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> |
Masami Hiramatsu | 4554dbc | 2010-02-02 16:49:18 -0500 | [diff] [blame^] | 47 | #include <linux/ftrace.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 48 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 49 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | #include <asm/cacheflush.h> |
| 51 | #include <asm/errno.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 52 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | #define KPROBE_HASH_BITS 6 |
| 55 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 56 | |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 57 | |
| 58 | /* |
| 59 | * Some oddball architectures like 64bit powerpc have function descriptors |
| 60 | * so this must be overridable. |
| 61 | */ |
| 62 | #ifndef kprobe_lookup_name |
| 63 | #define kprobe_lookup_name(name, addr) \ |
| 64 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) |
| 65 | #endif |
| 66 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 67 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 69 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 71 | /* NOTE: change this value only with kprobe_mutex held */ |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 72 | static bool kprobes_all_disarmed; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 73 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 74 | static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 75 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 76 | static struct { |
Andrew Morton | 7e036d0 | 2008-11-12 13:26:57 -0800 | [diff] [blame] | 77 | spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 78 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 79 | |
| 80 | static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
| 81 | { |
| 82 | return &(kretprobe_table_locks[hash].lock); |
| 83 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 85 | /* |
| 86 | * Normally, functions that we'd want to prohibit kprobes in, are marked |
| 87 | * __kprobes. But, there are cases where such functions already belong to |
| 88 | * a different section (__sched for preempt_schedule) |
| 89 | * |
| 90 | * For such cases, we now have a blacklist |
| 91 | */ |
Daniel Guilak | 544304b | 2008-07-10 09:38:19 -0700 | [diff] [blame] | 92 | static struct kprobe_blackpoint kprobe_blacklist[] = { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 93 | {"preempt_schedule",}, |
Masami Hiramatsu | 65e234e | 2009-08-27 13:23:32 -0400 | [diff] [blame] | 94 | {"native_get_debugreg",}, |
Masami Hiramatsu | a00e817 | 2009-09-08 12:47:55 -0400 | [diff] [blame] | 95 | {"irq_entries_start",}, |
| 96 | {"common_interrupt",}, |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 97 | {NULL} /* Terminator */ |
| 98 | }; |
| 99 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 100 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 101 | /* |
| 102 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 103 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 104 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 105 | * is a recipe for disaster |
| 106 | */ |
| 107 | #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) |
| 108 | |
| 109 | struct kprobe_insn_page { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 110 | struct list_head list; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 111 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
| 112 | char slot_used[INSNS_PER_PAGE]; |
| 113 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 114 | int ngarbage; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 115 | }; |
| 116 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 117 | enum kprobe_slot_state { |
| 118 | SLOT_CLEAN = 0, |
| 119 | SLOT_DIRTY = 1, |
| 120 | SLOT_USED = 2, |
| 121 | }; |
| 122 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 123 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 124 | static LIST_HEAD(kprobe_insn_pages); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 125 | static int kprobe_garbage_slots; |
| 126 | static int collect_garbage_slots(void); |
| 127 | |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 128 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 129 | * __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] | 130 | * We allocate an executable page if there's no room on existing ones. |
| 131 | */ |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 132 | static kprobe_opcode_t __kprobes *__get_insn_slot(void) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 133 | { |
| 134 | struct kprobe_insn_page *kip; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 135 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 136 | retry: |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 137 | list_for_each_entry(kip, &kprobe_insn_pages, list) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 138 | if (kip->nused < INSNS_PER_PAGE) { |
| 139 | int i; |
| 140 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 141 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 142 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 143 | kip->nused++; |
| 144 | return kip->insns + (i * MAX_INSN_SIZE); |
| 145 | } |
| 146 | } |
| 147 | /* Surprise! No unused slots. Fix kip->nused. */ |
| 148 | kip->nused = INSNS_PER_PAGE; |
| 149 | } |
| 150 | } |
| 151 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 152 | /* If there are any garbage slots, collect it and try again. */ |
| 153 | if (kprobe_garbage_slots && collect_garbage_slots() == 0) { |
| 154 | goto retry; |
| 155 | } |
| 156 | /* 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] | 157 | kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 158 | if (!kip) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 159 | return NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 160 | |
| 161 | /* |
| 162 | * Use module_alloc so this page is within +/- 2GB of where the |
| 163 | * kernel image and loaded module images reside. This is required |
| 164 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 165 | */ |
| 166 | kip->insns = module_alloc(PAGE_SIZE); |
| 167 | if (!kip->insns) { |
| 168 | kfree(kip); |
| 169 | return NULL; |
| 170 | } |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 171 | INIT_LIST_HEAD(&kip->list); |
| 172 | list_add(&kip->list, &kprobe_insn_pages); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 173 | memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); |
| 174 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 175 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 176 | kip->ngarbage = 0; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 177 | return kip->insns; |
| 178 | } |
| 179 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 180 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
| 181 | { |
| 182 | kprobe_opcode_t *ret; |
| 183 | mutex_lock(&kprobe_insn_mutex); |
| 184 | ret = __get_insn_slot(); |
| 185 | mutex_unlock(&kprobe_insn_mutex); |
| 186 | return ret; |
| 187 | } |
| 188 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 189 | /* Return 1 if all garbages are collected, otherwise 0. */ |
| 190 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) |
| 191 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 192 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 193 | kip->nused--; |
| 194 | if (kip->nused == 0) { |
| 195 | /* |
| 196 | * Page is no longer in use. Free it unless |
| 197 | * it's the last one. We keep the last one |
| 198 | * so as not to have to set it up again the |
| 199 | * next time somebody inserts a probe. |
| 200 | */ |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 201 | if (!list_is_singular(&kprobe_insn_pages)) { |
| 202 | list_del(&kip->list); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 203 | module_free(NULL, kip->insns); |
| 204 | kfree(kip); |
| 205 | } |
| 206 | return 1; |
| 207 | } |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static int __kprobes collect_garbage_slots(void) |
| 212 | { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 213 | struct kprobe_insn_page *kip, *next; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 214 | |
Masami Hiramatsu | 615d0eb | 2010-02-02 16:49:04 -0500 | [diff] [blame] | 215 | /* Ensure no-one is interrupted on the garbages */ |
| 216 | synchronize_sched(); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 217 | |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 218 | list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 219 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 220 | if (kip->ngarbage == 0) |
| 221 | continue; |
| 222 | kip->ngarbage = 0; /* we will collect all garbages */ |
| 223 | for (i = 0; i < INSNS_PER_PAGE; i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 224 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 225 | collect_one_slot(kip, i)) |
| 226 | break; |
| 227 | } |
| 228 | } |
| 229 | kprobe_garbage_slots = 0; |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 234 | { |
| 235 | struct kprobe_insn_page *kip; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 236 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 237 | mutex_lock(&kprobe_insn_mutex); |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 238 | list_for_each_entry(kip, &kprobe_insn_pages, list) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 239 | if (kip->insns <= slot && |
| 240 | slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { |
| 241 | int i = (slot - kip->insns) / MAX_INSN_SIZE; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 242 | if (dirty) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 243 | kip->slot_used[i] = SLOT_DIRTY; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 244 | kip->ngarbage++; |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 245 | } else |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 246 | collect_one_slot(kip, i); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 247 | break; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 248 | } |
| 249 | } |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 250 | |
| 251 | if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 252 | collect_garbage_slots(); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 253 | |
| 254 | mutex_unlock(&kprobe_insn_mutex); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 255 | } |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 256 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 257 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 258 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 259 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 260 | { |
| 261 | __get_cpu_var(kprobe_instance) = kp; |
| 262 | } |
| 263 | |
| 264 | static inline void reset_kprobe_instance(void) |
| 265 | { |
| 266 | __get_cpu_var(kprobe_instance) = NULL; |
| 267 | } |
| 268 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 269 | /* |
| 270 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 271 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 272 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 273 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 274 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 275 | struct kprobe __kprobes *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | { |
| 277 | struct hlist_head *head; |
| 278 | struct hlist_node *node; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 279 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | |
| 281 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 282 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | if (p->addr == addr) |
| 284 | return p; |
| 285 | } |
| 286 | return NULL; |
| 287 | } |
| 288 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 289 | /* Arm a kprobe with text_mutex */ |
| 290 | static void __kprobes arm_kprobe(struct kprobe *kp) |
| 291 | { |
| 292 | mutex_lock(&text_mutex); |
| 293 | arch_arm_kprobe(kp); |
| 294 | mutex_unlock(&text_mutex); |
| 295 | } |
| 296 | |
| 297 | /* Disarm a kprobe with text_mutex */ |
| 298 | static void __kprobes disarm_kprobe(struct kprobe *kp) |
| 299 | { |
| 300 | mutex_lock(&text_mutex); |
| 301 | arch_disarm_kprobe(kp); |
| 302 | mutex_unlock(&text_mutex); |
| 303 | } |
| 304 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 305 | /* |
| 306 | * Aggregate handlers for multiple kprobes support - these handlers |
| 307 | * take care of invoking the individual kprobe handlers on p->list |
| 308 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 309 | 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] | 310 | { |
| 311 | struct kprobe *kp; |
| 312 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 313 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 314 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 315 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 316 | if (kp->pre_handler(kp, regs)) |
| 317 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 318 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 319 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 320 | } |
| 321 | return 0; |
| 322 | } |
| 323 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 324 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 325 | unsigned long flags) |
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 | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 330 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 331 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 332 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 333 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 334 | } |
| 335 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 336 | } |
| 337 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 338 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 339 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 340 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 341 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 342 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 343 | /* |
| 344 | * if we faulted "during" the execution of a user specified |
| 345 | * probe handler, invoke just that probe's fault handler |
| 346 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 347 | if (cur && cur->fault_handler) { |
| 348 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 349 | return 1; |
| 350 | } |
| 351 | return 0; |
| 352 | } |
| 353 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 354 | 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] | 355 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 356 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 357 | int ret = 0; |
| 358 | |
| 359 | if (cur && cur->break_handler) { |
| 360 | if (cur->break_handler(cur, regs)) |
| 361 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 362 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 363 | reset_kprobe_instance(); |
| 364 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 365 | } |
| 366 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 367 | /* Walks the list and increments nmissed count for multiprobe case */ |
| 368 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
| 369 | { |
| 370 | struct kprobe *kp; |
| 371 | if (p->pre_handler != aggr_pre_handler) { |
| 372 | p->nmissed++; |
| 373 | } else { |
| 374 | list_for_each_entry_rcu(kp, &p->list, list) |
| 375 | kp->nmissed++; |
| 376 | } |
| 377 | return; |
| 378 | } |
| 379 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 380 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
| 381 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 382 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 383 | struct kretprobe *rp = ri->rp; |
| 384 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 385 | /* remove rp inst off the rprobe_inst_table */ |
| 386 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 387 | INIT_HLIST_NODE(&ri->hlist); |
| 388 | if (likely(rp)) { |
| 389 | spin_lock(&rp->lock); |
| 390 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 391 | spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 392 | } else |
| 393 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 394 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 395 | } |
| 396 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 397 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 398 | struct hlist_head **head, unsigned long *flags) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 399 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 400 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 401 | spinlock_t *hlist_lock; |
| 402 | |
| 403 | *head = &kretprobe_inst_table[hash]; |
| 404 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 405 | spin_lock_irqsave(hlist_lock, *flags); |
| 406 | } |
| 407 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 408 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
| 409 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 410 | { |
| 411 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 412 | spin_lock_irqsave(hlist_lock, *flags); |
| 413 | } |
| 414 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 415 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
| 416 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 417 | { |
| 418 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 419 | spinlock_t *hlist_lock; |
| 420 | |
| 421 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 422 | spin_unlock_irqrestore(hlist_lock, *flags); |
| 423 | } |
| 424 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 425 | void __kprobes kretprobe_table_unlock(unsigned long hash, 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_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 429 | } |
| 430 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 431 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 432 | * This function is called from finish_task_switch when task tk becomes dead, |
| 433 | * so that we can recycle any function-return probe instances associated |
| 434 | * with this task. These left over instances represent probed functions |
| 435 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 436 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 437 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 438 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 439 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 440 | struct hlist_head *head, empty_rp; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 441 | struct hlist_node *node, *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 442 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 443 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 444 | if (unlikely(!kprobes_initialized)) |
| 445 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 446 | return; |
| 447 | |
| 448 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 449 | head = &kretprobe_inst_table[hash]; |
| 450 | kretprobe_table_lock(hash, &flags); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 451 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
| 452 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 453 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 454 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 455 | kretprobe_table_unlock(hash, &flags); |
| 456 | INIT_HLIST_HEAD(&empty_rp); |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 457 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
| 458 | hlist_del(&ri->hlist); |
| 459 | kfree(ri); |
| 460 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 461 | } |
| 462 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 463 | static inline void free_rp_inst(struct kretprobe *rp) |
| 464 | { |
| 465 | struct kretprobe_instance *ri; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 466 | struct hlist_node *pos, *next; |
| 467 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 468 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
| 469 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 470 | kfree(ri); |
| 471 | } |
| 472 | } |
| 473 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 474 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
| 475 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 476 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 477 | struct kretprobe_instance *ri; |
| 478 | struct hlist_node *pos, *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 479 | struct hlist_head *head; |
| 480 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 481 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 482 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 483 | kretprobe_table_lock(hash, &flags); |
| 484 | head = &kretprobe_inst_table[hash]; |
| 485 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { |
| 486 | if (ri->rp == rp) |
| 487 | ri->rp = NULL; |
| 488 | } |
| 489 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 490 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 491 | free_rp_inst(rp); |
| 492 | } |
| 493 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 494 | /* |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 495 | * Keep all fields in the kprobe consistent |
| 496 | */ |
| 497 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) |
| 498 | { |
| 499 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); |
| 500 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); |
| 501 | } |
| 502 | |
| 503 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 504 | * 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] | 505 | * second jprobe at the address - two jprobes can't coexist |
| 506 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 507 | 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] | 508 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 509 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 510 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 511 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 512 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 513 | list_add_tail_rcu(&p->list, &ap->list); |
| 514 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 515 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 516 | list_add_rcu(&p->list, &ap->list); |
| 517 | if (p->post_handler && !ap->post_handler) |
| 518 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 519 | |
| 520 | if (kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 521 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 522 | if (!kprobes_all_disarmed) |
| 523 | /* Arm the breakpoint again. */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 524 | arm_kprobe(ap); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 525 | } |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 526 | return 0; |
| 527 | } |
| 528 | |
| 529 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 530 | * Fill in the required fields of the "manager kprobe". Replace the |
| 531 | * earlier kprobe in the hlist with the manager kprobe |
| 532 | */ |
| 533 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
| 534 | { |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 535 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 536 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 537 | ap->addr = p->addr; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 538 | ap->flags = p->flags; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 539 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 540 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 541 | /* We don't care the kprobe which has gone. */ |
| 542 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 543 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 544 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 545 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 546 | |
| 547 | INIT_LIST_HEAD(&ap->list); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 548 | list_add_rcu(&p->list, &ap->list); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 549 | |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 550 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 551 | } |
| 552 | |
| 553 | /* |
| 554 | * This is the second or subsequent kprobe at the address - handle |
| 555 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 556 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 557 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
| 558 | struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 559 | { |
| 560 | int ret = 0; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 561 | struct kprobe *ap = old_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 562 | |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 563 | if (old_p->pre_handler != aggr_pre_handler) { |
| 564 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ |
| 565 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 566 | if (!ap) |
| 567 | return -ENOMEM; |
| 568 | add_aggr_kprobe(ap, old_p); |
| 569 | } |
| 570 | |
| 571 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 572 | /* |
| 573 | * Attempting to insert new probe at the same location that |
| 574 | * had a probe in the module vaddr area which already |
| 575 | * freed. So, the instruction slot has already been |
| 576 | * released. We need a new slot for the new probe. |
| 577 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 578 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 579 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 580 | /* |
| 581 | * Even if fail to allocate new slot, don't need to |
| 582 | * free aggr_probe. It will be used next time, or |
| 583 | * freed by unregister_kprobe. |
| 584 | */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 585 | return ret; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 586 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 587 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 588 | * Clear gone flag to prevent allocating new slot again, and |
| 589 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 590 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 591 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 592 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 593 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 594 | |
| 595 | copy_kprobe(ap, p); |
| 596 | return add_new_kprobe(ap, p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 597 | } |
| 598 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 599 | /* Try to disable aggr_kprobe, and return 1 if succeeded.*/ |
| 600 | static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) |
| 601 | { |
| 602 | struct kprobe *kp; |
| 603 | |
| 604 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 605 | if (!kprobe_disabled(kp)) |
| 606 | /* |
| 607 | * There is an active probe on the list. |
| 608 | * We can't disable aggr_kprobe. |
| 609 | */ |
| 610 | return 0; |
| 611 | } |
| 612 | p->flags |= KPROBE_FLAG_DISABLED; |
| 613 | return 1; |
| 614 | } |
| 615 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 616 | static int __kprobes in_kprobes_functions(unsigned long addr) |
| 617 | { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 618 | struct kprobe_blackpoint *kb; |
| 619 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 620 | if (addr >= (unsigned long)__kprobes_text_start && |
| 621 | addr < (unsigned long)__kprobes_text_end) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 622 | return -EINVAL; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 623 | /* |
| 624 | * If there exists a kprobe_blacklist, verify and |
| 625 | * fail any probe registration in the prohibited area |
| 626 | */ |
| 627 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 628 | if (kb->start_addr) { |
| 629 | if (addr >= kb->start_addr && |
| 630 | addr < (kb->start_addr + kb->range)) |
| 631 | return -EINVAL; |
| 632 | } |
| 633 | } |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 634 | return 0; |
| 635 | } |
| 636 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 637 | /* |
| 638 | * If we have a symbol_name argument, look it up and add the offset field |
| 639 | * to it. This way, we can specify a relative address to a symbol. |
| 640 | */ |
| 641 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) |
| 642 | { |
| 643 | kprobe_opcode_t *addr = p->addr; |
| 644 | if (p->symbol_name) { |
| 645 | if (addr) |
| 646 | return NULL; |
| 647 | kprobe_lookup_name(p->symbol_name, addr); |
| 648 | } |
| 649 | |
| 650 | if (!addr) |
| 651 | return NULL; |
| 652 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 653 | } |
| 654 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 655 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
| 656 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) |
| 657 | { |
| 658 | struct kprobe *old_p, *list_p; |
| 659 | |
| 660 | old_p = get_kprobe(p->addr); |
| 661 | if (unlikely(!old_p)) |
| 662 | return NULL; |
| 663 | |
| 664 | if (p != old_p) { |
| 665 | list_for_each_entry_rcu(list_p, &old_p->list, list) |
| 666 | if (list_p == p) |
| 667 | /* kprobe p is a valid probe */ |
| 668 | goto valid; |
| 669 | return NULL; |
| 670 | } |
| 671 | valid: |
| 672 | return old_p; |
| 673 | } |
| 674 | |
| 675 | /* Return error if the kprobe is being re-registered */ |
| 676 | static inline int check_kprobe_rereg(struct kprobe *p) |
| 677 | { |
| 678 | int ret = 0; |
| 679 | struct kprobe *old_p; |
| 680 | |
| 681 | mutex_lock(&kprobe_mutex); |
| 682 | old_p = __get_valid_kprobe(p); |
| 683 | if (old_p) |
| 684 | ret = -EINVAL; |
| 685 | mutex_unlock(&kprobe_mutex); |
| 686 | return ret; |
| 687 | } |
| 688 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 689 | int __kprobes register_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | { |
| 691 | int ret = 0; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 692 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 693 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 694 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 696 | addr = kprobe_addr(p); |
| 697 | if (!addr) |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 698 | return -EINVAL; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 699 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 700 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 701 | ret = check_kprobe_rereg(p); |
| 702 | if (ret) |
| 703 | return ret; |
| 704 | |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 705 | preempt_disable(); |
Masami Hiramatsu | ec30c5f | 2009-07-28 19:47:23 -0400 | [diff] [blame] | 706 | if (!kernel_text_address((unsigned long) p->addr) || |
Masami Hiramatsu | 4554dbc | 2010-02-02 16:49:18 -0500 | [diff] [blame^] | 707 | in_kprobes_functions((unsigned long) p->addr) || |
| 708 | ftrace_text_reserved(p->addr, p->addr)) { |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 709 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 710 | return -EINVAL; |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 711 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 712 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 713 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 714 | p->flags &= KPROBE_FLAG_DISABLED; |
| 715 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 716 | /* |
| 717 | * Check if are we probing a module. |
| 718 | */ |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 719 | probed_mod = __module_text_address((unsigned long) p->addr); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 720 | if (probed_mod) { |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 721 | /* |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 722 | * We must hold a refcount of the probed module while updating |
| 723 | * its code to prohibit unexpected unloading. |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 724 | */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 725 | if (unlikely(!try_module_get(probed_mod))) { |
| 726 | preempt_enable(); |
| 727 | return -EINVAL; |
| 728 | } |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 729 | /* |
| 730 | * If the module freed .init.text, we couldn't insert |
| 731 | * kprobes in there. |
| 732 | */ |
| 733 | if (within_module_init((unsigned long)p->addr, probed_mod) && |
| 734 | probed_mod->state != MODULE_STATE_COMING) { |
| 735 | module_put(probed_mod); |
| 736 | preempt_enable(); |
| 737 | return -EINVAL; |
| 738 | } |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 739 | } |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 740 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 741 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 742 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 743 | INIT_LIST_HEAD(&p->list); |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 744 | mutex_lock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 745 | old_p = get_kprobe(p->addr); |
| 746 | if (old_p) { |
| 747 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | goto out; |
| 749 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 751 | mutex_lock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 752 | ret = arch_prepare_kprobe(p); |
| 753 | if (ret) |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 754 | goto out_unlock_text; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 755 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 756 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 757 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 759 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 760 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 761 | arch_arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 762 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 763 | out_unlock_text: |
| 764 | mutex_unlock(&text_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 766 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 767 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 768 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 769 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 770 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | return ret; |
| 772 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 773 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 775 | /* |
| 776 | * Unregister a kprobe without a scheduler synchronization. |
| 777 | */ |
| 778 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 779 | { |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 780 | struct kprobe *old_p, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 781 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 782 | old_p = __get_valid_kprobe(p); |
| 783 | if (old_p == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 784 | return -EINVAL; |
| 785 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 786 | if (old_p == p || |
| 787 | (old_p->pre_handler == aggr_pre_handler && |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 788 | list_is_singular(&old_p->list))) { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 789 | /* |
| 790 | * Only probe on the hash list. Disarm only if kprobes are |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 791 | * enabled and not gone - otherwise, the breakpoint would |
| 792 | * already have been removed. We save on flushing icache. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 793 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 794 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
| 795 | disarm_kprobe(p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 796 | hlist_del_rcu(&old_p->hlist); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 797 | } else { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 798 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 799 | old_p->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 800 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 801 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
| 802 | if ((list_p != p) && (list_p->post_handler)) |
| 803 | goto noclean; |
| 804 | } |
| 805 | old_p->post_handler = NULL; |
| 806 | } |
| 807 | noclean: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 808 | list_del_rcu(&p->list); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 809 | if (!kprobe_disabled(old_p)) { |
| 810 | try_to_disable_aggr_kprobe(old_p); |
| 811 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 812 | disarm_kprobe(old_p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 813 | } |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 814 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 815 | return 0; |
| 816 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 817 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 818 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
| 819 | { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 820 | struct kprobe *old_p; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 821 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 822 | if (list_empty(&p->list)) |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 823 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 824 | else if (list_is_singular(&p->list)) { |
| 825 | /* "p" is the last child of an aggr_kprobe */ |
| 826 | old_p = list_entry(p->list.next, struct kprobe, list); |
| 827 | list_del(&p->list); |
| 828 | arch_remove_kprobe(old_p); |
| 829 | kfree(old_p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 830 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | } |
| 832 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 833 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 834 | { |
| 835 | int i, ret = 0; |
| 836 | |
| 837 | if (num <= 0) |
| 838 | return -EINVAL; |
| 839 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 840 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 841 | if (ret < 0) { |
| 842 | if (i > 0) |
| 843 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 844 | break; |
| 845 | } |
| 846 | } |
| 847 | return ret; |
| 848 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 849 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 850 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 851 | void __kprobes unregister_kprobe(struct kprobe *p) |
| 852 | { |
| 853 | unregister_kprobes(&p, 1); |
| 854 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 855 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 856 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 857 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
| 858 | { |
| 859 | int i; |
| 860 | |
| 861 | if (num <= 0) |
| 862 | return; |
| 863 | mutex_lock(&kprobe_mutex); |
| 864 | for (i = 0; i < num; i++) |
| 865 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 866 | kps[i]->addr = NULL; |
| 867 | mutex_unlock(&kprobe_mutex); |
| 868 | |
| 869 | synchronize_sched(); |
| 870 | for (i = 0; i < num; i++) |
| 871 | if (kps[i]->addr) |
| 872 | __unregister_kprobe_bottom(kps[i]); |
| 873 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 874 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 875 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | static struct notifier_block kprobe_exceptions_nb = { |
| 877 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 878 | .priority = 0x7fffffff /* we need to be notified first */ |
| 879 | }; |
| 880 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 881 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 882 | { |
| 883 | return (unsigned long)entry; |
| 884 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 885 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 886 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 887 | { |
| 888 | struct jprobe *jp; |
| 889 | int ret = 0, i; |
| 890 | |
| 891 | if (num <= 0) |
| 892 | return -EINVAL; |
| 893 | for (i = 0; i < num; i++) { |
| 894 | unsigned long addr; |
| 895 | jp = jps[i]; |
| 896 | addr = arch_deref_entry_point(jp->entry); |
| 897 | |
| 898 | if (!kernel_text_address(addr)) |
| 899 | ret = -EINVAL; |
| 900 | else { |
| 901 | /* Todo: Verify probepoint is a function entry point */ |
| 902 | jp->kp.pre_handler = setjmp_pre_handler; |
| 903 | jp->kp.break_handler = longjmp_break_handler; |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 904 | ret = register_kprobe(&jp->kp); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 905 | } |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 906 | if (ret < 0) { |
| 907 | if (i > 0) |
| 908 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 909 | break; |
| 910 | } |
| 911 | } |
| 912 | return ret; |
| 913 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 914 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 915 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 916 | int __kprobes register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 918 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 919 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 920 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 922 | void __kprobes unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 924 | unregister_jprobes(&jp, 1); |
| 925 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 926 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 927 | |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 928 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
| 929 | { |
| 930 | int i; |
| 931 | |
| 932 | if (num <= 0) |
| 933 | return; |
| 934 | mutex_lock(&kprobe_mutex); |
| 935 | for (i = 0; i < num; i++) |
| 936 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 937 | jps[i]->kp.addr = NULL; |
| 938 | mutex_unlock(&kprobe_mutex); |
| 939 | |
| 940 | synchronize_sched(); |
| 941 | for (i = 0; i < num; i++) { |
| 942 | if (jps[i]->kp.addr) |
| 943 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 944 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 946 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 948 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 949 | /* |
| 950 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 951 | * hits it will set up the return probe. |
| 952 | */ |
| 953 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 954 | struct pt_regs *regs) |
| 955 | { |
| 956 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 957 | unsigned long hash, flags = 0; |
| 958 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 959 | |
| 960 | /*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] | 961 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
| 962 | spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 963 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 964 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 965 | struct kretprobe_instance, hlist); |
| 966 | hlist_del(&ri->hlist); |
| 967 | spin_unlock_irqrestore(&rp->lock, flags); |
| 968 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 969 | ri->rp = rp; |
| 970 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 971 | |
Ananth N Mavinakayanahalli | f02b862 | 2009-03-18 17:06:21 +0530 | [diff] [blame] | 972 | if (rp->entry_handler && rp->entry_handler(ri, regs)) |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 973 | return 0; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 974 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 975 | arch_prepare_kretprobe(ri, regs); |
| 976 | |
| 977 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 978 | INIT_HLIST_NODE(&ri->hlist); |
| 979 | kretprobe_table_lock(hash, &flags); |
| 980 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 981 | kretprobe_table_unlock(hash, &flags); |
| 982 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 983 | rp->nmissed++; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 984 | spin_unlock_irqrestore(&rp->lock, flags); |
| 985 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 986 | return 0; |
| 987 | } |
| 988 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 989 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 990 | { |
| 991 | int ret = 0; |
| 992 | struct kretprobe_instance *inst; |
| 993 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 994 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 995 | |
| 996 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 997 | addr = kprobe_addr(&rp->kp); |
| 998 | if (!addr) |
| 999 | return -EINVAL; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1000 | |
| 1001 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1002 | if (kretprobe_blacklist[i].addr == addr) |
| 1003 | return -EINVAL; |
| 1004 | } |
| 1005 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1006 | |
| 1007 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1008 | rp->kp.post_handler = NULL; |
| 1009 | rp->kp.fault_handler = NULL; |
| 1010 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1011 | |
| 1012 | /* Pre-allocate memory for max kretprobe instances */ |
| 1013 | if (rp->maxactive <= 0) { |
| 1014 | #ifdef CONFIG_PREEMPT |
Heiko Carstens | c2ef666 | 2009-12-21 13:02:24 +0100 | [diff] [blame] | 1015 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1016 | #else |
Ananth N Mavinakayanahalli | 4dae560 | 2009-10-30 19:23:10 +0530 | [diff] [blame] | 1017 | rp->maxactive = num_possible_cpus(); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1018 | #endif |
| 1019 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1020 | spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1021 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1022 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1023 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1024 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1025 | if (inst == NULL) { |
| 1026 | free_rp_inst(rp); |
| 1027 | return -ENOMEM; |
| 1028 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1029 | INIT_HLIST_NODE(&inst->hlist); |
| 1030 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1031 | } |
| 1032 | |
| 1033 | rp->nmissed = 0; |
| 1034 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1035 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1036 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1037 | free_rp_inst(rp); |
| 1038 | return ret; |
| 1039 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1040 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1041 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1042 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1043 | { |
| 1044 | int ret = 0, i; |
| 1045 | |
| 1046 | if (num <= 0) |
| 1047 | return -EINVAL; |
| 1048 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1049 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1050 | if (ret < 0) { |
| 1051 | if (i > 0) |
| 1052 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1053 | break; |
| 1054 | } |
| 1055 | } |
| 1056 | return ret; |
| 1057 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1058 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1059 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1060 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1061 | { |
| 1062 | unregister_kretprobes(&rp, 1); |
| 1063 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1064 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1065 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1066 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1067 | { |
| 1068 | int i; |
| 1069 | |
| 1070 | if (num <= 0) |
| 1071 | return; |
| 1072 | mutex_lock(&kprobe_mutex); |
| 1073 | for (i = 0; i < num; i++) |
| 1074 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1075 | rps[i]->kp.addr = NULL; |
| 1076 | mutex_unlock(&kprobe_mutex); |
| 1077 | |
| 1078 | synchronize_sched(); |
| 1079 | for (i = 0; i < num; i++) { |
| 1080 | if (rps[i]->kp.addr) { |
| 1081 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1082 | cleanup_rp_inst(rps[i]); |
| 1083 | } |
| 1084 | } |
| 1085 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1086 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1087 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1088 | #else /* CONFIG_KRETPROBES */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1089 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1090 | { |
| 1091 | return -ENOSYS; |
| 1092 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1093 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1094 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1095 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
| 1096 | { |
| 1097 | return -ENOSYS; |
| 1098 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1099 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1100 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1101 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1102 | { |
| 1103 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1104 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1105 | |
| 1106 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1107 | { |
| 1108 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1109 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1110 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1111 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1112 | struct pt_regs *regs) |
| 1113 | { |
| 1114 | return 0; |
| 1115 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1116 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1117 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1118 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1119 | /* Set the kprobe gone and remove its instruction buffer. */ |
| 1120 | static void __kprobes kill_kprobe(struct kprobe *p) |
| 1121 | { |
| 1122 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1123 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1124 | p->flags |= KPROBE_FLAG_GONE; |
| 1125 | if (p->pre_handler == aggr_pre_handler) { |
| 1126 | /* |
| 1127 | * If this is an aggr_kprobe, we have to list all the |
| 1128 | * chained probes and mark them GONE. |
| 1129 | */ |
| 1130 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1131 | kp->flags |= KPROBE_FLAG_GONE; |
| 1132 | p->post_handler = NULL; |
| 1133 | p->break_handler = NULL; |
| 1134 | } |
| 1135 | /* |
| 1136 | * Here, we can remove insn_slot safely, because no thread calls |
| 1137 | * the original probed function (which will be freed soon) any more. |
| 1138 | */ |
| 1139 | arch_remove_kprobe(p); |
| 1140 | } |
| 1141 | |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 1142 | void __kprobes dump_kprobe(struct kprobe *kp) |
| 1143 | { |
| 1144 | printk(KERN_WARNING "Dumping kprobe:\n"); |
| 1145 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", |
| 1146 | kp->symbol_name, kp->addr, kp->offset); |
| 1147 | } |
| 1148 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1149 | /* Module notifier call back, checking kprobes on the module */ |
| 1150 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, |
| 1151 | unsigned long val, void *data) |
| 1152 | { |
| 1153 | struct module *mod = data; |
| 1154 | struct hlist_head *head; |
| 1155 | struct hlist_node *node; |
| 1156 | struct kprobe *p; |
| 1157 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1158 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1159 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1160 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1161 | return NOTIFY_DONE; |
| 1162 | |
| 1163 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1164 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 1165 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 1166 | * notified, only .init.text section would be freed. We need to |
| 1167 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1168 | */ |
| 1169 | mutex_lock(&kprobe_mutex); |
| 1170 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1171 | head = &kprobe_table[i]; |
| 1172 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1173 | if (within_module_init((unsigned long)p->addr, mod) || |
| 1174 | (checkcore && |
| 1175 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1176 | /* |
| 1177 | * The vaddr this probe is installed will soon |
| 1178 | * be vfreed buy not synced to disk. Hence, |
| 1179 | * disarming the breakpoint isn't needed. |
| 1180 | */ |
| 1181 | kill_kprobe(p); |
| 1182 | } |
| 1183 | } |
| 1184 | mutex_unlock(&kprobe_mutex); |
| 1185 | return NOTIFY_DONE; |
| 1186 | } |
| 1187 | |
| 1188 | static struct notifier_block kprobe_module_nb = { |
| 1189 | .notifier_call = kprobes_module_callback, |
| 1190 | .priority = 0 |
| 1191 | }; |
| 1192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1193 | static int __init init_kprobes(void) |
| 1194 | { |
| 1195 | int i, err = 0; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1196 | unsigned long offset = 0, size = 0; |
| 1197 | char *modname, namebuf[128]; |
| 1198 | const char *symbol_name; |
| 1199 | void *addr; |
| 1200 | struct kprobe_blackpoint *kb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | |
| 1202 | /* FIXME allocate the probe table, currently defined statically */ |
| 1203 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1204 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1206 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1207 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1208 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1210 | /* |
| 1211 | * Lookup and populate the kprobe_blacklist. |
| 1212 | * |
| 1213 | * Unlike the kretprobe blacklist, we'll need to determine |
| 1214 | * the range of addresses that belong to the said functions, |
| 1215 | * since a kprobe need not necessarily be at the beginning |
| 1216 | * of a function. |
| 1217 | */ |
| 1218 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 1219 | kprobe_lookup_name(kb->name, addr); |
| 1220 | if (!addr) |
| 1221 | continue; |
| 1222 | |
| 1223 | kb->start_addr = (unsigned long)addr; |
| 1224 | symbol_name = kallsyms_lookup(kb->start_addr, |
| 1225 | &size, &offset, &modname, namebuf); |
| 1226 | if (!symbol_name) |
| 1227 | kb->range = 0; |
| 1228 | else |
| 1229 | kb->range = size; |
| 1230 | } |
| 1231 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1232 | if (kretprobe_blacklist_size) { |
| 1233 | /* lookup the function address from its name */ |
| 1234 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1235 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 1236 | kretprobe_blacklist[i].addr); |
| 1237 | if (!kretprobe_blacklist[i].addr) |
| 1238 | printk("kretprobe: lookup failed: %s\n", |
| 1239 | kretprobe_blacklist[i].name); |
| 1240 | } |
| 1241 | } |
| 1242 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1243 | /* By default, kprobes are armed */ |
| 1244 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1245 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 1246 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1247 | if (!err) |
| 1248 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1249 | if (!err) |
| 1250 | err = register_module_notifier(&kprobe_module_nb); |
| 1251 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1252 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1253 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 1254 | if (!err) |
| 1255 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | return err; |
| 1257 | } |
| 1258 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1259 | #ifdef CONFIG_DEBUG_FS |
| 1260 | 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] | 1261 | const char *sym, int offset,char *modname) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1262 | { |
| 1263 | char *kprobe_type; |
| 1264 | |
| 1265 | if (p->pre_handler == pre_handler_kretprobe) |
| 1266 | kprobe_type = "r"; |
| 1267 | else if (p->pre_handler == setjmp_pre_handler) |
| 1268 | kprobe_type = "j"; |
| 1269 | else |
| 1270 | kprobe_type = "k"; |
| 1271 | if (sym) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1272 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", |
| 1273 | p->addr, kprobe_type, sym, offset, |
| 1274 | (modname ? modname : " "), |
| 1275 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1276 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1277 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1278 | else |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1279 | seq_printf(pi, "%p %s %p %s%s\n", |
| 1280 | p->addr, kprobe_type, p->addr, |
| 1281 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1282 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1283 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1284 | } |
| 1285 | |
| 1286 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
| 1287 | { |
| 1288 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 1289 | } |
| 1290 | |
| 1291 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
| 1292 | { |
| 1293 | (*pos)++; |
| 1294 | if (*pos >= KPROBE_TABLE_SIZE) |
| 1295 | return NULL; |
| 1296 | return pos; |
| 1297 | } |
| 1298 | |
| 1299 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) |
| 1300 | { |
| 1301 | /* Nothing to do */ |
| 1302 | } |
| 1303 | |
| 1304 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) |
| 1305 | { |
| 1306 | struct hlist_head *head; |
| 1307 | struct hlist_node *node; |
| 1308 | struct kprobe *p, *kp; |
| 1309 | const char *sym = NULL; |
| 1310 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1311 | unsigned long offset = 0; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1312 | char *modname, namebuf[128]; |
| 1313 | |
| 1314 | head = &kprobe_table[i]; |
| 1315 | preempt_disable(); |
| 1316 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1317 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1318 | &offset, &modname, namebuf); |
| 1319 | if (p->pre_handler == aggr_pre_handler) { |
| 1320 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1321 | report_probe(pi, kp, sym, offset, modname); |
| 1322 | } else |
| 1323 | report_probe(pi, p, sym, offset, modname); |
| 1324 | } |
| 1325 | preempt_enable(); |
| 1326 | return 0; |
| 1327 | } |
| 1328 | |
James Morris | 88e9d34 | 2009-09-22 16:43:43 -0700 | [diff] [blame] | 1329 | static const struct seq_operations kprobes_seq_ops = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1330 | .start = kprobe_seq_start, |
| 1331 | .next = kprobe_seq_next, |
| 1332 | .stop = kprobe_seq_stop, |
| 1333 | .show = show_kprobe_addr |
| 1334 | }; |
| 1335 | |
| 1336 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) |
| 1337 | { |
| 1338 | return seq_open(filp, &kprobes_seq_ops); |
| 1339 | } |
| 1340 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 1341 | static const struct file_operations debugfs_kprobes_operations = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1342 | .open = kprobes_open, |
| 1343 | .read = seq_read, |
| 1344 | .llseek = seq_lseek, |
| 1345 | .release = seq_release, |
| 1346 | }; |
| 1347 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1348 | /* Disable one kprobe */ |
| 1349 | int __kprobes disable_kprobe(struct kprobe *kp) |
| 1350 | { |
| 1351 | int ret = 0; |
| 1352 | struct kprobe *p; |
| 1353 | |
| 1354 | mutex_lock(&kprobe_mutex); |
| 1355 | |
| 1356 | /* Check whether specified probe is valid. */ |
| 1357 | p = __get_valid_kprobe(kp); |
| 1358 | if (unlikely(p == NULL)) { |
| 1359 | ret = -EINVAL; |
| 1360 | goto out; |
| 1361 | } |
| 1362 | |
| 1363 | /* If the probe is already disabled (or gone), just return */ |
| 1364 | if (kprobe_disabled(kp)) |
| 1365 | goto out; |
| 1366 | |
| 1367 | kp->flags |= KPROBE_FLAG_DISABLED; |
| 1368 | if (p != kp) |
| 1369 | /* When kp != p, p is always enabled. */ |
| 1370 | try_to_disable_aggr_kprobe(p); |
| 1371 | |
| 1372 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1373 | disarm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1374 | out: |
| 1375 | mutex_unlock(&kprobe_mutex); |
| 1376 | return ret; |
| 1377 | } |
| 1378 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 1379 | |
| 1380 | /* Enable one kprobe */ |
| 1381 | int __kprobes enable_kprobe(struct kprobe *kp) |
| 1382 | { |
| 1383 | int ret = 0; |
| 1384 | struct kprobe *p; |
| 1385 | |
| 1386 | mutex_lock(&kprobe_mutex); |
| 1387 | |
| 1388 | /* Check whether specified probe is valid. */ |
| 1389 | p = __get_valid_kprobe(kp); |
| 1390 | if (unlikely(p == NULL)) { |
| 1391 | ret = -EINVAL; |
| 1392 | goto out; |
| 1393 | } |
| 1394 | |
| 1395 | if (kprobe_gone(kp)) { |
| 1396 | /* This kprobe has gone, we couldn't enable it. */ |
| 1397 | ret = -EINVAL; |
| 1398 | goto out; |
| 1399 | } |
| 1400 | |
| 1401 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1402 | arm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1403 | |
| 1404 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 1405 | if (p != kp) |
| 1406 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 1407 | out: |
| 1408 | mutex_unlock(&kprobe_mutex); |
| 1409 | return ret; |
| 1410 | } |
| 1411 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 1412 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1413 | static void __kprobes arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1414 | { |
| 1415 | struct hlist_head *head; |
| 1416 | struct hlist_node *node; |
| 1417 | struct kprobe *p; |
| 1418 | unsigned int i; |
| 1419 | |
| 1420 | mutex_lock(&kprobe_mutex); |
| 1421 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1422 | /* If kprobes are armed, just return */ |
| 1423 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1424 | goto already_enabled; |
| 1425 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1426 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1427 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1428 | head = &kprobe_table[i]; |
| 1429 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1430 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1431 | arch_arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1432 | } |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1433 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1434 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1435 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1436 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 1437 | |
| 1438 | already_enabled: |
| 1439 | mutex_unlock(&kprobe_mutex); |
| 1440 | return; |
| 1441 | } |
| 1442 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1443 | static void __kprobes disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1444 | { |
| 1445 | struct hlist_head *head; |
| 1446 | struct hlist_node *node; |
| 1447 | struct kprobe *p; |
| 1448 | unsigned int i; |
| 1449 | |
| 1450 | mutex_lock(&kprobe_mutex); |
| 1451 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1452 | /* If kprobes are already disarmed, just return */ |
| 1453 | if (kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1454 | goto already_disabled; |
| 1455 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1456 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1457 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1458 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1459 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1460 | head = &kprobe_table[i]; |
| 1461 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1462 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1463 | arch_disarm_kprobe(p); |
| 1464 | } |
| 1465 | } |
| 1466 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1467 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1468 | mutex_unlock(&kprobe_mutex); |
| 1469 | /* Allow all currently running kprobes to complete */ |
| 1470 | synchronize_sched(); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1471 | return; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1472 | |
| 1473 | already_disabled: |
| 1474 | mutex_unlock(&kprobe_mutex); |
| 1475 | return; |
| 1476 | } |
| 1477 | |
| 1478 | /* |
| 1479 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 1480 | * when the bool state is switched. We can reuse that facility when |
| 1481 | * available |
| 1482 | */ |
| 1483 | static ssize_t read_enabled_file_bool(struct file *file, |
| 1484 | char __user *user_buf, size_t count, loff_t *ppos) |
| 1485 | { |
| 1486 | char buf[3]; |
| 1487 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1488 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1489 | buf[0] = '1'; |
| 1490 | else |
| 1491 | buf[0] = '0'; |
| 1492 | buf[1] = '\n'; |
| 1493 | buf[2] = 0x00; |
| 1494 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 1495 | } |
| 1496 | |
| 1497 | static ssize_t write_enabled_file_bool(struct file *file, |
| 1498 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 1499 | { |
| 1500 | char buf[32]; |
| 1501 | int buf_size; |
| 1502 | |
| 1503 | buf_size = min(count, (sizeof(buf)-1)); |
| 1504 | if (copy_from_user(buf, user_buf, buf_size)) |
| 1505 | return -EFAULT; |
| 1506 | |
| 1507 | switch (buf[0]) { |
| 1508 | case 'y': |
| 1509 | case 'Y': |
| 1510 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1511 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1512 | break; |
| 1513 | case 'n': |
| 1514 | case 'N': |
| 1515 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1516 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1517 | break; |
| 1518 | } |
| 1519 | |
| 1520 | return count; |
| 1521 | } |
| 1522 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 1523 | static const struct file_operations fops_kp = { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1524 | .read = read_enabled_file_bool, |
| 1525 | .write = write_enabled_file_bool, |
| 1526 | }; |
| 1527 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1528 | static int __kprobes debugfs_kprobe_init(void) |
| 1529 | { |
| 1530 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1531 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1532 | |
| 1533 | dir = debugfs_create_dir("kprobes", NULL); |
| 1534 | if (!dir) |
| 1535 | return -ENOMEM; |
| 1536 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 1537 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1538 | &debugfs_kprobes_operations); |
| 1539 | if (!file) { |
| 1540 | debugfs_remove(dir); |
| 1541 | return -ENOMEM; |
| 1542 | } |
| 1543 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1544 | file = debugfs_create_file("enabled", 0600, dir, |
| 1545 | &value, &fops_kp); |
| 1546 | if (!file) { |
| 1547 | debugfs_remove(dir); |
| 1548 | return -ENOMEM; |
| 1549 | } |
| 1550 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1551 | return 0; |
| 1552 | } |
| 1553 | |
| 1554 | late_initcall(debugfs_kprobe_init); |
| 1555 | #endif /* CONFIG_DEBUG_FS */ |
| 1556 | |
| 1557 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1558 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1559 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | EXPORT_SYMBOL_GPL(jprobe_return); |