| 182 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | int register_kprobe(struct kprobe *p); |
| 184 | void unregister_kprobe(struct kprobe *p); |
| 185 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
| 186 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); |
| 187 | int register_jprobe(struct jprobe *p); |
| 188 | void unregister_jprobe(struct jprobe *p); |
| 189 | void jprobe_return(void); |
| 190 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 191 | int register_kretprobe(struct kretprobe *rp); |
| 192 | void unregister_kretprobe(struct kretprobe *rp); |
| 193 | |
| 194 | struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 195 | void add_rp_inst(struct kretprobe_instance *ri); |
| 196 | void kprobe_flush_task(struct task_struct *tk); |
| 197 | void recycle_rp_inst(struct kretprobe_instance *ri); |
| 198 | #else /* CONFIG_KPROBES */ |
Keshavamurthy Anil S | 00d7c05 | 2005-12-12 00:37:33 -0800 | [diff] [blame] | 199 | |
| 200 | #define __kprobes /**/ |
| 201 | struct jprobe; |
| 202 | struct kretprobe; |
| 203 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 204 | static inline struct kprobe *kprobe_running(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 206 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | } |
| 208 | static inline int register_kprobe(struct kprobe *p) |
| 209 | { |
| 210 | return -ENOSYS; |
| 211 | } |
| 212 | static inline void unregister_kprobe(struct kprobe *p) |
| 213 | { |
| 214 | } |
| 215 | static inline int register_jprobe(struct jprobe *p) |
| 216 | { |
| 217 | return -ENOSYS; |
| 218 | } |
| 219 | static inline void unregister_jprobe(struct jprobe *p) |
| 220 | { |
| 221 | } |
| 222 | static inline void jprobe_return(void) |
| 223 | { |
| 224 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 225 | static inline int register_kretprobe(struct kretprobe *rp) |
| 226 | { |
| 227 | return -ENOSYS; |
| 228 | } |
| 229 | static inline void unregister_kretprobe(struct kretprobe *rp) |
| 230 | { |
| 231 | } |
| 232 | static inline void kprobe_flush_task(struct task_struct *tk) |
| 233 | { |
| 234 | } |
| 235 | #endif /* CONFIG_KPROBES */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | #endif /* _LINUX_KPROBES_H */ |