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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <linux/hash.h> |
| 36 | #include <linux/init.h> |
Tim Schmielau | 4e57b68 | 2005-10-30 15:03:48 -0800 | [diff] [blame] | 37 | #include <linux/slab.h> |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 38 | #include <linux/stddef.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | #include <linux/module.h> |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 40 | #include <linux/moduleloader.h> |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 41 | #include <linux/kallsyms.h> |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 42 | #include <linux/freezer.h> |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 43 | #include <linux/seq_file.h> |
| 44 | #include <linux/debugfs.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 45 | #include <linux/kdebug.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 46 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 47 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | #include <asm/cacheflush.h> |
| 49 | #include <asm/errno.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 50 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
| 52 | #define KPROBE_HASH_BITS 6 |
| 53 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 54 | |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 55 | |
| 56 | /* |
| 57 | * Some oddball architectures like 64bit powerpc have function descriptors |
| 58 | * so this must be overridable. |
| 59 | */ |
| 60 | #ifndef kprobe_lookup_name |
| 61 | #define kprobe_lookup_name(name, addr) \ |
| 62 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) |
| 63 | #endif |
| 64 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 65 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 67 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 69 | /* NOTE: change this value only with kprobe_mutex held */ |
| 70 | static bool kprobe_enabled; |
| 71 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 72 | static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 73 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 74 | static struct { |
Andrew Morton | 7e036d0 | 2008-11-12 13:26:57 -0800 | [diff] [blame] | 75 | spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 76 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 77 | |
| 78 | static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
| 79 | { |
| 80 | return &(kretprobe_table_locks[hash].lock); |
| 81 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 83 | /* |
| 84 | * Normally, functions that we'd want to prohibit kprobes in, are marked |
| 85 | * __kprobes. But, there are cases where such functions already belong to |
| 86 | * a different section (__sched for preempt_schedule) |
| 87 | * |
| 88 | * For such cases, we now have a blacklist |
| 89 | */ |
Daniel Guilak | 544304b | 2008-07-10 09:38:19 -0700 | [diff] [blame] | 90 | static struct kprobe_blackpoint kprobe_blacklist[] = { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 91 | {"preempt_schedule",}, |
| 92 | {NULL} /* Terminator */ |
| 93 | }; |
| 94 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 95 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 96 | /* |
| 97 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 98 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 99 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 100 | * is a recipe for disaster |
| 101 | */ |
| 102 | #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) |
| 103 | |
| 104 | struct kprobe_insn_page { |
| 105 | struct hlist_node hlist; |
| 106 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
| 107 | char slot_used[INSNS_PER_PAGE]; |
| 108 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 109 | int ngarbage; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 110 | }; |
| 111 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 112 | enum kprobe_slot_state { |
| 113 | SLOT_CLEAN = 0, |
| 114 | SLOT_DIRTY = 1, |
| 115 | SLOT_USED = 2, |
| 116 | }; |
| 117 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 118 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 119 | static struct hlist_head kprobe_insn_pages; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 120 | static int kprobe_garbage_slots; |
| 121 | static int collect_garbage_slots(void); |
| 122 | |
| 123 | static int __kprobes check_safety(void) |
| 124 | { |
| 125 | int ret = 0; |
| 126 | #if defined(CONFIG_PREEMPT) && defined(CONFIG_PM) |
| 127 | ret = freeze_processes(); |
| 128 | if (ret == 0) { |
| 129 | struct task_struct *p, *q; |
| 130 | do_each_thread(p, q) { |
| 131 | if (p != current && p->state == TASK_RUNNING && |
| 132 | p->pid != 0) { |
| 133 | printk("Check failed: %s is running\n",p->comm); |
| 134 | ret = -1; |
| 135 | goto loop_end; |
| 136 | } |
| 137 | } while_each_thread(p, q); |
| 138 | } |
| 139 | loop_end: |
| 140 | thaw_processes(); |
| 141 | #else |
| 142 | synchronize_sched(); |
| 143 | #endif |
| 144 | return ret; |
| 145 | } |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 146 | |
| 147 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 148 | * __get_insn_slot() - Find a slot on an executable page for an instruction. |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 149 | * We allocate an executable page if there's no room on existing ones. |
| 150 | */ |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 151 | static kprobe_opcode_t __kprobes *__get_insn_slot(void) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 152 | { |
| 153 | struct kprobe_insn_page *kip; |
| 154 | struct hlist_node *pos; |
| 155 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 156 | retry: |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 157 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 158 | if (kip->nused < INSNS_PER_PAGE) { |
| 159 | int i; |
| 160 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 161 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 162 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 163 | kip->nused++; |
| 164 | return kip->insns + (i * MAX_INSN_SIZE); |
| 165 | } |
| 166 | } |
| 167 | /* Surprise! No unused slots. Fix kip->nused. */ |
| 168 | kip->nused = INSNS_PER_PAGE; |
| 169 | } |
| 170 | } |
| 171 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 172 | /* If there are any garbage slots, collect it and try again. */ |
| 173 | if (kprobe_garbage_slots && collect_garbage_slots() == 0) { |
| 174 | goto retry; |
| 175 | } |
| 176 | /* All out of space. Need to allocate a new page. Use slot 0. */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 177 | kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 178 | if (!kip) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 179 | return NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 180 | |
| 181 | /* |
| 182 | * Use module_alloc so this page is within +/- 2GB of where the |
| 183 | * kernel image and loaded module images reside. This is required |
| 184 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 185 | */ |
| 186 | kip->insns = module_alloc(PAGE_SIZE); |
| 187 | if (!kip->insns) { |
| 188 | kfree(kip); |
| 189 | return NULL; |
| 190 | } |
| 191 | INIT_HLIST_NODE(&kip->hlist); |
| 192 | hlist_add_head(&kip->hlist, &kprobe_insn_pages); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 193 | memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); |
| 194 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 195 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 196 | kip->ngarbage = 0; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 197 | return kip->insns; |
| 198 | } |
| 199 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 200 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
| 201 | { |
| 202 | kprobe_opcode_t *ret; |
| 203 | mutex_lock(&kprobe_insn_mutex); |
| 204 | ret = __get_insn_slot(); |
| 205 | mutex_unlock(&kprobe_insn_mutex); |
| 206 | return ret; |
| 207 | } |
| 208 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 209 | /* Return 1 if all garbages are collected, otherwise 0. */ |
| 210 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) |
| 211 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 212 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 213 | kip->nused--; |
| 214 | if (kip->nused == 0) { |
| 215 | /* |
| 216 | * Page is no longer in use. Free it unless |
| 217 | * it's the last one. We keep the last one |
| 218 | * so as not to have to set it up again the |
| 219 | * next time somebody inserts a probe. |
| 220 | */ |
| 221 | hlist_del(&kip->hlist); |
| 222 | if (hlist_empty(&kprobe_insn_pages)) { |
| 223 | INIT_HLIST_NODE(&kip->hlist); |
| 224 | hlist_add_head(&kip->hlist, |
| 225 | &kprobe_insn_pages); |
| 226 | } else { |
| 227 | module_free(NULL, kip->insns); |
| 228 | kfree(kip); |
| 229 | } |
| 230 | return 1; |
| 231 | } |
| 232 | return 0; |
| 233 | } |
| 234 | |
| 235 | static int __kprobes collect_garbage_slots(void) |
| 236 | { |
| 237 | struct kprobe_insn_page *kip; |
| 238 | struct hlist_node *pos, *next; |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 239 | int safety; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 240 | |
| 241 | /* Ensure no-one is preepmted on the garbages */ |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 242 | mutex_unlock(&kprobe_insn_mutex); |
| 243 | safety = check_safety(); |
| 244 | mutex_lock(&kprobe_insn_mutex); |
| 245 | if (safety != 0) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 246 | return -EAGAIN; |
| 247 | |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 248 | hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 249 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 250 | if (kip->ngarbage == 0) |
| 251 | continue; |
| 252 | kip->ngarbage = 0; /* we will collect all garbages */ |
| 253 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 254 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 255 | collect_one_slot(kip, i)) |
| 256 | break; |
| 257 | } |
| 258 | } |
| 259 | kprobe_garbage_slots = 0; |
| 260 | return 0; |
| 261 | } |
| 262 | |
| 263 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 264 | { |
| 265 | struct kprobe_insn_page *kip; |
| 266 | struct hlist_node *pos; |
| 267 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 268 | mutex_lock(&kprobe_insn_mutex); |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 269 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 270 | if (kip->insns <= slot && |
| 271 | slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { |
| 272 | int i = (slot - kip->insns) / MAX_INSN_SIZE; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 273 | if (dirty) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 274 | kip->slot_used[i] = SLOT_DIRTY; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 275 | kip->ngarbage++; |
| 276 | } else { |
| 277 | collect_one_slot(kip, i); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 278 | } |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 279 | break; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 280 | } |
| 281 | } |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 282 | |
| 283 | if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 284 | collect_garbage_slots(); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 285 | |
| 286 | mutex_unlock(&kprobe_insn_mutex); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 287 | } |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 288 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 289 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 290 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 291 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 292 | { |
| 293 | __get_cpu_var(kprobe_instance) = kp; |
| 294 | } |
| 295 | |
| 296 | static inline void reset_kprobe_instance(void) |
| 297 | { |
| 298 | __get_cpu_var(kprobe_instance) = NULL; |
| 299 | } |
| 300 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 301 | /* |
| 302 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 303 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 304 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 305 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 306 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 307 | struct kprobe __kprobes *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | { |
| 309 | struct hlist_head *head; |
| 310 | struct hlist_node *node; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 311 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | |
| 313 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 314 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | if (p->addr == addr) |
| 316 | return p; |
| 317 | } |
| 318 | return NULL; |
| 319 | } |
| 320 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 321 | /* |
| 322 | * Aggregate handlers for multiple kprobes support - these handlers |
| 323 | * take care of invoking the individual kprobe handlers on p->list |
| 324 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 325 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 326 | { |
| 327 | struct kprobe *kp; |
| 328 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 329 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 330 | if (kp->pre_handler && !kprobe_gone(kp)) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 331 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 332 | if (kp->pre_handler(kp, regs)) |
| 333 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 334 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 335 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 336 | } |
| 337 | return 0; |
| 338 | } |
| 339 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 340 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 341 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 342 | { |
| 343 | struct kprobe *kp; |
| 344 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 345 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 346 | if (kp->post_handler && !kprobe_gone(kp)) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 347 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 348 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 349 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 350 | } |
| 351 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 352 | } |
| 353 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 354 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 355 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 356 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 357 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 358 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 359 | /* |
| 360 | * if we faulted "during" the execution of a user specified |
| 361 | * probe handler, invoke just that probe's fault handler |
| 362 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 363 | if (cur && cur->fault_handler) { |
| 364 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 365 | return 1; |
| 366 | } |
| 367 | return 0; |
| 368 | } |
| 369 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 370 | static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 371 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 372 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 373 | int ret = 0; |
| 374 | |
| 375 | if (cur && cur->break_handler) { |
| 376 | if (cur->break_handler(cur, regs)) |
| 377 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 378 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 379 | reset_kprobe_instance(); |
| 380 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 381 | } |
| 382 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 383 | /* Walks the list and increments nmissed count for multiprobe case */ |
| 384 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
| 385 | { |
| 386 | struct kprobe *kp; |
| 387 | if (p->pre_handler != aggr_pre_handler) { |
| 388 | p->nmissed++; |
| 389 | } else { |
| 390 | list_for_each_entry_rcu(kp, &p->list, list) |
| 391 | kp->nmissed++; |
| 392 | } |
| 393 | return; |
| 394 | } |
| 395 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 396 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
| 397 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 398 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 399 | struct kretprobe *rp = ri->rp; |
| 400 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 401 | /* remove rp inst off the rprobe_inst_table */ |
| 402 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 403 | INIT_HLIST_NODE(&ri->hlist); |
| 404 | if (likely(rp)) { |
| 405 | spin_lock(&rp->lock); |
| 406 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 407 | spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 408 | } else |
| 409 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 410 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 411 | } |
| 412 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 413 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 414 | struct hlist_head **head, unsigned long *flags) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 415 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 416 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 417 | spinlock_t *hlist_lock; |
| 418 | |
| 419 | *head = &kretprobe_inst_table[hash]; |
| 420 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 421 | spin_lock_irqsave(hlist_lock, *flags); |
| 422 | } |
| 423 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 424 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
| 425 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 426 | { |
| 427 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 428 | spin_lock_irqsave(hlist_lock, *flags); |
| 429 | } |
| 430 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 431 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
| 432 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 433 | { |
| 434 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 435 | spinlock_t *hlist_lock; |
| 436 | |
| 437 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 438 | spin_unlock_irqrestore(hlist_lock, *flags); |
| 439 | } |
| 440 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 441 | void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 442 | { |
| 443 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 444 | spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 445 | } |
| 446 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 447 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 448 | * This function is called from finish_task_switch when task tk becomes dead, |
| 449 | * so that we can recycle any function-return probe instances associated |
| 450 | * with this task. These left over instances represent probed functions |
| 451 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 452 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 453 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 454 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 455 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 456 | struct hlist_head *head, empty_rp; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 457 | struct hlist_node *node, *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 458 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 459 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 460 | if (unlikely(!kprobes_initialized)) |
| 461 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 462 | return; |
| 463 | |
| 464 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 465 | head = &kretprobe_inst_table[hash]; |
| 466 | kretprobe_table_lock(hash, &flags); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 467 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
| 468 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 469 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 470 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 471 | kretprobe_table_unlock(hash, &flags); |
| 472 | INIT_HLIST_HEAD(&empty_rp); |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 473 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
| 474 | hlist_del(&ri->hlist); |
| 475 | kfree(ri); |
| 476 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 477 | } |
| 478 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 479 | static inline void free_rp_inst(struct kretprobe *rp) |
| 480 | { |
| 481 | struct kretprobe_instance *ri; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 482 | struct hlist_node *pos, *next; |
| 483 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 484 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
| 485 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 486 | kfree(ri); |
| 487 | } |
| 488 | } |
| 489 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 490 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
| 491 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 492 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 493 | struct kretprobe_instance *ri; |
| 494 | struct hlist_node *pos, *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 495 | struct hlist_head *head; |
| 496 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 497 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 498 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 499 | kretprobe_table_lock(hash, &flags); |
| 500 | head = &kretprobe_inst_table[hash]; |
| 501 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { |
| 502 | if (ri->rp == rp) |
| 503 | ri->rp = NULL; |
| 504 | } |
| 505 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 506 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 507 | free_rp_inst(rp); |
| 508 | } |
| 509 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 510 | /* |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 511 | * Keep all fields in the kprobe consistent |
| 512 | */ |
| 513 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) |
| 514 | { |
| 515 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); |
| 516 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); |
| 517 | } |
| 518 | |
| 519 | /* |
| 520 | * Add the new probe to old_p->list. Fail if this is the |
| 521 | * second jprobe at the address - two jprobes can't coexist |
| 522 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 523 | static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 524 | { |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 525 | if (p->break_handler) { |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 526 | if (old_p->break_handler) |
| 527 | return -EEXIST; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 528 | list_add_tail_rcu(&p->list, &old_p->list); |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 529 | old_p->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 530 | } else |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 531 | list_add_rcu(&p->list, &old_p->list); |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 532 | if (p->post_handler && !old_p->post_handler) |
| 533 | old_p->post_handler = aggr_post_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 534 | return 0; |
| 535 | } |
| 536 | |
| 537 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 538 | * Fill in the required fields of the "manager kprobe". Replace the |
| 539 | * earlier kprobe in the hlist with the manager kprobe |
| 540 | */ |
| 541 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
| 542 | { |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 543 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 544 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 545 | ap->addr = p->addr; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 546 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 547 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 548 | /* We don't care the kprobe which has gone. */ |
| 549 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 550 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 551 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 552 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 553 | |
| 554 | INIT_LIST_HEAD(&ap->list); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 555 | list_add_rcu(&p->list, &ap->list); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 556 | |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 557 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 558 | } |
| 559 | |
| 560 | /* |
| 561 | * This is the second or subsequent kprobe at the address - handle |
| 562 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 563 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 564 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
| 565 | struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 566 | { |
| 567 | int ret = 0; |
| 568 | struct kprobe *ap; |
| 569 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 570 | if (kprobe_gone(old_p)) { |
| 571 | /* |
| 572 | * Attempting to insert new probe at the same location that |
| 573 | * had a probe in the module vaddr area which already |
| 574 | * freed. So, the instruction slot has already been |
| 575 | * released. We need a new slot for the new probe. |
| 576 | */ |
| 577 | ret = arch_prepare_kprobe(old_p); |
| 578 | if (ret) |
| 579 | return ret; |
| 580 | } |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 581 | if (old_p->pre_handler == aggr_pre_handler) { |
| 582 | copy_kprobe(old_p, p); |
| 583 | ret = add_new_kprobe(old_p, p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 584 | ap = old_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 585 | } else { |
Keshavamurthy Anil S | a0d5006 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 586 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 587 | if (!ap) { |
| 588 | if (kprobe_gone(old_p)) |
| 589 | arch_remove_kprobe(old_p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 590 | return -ENOMEM; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 591 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 592 | add_aggr_kprobe(ap, old_p); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 593 | copy_kprobe(ap, p); |
| 594 | ret = add_new_kprobe(ap, p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 595 | } |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 596 | if (kprobe_gone(old_p)) { |
| 597 | /* |
| 598 | * If the old_p has gone, its breakpoint has been disarmed. |
| 599 | * We have to arm it again after preparing real kprobes. |
| 600 | */ |
| 601 | ap->flags &= ~KPROBE_FLAG_GONE; |
| 602 | if (kprobe_enabled) |
| 603 | arch_arm_kprobe(ap); |
| 604 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 605 | return ret; |
| 606 | } |
| 607 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 608 | static int __kprobes in_kprobes_functions(unsigned long addr) |
| 609 | { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 610 | struct kprobe_blackpoint *kb; |
| 611 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 612 | if (addr >= (unsigned long)__kprobes_text_start && |
| 613 | addr < (unsigned long)__kprobes_text_end) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 614 | return -EINVAL; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 615 | /* |
| 616 | * If there exists a kprobe_blacklist, verify and |
| 617 | * fail any probe registration in the prohibited area |
| 618 | */ |
| 619 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 620 | if (kb->start_addr) { |
| 621 | if (addr >= kb->start_addr && |
| 622 | addr < (kb->start_addr + kb->range)) |
| 623 | return -EINVAL; |
| 624 | } |
| 625 | } |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 626 | return 0; |
| 627 | } |
| 628 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 629 | /* |
| 630 | * If we have a symbol_name argument, look it up and add the offset field |
| 631 | * to it. This way, we can specify a relative address to a symbol. |
| 632 | */ |
| 633 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) |
| 634 | { |
| 635 | kprobe_opcode_t *addr = p->addr; |
| 636 | if (p->symbol_name) { |
| 637 | if (addr) |
| 638 | return NULL; |
| 639 | kprobe_lookup_name(p->symbol_name, addr); |
| 640 | } |
| 641 | |
| 642 | if (!addr) |
| 643 | return NULL; |
| 644 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 645 | } |
| 646 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 647 | int __kprobes register_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | { |
| 649 | int ret = 0; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 650 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 651 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 652 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 654 | addr = kprobe_addr(p); |
| 655 | if (!addr) |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 656 | return -EINVAL; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 657 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 658 | |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 659 | preempt_disable(); |
| 660 | if (!__kernel_text_address((unsigned long) p->addr) || |
| 661 | in_kprobes_functions((unsigned long) p->addr)) { |
| 662 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 663 | return -EINVAL; |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 664 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 665 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 666 | p->flags = 0; |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 667 | /* |
| 668 | * Check if are we probing a module. |
| 669 | */ |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 670 | probed_mod = __module_text_address((unsigned long) p->addr); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 671 | if (probed_mod) { |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 672 | /* |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 673 | * We must hold a refcount of the probed module while updating |
| 674 | * its code to prohibit unexpected unloading. |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 675 | */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 676 | if (unlikely(!try_module_get(probed_mod))) { |
| 677 | preempt_enable(); |
| 678 | return -EINVAL; |
| 679 | } |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 680 | } |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 681 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 682 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 683 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 684 | INIT_LIST_HEAD(&p->list); |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 685 | mutex_lock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 686 | old_p = get_kprobe(p->addr); |
| 687 | if (old_p) { |
| 688 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | goto out; |
| 690 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 692 | ret = arch_prepare_kprobe(p); |
| 693 | if (ret) |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 694 | goto out; |
| 695 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 696 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 697 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 699 | |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 700 | if (kprobe_enabled) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 701 | arch_arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 702 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 704 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 705 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 706 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 707 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 708 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | return ret; |
| 710 | } |
| 711 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 712 | /* |
| 713 | * Unregister a kprobe without a scheduler synchronization. |
| 714 | */ |
| 715 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 716 | { |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 717 | struct kprobe *old_p, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 718 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 719 | old_p = get_kprobe(p->addr); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 720 | if (unlikely(!old_p)) |
| 721 | return -EINVAL; |
| 722 | |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 723 | if (p != old_p) { |
| 724 | list_for_each_entry_rcu(list_p, &old_p->list, list) |
| 725 | if (list_p == p) |
| 726 | /* kprobe p is a valid probe */ |
| 727 | goto valid_p; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 728 | return -EINVAL; |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 729 | } |
| 730 | valid_p: |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 731 | if (old_p == p || |
| 732 | (old_p->pre_handler == aggr_pre_handler && |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 733 | list_is_singular(&old_p->list))) { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 734 | /* |
| 735 | * Only probe on the hash list. Disarm only if kprobes are |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 736 | * enabled and not gone - otherwise, the breakpoint would |
| 737 | * already have been removed. We save on flushing icache. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 738 | */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 739 | if (kprobe_enabled && !kprobe_gone(old_p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 740 | arch_disarm_kprobe(p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 741 | hlist_del_rcu(&old_p->hlist); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 742 | } else { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 743 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 744 | old_p->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 745 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 746 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
| 747 | if ((list_p != p) && (list_p->post_handler)) |
| 748 | goto noclean; |
| 749 | } |
| 750 | old_p->post_handler = NULL; |
| 751 | } |
| 752 | noclean: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 753 | list_del_rcu(&p->list); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 754 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 755 | return 0; |
| 756 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 757 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 758 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
| 759 | { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 760 | struct kprobe *old_p; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 761 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 762 | if (list_empty(&p->list)) |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 763 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 764 | else if (list_is_singular(&p->list)) { |
| 765 | /* "p" is the last child of an aggr_kprobe */ |
| 766 | old_p = list_entry(p->list.next, struct kprobe, list); |
| 767 | list_del(&p->list); |
| 768 | arch_remove_kprobe(old_p); |
| 769 | kfree(old_p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 770 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | } |
| 772 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 773 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 774 | { |
| 775 | int i, ret = 0; |
| 776 | |
| 777 | if (num <= 0) |
| 778 | return -EINVAL; |
| 779 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 780 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 781 | if (ret < 0) { |
| 782 | if (i > 0) |
| 783 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 784 | break; |
| 785 | } |
| 786 | } |
| 787 | return ret; |
| 788 | } |
| 789 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 790 | void __kprobes unregister_kprobe(struct kprobe *p) |
| 791 | { |
| 792 | unregister_kprobes(&p, 1); |
| 793 | } |
| 794 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 795 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
| 796 | { |
| 797 | int i; |
| 798 | |
| 799 | if (num <= 0) |
| 800 | return; |
| 801 | mutex_lock(&kprobe_mutex); |
| 802 | for (i = 0; i < num; i++) |
| 803 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 804 | kps[i]->addr = NULL; |
| 805 | mutex_unlock(&kprobe_mutex); |
| 806 | |
| 807 | synchronize_sched(); |
| 808 | for (i = 0; i < num; i++) |
| 809 | if (kps[i]->addr) |
| 810 | __unregister_kprobe_bottom(kps[i]); |
| 811 | } |
| 812 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | static struct notifier_block kprobe_exceptions_nb = { |
| 814 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 815 | .priority = 0x7fffffff /* we need to be notified first */ |
| 816 | }; |
| 817 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 818 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 819 | { |
| 820 | return (unsigned long)entry; |
| 821 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 823 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 824 | { |
| 825 | struct jprobe *jp; |
| 826 | int ret = 0, i; |
| 827 | |
| 828 | if (num <= 0) |
| 829 | return -EINVAL; |
| 830 | for (i = 0; i < num; i++) { |
| 831 | unsigned long addr; |
| 832 | jp = jps[i]; |
| 833 | addr = arch_deref_entry_point(jp->entry); |
| 834 | |
| 835 | if (!kernel_text_address(addr)) |
| 836 | ret = -EINVAL; |
| 837 | else { |
| 838 | /* Todo: Verify probepoint is a function entry point */ |
| 839 | jp->kp.pre_handler = setjmp_pre_handler; |
| 840 | jp->kp.break_handler = longjmp_break_handler; |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 841 | ret = register_kprobe(&jp->kp); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 842 | } |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 843 | if (ret < 0) { |
| 844 | if (i > 0) |
| 845 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 846 | break; |
| 847 | } |
| 848 | } |
| 849 | return ret; |
| 850 | } |
| 851 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 852 | int __kprobes register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 854 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | } |
| 856 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 857 | void __kprobes unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 859 | unregister_jprobes(&jp, 1); |
| 860 | } |
| 861 | |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 862 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
| 863 | { |
| 864 | int i; |
| 865 | |
| 866 | if (num <= 0) |
| 867 | return; |
| 868 | mutex_lock(&kprobe_mutex); |
| 869 | for (i = 0; i < num; i++) |
| 870 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 871 | jps[i]->kp.addr = NULL; |
| 872 | mutex_unlock(&kprobe_mutex); |
| 873 | |
| 874 | synchronize_sched(); |
| 875 | for (i = 0; i < num; i++) { |
| 876 | if (jps[i]->kp.addr) |
| 877 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 878 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | } |
| 880 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 881 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 882 | /* |
| 883 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 884 | * hits it will set up the return probe. |
| 885 | */ |
| 886 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 887 | struct pt_regs *regs) |
| 888 | { |
| 889 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 890 | unsigned long hash, flags = 0; |
| 891 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 892 | |
| 893 | /*TODO: consider to only swap the RA after the last pre_handler fired */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 894 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
| 895 | spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 896 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 897 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 898 | struct kretprobe_instance, hlist); |
| 899 | hlist_del(&ri->hlist); |
| 900 | spin_unlock_irqrestore(&rp->lock, flags); |
| 901 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 902 | ri->rp = rp; |
| 903 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 904 | |
| 905 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 906 | spin_unlock_irqrestore(&rp->lock, flags); |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 907 | return 0; |
| 908 | } |
| 909 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 910 | arch_prepare_kretprobe(ri, regs); |
| 911 | |
| 912 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 913 | INIT_HLIST_NODE(&ri->hlist); |
| 914 | kretprobe_table_lock(hash, &flags); |
| 915 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 916 | kretprobe_table_unlock(hash, &flags); |
| 917 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 918 | rp->nmissed++; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 919 | spin_unlock_irqrestore(&rp->lock, flags); |
| 920 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 921 | return 0; |
| 922 | } |
| 923 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 924 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 925 | { |
| 926 | int ret = 0; |
| 927 | struct kretprobe_instance *inst; |
| 928 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 929 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 930 | |
| 931 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 932 | addr = kprobe_addr(&rp->kp); |
| 933 | if (!addr) |
| 934 | return -EINVAL; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 935 | |
| 936 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 937 | if (kretprobe_blacklist[i].addr == addr) |
| 938 | return -EINVAL; |
| 939 | } |
| 940 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 941 | |
| 942 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 943 | rp->kp.post_handler = NULL; |
| 944 | rp->kp.fault_handler = NULL; |
| 945 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 946 | |
| 947 | /* Pre-allocate memory for max kretprobe instances */ |
| 948 | if (rp->maxactive <= 0) { |
| 949 | #ifdef CONFIG_PREEMPT |
| 950 | rp->maxactive = max(10, 2 * NR_CPUS); |
| 951 | #else |
| 952 | rp->maxactive = NR_CPUS; |
| 953 | #endif |
| 954 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 955 | spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 956 | INIT_HLIST_HEAD(&rp->free_instances); |
| 957 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 958 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 959 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 960 | if (inst == NULL) { |
| 961 | free_rp_inst(rp); |
| 962 | return -ENOMEM; |
| 963 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 964 | INIT_HLIST_NODE(&inst->hlist); |
| 965 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 966 | } |
| 967 | |
| 968 | rp->nmissed = 0; |
| 969 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 970 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 971 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 972 | free_rp_inst(rp); |
| 973 | return ret; |
| 974 | } |
| 975 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 976 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 977 | { |
| 978 | int ret = 0, i; |
| 979 | |
| 980 | if (num <= 0) |
| 981 | return -EINVAL; |
| 982 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 983 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 984 | if (ret < 0) { |
| 985 | if (i > 0) |
| 986 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 987 | break; |
| 988 | } |
| 989 | } |
| 990 | return ret; |
| 991 | } |
| 992 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 993 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 994 | { |
| 995 | unregister_kretprobes(&rp, 1); |
| 996 | } |
| 997 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 998 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 999 | { |
| 1000 | int i; |
| 1001 | |
| 1002 | if (num <= 0) |
| 1003 | return; |
| 1004 | mutex_lock(&kprobe_mutex); |
| 1005 | for (i = 0; i < num; i++) |
| 1006 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1007 | rps[i]->kp.addr = NULL; |
| 1008 | mutex_unlock(&kprobe_mutex); |
| 1009 | |
| 1010 | synchronize_sched(); |
| 1011 | for (i = 0; i < num; i++) { |
| 1012 | if (rps[i]->kp.addr) { |
| 1013 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1014 | cleanup_rp_inst(rps[i]); |
| 1015 | } |
| 1016 | } |
| 1017 | } |
| 1018 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1019 | #else /* CONFIG_KRETPROBES */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1020 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1021 | { |
| 1022 | return -ENOSYS; |
| 1023 | } |
| 1024 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1025 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
| 1026 | { |
| 1027 | return -ENOSYS; |
| 1028 | } |
| 1029 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1030 | { |
| 1031 | } |
| 1032 | |
| 1033 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1034 | { |
| 1035 | } |
| 1036 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1037 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1038 | struct pt_regs *regs) |
| 1039 | { |
| 1040 | return 0; |
| 1041 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1042 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1043 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1044 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1045 | /* Set the kprobe gone and remove its instruction buffer. */ |
| 1046 | static void __kprobes kill_kprobe(struct kprobe *p) |
| 1047 | { |
| 1048 | struct kprobe *kp; |
| 1049 | p->flags |= KPROBE_FLAG_GONE; |
| 1050 | if (p->pre_handler == aggr_pre_handler) { |
| 1051 | /* |
| 1052 | * If this is an aggr_kprobe, we have to list all the |
| 1053 | * chained probes and mark them GONE. |
| 1054 | */ |
| 1055 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1056 | kp->flags |= KPROBE_FLAG_GONE; |
| 1057 | p->post_handler = NULL; |
| 1058 | p->break_handler = NULL; |
| 1059 | } |
| 1060 | /* |
| 1061 | * Here, we can remove insn_slot safely, because no thread calls |
| 1062 | * the original probed function (which will be freed soon) any more. |
| 1063 | */ |
| 1064 | arch_remove_kprobe(p); |
| 1065 | } |
| 1066 | |
| 1067 | /* Module notifier call back, checking kprobes on the module */ |
| 1068 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, |
| 1069 | unsigned long val, void *data) |
| 1070 | { |
| 1071 | struct module *mod = data; |
| 1072 | struct hlist_head *head; |
| 1073 | struct hlist_node *node; |
| 1074 | struct kprobe *p; |
| 1075 | unsigned int i; |
| 1076 | |
| 1077 | if (val != MODULE_STATE_GOING) |
| 1078 | return NOTIFY_DONE; |
| 1079 | |
| 1080 | /* |
| 1081 | * module .text section will be freed. We need to |
| 1082 | * disable kprobes which have been inserted in the section. |
| 1083 | */ |
| 1084 | mutex_lock(&kprobe_mutex); |
| 1085 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1086 | head = &kprobe_table[i]; |
| 1087 | hlist_for_each_entry_rcu(p, node, head, hlist) |
| 1088 | if (within_module_core((unsigned long)p->addr, mod)) { |
| 1089 | /* |
| 1090 | * The vaddr this probe is installed will soon |
| 1091 | * be vfreed buy not synced to disk. Hence, |
| 1092 | * disarming the breakpoint isn't needed. |
| 1093 | */ |
| 1094 | kill_kprobe(p); |
| 1095 | } |
| 1096 | } |
| 1097 | mutex_unlock(&kprobe_mutex); |
| 1098 | return NOTIFY_DONE; |
| 1099 | } |
| 1100 | |
| 1101 | static struct notifier_block kprobe_module_nb = { |
| 1102 | .notifier_call = kprobes_module_callback, |
| 1103 | .priority = 0 |
| 1104 | }; |
| 1105 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | static int __init init_kprobes(void) |
| 1107 | { |
| 1108 | int i, err = 0; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1109 | unsigned long offset = 0, size = 0; |
| 1110 | char *modname, namebuf[128]; |
| 1111 | const char *symbol_name; |
| 1112 | void *addr; |
| 1113 | struct kprobe_blackpoint *kb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | |
| 1115 | /* FIXME allocate the probe table, currently defined statically */ |
| 1116 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1117 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1119 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1120 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1121 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1122 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1123 | /* |
| 1124 | * Lookup and populate the kprobe_blacklist. |
| 1125 | * |
| 1126 | * Unlike the kretprobe blacklist, we'll need to determine |
| 1127 | * the range of addresses that belong to the said functions, |
| 1128 | * since a kprobe need not necessarily be at the beginning |
| 1129 | * of a function. |
| 1130 | */ |
| 1131 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 1132 | kprobe_lookup_name(kb->name, addr); |
| 1133 | if (!addr) |
| 1134 | continue; |
| 1135 | |
| 1136 | kb->start_addr = (unsigned long)addr; |
| 1137 | symbol_name = kallsyms_lookup(kb->start_addr, |
| 1138 | &size, &offset, &modname, namebuf); |
| 1139 | if (!symbol_name) |
| 1140 | kb->range = 0; |
| 1141 | else |
| 1142 | kb->range = size; |
| 1143 | } |
| 1144 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1145 | if (kretprobe_blacklist_size) { |
| 1146 | /* lookup the function address from its name */ |
| 1147 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1148 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 1149 | kretprobe_blacklist[i].addr); |
| 1150 | if (!kretprobe_blacklist[i].addr) |
| 1151 | printk("kretprobe: lookup failed: %s\n", |
| 1152 | kretprobe_blacklist[i].name); |
| 1153 | } |
| 1154 | } |
| 1155 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1156 | /* By default, kprobes are enabled */ |
| 1157 | kprobe_enabled = true; |
| 1158 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 1159 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1160 | if (!err) |
| 1161 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1162 | if (!err) |
| 1163 | err = register_module_notifier(&kprobe_module_nb); |
| 1164 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1165 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1166 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 1167 | if (!err) |
| 1168 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | return err; |
| 1170 | } |
| 1171 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1172 | #ifdef CONFIG_DEBUG_FS |
| 1173 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1174 | const char *sym, int offset,char *modname) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1175 | { |
| 1176 | char *kprobe_type; |
| 1177 | |
| 1178 | if (p->pre_handler == pre_handler_kretprobe) |
| 1179 | kprobe_type = "r"; |
| 1180 | else if (p->pre_handler == setjmp_pre_handler) |
| 1181 | kprobe_type = "j"; |
| 1182 | else |
| 1183 | kprobe_type = "k"; |
| 1184 | if (sym) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1185 | seq_printf(pi, "%p %s %s+0x%x %s %s\n", p->addr, kprobe_type, |
| 1186 | sym, offset, (modname ? modname : " "), |
| 1187 | (kprobe_gone(p) ? "[GONE]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1188 | else |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1189 | seq_printf(pi, "%p %s %p %s\n", p->addr, kprobe_type, p->addr, |
| 1190 | (kprobe_gone(p) ? "[GONE]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1191 | } |
| 1192 | |
| 1193 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
| 1194 | { |
| 1195 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 1196 | } |
| 1197 | |
| 1198 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
| 1199 | { |
| 1200 | (*pos)++; |
| 1201 | if (*pos >= KPROBE_TABLE_SIZE) |
| 1202 | return NULL; |
| 1203 | return pos; |
| 1204 | } |
| 1205 | |
| 1206 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) |
| 1207 | { |
| 1208 | /* Nothing to do */ |
| 1209 | } |
| 1210 | |
| 1211 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) |
| 1212 | { |
| 1213 | struct hlist_head *head; |
| 1214 | struct hlist_node *node; |
| 1215 | struct kprobe *p, *kp; |
| 1216 | const char *sym = NULL; |
| 1217 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1218 | unsigned long offset = 0; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1219 | char *modname, namebuf[128]; |
| 1220 | |
| 1221 | head = &kprobe_table[i]; |
| 1222 | preempt_disable(); |
| 1223 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1224 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1225 | &offset, &modname, namebuf); |
| 1226 | if (p->pre_handler == aggr_pre_handler) { |
| 1227 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1228 | report_probe(pi, kp, sym, offset, modname); |
| 1229 | } else |
| 1230 | report_probe(pi, p, sym, offset, modname); |
| 1231 | } |
| 1232 | preempt_enable(); |
| 1233 | return 0; |
| 1234 | } |
| 1235 | |
| 1236 | static struct seq_operations kprobes_seq_ops = { |
| 1237 | .start = kprobe_seq_start, |
| 1238 | .next = kprobe_seq_next, |
| 1239 | .stop = kprobe_seq_stop, |
| 1240 | .show = show_kprobe_addr |
| 1241 | }; |
| 1242 | |
| 1243 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) |
| 1244 | { |
| 1245 | return seq_open(filp, &kprobes_seq_ops); |
| 1246 | } |
| 1247 | |
| 1248 | static struct file_operations debugfs_kprobes_operations = { |
| 1249 | .open = kprobes_open, |
| 1250 | .read = seq_read, |
| 1251 | .llseek = seq_lseek, |
| 1252 | .release = seq_release, |
| 1253 | }; |
| 1254 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1255 | static void __kprobes enable_all_kprobes(void) |
| 1256 | { |
| 1257 | struct hlist_head *head; |
| 1258 | struct hlist_node *node; |
| 1259 | struct kprobe *p; |
| 1260 | unsigned int i; |
| 1261 | |
| 1262 | mutex_lock(&kprobe_mutex); |
| 1263 | |
| 1264 | /* If kprobes are already enabled, just return */ |
| 1265 | if (kprobe_enabled) |
| 1266 | goto already_enabled; |
| 1267 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1268 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1269 | head = &kprobe_table[i]; |
| 1270 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1271 | if (!kprobe_gone(p)) |
| 1272 | arch_arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1273 | } |
| 1274 | |
| 1275 | kprobe_enabled = true; |
| 1276 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 1277 | |
| 1278 | already_enabled: |
| 1279 | mutex_unlock(&kprobe_mutex); |
| 1280 | return; |
| 1281 | } |
| 1282 | |
| 1283 | static void __kprobes disable_all_kprobes(void) |
| 1284 | { |
| 1285 | struct hlist_head *head; |
| 1286 | struct hlist_node *node; |
| 1287 | struct kprobe *p; |
| 1288 | unsigned int i; |
| 1289 | |
| 1290 | mutex_lock(&kprobe_mutex); |
| 1291 | |
| 1292 | /* If kprobes are already disabled, just return */ |
| 1293 | if (!kprobe_enabled) |
| 1294 | goto already_disabled; |
| 1295 | |
| 1296 | kprobe_enabled = false; |
| 1297 | printk(KERN_INFO "Kprobes globally disabled\n"); |
| 1298 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1299 | head = &kprobe_table[i]; |
| 1300 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1301 | if (!arch_trampoline_kprobe(p) && !kprobe_gone(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1302 | arch_disarm_kprobe(p); |
| 1303 | } |
| 1304 | } |
| 1305 | |
| 1306 | mutex_unlock(&kprobe_mutex); |
| 1307 | /* Allow all currently running kprobes to complete */ |
| 1308 | synchronize_sched(); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1309 | return; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1310 | |
| 1311 | already_disabled: |
| 1312 | mutex_unlock(&kprobe_mutex); |
| 1313 | return; |
| 1314 | } |
| 1315 | |
| 1316 | /* |
| 1317 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 1318 | * when the bool state is switched. We can reuse that facility when |
| 1319 | * available |
| 1320 | */ |
| 1321 | static ssize_t read_enabled_file_bool(struct file *file, |
| 1322 | char __user *user_buf, size_t count, loff_t *ppos) |
| 1323 | { |
| 1324 | char buf[3]; |
| 1325 | |
| 1326 | if (kprobe_enabled) |
| 1327 | buf[0] = '1'; |
| 1328 | else |
| 1329 | buf[0] = '0'; |
| 1330 | buf[1] = '\n'; |
| 1331 | buf[2] = 0x00; |
| 1332 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 1333 | } |
| 1334 | |
| 1335 | static ssize_t write_enabled_file_bool(struct file *file, |
| 1336 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 1337 | { |
| 1338 | char buf[32]; |
| 1339 | int buf_size; |
| 1340 | |
| 1341 | buf_size = min(count, (sizeof(buf)-1)); |
| 1342 | if (copy_from_user(buf, user_buf, buf_size)) |
| 1343 | return -EFAULT; |
| 1344 | |
| 1345 | switch (buf[0]) { |
| 1346 | case 'y': |
| 1347 | case 'Y': |
| 1348 | case '1': |
| 1349 | enable_all_kprobes(); |
| 1350 | break; |
| 1351 | case 'n': |
| 1352 | case 'N': |
| 1353 | case '0': |
| 1354 | disable_all_kprobes(); |
| 1355 | break; |
| 1356 | } |
| 1357 | |
| 1358 | return count; |
| 1359 | } |
| 1360 | |
| 1361 | static struct file_operations fops_kp = { |
| 1362 | .read = read_enabled_file_bool, |
| 1363 | .write = write_enabled_file_bool, |
| 1364 | }; |
| 1365 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1366 | static int __kprobes debugfs_kprobe_init(void) |
| 1367 | { |
| 1368 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1369 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1370 | |
| 1371 | dir = debugfs_create_dir("kprobes", NULL); |
| 1372 | if (!dir) |
| 1373 | return -ENOMEM; |
| 1374 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 1375 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1376 | &debugfs_kprobes_operations); |
| 1377 | if (!file) { |
| 1378 | debugfs_remove(dir); |
| 1379 | return -ENOMEM; |
| 1380 | } |
| 1381 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1382 | file = debugfs_create_file("enabled", 0600, dir, |
| 1383 | &value, &fops_kp); |
| 1384 | if (!file) { |
| 1385 | debugfs_remove(dir); |
| 1386 | return -ENOMEM; |
| 1387 | } |
| 1388 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1389 | return 0; |
| 1390 | } |
| 1391 | |
| 1392 | late_initcall(debugfs_kprobe_init); |
| 1393 | #endif /* CONFIG_DEBUG_FS */ |
| 1394 | |
| 1395 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | |
| 1397 | EXPORT_SYMBOL_GPL(register_kprobe); |
| 1398 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1399 | EXPORT_SYMBOL_GPL(register_kprobes); |
| 1400 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1401 | EXPORT_SYMBOL_GPL(register_jprobe); |
| 1402 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1403 | EXPORT_SYMBOL_GPL(register_jprobes); |
| 1404 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1405 | EXPORT_SYMBOL_GPL(jprobe_return); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1406 | EXPORT_SYMBOL_GPL(register_kretprobe); |
| 1407 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1408 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1409 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |