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 * 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. 31 */ 32 #include <linux/linkage.h> 33 #include <linux/list.h> 34 #include <linux/notifier.h> 35 #include <linux/smp.h> 36 #include <linux/percpu.h> 37 #include <linux/spinlock.h> 38 #include <linux/rcupdate.h> 39 #include <linux/mutex.h> 40 41 #ifdef CONFIG_KPROBES 42 #include <asm/kprobes.h> 43 44 /* kprobe_status settings */ 45 #define KPROBE_HIT_ACTIVE 0x00000001 46 #define KPROBE_HIT_SS 0x00000002 47 #define KPROBE_REENTER 0x00000004 48 #define KPROBE_HIT_SSDONE 0x00000008 49 50 /* Attach to insert probes on any functions which should be ignored*/ 51 #define __kprobes __attribute__((__section__(".kprobes.text"))) notrace 52 53 struct kprobe; 54 struct pt_regs; 55 struct kretprobe; 56 struct kretprobe_instance; 57 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); 58 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); 59 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, 60 unsigned long flags); 61 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, 62 int trapnr); 63 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, 64 struct pt_regs *); 65 66 struct kprobe { 67 struct hlist_node hlist; 68 69 /* list of kprobes for multi-handler support */ 70 struct list_head list; 71 72 /* Indicates that the corresponding module has been ref counted */ 73 unsigned int mod_refcounted; 74 75 /*count the number of times this probe was temporarily disarmed */ 76 unsigned long nmissed; 77 78 /* location of the probe point */ 79 kprobe_opcode_t *addr; 80 81 /* Allow user to indicate symbol name of the probe point */ 82 const char *symbol_name; 83 84 /* Offset into the symbol */ 85 unsigned int offset; 86 87 /* Called before addr is executed. */ 88 kprobe_pre_handler_t pre_handler; 89 90 /* Called after addr is executed, unless... */ 91 kprobe_post_handler_t post_handler; 92 93 /* ... called if executing addr causes a fault (eg. page fault). 94 * Return 1 if it handled fault, otherwise kernel will see it. */ 95 kprobe_fault_handler_t fault_handler; 96 97 /* ... called if breakpoint trap occurs in probe handler. 98 * Return 1 if it handled break, otherwise kernel will see it. */ 99 kprobe_break_handler_t break_handler; 100 101 /* Saved opcode (which has been replaced with breakpoint) */ 102 kprobe_opcode_t opcode; 103 104 /* copy of the original instruction */ 105 struct arch_specific_insn ainsn; 106 }; 107 108 /* 109 * Special probe type that uses setjmp-longjmp type tricks to resume 110 * execution at a specified entry with a matching prototype corresponding 111 * to the probed function - a trick to enable arguments to become 112 * accessible seamlessly by probe handling logic. 113 * Note: 114 * Because of the way compilers allocate stack space for local variables 115 * etc upfront, regardless of sub-scopes within a function, this mirroring 116 * principle currently works only for probes placed on function entry points. 117 */ 118 struct jprobe { 119 struct kprobe kp; 120 void *entry; /* probe handling code to jump to */ 121 }; 122 123 /* For backward compatibility with old code using JPROBE_ENTRY() */ 124 #define JPROBE_ENTRY(handler) (handler) 125 126 DECLARE_PER_CPU(struct kprobe *, current_kprobe); 127 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); 128 129 #ifdef CONFIG_KRETPROBES 130 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, 131 struct pt_regs *regs); 132 extern int arch_trampoline_kprobe(struct kprobe *p); 133 #else /* CONFIG_KRETPROBES */ 134 static inline void arch_prepare_kretprobe(struct kretprobe *rp, 135 struct pt_regs *regs) 136 { 137 } 138 static inline int arch_trampoline_kprobe(struct kprobe *p) 139 { 140 return 0; 141 } 142 #endif /* CONFIG_KRETPROBES */ 143 /* 144 * Function-return probe - 145 * Note: 146 * User needs to provide a handler function, and initialize maxactive. 147 * maxactive - The maximum number of instances of the probed function that 148 * can be active concurrently. 149 * nmissed - tracks the number of times the probed function's return was 150 * ignored, due to maxactive being too low. 151 * 152 */ 153 struct kretprobe { 154 struct kprobe kp; 155 kretprobe_handler_t handler; 156 kretprobe_handler_t entry_handler; 157 int maxactive; 158 int nmissed; 159 size_t data_size; 160 struct hlist_head free_instances; 161 spinlock_t lock; 162 }; 163 164 struct kretprobe_instance { 165 struct hlist_node hlist; 166 struct kretprobe *rp; 167 kprobe_opcode_t *ret_addr; 168 struct task_struct *task; 169 char data[0]; 170 }; 171 172 struct kretprobe_blackpoint { 173 const char *name; 174 void *addr; 175 }; 176 177 struct kprobe_blackpoint { 178 const char *name; 179 unsigned long start_addr; 180 unsigned long range; 181 }; 182 183 extern struct kretprobe_blackpoint kretprobe_blacklist[]; 184 185 static inline void kretprobe_assert(struct kretprobe_instance *ri, 186 unsigned long orig_ret_address, unsigned long trampoline_address) 187 { 188 if (!orig_ret_address || (orig_ret_address == trampoline_address)) { 189 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", 190 ri->rp, ri->rp->kp.addr); 191 BUG(); 192 } 193 } 194 195 #ifdef CONFIG_KPROBES_SANITY_TEST 196 extern int init_test_probes(void); 197 #else 198 static inline int init_test_probes(void) 199 { 200 return 0; 201 } 202 #endif /* CONFIG_KPROBES_SANITY_TEST */ 203 204 extern struct mutex kprobe_mutex; 205 extern int arch_prepare_kprobe(struct kprobe *p); 206 extern void arch_arm_kprobe(struct kprobe *p); 207 extern void arch_disarm_kprobe(struct kprobe *p); 208 extern int arch_init_kprobes(void); 209 extern void show_registers(struct pt_regs *regs); 210 extern kprobe_opcode_t *get_insn_slot(void); 211 extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); 212 extern void kprobes_inc_nmissed_count(struct kprobe *p); 213 214 /* Get the kprobe at this addr (if any) - called with preemption disabled */ 215 struct kprobe *get_kprobe(void *addr); 216 void kretprobe_hash_lock(struct task_struct *tsk, 217 struct hlist_head **head, unsigned long *flags); 218 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); 219 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); 220 221 /* kprobe_running() will just return the current_kprobe on this CPU */ 222 static inline struct kprobe *kprobe_running(void) 223 { 224 return (__get_cpu_var(current_kprobe)); 225 } 226 227 static inline void reset_current_kprobe(void) 228 { 229 __get_cpu_var(current_kprobe) = NULL; 230 } 231 232 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) 233 { 234 return (&__get_cpu_var(kprobe_ctlblk)); 235 } 236 237 int register_kprobe(struct kprobe *p); 238 void unregister_kprobe(struct kprobe *p); 239 int register_kprobes(struct kprobe **kps, int num); 240 void unregister_kprobes(struct kprobe **kps, int num); 241 int setjmp_pre_handler(struct kprobe *, struct pt_regs *); 242 int longjmp_break_handler(struct kprobe *, struct pt_regs *); 243 int register_jprobe(struct jprobe *p); 244 void unregister_jprobe(struct jprobe *p); 245 int register_jprobes(struct jprobe **jps, int num); 246 void unregister_jprobes(struct jprobe **jps, int num); 247 void jprobe_return(void); 248 unsigned long arch_deref_entry_point(void *); 249 250 int register_kretprobe(struct kretprobe *rp); 251 void unregister_kretprobe(struct kretprobe *rp); 252 int register_kretprobes(struct kretprobe **rps, int num); 253 void unregister_kretprobes(struct kretprobe **rps, int num); 254 255 void kprobe_flush_task(struct task_struct *tk); 256 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); 257 258 #else /* CONFIG_KPROBES */ 259 260 #define __kprobes notrace 261 struct jprobe; 262 struct kretprobe; 263 264 static inline struct kprobe *get_kprobe(void *addr) 265 { 266 return NULL; 267 } 268 static inline struct kprobe *kprobe_running(void) 269 { 270 return NULL; 271 } 272 static inline int register_kprobe(struct kprobe *p) 273 { 274 return -ENOSYS; 275 } 276 static inline int register_kprobes(struct kprobe **kps, int num) 277 { 278 return -ENOSYS; 279 } 280 static inline void unregister_kprobe(struct kprobe *p) 281 { 282 } 283 static inline void unregister_kprobes(struct kprobe **kps, int num) 284 { 285 } 286 static inline int register_jprobe(struct jprobe *p) 287 { 288 return -ENOSYS; 289 } 290 static inline int register_jprobes(struct jprobe **jps, int num) 291 { 292 return -ENOSYS; 293 } 294 static inline void unregister_jprobe(struct jprobe *p) 295 { 296 } 297 static inline void unregister_jprobes(struct jprobe **jps, int num) 298 { 299 } 300 static inline void jprobe_return(void) 301 { 302 } 303 static inline int register_kretprobe(struct kretprobe *rp) 304 { 305 return -ENOSYS; 306 } 307 static inline int register_kretprobes(struct kretprobe **rps, int num) 308 { 309 return -ENOSYS; 310 } 311 static inline void unregister_kretprobe(struct kretprobe *rp) 312 { 313 } 314 static inline void unregister_kretprobes(struct kretprobe **rps, int num) 315 { 316 } 317 static inline void kprobe_flush_task(struct task_struct *tk) 318 { 319 } 320 #endif /* CONFIG_KPROBES */ 321 #endif /* _LINUX_KPROBES_H */ 322