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> |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 46 | #include <linux/memory.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 47 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 48 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | #include <asm/cacheflush.h> |
| 50 | #include <asm/errno.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 51 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
| 53 | #define KPROBE_HASH_BITS 6 |
| 54 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 55 | |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 56 | |
| 57 | /* |
| 58 | * Some oddball architectures like 64bit powerpc have function descriptors |
| 59 | * so this must be overridable. |
| 60 | */ |
| 61 | #ifndef kprobe_lookup_name |
| 62 | #define kprobe_lookup_name(name, addr) \ |
| 63 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) |
| 64 | #endif |
| 65 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 66 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 68 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 70 | /* NOTE: change this value only with kprobe_mutex held */ |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 71 | static bool kprobes_all_disarmed; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 72 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 73 | static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 74 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 75 | static struct { |
Andrew Morton | 7e036d0 | 2008-11-12 13:26:57 -0800 | [diff] [blame] | 76 | spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 77 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 78 | |
| 79 | static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
| 80 | { |
| 81 | return &(kretprobe_table_locks[hash].lock); |
| 82 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 84 | /* |
| 85 | * Normally, functions that we'd want to prohibit kprobes in, are marked |
| 86 | * __kprobes. But, there are cases where such functions already belong to |
| 87 | * a different section (__sched for preempt_schedule) |
| 88 | * |
| 89 | * For such cases, we now have a blacklist |
| 90 | */ |
Daniel Guilak | 544304b | 2008-07-10 09:38:19 -0700 | [diff] [blame] | 91 | static struct kprobe_blackpoint kprobe_blacklist[] = { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 92 | {"preempt_schedule",}, |
| 93 | {NULL} /* Terminator */ |
| 94 | }; |
| 95 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 96 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 97 | /* |
| 98 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 99 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 100 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 101 | * is a recipe for disaster |
| 102 | */ |
| 103 | #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) |
| 104 | |
| 105 | struct kprobe_insn_page { |
| 106 | struct hlist_node hlist; |
| 107 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
| 108 | char slot_used[INSNS_PER_PAGE]; |
| 109 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 110 | int ngarbage; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 111 | }; |
| 112 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 113 | enum kprobe_slot_state { |
| 114 | SLOT_CLEAN = 0, |
| 115 | SLOT_DIRTY = 1, |
| 116 | SLOT_USED = 2, |
| 117 | }; |
| 118 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 119 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 120 | static struct hlist_head kprobe_insn_pages; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 121 | static int kprobe_garbage_slots; |
| 122 | static int collect_garbage_slots(void); |
| 123 | |
| 124 | static int __kprobes check_safety(void) |
| 125 | { |
| 126 | int ret = 0; |
Masami Hiramatsu | 5a4ccaf | 2009-01-06 21:15:32 +0100 | [diff] [blame] | 127 | #if defined(CONFIG_PREEMPT) && defined(CONFIG_FREEZER) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 128 | ret = freeze_processes(); |
| 129 | if (ret == 0) { |
| 130 | struct task_struct *p, *q; |
| 131 | do_each_thread(p, q) { |
| 132 | if (p != current && p->state == TASK_RUNNING && |
| 133 | p->pid != 0) { |
| 134 | printk("Check failed: %s is running\n",p->comm); |
| 135 | ret = -1; |
| 136 | goto loop_end; |
| 137 | } |
| 138 | } while_each_thread(p, q); |
| 139 | } |
| 140 | loop_end: |
| 141 | thaw_processes(); |
| 142 | #else |
| 143 | synchronize_sched(); |
| 144 | #endif |
| 145 | return ret; |
| 146 | } |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 147 | |
| 148 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 149 | * __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] | 150 | * We allocate an executable page if there's no room on existing ones. |
| 151 | */ |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 152 | static kprobe_opcode_t __kprobes *__get_insn_slot(void) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 153 | { |
| 154 | struct kprobe_insn_page *kip; |
| 155 | struct hlist_node *pos; |
| 156 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 157 | retry: |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 158 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 159 | if (kip->nused < INSNS_PER_PAGE) { |
| 160 | int i; |
| 161 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 162 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 163 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 164 | kip->nused++; |
| 165 | return kip->insns + (i * MAX_INSN_SIZE); |
| 166 | } |
| 167 | } |
| 168 | /* Surprise! No unused slots. Fix kip->nused. */ |
| 169 | kip->nused = INSNS_PER_PAGE; |
| 170 | } |
| 171 | } |
| 172 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 173 | /* If there are any garbage slots, collect it and try again. */ |
| 174 | if (kprobe_garbage_slots && collect_garbage_slots() == 0) { |
| 175 | goto retry; |
| 176 | } |
| 177 | /* 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] | 178 | kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 179 | if (!kip) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 180 | return NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 181 | |
| 182 | /* |
| 183 | * Use module_alloc so this page is within +/- 2GB of where the |
| 184 | * kernel image and loaded module images reside. This is required |
| 185 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 186 | */ |
| 187 | kip->insns = module_alloc(PAGE_SIZE); |
| 188 | if (!kip->insns) { |
| 189 | kfree(kip); |
| 190 | return NULL; |
| 191 | } |
| 192 | INIT_HLIST_NODE(&kip->hlist); |
| 193 | hlist_add_head(&kip->hlist, &kprobe_insn_pages); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 194 | memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); |
| 195 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 196 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 197 | kip->ngarbage = 0; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 198 | return kip->insns; |
| 199 | } |
| 200 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 201 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
| 202 | { |
| 203 | kprobe_opcode_t *ret; |
| 204 | mutex_lock(&kprobe_insn_mutex); |
| 205 | ret = __get_insn_slot(); |
| 206 | mutex_unlock(&kprobe_insn_mutex); |
| 207 | return ret; |
| 208 | } |
| 209 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 210 | /* Return 1 if all garbages are collected, otherwise 0. */ |
| 211 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) |
| 212 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 213 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 214 | kip->nused--; |
| 215 | if (kip->nused == 0) { |
| 216 | /* |
| 217 | * Page is no longer in use. Free it unless |
| 218 | * it's the last one. We keep the last one |
| 219 | * so as not to have to set it up again the |
| 220 | * next time somebody inserts a probe. |
| 221 | */ |
| 222 | hlist_del(&kip->hlist); |
| 223 | if (hlist_empty(&kprobe_insn_pages)) { |
| 224 | INIT_HLIST_NODE(&kip->hlist); |
| 225 | hlist_add_head(&kip->hlist, |
| 226 | &kprobe_insn_pages); |
| 227 | } else { |
| 228 | module_free(NULL, kip->insns); |
| 229 | kfree(kip); |
| 230 | } |
| 231 | return 1; |
| 232 | } |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | static int __kprobes collect_garbage_slots(void) |
| 237 | { |
| 238 | struct kprobe_insn_page *kip; |
| 239 | struct hlist_node *pos, *next; |
| 240 | |
| 241 | /* Ensure no-one is preepmted on the garbages */ |
Masami Hiramatsu | 4a2bb6f | 2009-06-30 17:08:09 -0400 | [diff] [blame] | 242 | if (check_safety()) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 243 | return -EAGAIN; |
| 244 | |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 245 | hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 246 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 247 | if (kip->ngarbage == 0) |
| 248 | continue; |
| 249 | kip->ngarbage = 0; /* we will collect all garbages */ |
| 250 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 251 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 252 | collect_one_slot(kip, i)) |
| 253 | break; |
| 254 | } |
| 255 | } |
| 256 | kprobe_garbage_slots = 0; |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 261 | { |
| 262 | struct kprobe_insn_page *kip; |
| 263 | struct hlist_node *pos; |
| 264 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 265 | mutex_lock(&kprobe_insn_mutex); |
Christoph Hellwig | b0bb501 | 2007-05-08 00:34:11 -0700 | [diff] [blame] | 266 | hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 267 | if (kip->insns <= slot && |
| 268 | slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { |
| 269 | int i = (slot - kip->insns) / MAX_INSN_SIZE; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 270 | if (dirty) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 271 | kip->slot_used[i] = SLOT_DIRTY; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 272 | kip->ngarbage++; |
| 273 | } else { |
| 274 | collect_one_slot(kip, i); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 275 | } |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 276 | break; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 277 | } |
| 278 | } |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 279 | |
| 280 | if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 281 | collect_garbage_slots(); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 282 | |
| 283 | mutex_unlock(&kprobe_insn_mutex); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 284 | } |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 285 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 286 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 287 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 288 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 289 | { |
| 290 | __get_cpu_var(kprobe_instance) = kp; |
| 291 | } |
| 292 | |
| 293 | static inline void reset_kprobe_instance(void) |
| 294 | { |
| 295 | __get_cpu_var(kprobe_instance) = NULL; |
| 296 | } |
| 297 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 298 | /* |
| 299 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 300 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 301 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 302 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 303 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 304 | struct kprobe __kprobes *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | { |
| 306 | struct hlist_head *head; |
| 307 | struct hlist_node *node; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 308 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | |
| 310 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 311 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | if (p->addr == addr) |
| 313 | return p; |
| 314 | } |
| 315 | return NULL; |
| 316 | } |
| 317 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 318 | /* Arm a kprobe with text_mutex */ |
| 319 | static void __kprobes arm_kprobe(struct kprobe *kp) |
| 320 | { |
| 321 | mutex_lock(&text_mutex); |
| 322 | arch_arm_kprobe(kp); |
| 323 | mutex_unlock(&text_mutex); |
| 324 | } |
| 325 | |
| 326 | /* Disarm a kprobe with text_mutex */ |
| 327 | static void __kprobes disarm_kprobe(struct kprobe *kp) |
| 328 | { |
| 329 | mutex_lock(&text_mutex); |
| 330 | arch_disarm_kprobe(kp); |
| 331 | mutex_unlock(&text_mutex); |
| 332 | } |
| 333 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 334 | /* |
| 335 | * Aggregate handlers for multiple kprobes support - these handlers |
| 336 | * take care of invoking the individual kprobe handlers on p->list |
| 337 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 338 | 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] | 339 | { |
| 340 | struct kprobe *kp; |
| 341 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 342 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 343 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 344 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 345 | if (kp->pre_handler(kp, regs)) |
| 346 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 347 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 348 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 349 | } |
| 350 | return 0; |
| 351 | } |
| 352 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 353 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 354 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 355 | { |
| 356 | struct kprobe *kp; |
| 357 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 358 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 359 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 360 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 361 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 362 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 363 | } |
| 364 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 365 | } |
| 366 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 367 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 368 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 369 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 370 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 371 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 372 | /* |
| 373 | * if we faulted "during" the execution of a user specified |
| 374 | * probe handler, invoke just that probe's fault handler |
| 375 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 376 | if (cur && cur->fault_handler) { |
| 377 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 378 | return 1; |
| 379 | } |
| 380 | return 0; |
| 381 | } |
| 382 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 383 | 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] | 384 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 385 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 386 | int ret = 0; |
| 387 | |
| 388 | if (cur && cur->break_handler) { |
| 389 | if (cur->break_handler(cur, regs)) |
| 390 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 391 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 392 | reset_kprobe_instance(); |
| 393 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 394 | } |
| 395 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 396 | /* Walks the list and increments nmissed count for multiprobe case */ |
| 397 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
| 398 | { |
| 399 | struct kprobe *kp; |
| 400 | if (p->pre_handler != aggr_pre_handler) { |
| 401 | p->nmissed++; |
| 402 | } else { |
| 403 | list_for_each_entry_rcu(kp, &p->list, list) |
| 404 | kp->nmissed++; |
| 405 | } |
| 406 | return; |
| 407 | } |
| 408 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 409 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
| 410 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 411 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 412 | struct kretprobe *rp = ri->rp; |
| 413 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 414 | /* remove rp inst off the rprobe_inst_table */ |
| 415 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 416 | INIT_HLIST_NODE(&ri->hlist); |
| 417 | if (likely(rp)) { |
| 418 | spin_lock(&rp->lock); |
| 419 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 420 | spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 421 | } else |
| 422 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 423 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 424 | } |
| 425 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 426 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 427 | struct hlist_head **head, unsigned long *flags) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 428 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 429 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 430 | spinlock_t *hlist_lock; |
| 431 | |
| 432 | *head = &kretprobe_inst_table[hash]; |
| 433 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 434 | spin_lock_irqsave(hlist_lock, *flags); |
| 435 | } |
| 436 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 437 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
| 438 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 439 | { |
| 440 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 441 | spin_lock_irqsave(hlist_lock, *flags); |
| 442 | } |
| 443 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 444 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
| 445 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 446 | { |
| 447 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 448 | spinlock_t *hlist_lock; |
| 449 | |
| 450 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 451 | spin_unlock_irqrestore(hlist_lock, *flags); |
| 452 | } |
| 453 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 454 | void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 455 | { |
| 456 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 457 | spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 458 | } |
| 459 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 460 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 461 | * This function is called from finish_task_switch when task tk becomes dead, |
| 462 | * so that we can recycle any function-return probe instances associated |
| 463 | * with this task. These left over instances represent probed functions |
| 464 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 465 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 466 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 467 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 468 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 469 | struct hlist_head *head, empty_rp; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 470 | struct hlist_node *node, *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 471 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 472 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 473 | if (unlikely(!kprobes_initialized)) |
| 474 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 475 | return; |
| 476 | |
| 477 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 478 | head = &kretprobe_inst_table[hash]; |
| 479 | kretprobe_table_lock(hash, &flags); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 480 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
| 481 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 482 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 483 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 484 | kretprobe_table_unlock(hash, &flags); |
| 485 | INIT_HLIST_HEAD(&empty_rp); |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 486 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
| 487 | hlist_del(&ri->hlist); |
| 488 | kfree(ri); |
| 489 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 490 | } |
| 491 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 492 | static inline void free_rp_inst(struct kretprobe *rp) |
| 493 | { |
| 494 | struct kretprobe_instance *ri; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 495 | struct hlist_node *pos, *next; |
| 496 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 497 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
| 498 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 499 | kfree(ri); |
| 500 | } |
| 501 | } |
| 502 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 503 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
| 504 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 505 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 506 | struct kretprobe_instance *ri; |
| 507 | struct hlist_node *pos, *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 508 | struct hlist_head *head; |
| 509 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 510 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 511 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 512 | kretprobe_table_lock(hash, &flags); |
| 513 | head = &kretprobe_inst_table[hash]; |
| 514 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { |
| 515 | if (ri->rp == rp) |
| 516 | ri->rp = NULL; |
| 517 | } |
| 518 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 519 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 520 | free_rp_inst(rp); |
| 521 | } |
| 522 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 523 | /* |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 524 | * Keep all fields in the kprobe consistent |
| 525 | */ |
| 526 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) |
| 527 | { |
| 528 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); |
| 529 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); |
| 530 | } |
| 531 | |
| 532 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 533 | * Add the new probe to ap->list. Fail if this is the |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 534 | * second jprobe at the address - two jprobes can't coexist |
| 535 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 536 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 537 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 538 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 539 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 540 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 541 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 542 | list_add_tail_rcu(&p->list, &ap->list); |
| 543 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 544 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 545 | list_add_rcu(&p->list, &ap->list); |
| 546 | if (p->post_handler && !ap->post_handler) |
| 547 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 548 | |
| 549 | if (kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 550 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 551 | if (!kprobes_all_disarmed) |
| 552 | /* Arm the breakpoint again. */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 553 | arm_kprobe(ap); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 554 | } |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 555 | return 0; |
| 556 | } |
| 557 | |
| 558 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 559 | * Fill in the required fields of the "manager kprobe". Replace the |
| 560 | * earlier kprobe in the hlist with the manager kprobe |
| 561 | */ |
| 562 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
| 563 | { |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 564 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 565 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 566 | ap->addr = p->addr; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 567 | ap->flags = p->flags; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 568 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 569 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 570 | /* We don't care the kprobe which has gone. */ |
| 571 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 572 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 573 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 574 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 575 | |
| 576 | INIT_LIST_HEAD(&ap->list); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 577 | list_add_rcu(&p->list, &ap->list); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 578 | |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 579 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 580 | } |
| 581 | |
| 582 | /* |
| 583 | * This is the second or subsequent kprobe at the address - handle |
| 584 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 585 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 586 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
| 587 | struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 588 | { |
| 589 | int ret = 0; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 590 | struct kprobe *ap = old_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 591 | |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 592 | if (old_p->pre_handler != aggr_pre_handler) { |
| 593 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ |
| 594 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 595 | if (!ap) |
| 596 | return -ENOMEM; |
| 597 | add_aggr_kprobe(ap, old_p); |
| 598 | } |
| 599 | |
| 600 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 601 | /* |
| 602 | * Attempting to insert new probe at the same location that |
| 603 | * had a probe in the module vaddr area which already |
| 604 | * freed. So, the instruction slot has already been |
| 605 | * released. We need a new slot for the new probe. |
| 606 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 607 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 608 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 609 | /* |
| 610 | * Even if fail to allocate new slot, don't need to |
| 611 | * free aggr_probe. It will be used next time, or |
| 612 | * freed by unregister_kprobe. |
| 613 | */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 614 | return ret; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 615 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 616 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 617 | * Clear gone flag to prevent allocating new slot again, and |
| 618 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 619 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 620 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 621 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 622 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 623 | |
| 624 | copy_kprobe(ap, p); |
| 625 | return add_new_kprobe(ap, p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 626 | } |
| 627 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 628 | /* Try to disable aggr_kprobe, and return 1 if succeeded.*/ |
| 629 | static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) |
| 630 | { |
| 631 | struct kprobe *kp; |
| 632 | |
| 633 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 634 | if (!kprobe_disabled(kp)) |
| 635 | /* |
| 636 | * There is an active probe on the list. |
| 637 | * We can't disable aggr_kprobe. |
| 638 | */ |
| 639 | return 0; |
| 640 | } |
| 641 | p->flags |= KPROBE_FLAG_DISABLED; |
| 642 | return 1; |
| 643 | } |
| 644 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 645 | static int __kprobes in_kprobes_functions(unsigned long addr) |
| 646 | { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 647 | struct kprobe_blackpoint *kb; |
| 648 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 649 | if (addr >= (unsigned long)__kprobes_text_start && |
| 650 | addr < (unsigned long)__kprobes_text_end) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 651 | return -EINVAL; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 652 | /* |
| 653 | * If there exists a kprobe_blacklist, verify and |
| 654 | * fail any probe registration in the prohibited area |
| 655 | */ |
| 656 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 657 | if (kb->start_addr) { |
| 658 | if (addr >= kb->start_addr && |
| 659 | addr < (kb->start_addr + kb->range)) |
| 660 | return -EINVAL; |
| 661 | } |
| 662 | } |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 663 | return 0; |
| 664 | } |
| 665 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 666 | /* |
| 667 | * If we have a symbol_name argument, look it up and add the offset field |
| 668 | * to it. This way, we can specify a relative address to a symbol. |
| 669 | */ |
| 670 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) |
| 671 | { |
| 672 | kprobe_opcode_t *addr = p->addr; |
| 673 | if (p->symbol_name) { |
| 674 | if (addr) |
| 675 | return NULL; |
| 676 | kprobe_lookup_name(p->symbol_name, addr); |
| 677 | } |
| 678 | |
| 679 | if (!addr) |
| 680 | return NULL; |
| 681 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 682 | } |
| 683 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 684 | int __kprobes register_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | { |
| 686 | int ret = 0; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 687 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 688 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 689 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 691 | addr = kprobe_addr(p); |
| 692 | if (!addr) |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 693 | return -EINVAL; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 694 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 695 | |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 696 | preempt_disable(); |
Masami Hiramatsu | ec30c5f | 2009-07-28 19:47:23 -0400 | [diff] [blame] | 697 | if (!kernel_text_address((unsigned long) p->addr) || |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 698 | in_kprobes_functions((unsigned long) p->addr)) { |
| 699 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 700 | return -EINVAL; |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 701 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 702 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 703 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 704 | p->flags &= KPROBE_FLAG_DISABLED; |
| 705 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 706 | /* |
| 707 | * Check if are we probing a module. |
| 708 | */ |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 709 | probed_mod = __module_text_address((unsigned long) p->addr); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 710 | if (probed_mod) { |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 711 | /* |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 712 | * We must hold a refcount of the probed module while updating |
| 713 | * its code to prohibit unexpected unloading. |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 714 | */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 715 | if (unlikely(!try_module_get(probed_mod))) { |
| 716 | preempt_enable(); |
| 717 | return -EINVAL; |
| 718 | } |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 719 | /* |
| 720 | * If the module freed .init.text, we couldn't insert |
| 721 | * kprobes in there. |
| 722 | */ |
| 723 | if (within_module_init((unsigned long)p->addr, probed_mod) && |
| 724 | probed_mod->state != MODULE_STATE_COMING) { |
| 725 | module_put(probed_mod); |
| 726 | preempt_enable(); |
| 727 | return -EINVAL; |
| 728 | } |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 729 | } |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 730 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 731 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 732 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 733 | INIT_LIST_HEAD(&p->list); |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 734 | mutex_lock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 735 | old_p = get_kprobe(p->addr); |
| 736 | if (old_p) { |
| 737 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | goto out; |
| 739 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 741 | mutex_lock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 742 | ret = arch_prepare_kprobe(p); |
| 743 | if (ret) |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 744 | goto out_unlock_text; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 745 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 746 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 747 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 749 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 750 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 751 | arch_arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 752 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 753 | out_unlock_text: |
| 754 | mutex_unlock(&text_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 756 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 757 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 758 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 759 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 760 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | return ret; |
| 762 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 763 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 765 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
| 766 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) |
| 767 | { |
| 768 | struct kprobe *old_p, *list_p; |
| 769 | |
| 770 | old_p = get_kprobe(p->addr); |
| 771 | if (unlikely(!old_p)) |
| 772 | return NULL; |
| 773 | |
| 774 | if (p != old_p) { |
| 775 | list_for_each_entry_rcu(list_p, &old_p->list, list) |
| 776 | if (list_p == p) |
| 777 | /* kprobe p is a valid probe */ |
| 778 | goto valid; |
| 779 | return NULL; |
| 780 | } |
| 781 | valid: |
| 782 | return old_p; |
| 783 | } |
| 784 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 785 | /* |
| 786 | * Unregister a kprobe without a scheduler synchronization. |
| 787 | */ |
| 788 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 789 | { |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 790 | struct kprobe *old_p, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 791 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 792 | old_p = __get_valid_kprobe(p); |
| 793 | if (old_p == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 794 | return -EINVAL; |
| 795 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 796 | if (old_p == p || |
| 797 | (old_p->pre_handler == aggr_pre_handler && |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 798 | list_is_singular(&old_p->list))) { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 799 | /* |
| 800 | * Only probe on the hash list. Disarm only if kprobes are |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 801 | * enabled and not gone - otherwise, the breakpoint would |
| 802 | * already have been removed. We save on flushing icache. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 803 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 804 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
| 805 | disarm_kprobe(p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 806 | hlist_del_rcu(&old_p->hlist); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 807 | } else { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 808 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 809 | old_p->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 810 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 811 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
| 812 | if ((list_p != p) && (list_p->post_handler)) |
| 813 | goto noclean; |
| 814 | } |
| 815 | old_p->post_handler = NULL; |
| 816 | } |
| 817 | noclean: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 818 | list_del_rcu(&p->list); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 819 | if (!kprobe_disabled(old_p)) { |
| 820 | try_to_disable_aggr_kprobe(old_p); |
| 821 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 822 | disarm_kprobe(old_p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 823 | } |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 824 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 825 | return 0; |
| 826 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 827 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 828 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
| 829 | { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 830 | struct kprobe *old_p; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 831 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 832 | if (list_empty(&p->list)) |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 833 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 834 | else if (list_is_singular(&p->list)) { |
| 835 | /* "p" is the last child of an aggr_kprobe */ |
| 836 | old_p = list_entry(p->list.next, struct kprobe, list); |
| 837 | list_del(&p->list); |
| 838 | arch_remove_kprobe(old_p); |
| 839 | kfree(old_p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 840 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | } |
| 842 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 843 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 844 | { |
| 845 | int i, ret = 0; |
| 846 | |
| 847 | if (num <= 0) |
| 848 | return -EINVAL; |
| 849 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 850 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 851 | if (ret < 0) { |
| 852 | if (i > 0) |
| 853 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 854 | break; |
| 855 | } |
| 856 | } |
| 857 | return ret; |
| 858 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 859 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 860 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 861 | void __kprobes unregister_kprobe(struct kprobe *p) |
| 862 | { |
| 863 | unregister_kprobes(&p, 1); |
| 864 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 865 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 866 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 867 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
| 868 | { |
| 869 | int i; |
| 870 | |
| 871 | if (num <= 0) |
| 872 | return; |
| 873 | mutex_lock(&kprobe_mutex); |
| 874 | for (i = 0; i < num; i++) |
| 875 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 876 | kps[i]->addr = NULL; |
| 877 | mutex_unlock(&kprobe_mutex); |
| 878 | |
| 879 | synchronize_sched(); |
| 880 | for (i = 0; i < num; i++) |
| 881 | if (kps[i]->addr) |
| 882 | __unregister_kprobe_bottom(kps[i]); |
| 883 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 884 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 885 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | static struct notifier_block kprobe_exceptions_nb = { |
| 887 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 888 | .priority = 0x7fffffff /* we need to be notified first */ |
| 889 | }; |
| 890 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 891 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 892 | { |
| 893 | return (unsigned long)entry; |
| 894 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 896 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 897 | { |
| 898 | struct jprobe *jp; |
| 899 | int ret = 0, i; |
| 900 | |
| 901 | if (num <= 0) |
| 902 | return -EINVAL; |
| 903 | for (i = 0; i < num; i++) { |
| 904 | unsigned long addr; |
| 905 | jp = jps[i]; |
| 906 | addr = arch_deref_entry_point(jp->entry); |
| 907 | |
| 908 | if (!kernel_text_address(addr)) |
| 909 | ret = -EINVAL; |
| 910 | else { |
| 911 | /* Todo: Verify probepoint is a function entry point */ |
| 912 | jp->kp.pre_handler = setjmp_pre_handler; |
| 913 | jp->kp.break_handler = longjmp_break_handler; |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 914 | ret = register_kprobe(&jp->kp); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 915 | } |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 916 | if (ret < 0) { |
| 917 | if (i > 0) |
| 918 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 919 | break; |
| 920 | } |
| 921 | } |
| 922 | return ret; |
| 923 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 924 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 925 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 926 | int __kprobes register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 928 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 930 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 932 | void __kprobes unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 934 | unregister_jprobes(&jp, 1); |
| 935 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 936 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 937 | |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 938 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
| 939 | { |
| 940 | int i; |
| 941 | |
| 942 | if (num <= 0) |
| 943 | return; |
| 944 | mutex_lock(&kprobe_mutex); |
| 945 | for (i = 0; i < num; i++) |
| 946 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 947 | jps[i]->kp.addr = NULL; |
| 948 | mutex_unlock(&kprobe_mutex); |
| 949 | |
| 950 | synchronize_sched(); |
| 951 | for (i = 0; i < num; i++) { |
| 952 | if (jps[i]->kp.addr) |
| 953 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 954 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 956 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 958 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 959 | /* |
| 960 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 961 | * hits it will set up the return probe. |
| 962 | */ |
| 963 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 964 | struct pt_regs *regs) |
| 965 | { |
| 966 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 967 | unsigned long hash, flags = 0; |
| 968 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 969 | |
| 970 | /*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] | 971 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
| 972 | spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 973 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 974 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 975 | struct kretprobe_instance, hlist); |
| 976 | hlist_del(&ri->hlist); |
| 977 | spin_unlock_irqrestore(&rp->lock, flags); |
| 978 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 979 | ri->rp = rp; |
| 980 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 981 | |
Ananth N Mavinakayanahalli | f02b862 | 2009-03-18 17:06:21 +0530 | [diff] [blame] | 982 | if (rp->entry_handler && rp->entry_handler(ri, regs)) |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 983 | return 0; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 984 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 985 | arch_prepare_kretprobe(ri, regs); |
| 986 | |
| 987 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 988 | INIT_HLIST_NODE(&ri->hlist); |
| 989 | kretprobe_table_lock(hash, &flags); |
| 990 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 991 | kretprobe_table_unlock(hash, &flags); |
| 992 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 993 | rp->nmissed++; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 994 | spin_unlock_irqrestore(&rp->lock, flags); |
| 995 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 996 | return 0; |
| 997 | } |
| 998 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 999 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1000 | { |
| 1001 | int ret = 0; |
| 1002 | struct kretprobe_instance *inst; |
| 1003 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1004 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1005 | |
| 1006 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1007 | addr = kprobe_addr(&rp->kp); |
| 1008 | if (!addr) |
| 1009 | return -EINVAL; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1010 | |
| 1011 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1012 | if (kretprobe_blacklist[i].addr == addr) |
| 1013 | return -EINVAL; |
| 1014 | } |
| 1015 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1016 | |
| 1017 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1018 | rp->kp.post_handler = NULL; |
| 1019 | rp->kp.fault_handler = NULL; |
| 1020 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1021 | |
| 1022 | /* Pre-allocate memory for max kretprobe instances */ |
| 1023 | if (rp->maxactive <= 0) { |
| 1024 | #ifdef CONFIG_PREEMPT |
| 1025 | rp->maxactive = max(10, 2 * NR_CPUS); |
| 1026 | #else |
| 1027 | rp->maxactive = NR_CPUS; |
| 1028 | #endif |
| 1029 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1030 | spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1031 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1032 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1033 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1034 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1035 | if (inst == NULL) { |
| 1036 | free_rp_inst(rp); |
| 1037 | return -ENOMEM; |
| 1038 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1039 | INIT_HLIST_NODE(&inst->hlist); |
| 1040 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1041 | } |
| 1042 | |
| 1043 | rp->nmissed = 0; |
| 1044 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1045 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1046 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1047 | free_rp_inst(rp); |
| 1048 | return ret; |
| 1049 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1050 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1051 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1052 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1053 | { |
| 1054 | int ret = 0, i; |
| 1055 | |
| 1056 | if (num <= 0) |
| 1057 | return -EINVAL; |
| 1058 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1059 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1060 | if (ret < 0) { |
| 1061 | if (i > 0) |
| 1062 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1063 | break; |
| 1064 | } |
| 1065 | } |
| 1066 | return ret; |
| 1067 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1068 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1069 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1070 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1071 | { |
| 1072 | unregister_kretprobes(&rp, 1); |
| 1073 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1074 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1075 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1076 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1077 | { |
| 1078 | int i; |
| 1079 | |
| 1080 | if (num <= 0) |
| 1081 | return; |
| 1082 | mutex_lock(&kprobe_mutex); |
| 1083 | for (i = 0; i < num; i++) |
| 1084 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1085 | rps[i]->kp.addr = NULL; |
| 1086 | mutex_unlock(&kprobe_mutex); |
| 1087 | |
| 1088 | synchronize_sched(); |
| 1089 | for (i = 0; i < num; i++) { |
| 1090 | if (rps[i]->kp.addr) { |
| 1091 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1092 | cleanup_rp_inst(rps[i]); |
| 1093 | } |
| 1094 | } |
| 1095 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1096 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1097 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1098 | #else /* CONFIG_KRETPROBES */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1099 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1100 | { |
| 1101 | return -ENOSYS; |
| 1102 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1103 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1104 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1105 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
| 1106 | { |
| 1107 | return -ENOSYS; |
| 1108 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1109 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1110 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1111 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1112 | { |
| 1113 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1114 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1115 | |
| 1116 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1117 | { |
| 1118 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1119 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1120 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1121 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1122 | struct pt_regs *regs) |
| 1123 | { |
| 1124 | return 0; |
| 1125 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1126 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1127 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1128 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1129 | /* Set the kprobe gone and remove its instruction buffer. */ |
| 1130 | static void __kprobes kill_kprobe(struct kprobe *p) |
| 1131 | { |
| 1132 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1133 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1134 | p->flags |= KPROBE_FLAG_GONE; |
| 1135 | if (p->pre_handler == aggr_pre_handler) { |
| 1136 | /* |
| 1137 | * If this is an aggr_kprobe, we have to list all the |
| 1138 | * chained probes and mark them GONE. |
| 1139 | */ |
| 1140 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1141 | kp->flags |= KPROBE_FLAG_GONE; |
| 1142 | p->post_handler = NULL; |
| 1143 | p->break_handler = NULL; |
| 1144 | } |
| 1145 | /* |
| 1146 | * Here, we can remove insn_slot safely, because no thread calls |
| 1147 | * the original probed function (which will be freed soon) any more. |
| 1148 | */ |
| 1149 | arch_remove_kprobe(p); |
| 1150 | } |
| 1151 | |
| 1152 | /* Module notifier call back, checking kprobes on the module */ |
| 1153 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, |
| 1154 | unsigned long val, void *data) |
| 1155 | { |
| 1156 | struct module *mod = data; |
| 1157 | struct hlist_head *head; |
| 1158 | struct hlist_node *node; |
| 1159 | struct kprobe *p; |
| 1160 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1161 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1162 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1163 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1164 | return NOTIFY_DONE; |
| 1165 | |
| 1166 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1167 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 1168 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 1169 | * notified, only .init.text section would be freed. We need to |
| 1170 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1171 | */ |
| 1172 | mutex_lock(&kprobe_mutex); |
| 1173 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1174 | head = &kprobe_table[i]; |
| 1175 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1176 | if (within_module_init((unsigned long)p->addr, mod) || |
| 1177 | (checkcore && |
| 1178 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1179 | /* |
| 1180 | * The vaddr this probe is installed will soon |
| 1181 | * be vfreed buy not synced to disk. Hence, |
| 1182 | * disarming the breakpoint isn't needed. |
| 1183 | */ |
| 1184 | kill_kprobe(p); |
| 1185 | } |
| 1186 | } |
| 1187 | mutex_unlock(&kprobe_mutex); |
| 1188 | return NOTIFY_DONE; |
| 1189 | } |
| 1190 | |
| 1191 | static struct notifier_block kprobe_module_nb = { |
| 1192 | .notifier_call = kprobes_module_callback, |
| 1193 | .priority = 0 |
| 1194 | }; |
| 1195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | static int __init init_kprobes(void) |
| 1197 | { |
| 1198 | int i, err = 0; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1199 | unsigned long offset = 0, size = 0; |
| 1200 | char *modname, namebuf[128]; |
| 1201 | const char *symbol_name; |
| 1202 | void *addr; |
| 1203 | struct kprobe_blackpoint *kb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | |
| 1205 | /* FIXME allocate the probe table, currently defined statically */ |
| 1206 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1207 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1208 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1209 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1210 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1211 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1213 | /* |
| 1214 | * Lookup and populate the kprobe_blacklist. |
| 1215 | * |
| 1216 | * Unlike the kretprobe blacklist, we'll need to determine |
| 1217 | * the range of addresses that belong to the said functions, |
| 1218 | * since a kprobe need not necessarily be at the beginning |
| 1219 | * of a function. |
| 1220 | */ |
| 1221 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 1222 | kprobe_lookup_name(kb->name, addr); |
| 1223 | if (!addr) |
| 1224 | continue; |
| 1225 | |
| 1226 | kb->start_addr = (unsigned long)addr; |
| 1227 | symbol_name = kallsyms_lookup(kb->start_addr, |
| 1228 | &size, &offset, &modname, namebuf); |
| 1229 | if (!symbol_name) |
| 1230 | kb->range = 0; |
| 1231 | else |
| 1232 | kb->range = size; |
| 1233 | } |
| 1234 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1235 | if (kretprobe_blacklist_size) { |
| 1236 | /* lookup the function address from its name */ |
| 1237 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1238 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 1239 | kretprobe_blacklist[i].addr); |
| 1240 | if (!kretprobe_blacklist[i].addr) |
| 1241 | printk("kretprobe: lookup failed: %s\n", |
| 1242 | kretprobe_blacklist[i].name); |
| 1243 | } |
| 1244 | } |
| 1245 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1246 | /* By default, kprobes are armed */ |
| 1247 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1248 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 1249 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1250 | if (!err) |
| 1251 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1252 | if (!err) |
| 1253 | err = register_module_notifier(&kprobe_module_nb); |
| 1254 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1255 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1256 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 1257 | if (!err) |
| 1258 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | return err; |
| 1260 | } |
| 1261 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1262 | #ifdef CONFIG_DEBUG_FS |
| 1263 | 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] | 1264 | const char *sym, int offset,char *modname) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1265 | { |
| 1266 | char *kprobe_type; |
| 1267 | |
| 1268 | if (p->pre_handler == pre_handler_kretprobe) |
| 1269 | kprobe_type = "r"; |
| 1270 | else if (p->pre_handler == setjmp_pre_handler) |
| 1271 | kprobe_type = "j"; |
| 1272 | else |
| 1273 | kprobe_type = "k"; |
| 1274 | if (sym) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1275 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", |
| 1276 | p->addr, kprobe_type, sym, offset, |
| 1277 | (modname ? modname : " "), |
| 1278 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1279 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1280 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1281 | else |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1282 | seq_printf(pi, "%p %s %p %s%s\n", |
| 1283 | p->addr, kprobe_type, p->addr, |
| 1284 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1285 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1286 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1287 | } |
| 1288 | |
| 1289 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
| 1290 | { |
| 1291 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 1292 | } |
| 1293 | |
| 1294 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
| 1295 | { |
| 1296 | (*pos)++; |
| 1297 | if (*pos >= KPROBE_TABLE_SIZE) |
| 1298 | return NULL; |
| 1299 | return pos; |
| 1300 | } |
| 1301 | |
| 1302 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) |
| 1303 | { |
| 1304 | /* Nothing to do */ |
| 1305 | } |
| 1306 | |
| 1307 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) |
| 1308 | { |
| 1309 | struct hlist_head *head; |
| 1310 | struct hlist_node *node; |
| 1311 | struct kprobe *p, *kp; |
| 1312 | const char *sym = NULL; |
| 1313 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1314 | unsigned long offset = 0; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1315 | char *modname, namebuf[128]; |
| 1316 | |
| 1317 | head = &kprobe_table[i]; |
| 1318 | preempt_disable(); |
| 1319 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1320 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1321 | &offset, &modname, namebuf); |
| 1322 | if (p->pre_handler == aggr_pre_handler) { |
| 1323 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1324 | report_probe(pi, kp, sym, offset, modname); |
| 1325 | } else |
| 1326 | report_probe(pi, p, sym, offset, modname); |
| 1327 | } |
| 1328 | preempt_enable(); |
| 1329 | return 0; |
| 1330 | } |
| 1331 | |
| 1332 | static struct seq_operations kprobes_seq_ops = { |
| 1333 | .start = kprobe_seq_start, |
| 1334 | .next = kprobe_seq_next, |
| 1335 | .stop = kprobe_seq_stop, |
| 1336 | .show = show_kprobe_addr |
| 1337 | }; |
| 1338 | |
| 1339 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) |
| 1340 | { |
| 1341 | return seq_open(filp, &kprobes_seq_ops); |
| 1342 | } |
| 1343 | |
| 1344 | static struct file_operations debugfs_kprobes_operations = { |
| 1345 | .open = kprobes_open, |
| 1346 | .read = seq_read, |
| 1347 | .llseek = seq_lseek, |
| 1348 | .release = seq_release, |
| 1349 | }; |
| 1350 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1351 | /* Disable one kprobe */ |
| 1352 | int __kprobes disable_kprobe(struct kprobe *kp) |
| 1353 | { |
| 1354 | int ret = 0; |
| 1355 | struct kprobe *p; |
| 1356 | |
| 1357 | mutex_lock(&kprobe_mutex); |
| 1358 | |
| 1359 | /* Check whether specified probe is valid. */ |
| 1360 | p = __get_valid_kprobe(kp); |
| 1361 | if (unlikely(p == NULL)) { |
| 1362 | ret = -EINVAL; |
| 1363 | goto out; |
| 1364 | } |
| 1365 | |
| 1366 | /* If the probe is already disabled (or gone), just return */ |
| 1367 | if (kprobe_disabled(kp)) |
| 1368 | goto out; |
| 1369 | |
| 1370 | kp->flags |= KPROBE_FLAG_DISABLED; |
| 1371 | if (p != kp) |
| 1372 | /* When kp != p, p is always enabled. */ |
| 1373 | try_to_disable_aggr_kprobe(p); |
| 1374 | |
| 1375 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1376 | disarm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1377 | out: |
| 1378 | mutex_unlock(&kprobe_mutex); |
| 1379 | return ret; |
| 1380 | } |
| 1381 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 1382 | |
| 1383 | /* Enable one kprobe */ |
| 1384 | int __kprobes enable_kprobe(struct kprobe *kp) |
| 1385 | { |
| 1386 | int ret = 0; |
| 1387 | struct kprobe *p; |
| 1388 | |
| 1389 | mutex_lock(&kprobe_mutex); |
| 1390 | |
| 1391 | /* Check whether specified probe is valid. */ |
| 1392 | p = __get_valid_kprobe(kp); |
| 1393 | if (unlikely(p == NULL)) { |
| 1394 | ret = -EINVAL; |
| 1395 | goto out; |
| 1396 | } |
| 1397 | |
| 1398 | if (kprobe_gone(kp)) { |
| 1399 | /* This kprobe has gone, we couldn't enable it. */ |
| 1400 | ret = -EINVAL; |
| 1401 | goto out; |
| 1402 | } |
| 1403 | |
| 1404 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1405 | arm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1406 | |
| 1407 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 1408 | if (p != kp) |
| 1409 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 1410 | out: |
| 1411 | mutex_unlock(&kprobe_mutex); |
| 1412 | return ret; |
| 1413 | } |
| 1414 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 1415 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1416 | static void __kprobes arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1417 | { |
| 1418 | struct hlist_head *head; |
| 1419 | struct hlist_node *node; |
| 1420 | struct kprobe *p; |
| 1421 | unsigned int i; |
| 1422 | |
| 1423 | mutex_lock(&kprobe_mutex); |
| 1424 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1425 | /* If kprobes are armed, just return */ |
| 1426 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1427 | goto already_enabled; |
| 1428 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1429 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1430 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1431 | head = &kprobe_table[i]; |
| 1432 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1433 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1434 | arch_arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1435 | } |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1436 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1437 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1438 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1439 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 1440 | |
| 1441 | already_enabled: |
| 1442 | mutex_unlock(&kprobe_mutex); |
| 1443 | return; |
| 1444 | } |
| 1445 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1446 | static void __kprobes disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1447 | { |
| 1448 | struct hlist_head *head; |
| 1449 | struct hlist_node *node; |
| 1450 | struct kprobe *p; |
| 1451 | unsigned int i; |
| 1452 | |
| 1453 | mutex_lock(&kprobe_mutex); |
| 1454 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1455 | /* If kprobes are already disarmed, just return */ |
| 1456 | if (kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1457 | goto already_disabled; |
| 1458 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1459 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1460 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1461 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1462 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1463 | head = &kprobe_table[i]; |
| 1464 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1465 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1466 | arch_disarm_kprobe(p); |
| 1467 | } |
| 1468 | } |
| 1469 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1470 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1471 | mutex_unlock(&kprobe_mutex); |
| 1472 | /* Allow all currently running kprobes to complete */ |
| 1473 | synchronize_sched(); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1474 | return; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1475 | |
| 1476 | already_disabled: |
| 1477 | mutex_unlock(&kprobe_mutex); |
| 1478 | return; |
| 1479 | } |
| 1480 | |
| 1481 | /* |
| 1482 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 1483 | * when the bool state is switched. We can reuse that facility when |
| 1484 | * available |
| 1485 | */ |
| 1486 | static ssize_t read_enabled_file_bool(struct file *file, |
| 1487 | char __user *user_buf, size_t count, loff_t *ppos) |
| 1488 | { |
| 1489 | char buf[3]; |
| 1490 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1491 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1492 | buf[0] = '1'; |
| 1493 | else |
| 1494 | buf[0] = '0'; |
| 1495 | buf[1] = '\n'; |
| 1496 | buf[2] = 0x00; |
| 1497 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 1498 | } |
| 1499 | |
| 1500 | static ssize_t write_enabled_file_bool(struct file *file, |
| 1501 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 1502 | { |
| 1503 | char buf[32]; |
| 1504 | int buf_size; |
| 1505 | |
| 1506 | buf_size = min(count, (sizeof(buf)-1)); |
| 1507 | if (copy_from_user(buf, user_buf, buf_size)) |
| 1508 | return -EFAULT; |
| 1509 | |
| 1510 | switch (buf[0]) { |
| 1511 | case 'y': |
| 1512 | case 'Y': |
| 1513 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1514 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1515 | break; |
| 1516 | case 'n': |
| 1517 | case 'N': |
| 1518 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1519 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1520 | break; |
| 1521 | } |
| 1522 | |
| 1523 | return count; |
| 1524 | } |
| 1525 | |
| 1526 | static struct file_operations fops_kp = { |
| 1527 | .read = read_enabled_file_bool, |
| 1528 | .write = write_enabled_file_bool, |
| 1529 | }; |
| 1530 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1531 | static int __kprobes debugfs_kprobe_init(void) |
| 1532 | { |
| 1533 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1534 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1535 | |
| 1536 | dir = debugfs_create_dir("kprobes", NULL); |
| 1537 | if (!dir) |
| 1538 | return -ENOMEM; |
| 1539 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 1540 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1541 | &debugfs_kprobes_operations); |
| 1542 | if (!file) { |
| 1543 | debugfs_remove(dir); |
| 1544 | return -ENOMEM; |
| 1545 | } |
| 1546 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1547 | file = debugfs_create_file("enabled", 0600, dir, |
| 1548 | &value, &fops_kp); |
| 1549 | if (!file) { |
| 1550 | debugfs_remove(dir); |
| 1551 | return -ENOMEM; |
| 1552 | } |
| 1553 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1554 | return 0; |
| 1555 | } |
| 1556 | |
| 1557 | late_initcall(debugfs_kprobe_init); |
| 1558 | #endif /* CONFIG_DEBUG_FS */ |
| 1559 | |
| 1560 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1561 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1562 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | EXPORT_SYMBOL_GPL(jprobe_return); |