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/compiler.h> 33 #include <linux/linkage.h> 34 #include <linux/list.h> 35 #include <linux/notifier.h> 36 #include <linux/smp.h> 37 #include <linux/bug.h> 38 #include <linux/percpu.h> 39 #include <linux/spinlock.h> 40 #include <linux/rcupdate.h> 41 #include <linux/mutex.h> 42 #include <linux/ftrace.h> 43 #include <asm/kprobes.h> 44 45 #ifdef CONFIG_KPROBES 46 47 /* kprobe_status settings */ 48 #define KPROBE_HIT_ACTIVE 0x00000001 49 #define KPROBE_HIT_SS 0x00000002 50 #define KPROBE_REENTER 0x00000004 51 #define KPROBE_HIT_SSDONE 0x00000008 52 53 #else /* CONFIG_KPROBES */ 54 #include <asm-generic/kprobes.h> 55 typedef int kprobe_opcode_t; 56 struct arch_specific_insn { 57 int dummy; 58 }; 59 #endif /* CONFIG_KPROBES */ 60 61 struct kprobe; 62 struct pt_regs; 63 struct kretprobe; 64 struct kretprobe_instance; 65 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); 66 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, 67 unsigned long flags); 68 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, 69 int trapnr); 70 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, 71 struct pt_regs *); 72 73 struct kprobe { 74 struct hlist_node hlist; 75 76 /* list of kprobes for multi-handler support */ 77 struct list_head list; 78 79 /*count the number of times this probe was temporarily disarmed */ 80 unsigned long nmissed; 81 82 /* location of the probe point */ 83 kprobe_opcode_t *addr; 84 85 /* Allow user to indicate symbol name of the probe point */ 86 const char *symbol_name; 87 88 /* Offset into the symbol */ 89 unsigned int offset; 90 91 /* Called before addr is executed. */ 92 kprobe_pre_handler_t pre_handler; 93 94 /* Called after addr is executed, unless... */ 95 kprobe_post_handler_t post_handler; 96 97 /* 98 * ... called if executing addr causes a fault (eg. page fault). 99 * Return 1 if it handled fault, otherwise kernel will see it. 100 */ 101 kprobe_fault_handler_t fault_handler; 102 103 /* Saved opcode (which has been replaced with breakpoint) */ 104 kprobe_opcode_t opcode; 105 106 /* copy of the original instruction */ 107 struct arch_specific_insn ainsn; 108 109 /* 110 * Indicates various status flags. 111 * Protected by kprobe_mutex after this kprobe is registered. 112 */ 113 u32 flags; 114 }; 115 116 /* Kprobe status flags */ 117 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ 118 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ 119 #define KPROBE_FLAG_OPTIMIZED 4 /* 120 * probe is really optimized. 121 * NOTE: 122 * this flag is only for optimized_kprobe. 123 */ 124 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */ 125 126 /* Has this kprobe gone ? */ 127 static inline int kprobe_gone(struct kprobe *p) 128 { 129 return p->flags & KPROBE_FLAG_GONE; 130 } 131 132 /* Is this kprobe disabled ? */ 133 static inline int kprobe_disabled(struct kprobe *p) 134 { 135 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); 136 } 137 138 /* Is this kprobe really running optimized path ? */ 139 static inline int kprobe_optimized(struct kprobe *p) 140 { 141 return p->flags & KPROBE_FLAG_OPTIMIZED; 142 } 143 144 /* Is this kprobe uses ftrace ? */ 145 static inline int kprobe_ftrace(struct kprobe *p) 146 { 147 return p->flags & KPROBE_FLAG_FTRACE; 148 } 149 150 /* 151 * Function-return probe - 152 * Note: 153 * User needs to provide a handler function, and initialize maxactive. 154 * maxactive - The maximum number of instances of the probed function that 155 * can be active concurrently. 156 * nmissed - tracks the number of times the probed function's return was 157 * ignored, due to maxactive being too low. 158 * 159 */ 160 struct kretprobe { 161 struct kprobe kp; 162 kretprobe_handler_t handler; 163 kretprobe_handler_t entry_handler; 164 int maxactive; 165 int nmissed; 166 size_t data_size; 167 struct hlist_head free_instances; 168 raw_spinlock_t lock; 169 }; 170 171 struct kretprobe_instance { 172 struct hlist_node hlist; 173 struct kretprobe *rp; 174 kprobe_opcode_t *ret_addr; 175 struct task_struct *task; 176 char data[0]; 177 }; 178 179 struct kretprobe_blackpoint { 180 const char *name; 181 void *addr; 182 }; 183 184 struct kprobe_blacklist_entry { 185 struct list_head list; 186 unsigned long start_addr; 187 unsigned long end_addr; 188 }; 189 190 #ifdef CONFIG_KPROBES 191 DECLARE_PER_CPU(struct kprobe *, current_kprobe); 192 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); 193 194 /* 195 * For #ifdef avoidance: 196 */ 197 static inline int kprobes_built_in(void) 198 { 199 return 1; 200 } 201 202 #ifdef CONFIG_KRETPROBES 203 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, 204 struct pt_regs *regs); 205 extern int arch_trampoline_kprobe(struct kprobe *p); 206 #else /* CONFIG_KRETPROBES */ 207 static inline void arch_prepare_kretprobe(struct kretprobe *rp, 208 struct pt_regs *regs) 209 { 210 } 211 static inline int arch_trampoline_kprobe(struct kprobe *p) 212 { 213 return 0; 214 } 215 #endif /* CONFIG_KRETPROBES */ 216 217 extern struct kretprobe_blackpoint kretprobe_blacklist[]; 218 219 static inline void kretprobe_assert(struct kretprobe_instance *ri, 220 unsigned long orig_ret_address, unsigned long trampoline_address) 221 { 222 if (!orig_ret_address || (orig_ret_address == trampoline_address)) { 223 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", 224 ri->rp, ri->rp->kp.addr); 225 BUG(); 226 } 227 } 228 229 #ifdef CONFIG_KPROBES_SANITY_TEST 230 extern int init_test_probes(void); 231 #else 232 static inline int init_test_probes(void) 233 { 234 return 0; 235 } 236 #endif /* CONFIG_KPROBES_SANITY_TEST */ 237 238 extern int arch_prepare_kprobe(struct kprobe *p); 239 extern void arch_arm_kprobe(struct kprobe *p); 240 extern void arch_disarm_kprobe(struct kprobe *p); 241 extern int arch_init_kprobes(void); 242 extern void show_registers(struct pt_regs *regs); 243 extern void kprobes_inc_nmissed_count(struct kprobe *p); 244 extern bool arch_within_kprobe_blacklist(unsigned long addr); 245 extern bool arch_kprobe_on_func_entry(unsigned long offset); 246 extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset); 247 248 extern bool within_kprobe_blacklist(unsigned long addr); 249 250 struct kprobe_insn_cache { 251 struct mutex mutex; 252 void *(*alloc)(void); /* allocate insn page */ 253 void (*free)(void *); /* free insn page */ 254 struct list_head pages; /* list of kprobe_insn_page */ 255 size_t insn_size; /* size of instruction slot */ 256 int nr_garbage; 257 }; 258 259 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT 260 extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c); 261 extern void __free_insn_slot(struct kprobe_insn_cache *c, 262 kprobe_opcode_t *slot, int dirty); 263 /* sleep-less address checking routine */ 264 extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c, 265 unsigned long addr); 266 267 #define DEFINE_INSN_CACHE_OPS(__name) \ 268 extern struct kprobe_insn_cache kprobe_##__name##_slots; \ 269 \ 270 static inline kprobe_opcode_t *get_##__name##_slot(void) \ 271 { \ 272 return __get_insn_slot(&kprobe_##__name##_slots); \ 273 } \ 274 \ 275 static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\ 276 { \ 277 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \ 278 } \ 279 \ 280 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \ 281 { \ 282 return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \ 283 } 284 #else /* __ARCH_WANT_KPROBES_INSN_SLOT */ 285 #define DEFINE_INSN_CACHE_OPS(__name) \ 286 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \ 287 { \ 288 return 0; \ 289 } 290 #endif 291 292 DEFINE_INSN_CACHE_OPS(insn); 293 294 #ifdef CONFIG_OPTPROBES 295 /* 296 * Internal structure for direct jump optimized probe 297 */ 298 struct optimized_kprobe { 299 struct kprobe kp; 300 struct list_head list; /* list for optimizing queue */ 301 struct arch_optimized_insn optinsn; 302 }; 303 304 /* Architecture dependent functions for direct jump optimization */ 305 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); 306 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); 307 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, 308 struct kprobe *orig); 309 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); 310 extern void arch_optimize_kprobes(struct list_head *oplist); 311 extern void arch_unoptimize_kprobes(struct list_head *oplist, 312 struct list_head *done_list); 313 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); 314 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, 315 unsigned long addr); 316 317 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); 318 319 DEFINE_INSN_CACHE_OPS(optinsn); 320 321 #ifdef CONFIG_SYSCTL 322 extern int sysctl_kprobes_optimization; 323 extern int proc_kprobes_optimization_handler(struct ctl_table *table, 324 int write, void __user *buffer, 325 size_t *length, loff_t *ppos); 326 #endif 327 extern void wait_for_kprobe_optimizer(void); 328 #else 329 static inline void wait_for_kprobe_optimizer(void) { } 330 #endif /* CONFIG_OPTPROBES */ 331 #ifdef CONFIG_KPROBES_ON_FTRACE 332 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, 333 struct ftrace_ops *ops, struct pt_regs *regs); 334 extern int arch_prepare_kprobe_ftrace(struct kprobe *p); 335 #endif 336 337 int arch_check_ftrace_location(struct kprobe *p); 338 339 /* Get the kprobe at this addr (if any) - called with preemption disabled */ 340 struct kprobe *get_kprobe(void *addr); 341 void kretprobe_hash_lock(struct task_struct *tsk, 342 struct hlist_head **head, unsigned long *flags); 343 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); 344 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); 345 346 /* kprobe_running() will just return the current_kprobe on this CPU */ 347 static inline struct kprobe *kprobe_running(void) 348 { 349 return (__this_cpu_read(current_kprobe)); 350 } 351 352 static inline void reset_current_kprobe(void) 353 { 354 __this_cpu_write(current_kprobe, NULL); 355 } 356 357 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) 358 { 359 return this_cpu_ptr(&kprobe_ctlblk); 360 } 361 362 kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset); 363 int register_kprobe(struct kprobe *p); 364 void unregister_kprobe(struct kprobe *p); 365 int register_kprobes(struct kprobe **kps, int num); 366 void unregister_kprobes(struct kprobe **kps, int num); 367 unsigned long arch_deref_entry_point(void *); 368 369 int register_kretprobe(struct kretprobe *rp); 370 void unregister_kretprobe(struct kretprobe *rp); 371 int register_kretprobes(struct kretprobe **rps, int num); 372 void unregister_kretprobes(struct kretprobe **rps, int num); 373 374 void kprobe_flush_task(struct task_struct *tk); 375 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); 376 377 int disable_kprobe(struct kprobe *kp); 378 int enable_kprobe(struct kprobe *kp); 379 380 void dump_kprobe(struct kprobe *kp); 381 382 #else /* !CONFIG_KPROBES: */ 383 384 static inline int kprobes_built_in(void) 385 { 386 return 0; 387 } 388 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) 389 { 390 return 0; 391 } 392 static inline struct kprobe *get_kprobe(void *addr) 393 { 394 return NULL; 395 } 396 static inline struct kprobe *kprobe_running(void) 397 { 398 return NULL; 399 } 400 static inline int register_kprobe(struct kprobe *p) 401 { 402 return -ENOSYS; 403 } 404 static inline int register_kprobes(struct kprobe **kps, int num) 405 { 406 return -ENOSYS; 407 } 408 static inline void unregister_kprobe(struct kprobe *p) 409 { 410 } 411 static inline void unregister_kprobes(struct kprobe **kps, int num) 412 { 413 } 414 static inline int register_kretprobe(struct kretprobe *rp) 415 { 416 return -ENOSYS; 417 } 418 static inline int register_kretprobes(struct kretprobe **rps, int num) 419 { 420 return -ENOSYS; 421 } 422 static inline void unregister_kretprobe(struct kretprobe *rp) 423 { 424 } 425 static inline void unregister_kretprobes(struct kretprobe **rps, int num) 426 { 427 } 428 static inline void kprobe_flush_task(struct task_struct *tk) 429 { 430 } 431 static inline int disable_kprobe(struct kprobe *kp) 432 { 433 return -ENOSYS; 434 } 435 static inline int enable_kprobe(struct kprobe *kp) 436 { 437 return -ENOSYS; 438 } 439 #endif /* CONFIG_KPROBES */ 440 static inline int disable_kretprobe(struct kretprobe *rp) 441 { 442 return disable_kprobe(&rp->kp); 443 } 444 static inline int enable_kretprobe(struct kretprobe *rp) 445 { 446 return enable_kprobe(&rp->kp); 447 } 448 449 #ifndef CONFIG_KPROBES 450 static inline bool is_kprobe_insn_slot(unsigned long addr) 451 { 452 return false; 453 } 454 #endif 455 #ifndef CONFIG_OPTPROBES 456 static inline bool is_kprobe_optinsn_slot(unsigned long addr) 457 { 458 return false; 459 } 460 #endif 461 462 #endif /* _LINUX_KPROBES_H */ 463