| 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 | #else /* CONFIG_KPROBES */ |
| 53 | typedef int kprobe_opcode_t; |
| 54 | struct arch_specific_insn { |
| 55 | int dummy; |
| 56 | }; |
| 57 | #define __kprobes notrace |
| 58 | #endif /* CONFIG_KPROBES */ |
| 59 | |
| 60 | struct kprobe; |
| 61 | struct pt_regs; |
| 62 | struct kretprobe; |
| 63 | struct kretprobe_instance; |
| 64 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
| 65 | typedef int (*kprobe_break_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 | /* |
| 104 | * ... called if breakpoint trap occurs in probe handler. |
| 105 | * Return 1 if it handled break, otherwise kernel will see it. |
| 106 | */ |
| 107 | kprobe_break_handler_t break_handler; |
| 108 | |
| 109 | /* Saved opcode (which has been replaced with breakpoint) */ |
| 110 | kprobe_opcode_t opcode; |
| 111 | |
| 112 | /* copy of the original instruction */ |
| 113 | struct arch_specific_insn ainsn; |
| 114 | |
| 115 | /* |
| 116 | * Indicates various status flags. |
| 117 | * Protected by kprobe_mutex after this kprobe is registered. |
| 118 | */ |
| 119 | u32 flags; |
| 120 | }; |
| 121 | |
| 122 | /* Kprobe status flags */ |
| 123 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ |
| 124 | #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ |
| 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 | * Special probe type that uses setjmp-longjmp type tricks to resume |
| 139 | * execution at a specified entry with a matching prototype corresponding |
| 140 | * to the probed function - a trick to enable arguments to become |
| 141 | * accessible seamlessly by probe handling logic. |
| 142 | * Note: |
| 143 | * Because of the way compilers allocate stack space for local variables |
| 144 | * etc upfront, regardless of sub-scopes within a function, this mirroring |
| 145 | * principle currently works only for probes placed on function entry points. |
| 146 | */ |
| 147 | struct jprobe { |
| 148 | struct kprobe kp; |
| 149 | void *entry; /* probe handling code to jump to */ |
| 150 | }; |
| 151 | |
| 152 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
| 153 | #define JPROBE_ENTRY(handler) (handler) |
| 154 | |
| 155 | /* |
| 156 | * Function-return probe - |
| 157 | * Note: |
| 158 | * User needs to provide a handler function, and initialize maxactive. |
| 159 | * maxactive - The maximum number of instances of the probed function that |
| 160 | * can be active concurrently. |
| 161 | * nmissed - tracks the number of times the probed function's return was |
| 162 | * ignored, due to maxactive being too low. |
| 163 | * |
| 164 | */ |
| 165 | struct kretprobe { |
| 166 | struct kprobe kp; |
| 167 | kretprobe_handler_t handler; |
| 168 | kretprobe_handler_t entry_handler; |
| 169 | int maxactive; |
| 170 | int nmissed; |
| 171 | size_t data_size; |
| 172 | struct hlist_head free_instances; |
| 173 | spinlock_t lock; |
| 174 | }; |
| 175 | |
| 176 | struct kretprobe_instance { |
| 177 | struct hlist_node hlist; |
| 178 | struct kretprobe *rp; |
| 179 | kprobe_opcode_t *ret_addr; |
| 180 | struct task_struct *task; |
| 181 | char data[0]; |
| 182 | }; |
| 183 | |
| 184 | struct kretprobe_blackpoint { |
| 185 | const char *name; |
| 186 | void *addr; |
| 187 | }; |
| 188 | |
| 189 | struct kprobe_blackpoint { |
| 190 | const char *name; |
| 191 | unsigned long start_addr; |
| 192 | unsigned long range; |
| 193 | }; |
| 194 | |
| 195 | #ifdef CONFIG_KPROBES |
| 196 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
| 197 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); |
| 198 | |
| 199 | /* |
| 200 | * For #ifdef avoidance: |
| 201 | */ |
| 202 | static inline int kprobes_built_in(void) |
| 203 | { |
| 204 | return 1; |
| 205 | } |
| 206 | |
| 207 | #ifdef CONFIG_KRETPROBES |
| 208 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, |
| 209 | struct pt_regs *regs); |
| 210 | extern int arch_trampoline_kprobe(struct kprobe *p); |
| 211 | #else /* CONFIG_KRETPROBES */ |
| 212 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
| 213 | struct pt_regs *regs) |
| 214 | { |
| 215 | } |
| 216 | static inline int arch_trampoline_kprobe(struct kprobe *p) |
| 217 | { |
| 218 | return 0; |
| 219 | } |
| 220 | #endif /* CONFIG_KRETPROBES */ |
| 221 | |
| 222 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
| 223 | |
| 224 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
| 225 | unsigned long orig_ret_address, unsigned long trampoline_address) |
| 226 | { |
| 227 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { |
| 228 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", |
| 229 | ri->rp, ri->rp->kp.addr); |
| 230 | BUG(); |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | #ifdef CONFIG_KPROBES_SANITY_TEST |
| 235 | extern int init_test_probes(void); |
| 236 | #else |
| 237 | static inline int init_test_probes(void) |
| 238 | { |
| 239 | return 0; |
| 240 | } |
| 241 | #endif /* CONFIG_KPROBES_SANITY_TEST */ |
| 242 | |
| 243 | extern int arch_prepare_kprobe(struct kprobe *p); |
| 244 | extern void arch_arm_kprobe(struct kprobe *p); |
| 245 | extern void arch_disarm_kprobe(struct kprobe *p); |
| 246 | extern int arch_init_kprobes(void); |
| 247 | extern void show_registers(struct pt_regs *regs); |
| 248 | extern kprobe_opcode_t *get_insn_slot(void); |
| 249 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
| 250 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
| 251 | |
| 252 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
| 253 | struct kprobe *get_kprobe(void *addr); |
| 254 | void kretprobe_hash_lock(struct task_struct *tsk, |
| 255 | struct hlist_head **head, unsigned long *flags); |
| 256 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); |
| 257 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
| 258 | |
| 259 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
| 260 | static inline struct kprobe *kprobe_running(void) |
| 261 | { |
| 262 | return (__get_cpu_var(current_kprobe)); |
| 263 | } |
| 264 | |
| 265 | static inline void reset_current_kprobe(void) |
| 266 | { |
| 267 | __get_cpu_var(current_kprobe) = NULL; |
| 268 | } |
| 269 | |
| 270 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) |
| 271 | { |
| 272 | return (&__get_cpu_var(kprobe_ctlblk)); |
| 273 | } |
| 274 | |
| 275 | int register_kprobe(struct kprobe *p); |
| 276 | void unregister_kprobe(struct kprobe *p); |
| 277 | int register_kprobes(struct kprobe **kps, int num); |
| 278 | void unregister_kprobes(struct kprobe **kps, int num); |
| 279 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
| 280 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); |
| 281 | int register_jprobe(struct jprobe *p); |
| 282 | void unregister_jprobe(struct jprobe *p); |
| 283 | int register_jprobes(struct jprobe **jps, int num); |
| 284 | void unregister_jprobes(struct jprobe **jps, int num); |
| 285 | void jprobe_return(void); |
| 286 | unsigned long arch_deref_entry_point(void *); |
| 287 | |
| 288 | int register_kretprobe(struct kretprobe *rp); |
| 289 | void unregister_kretprobe(struct kretprobe *rp); |
| 290 | int register_kretprobes(struct kretprobe **rps, int num); |
| 291 | void unregister_kretprobes(struct kretprobe **rps, int num); |
| 292 | |
| 293 | void kprobe_flush_task(struct task_struct *tk); |
| 294 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
| 295 | |
| 296 | int disable_kprobe(struct kprobe *kp); |
| 297 | int enable_kprobe(struct kprobe *kp); |
| 298 | |
| 299 | #else /* !CONFIG_KPROBES: */ |
| 300 | |
| 301 | static inline int kprobes_built_in(void) |
| 302 | { |
| 303 | return 0; |
| 304 | } |
| 305 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) |
| 306 | { |
| 307 | return 0; |
| 308 | } |
| 309 | static inline struct kprobe *get_kprobe(void *addr) |
| 310 | { |
| 311 | return NULL; |
| 312 | } |
| 313 | static inline struct kprobe *kprobe_running(void) |
| 314 | { |
| 315 | return NULL; |
| 316 | } |
| 317 | static inline int register_kprobe(struct kprobe *p) |
| 318 | { |
| 319 | return -ENOSYS; |
| 320 | } |
| 321 | static inline int register_kprobes(struct kprobe **kps, int num) |
| 322 | { |
| 323 | return -ENOSYS; |
| 324 | } |
| 325 | static inline void unregister_kprobe(struct kprobe *p) |
| 326 | { |
| 327 | } |
| 328 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
| 329 | { |
| 330 | } |
| 331 | static inline int register_jprobe(struct jprobe *p) |
| 332 | { |
| 333 | return -ENOSYS; |
| 334 | } |
| 335 | static inline int register_jprobes(struct jprobe **jps, int num) |
| 336 | { |
| 337 | return -ENOSYS; |
| 338 | } |
| 339 | static inline void unregister_jprobe(struct jprobe *p) |
| 340 | { |
| 341 | } |
| 342 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
| 343 | { |
| 344 | } |
| 345 | static inline void jprobe_return(void) |
| 346 | { |
| 347 | } |
| 348 | static inline int register_kretprobe(struct kretprobe *rp) |
| 349 | { |
| 350 | return -ENOSYS; |
| 351 | } |
| 352 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
| 353 | { |
| 354 | return -ENOSYS; |
| 355 | } |
| 356 | static inline void unregister_kretprobe(struct kretprobe *rp) |
| 357 | { |
| 358 | } |
| 359 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
| 360 | { |
| 361 | } |
| 362 | static inline void kprobe_flush_task(struct task_struct *tk) |
| 363 | { |
| 364 | } |
| 365 | static inline int disable_kprobe(struct kprobe *kp) |
| 366 | { |
| 367 | return -ENOSYS; |
| 368 | } |
| 369 | static inline int enable_kprobe(struct kprobe *kp) |
| 370 | { |
| 371 | return -ENOSYS; |
| 372 | } |
| 373 | #endif /* CONFIG_KPROBES */ |
| 374 | static inline int disable_kretprobe(struct kretprobe *rp) |
| 375 | { |
| 376 | return disable_kprobe(&rp->kp); |
| 377 | } |
| 378 | static inline int enable_kretprobe(struct kretprobe *rp) |
| 379 | { |
| 380 | return enable_kprobe(&rp->kp); |
| 381 | } |
| 382 | static inline int disable_jprobe(struct jprobe *jp) |
| 383 | { |
| 384 | return disable_kprobe(&jp->kp); |
| 385 | } |
| 386 | static inline int enable_jprobe(struct jprobe *jp) |
| 387 | { |
| 388 | return enable_kprobe(&jp->kp); |
| 389 | } |
| 390 | |
| 391 | #endif /* _LINUX_KPROBES_H */ |