Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Kernel Probes (KProbes) |
| 3 | * kernel/kprobes.c |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 18 | * |
| 19 | * Copyright (C) IBM Corporation, 2002, 2004 |
| 20 | * |
| 21 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel |
| 22 | * Probes initial implementation (includes suggestions from |
| 23 | * Rusty Russell). |
| 24 | * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with |
| 25 | * hlists and exceptions notifier as suggested by Andi Kleen. |
| 26 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes |
| 27 | * interface to access function arguments. |
| 28 | * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes |
| 29 | * exceptions notifier to be first on the priority list. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 30 | * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston |
| 31 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| 32 | * <prasanna@in.ibm.com> added function-return probes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | */ |
| 34 | #include <linux/kprobes.h> |
| 35 | #include <linux/spinlock.h> |
| 36 | #include <linux/hash.h> |
| 37 | #include <linux/init.h> |
| 38 | #include <linux/module.h> |
| 39 | #include <asm/cacheflush.h> |
| 40 | #include <asm/errno.h> |
| 41 | #include <asm/kdebug.h> |
| 42 | |
| 43 | #define KPROBE_HASH_BITS 6 |
| 44 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 45 | |
| 46 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 47 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | unsigned int kprobe_cpu = NR_CPUS; |
| 50 | static DEFINE_SPINLOCK(kprobe_lock); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 51 | static struct kprobe *curr_kprobe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
| 53 | /* Locks kprobe: irqs must be disabled */ |
| 54 | void lock_kprobes(void) |
| 55 | { |
| 56 | spin_lock(&kprobe_lock); |
| 57 | kprobe_cpu = smp_processor_id(); |
| 58 | } |
| 59 | |
| 60 | void unlock_kprobes(void) |
| 61 | { |
| 62 | kprobe_cpu = NR_CPUS; |
| 63 | spin_unlock(&kprobe_lock); |
| 64 | } |
| 65 | |
| 66 | /* You have to be holding the kprobe_lock */ |
| 67 | struct kprobe *get_kprobe(void *addr) |
| 68 | { |
| 69 | struct hlist_head *head; |
| 70 | struct hlist_node *node; |
| 71 | |
| 72 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
| 73 | hlist_for_each(node, head) { |
| 74 | struct kprobe *p = hlist_entry(node, struct kprobe, hlist); |
| 75 | if (p->addr == addr) |
| 76 | return p; |
| 77 | } |
| 78 | return NULL; |
| 79 | } |
| 80 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 81 | /* |
| 82 | * Aggregate handlers for multiple kprobes support - these handlers |
| 83 | * take care of invoking the individual kprobe handlers on p->list |
| 84 | */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 85 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 86 | { |
| 87 | struct kprobe *kp; |
| 88 | |
| 89 | list_for_each_entry(kp, &p->list, list) { |
| 90 | if (kp->pre_handler) { |
| 91 | curr_kprobe = kp; |
| 92 | kp->pre_handler(kp, regs); |
| 93 | curr_kprobe = NULL; |
| 94 | } |
| 95 | } |
| 96 | return 0; |
| 97 | } |
| 98 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 99 | static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 100 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 101 | { |
| 102 | struct kprobe *kp; |
| 103 | |
| 104 | list_for_each_entry(kp, &p->list, list) { |
| 105 | if (kp->post_handler) { |
| 106 | curr_kprobe = kp; |
| 107 | kp->post_handler(kp, regs, flags); |
| 108 | curr_kprobe = NULL; |
| 109 | } |
| 110 | } |
| 111 | return; |
| 112 | } |
| 113 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 114 | static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 115 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 116 | { |
| 117 | /* |
| 118 | * if we faulted "during" the execution of a user specified |
| 119 | * probe handler, invoke just that probe's fault handler |
| 120 | */ |
| 121 | if (curr_kprobe && curr_kprobe->fault_handler) { |
| 122 | if (curr_kprobe->fault_handler(curr_kprobe, regs, trapnr)) |
| 123 | return 1; |
| 124 | } |
| 125 | return 0; |
| 126 | } |
| 127 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 128 | struct kprobe trampoline_p = { |
| 129 | .addr = (kprobe_opcode_t *) &kretprobe_trampoline, |
| 130 | .pre_handler = trampoline_probe_handler, |
| 131 | .post_handler = trampoline_post_handler |
| 132 | }; |
| 133 | |
| 134 | struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp) |
| 135 | { |
| 136 | struct hlist_node *node; |
| 137 | struct kretprobe_instance *ri; |
| 138 | hlist_for_each_entry(ri, node, &rp->free_instances, uflist) |
| 139 | return ri; |
| 140 | return NULL; |
| 141 | } |
| 142 | |
| 143 | static struct kretprobe_instance *get_used_rp_inst(struct kretprobe *rp) |
| 144 | { |
| 145 | struct hlist_node *node; |
| 146 | struct kretprobe_instance *ri; |
| 147 | hlist_for_each_entry(ri, node, &rp->used_instances, uflist) |
| 148 | return ri; |
| 149 | return NULL; |
| 150 | } |
| 151 | |
| 152 | struct kretprobe_instance *get_rp_inst(void *sara) |
| 153 | { |
| 154 | struct hlist_head *head; |
| 155 | struct hlist_node *node; |
| 156 | struct task_struct *tsk; |
| 157 | struct kretprobe_instance *ri; |
| 158 | |
| 159 | tsk = arch_get_kprobe_task(sara); |
| 160 | head = &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)]; |
| 161 | hlist_for_each_entry(ri, node, head, hlist) { |
| 162 | if (ri->stack_addr == sara) |
| 163 | return ri; |
| 164 | } |
| 165 | return NULL; |
| 166 | } |
| 167 | |
| 168 | void add_rp_inst(struct kretprobe_instance *ri) |
| 169 | { |
| 170 | struct task_struct *tsk; |
| 171 | /* |
| 172 | * Remove rp inst off the free list - |
| 173 | * Add it back when probed function returns |
| 174 | */ |
| 175 | hlist_del(&ri->uflist); |
| 176 | tsk = arch_get_kprobe_task(ri->stack_addr); |
| 177 | /* Add rp inst onto table */ |
| 178 | INIT_HLIST_NODE(&ri->hlist); |
| 179 | hlist_add_head(&ri->hlist, |
| 180 | &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)]); |
| 181 | |
| 182 | /* Also add this rp inst to the used list. */ |
| 183 | INIT_HLIST_NODE(&ri->uflist); |
| 184 | hlist_add_head(&ri->uflist, &ri->rp->used_instances); |
| 185 | } |
| 186 | |
| 187 | void recycle_rp_inst(struct kretprobe_instance *ri) |
| 188 | { |
| 189 | /* remove rp inst off the rprobe_inst_table */ |
| 190 | hlist_del(&ri->hlist); |
| 191 | if (ri->rp) { |
| 192 | /* remove rp inst off the used list */ |
| 193 | hlist_del(&ri->uflist); |
| 194 | /* put rp inst back onto the free list */ |
| 195 | INIT_HLIST_NODE(&ri->uflist); |
| 196 | hlist_add_head(&ri->uflist, &ri->rp->free_instances); |
| 197 | } else |
| 198 | /* Unregistering */ |
| 199 | kfree(ri); |
| 200 | } |
| 201 | |
| 202 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk) |
| 203 | { |
| 204 | return &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)]; |
| 205 | } |
| 206 | |
| 207 | struct kretprobe_instance *get_rp_inst_tsk(struct task_struct *tk) |
| 208 | { |
| 209 | struct task_struct *tsk; |
| 210 | struct hlist_head *head; |
| 211 | struct hlist_node *node; |
| 212 | struct kretprobe_instance *ri; |
| 213 | |
| 214 | head = &kretprobe_inst_table[hash_ptr(tk, KPROBE_HASH_BITS)]; |
| 215 | |
| 216 | hlist_for_each_entry(ri, node, head, hlist) { |
| 217 | tsk = arch_get_kprobe_task(ri->stack_addr); |
| 218 | if (tsk == tk) |
| 219 | return ri; |
| 220 | } |
| 221 | return NULL; |
| 222 | } |
| 223 | |
| 224 | /* |
| 225 | * This function is called from do_exit or do_execv when task tk's stack is |
| 226 | * about to be recycled. Recycle any function-return probe instances |
| 227 | * associated with this task. These represent probed functions that have |
| 228 | * been called but may never return. |
| 229 | */ |
| 230 | void kprobe_flush_task(struct task_struct *tk) |
| 231 | { |
| 232 | arch_kprobe_flush_task(tk, &kprobe_lock); |
| 233 | } |
| 234 | |
| 235 | /* |
| 236 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 237 | * hits it will set up the return probe. |
| 238 | */ |
| 239 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
| 240 | { |
| 241 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
| 242 | |
| 243 | /*TODO: consider to only swap the RA after the last pre_handler fired */ |
| 244 | arch_prepare_kretprobe(rp, regs); |
| 245 | return 0; |
| 246 | } |
| 247 | |
| 248 | static inline void free_rp_inst(struct kretprobe *rp) |
| 249 | { |
| 250 | struct kretprobe_instance *ri; |
| 251 | while ((ri = get_free_rp_inst(rp)) != NULL) { |
| 252 | hlist_del(&ri->uflist); |
| 253 | kfree(ri); |
| 254 | } |
| 255 | } |
| 256 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 257 | /* |
| 258 | * Fill in the required fields of the "manager kprobe". Replace the |
| 259 | * earlier kprobe in the hlist with the manager kprobe |
| 260 | */ |
| 261 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
| 262 | { |
| 263 | ap->addr = p->addr; |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame^] | 264 | memcpy(&ap->opcode, &p->opcode, sizeof(kprobe_opcode_t)); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 265 | memcpy(&ap->ainsn, &p->ainsn, sizeof(struct arch_specific_insn)); |
| 266 | |
| 267 | ap->pre_handler = aggr_pre_handler; |
| 268 | ap->post_handler = aggr_post_handler; |
| 269 | ap->fault_handler = aggr_fault_handler; |
| 270 | |
| 271 | INIT_LIST_HEAD(&ap->list); |
| 272 | list_add(&p->list, &ap->list); |
| 273 | |
| 274 | INIT_HLIST_NODE(&ap->hlist); |
| 275 | hlist_del(&p->hlist); |
| 276 | hlist_add_head(&ap->hlist, |
| 277 | &kprobe_table[hash_ptr(ap->addr, KPROBE_HASH_BITS)]); |
| 278 | } |
| 279 | |
| 280 | /* |
| 281 | * This is the second or subsequent kprobe at the address - handle |
| 282 | * the intricacies |
| 283 | * TODO: Move kcalloc outside the spinlock |
| 284 | */ |
| 285 | static int register_aggr_kprobe(struct kprobe *old_p, struct kprobe *p) |
| 286 | { |
| 287 | int ret = 0; |
| 288 | struct kprobe *ap; |
| 289 | |
| 290 | if (old_p->break_handler || p->break_handler) { |
| 291 | ret = -EEXIST; /* kprobe and jprobe can't (yet) coexist */ |
| 292 | } else if (old_p->pre_handler == aggr_pre_handler) { |
| 293 | list_add(&p->list, &old_p->list); |
| 294 | } else { |
| 295 | ap = kcalloc(1, sizeof(struct kprobe), GFP_ATOMIC); |
| 296 | if (!ap) |
| 297 | return -ENOMEM; |
| 298 | add_aggr_kprobe(ap, old_p); |
| 299 | list_add(&p->list, &ap->list); |
| 300 | } |
| 301 | return ret; |
| 302 | } |
| 303 | |
| 304 | /* kprobe removal house-keeping routines */ |
| 305 | static inline void cleanup_kprobe(struct kprobe *p, unsigned long flags) |
| 306 | { |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame^] | 307 | arch_disarm_kprobe(p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 308 | hlist_del(&p->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 309 | spin_unlock_irqrestore(&kprobe_lock, flags); |
| 310 | arch_remove_kprobe(p); |
| 311 | } |
| 312 | |
| 313 | static inline void cleanup_aggr_kprobe(struct kprobe *old_p, |
| 314 | struct kprobe *p, unsigned long flags) |
| 315 | { |
| 316 | list_del(&p->list); |
| 317 | if (list_empty(&old_p->list)) { |
| 318 | cleanup_kprobe(old_p, flags); |
| 319 | kfree(old_p); |
| 320 | } else |
| 321 | spin_unlock_irqrestore(&kprobe_lock, flags); |
| 322 | } |
| 323 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | int register_kprobe(struct kprobe *p) |
| 325 | { |
| 326 | int ret = 0; |
| 327 | unsigned long flags = 0; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 328 | struct kprobe *old_p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
| 330 | if ((ret = arch_prepare_kprobe(p)) != 0) { |
| 331 | goto rm_kprobe; |
| 332 | } |
| 333 | spin_lock_irqsave(&kprobe_lock, flags); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 334 | old_p = get_kprobe(p->addr); |
| 335 | if (old_p) { |
| 336 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | goto out; |
| 338 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 340 | arch_copy_kprobe(p); |
| 341 | INIT_HLIST_NODE(&p->hlist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | hlist_add_head(&p->hlist, |
| 343 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 344 | |
Rusty Lynch | 7e1048b | 2005-06-23 00:09:25 -0700 | [diff] [blame^] | 345 | arch_arm_kprobe(p); |
| 346 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | out: |
| 348 | spin_unlock_irqrestore(&kprobe_lock, flags); |
| 349 | rm_kprobe: |
| 350 | if (ret == -EEXIST) |
| 351 | arch_remove_kprobe(p); |
| 352 | return ret; |
| 353 | } |
| 354 | |
| 355 | void unregister_kprobe(struct kprobe *p) |
| 356 | { |
| 357 | unsigned long flags; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 358 | struct kprobe *old_p; |
| 359 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | spin_lock_irqsave(&kprobe_lock, flags); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 361 | old_p = get_kprobe(p->addr); |
| 362 | if (old_p) { |
| 363 | if (old_p->pre_handler == aggr_pre_handler) |
| 364 | cleanup_aggr_kprobe(old_p, p, flags); |
| 365 | else |
| 366 | cleanup_kprobe(p, flags); |
| 367 | } else |
Prasanna S Panchamukhi | 04dea5f | 2005-05-05 16:15:41 -0700 | [diff] [blame] | 368 | spin_unlock_irqrestore(&kprobe_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | } |
| 370 | |
| 371 | static struct notifier_block kprobe_exceptions_nb = { |
| 372 | .notifier_call = kprobe_exceptions_notify, |
| 373 | .priority = 0x7fffffff /* we need to notified first */ |
| 374 | }; |
| 375 | |
| 376 | int register_jprobe(struct jprobe *jp) |
| 377 | { |
| 378 | /* Todo: Verify probepoint is a function entry point */ |
| 379 | jp->kp.pre_handler = setjmp_pre_handler; |
| 380 | jp->kp.break_handler = longjmp_break_handler; |
| 381 | |
| 382 | return register_kprobe(&jp->kp); |
| 383 | } |
| 384 | |
| 385 | void unregister_jprobe(struct jprobe *jp) |
| 386 | { |
| 387 | unregister_kprobe(&jp->kp); |
| 388 | } |
| 389 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 390 | #ifdef ARCH_SUPPORTS_KRETPROBES |
| 391 | |
| 392 | int register_kretprobe(struct kretprobe *rp) |
| 393 | { |
| 394 | int ret = 0; |
| 395 | struct kretprobe_instance *inst; |
| 396 | int i; |
| 397 | |
| 398 | rp->kp.pre_handler = pre_handler_kretprobe; |
| 399 | |
| 400 | /* Pre-allocate memory for max kretprobe instances */ |
| 401 | if (rp->maxactive <= 0) { |
| 402 | #ifdef CONFIG_PREEMPT |
| 403 | rp->maxactive = max(10, 2 * NR_CPUS); |
| 404 | #else |
| 405 | rp->maxactive = NR_CPUS; |
| 406 | #endif |
| 407 | } |
| 408 | INIT_HLIST_HEAD(&rp->used_instances); |
| 409 | INIT_HLIST_HEAD(&rp->free_instances); |
| 410 | for (i = 0; i < rp->maxactive; i++) { |
| 411 | inst = kmalloc(sizeof(struct kretprobe_instance), GFP_KERNEL); |
| 412 | if (inst == NULL) { |
| 413 | free_rp_inst(rp); |
| 414 | return -ENOMEM; |
| 415 | } |
| 416 | INIT_HLIST_NODE(&inst->uflist); |
| 417 | hlist_add_head(&inst->uflist, &rp->free_instances); |
| 418 | } |
| 419 | |
| 420 | rp->nmissed = 0; |
| 421 | /* Establish function entry probe point */ |
| 422 | if ((ret = register_kprobe(&rp->kp)) != 0) |
| 423 | free_rp_inst(rp); |
| 424 | return ret; |
| 425 | } |
| 426 | |
| 427 | #else /* ARCH_SUPPORTS_KRETPROBES */ |
| 428 | |
| 429 | int register_kretprobe(struct kretprobe *rp) |
| 430 | { |
| 431 | return -ENOSYS; |
| 432 | } |
| 433 | |
| 434 | #endif /* ARCH_SUPPORTS_KRETPROBES */ |
| 435 | |
| 436 | void unregister_kretprobe(struct kretprobe *rp) |
| 437 | { |
| 438 | unsigned long flags; |
| 439 | struct kretprobe_instance *ri; |
| 440 | |
| 441 | unregister_kprobe(&rp->kp); |
| 442 | /* No race here */ |
| 443 | spin_lock_irqsave(&kprobe_lock, flags); |
| 444 | free_rp_inst(rp); |
| 445 | while ((ri = get_used_rp_inst(rp)) != NULL) { |
| 446 | ri->rp = NULL; |
| 447 | hlist_del(&ri->uflist); |
| 448 | } |
| 449 | spin_unlock_irqrestore(&kprobe_lock, flags); |
| 450 | } |
| 451 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | static int __init init_kprobes(void) |
| 453 | { |
| 454 | int i, err = 0; |
| 455 | |
| 456 | /* FIXME allocate the probe table, currently defined statically */ |
| 457 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 458 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 460 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
| 461 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
| 463 | err = register_die_notifier(&kprobe_exceptions_nb); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 464 | /* Register the trampoline probe for return probe */ |
| 465 | register_kprobe(&trampoline_p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | return err; |
| 467 | } |
| 468 | |
| 469 | __initcall(init_kprobes); |
| 470 | |
| 471 | EXPORT_SYMBOL_GPL(register_kprobe); |
| 472 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
| 473 | EXPORT_SYMBOL_GPL(register_jprobe); |
| 474 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
| 475 | EXPORT_SYMBOL_GPL(jprobe_return); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 476 | EXPORT_SYMBOL_GPL(register_kretprobe); |
| 477 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
| 478 | |