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",}, |
Masami Hiramatsu | 5ecaafd | 2010-02-05 01:24:34 -0500 | [diff] [blame] | 97 | {"mcount",}, /* mcount can be called from everywhere */ |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 98 | {NULL} /* Terminator */ |
| 99 | }; |
| 100 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 101 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 102 | /* |
| 103 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 104 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 105 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 106 | * is a recipe for disaster |
| 107 | */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 108 | struct kprobe_insn_page { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 109 | struct list_head list; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 110 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 111 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 112 | int ngarbage; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 113 | char slot_used[]; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 114 | }; |
| 115 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 116 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
| 117 | (offsetof(struct kprobe_insn_page, slot_used) + \ |
| 118 | (sizeof(char) * (slots))) |
| 119 | |
| 120 | struct kprobe_insn_cache { |
| 121 | struct list_head pages; /* list of kprobe_insn_page */ |
| 122 | size_t insn_size; /* size of instruction slot */ |
| 123 | int nr_garbage; |
| 124 | }; |
| 125 | |
| 126 | static int slots_per_page(struct kprobe_insn_cache *c) |
| 127 | { |
| 128 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); |
| 129 | } |
| 130 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 131 | enum kprobe_slot_state { |
| 132 | SLOT_CLEAN = 0, |
| 133 | SLOT_DIRTY = 1, |
| 134 | SLOT_USED = 2, |
| 135 | }; |
| 136 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 137 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */ |
| 138 | static struct kprobe_insn_cache kprobe_insn_slots = { |
| 139 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
| 140 | .insn_size = MAX_INSN_SIZE, |
| 141 | .nr_garbage = 0, |
| 142 | }; |
| 143 | static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 144 | |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 145 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 146 | * __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] | 147 | * We allocate an executable page if there's no room on existing ones. |
| 148 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 149 | static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 150 | { |
| 151 | struct kprobe_insn_page *kip; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 152 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 153 | retry: |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 154 | list_for_each_entry(kip, &c->pages, list) { |
| 155 | if (kip->nused < slots_per_page(c)) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 156 | int i; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 157 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 158 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 159 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 160 | kip->nused++; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 161 | return kip->insns + (i * c->insn_size); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 162 | } |
| 163 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 164 | /* kip->nused is broken. Fix it. */ |
| 165 | kip->nused = slots_per_page(c); |
| 166 | WARN_ON(1); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 167 | } |
| 168 | } |
| 169 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 170 | /* If there are any garbage slots, collect it and try again. */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 171 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 172 | goto retry; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 173 | |
| 174 | /* All out of space. Need to allocate a new page. */ |
| 175 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 176 | if (!kip) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 177 | return NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 178 | |
| 179 | /* |
| 180 | * Use module_alloc so this page is within +/- 2GB of where the |
| 181 | * kernel image and loaded module images reside. This is required |
| 182 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 183 | */ |
| 184 | kip->insns = module_alloc(PAGE_SIZE); |
| 185 | if (!kip->insns) { |
| 186 | kfree(kip); |
| 187 | return NULL; |
| 188 | } |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 189 | INIT_LIST_HEAD(&kip->list); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 190 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 191 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 192 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 193 | kip->ngarbage = 0; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 194 | list_add(&kip->list, &c->pages); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 195 | return kip->insns; |
| 196 | } |
| 197 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 198 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 199 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
| 200 | { |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 201 | kprobe_opcode_t *ret = NULL; |
| 202 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 203 | mutex_lock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 204 | ret = __get_insn_slot(&kprobe_insn_slots); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 205 | mutex_unlock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 206 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 207 | return ret; |
| 208 | } |
| 209 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 210 | /* Return 1 if all garbages are collected, otherwise 0. */ |
| 211 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) |
| 212 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 213 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 214 | kip->nused--; |
| 215 | if (kip->nused == 0) { |
| 216 | /* |
| 217 | * Page is no longer in use. Free it unless |
| 218 | * it's the last one. We keep the last one |
| 219 | * so as not to have to set it up again the |
| 220 | * next time somebody inserts a probe. |
| 221 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 222 | if (!list_is_singular(&kip->list)) { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 223 | list_del(&kip->list); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 224 | module_free(NULL, kip->insns); |
| 225 | kfree(kip); |
| 226 | } |
| 227 | return 1; |
| 228 | } |
| 229 | return 0; |
| 230 | } |
| 231 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 232 | static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 233 | { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 234 | struct kprobe_insn_page *kip, *next; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 235 | |
Masami Hiramatsu | 615d0eb | 2010-02-02 16:49:04 -0500 | [diff] [blame] | 236 | /* Ensure no-one is interrupted on the garbages */ |
| 237 | synchronize_sched(); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 238 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 239 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 240 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 241 | if (kip->ngarbage == 0) |
| 242 | continue; |
| 243 | kip->ngarbage = 0; /* we will collect all garbages */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 244 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 245 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 246 | collect_one_slot(kip, i)) |
| 247 | break; |
| 248 | } |
| 249 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 250 | c->nr_garbage = 0; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 251 | return 0; |
| 252 | } |
| 253 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 254 | static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, |
| 255 | kprobe_opcode_t *slot, int dirty) |
| 256 | { |
| 257 | struct kprobe_insn_page *kip; |
| 258 | |
| 259 | list_for_each_entry(kip, &c->pages, list) { |
| 260 | long idx = ((long)slot - (long)kip->insns) / c->insn_size; |
| 261 | if (idx >= 0 && idx < slots_per_page(c)) { |
| 262 | WARN_ON(kip->slot_used[idx] != SLOT_USED); |
| 263 | if (dirty) { |
| 264 | kip->slot_used[idx] = SLOT_DIRTY; |
| 265 | kip->ngarbage++; |
| 266 | if (++c->nr_garbage > slots_per_page(c)) |
| 267 | collect_garbage_slots(c); |
| 268 | } else |
| 269 | collect_one_slot(kip, idx); |
| 270 | return; |
| 271 | } |
| 272 | } |
| 273 | /* Could not free this slot. */ |
| 274 | WARN_ON(1); |
| 275 | } |
| 276 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 277 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 278 | { |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 279 | mutex_lock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame^] | 280 | __free_insn_slot(&kprobe_insn_slots, slot, dirty); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 281 | mutex_unlock(&kprobe_insn_mutex); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 282 | } |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 283 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 284 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 285 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 286 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 287 | { |
| 288 | __get_cpu_var(kprobe_instance) = kp; |
| 289 | } |
| 290 | |
| 291 | static inline void reset_kprobe_instance(void) |
| 292 | { |
| 293 | __get_cpu_var(kprobe_instance) = NULL; |
| 294 | } |
| 295 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 296 | /* |
| 297 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 298 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 299 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 300 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 301 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 302 | struct kprobe __kprobes *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | { |
| 304 | struct hlist_head *head; |
| 305 | struct hlist_node *node; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 306 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | |
| 308 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 309 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | if (p->addr == addr) |
| 311 | return p; |
| 312 | } |
| 313 | return NULL; |
| 314 | } |
| 315 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 316 | /* Arm a kprobe with text_mutex */ |
| 317 | static void __kprobes arm_kprobe(struct kprobe *kp) |
| 318 | { |
| 319 | mutex_lock(&text_mutex); |
| 320 | arch_arm_kprobe(kp); |
| 321 | mutex_unlock(&text_mutex); |
| 322 | } |
| 323 | |
| 324 | /* Disarm a kprobe with text_mutex */ |
| 325 | static void __kprobes disarm_kprobe(struct kprobe *kp) |
| 326 | { |
| 327 | mutex_lock(&text_mutex); |
| 328 | arch_disarm_kprobe(kp); |
| 329 | mutex_unlock(&text_mutex); |
| 330 | } |
| 331 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 332 | /* |
| 333 | * Aggregate handlers for multiple kprobes support - these handlers |
| 334 | * take care of invoking the individual kprobe handlers on p->list |
| 335 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 336 | 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] | 337 | { |
| 338 | struct kprobe *kp; |
| 339 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 340 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 341 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 342 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 343 | if (kp->pre_handler(kp, regs)) |
| 344 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 345 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 346 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 347 | } |
| 348 | return 0; |
| 349 | } |
| 350 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 351 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 352 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 353 | { |
| 354 | struct kprobe *kp; |
| 355 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 356 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 357 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 358 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 359 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 360 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 361 | } |
| 362 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 363 | } |
| 364 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 365 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 366 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 367 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 368 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 369 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 370 | /* |
| 371 | * if we faulted "during" the execution of a user specified |
| 372 | * probe handler, invoke just that probe's fault handler |
| 373 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 374 | if (cur && cur->fault_handler) { |
| 375 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 376 | return 1; |
| 377 | } |
| 378 | return 0; |
| 379 | } |
| 380 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 381 | 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] | 382 | { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 383 | struct kprobe *cur = __get_cpu_var(kprobe_instance); |
| 384 | int ret = 0; |
| 385 | |
| 386 | if (cur && cur->break_handler) { |
| 387 | if (cur->break_handler(cur, regs)) |
| 388 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 389 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 390 | reset_kprobe_instance(); |
| 391 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 392 | } |
| 393 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 394 | /* Walks the list and increments nmissed count for multiprobe case */ |
| 395 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
| 396 | { |
| 397 | struct kprobe *kp; |
| 398 | if (p->pre_handler != aggr_pre_handler) { |
| 399 | p->nmissed++; |
| 400 | } else { |
| 401 | list_for_each_entry_rcu(kp, &p->list, list) |
| 402 | kp->nmissed++; |
| 403 | } |
| 404 | return; |
| 405 | } |
| 406 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 407 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
| 408 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 409 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 410 | struct kretprobe *rp = ri->rp; |
| 411 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 412 | /* remove rp inst off the rprobe_inst_table */ |
| 413 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 414 | INIT_HLIST_NODE(&ri->hlist); |
| 415 | if (likely(rp)) { |
| 416 | spin_lock(&rp->lock); |
| 417 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 418 | spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 419 | } else |
| 420 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 421 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 422 | } |
| 423 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 424 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 425 | struct hlist_head **head, unsigned long *flags) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 426 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 427 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 428 | spinlock_t *hlist_lock; |
| 429 | |
| 430 | *head = &kretprobe_inst_table[hash]; |
| 431 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 432 | spin_lock_irqsave(hlist_lock, *flags); |
| 433 | } |
| 434 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 435 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
| 436 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 437 | { |
| 438 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 439 | spin_lock_irqsave(hlist_lock, *flags); |
| 440 | } |
| 441 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 442 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
| 443 | unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 444 | { |
| 445 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
| 446 | spinlock_t *hlist_lock; |
| 447 | |
| 448 | hlist_lock = kretprobe_table_lock_ptr(hash); |
| 449 | spin_unlock_irqrestore(hlist_lock, *flags); |
| 450 | } |
| 451 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 452 | void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 453 | { |
| 454 | spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 455 | spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 456 | } |
| 457 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 458 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 459 | * This function is called from finish_task_switch when task tk becomes dead, |
| 460 | * so that we can recycle any function-return probe instances associated |
| 461 | * with this task. These left over instances represent probed functions |
| 462 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 463 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 464 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 465 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 466 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 467 | struct hlist_head *head, empty_rp; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 468 | struct hlist_node *node, *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 469 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 470 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 471 | if (unlikely(!kprobes_initialized)) |
| 472 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 473 | return; |
| 474 | |
| 475 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 476 | head = &kretprobe_inst_table[hash]; |
| 477 | kretprobe_table_lock(hash, &flags); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 478 | hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { |
| 479 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 480 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 481 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 482 | kretprobe_table_unlock(hash, &flags); |
| 483 | INIT_HLIST_HEAD(&empty_rp); |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 484 | hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { |
| 485 | hlist_del(&ri->hlist); |
| 486 | kfree(ri); |
| 487 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 488 | } |
| 489 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 490 | static inline void free_rp_inst(struct kretprobe *rp) |
| 491 | { |
| 492 | struct kretprobe_instance *ri; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 493 | struct hlist_node *pos, *next; |
| 494 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 495 | hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { |
| 496 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 497 | kfree(ri); |
| 498 | } |
| 499 | } |
| 500 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 501 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
| 502 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 503 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 504 | struct kretprobe_instance *ri; |
| 505 | struct hlist_node *pos, *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 506 | struct hlist_head *head; |
| 507 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 508 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 509 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 510 | kretprobe_table_lock(hash, &flags); |
| 511 | head = &kretprobe_inst_table[hash]; |
| 512 | hlist_for_each_entry_safe(ri, pos, next, head, hlist) { |
| 513 | if (ri->rp == rp) |
| 514 | ri->rp = NULL; |
| 515 | } |
| 516 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 517 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 518 | free_rp_inst(rp); |
| 519 | } |
| 520 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 521 | /* |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 522 | * Keep all fields in the kprobe consistent |
| 523 | */ |
| 524 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) |
| 525 | { |
| 526 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); |
| 527 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); |
| 528 | } |
| 529 | |
| 530 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 531 | * 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] | 532 | * second jprobe at the address - two jprobes can't coexist |
| 533 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 534 | 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] | 535 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 536 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 537 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 538 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 539 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 540 | list_add_tail_rcu(&p->list, &ap->list); |
| 541 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 542 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 543 | list_add_rcu(&p->list, &ap->list); |
| 544 | if (p->post_handler && !ap->post_handler) |
| 545 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 546 | |
| 547 | if (kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 548 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 549 | if (!kprobes_all_disarmed) |
| 550 | /* Arm the breakpoint again. */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 551 | arm_kprobe(ap); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 552 | } |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 553 | return 0; |
| 554 | } |
| 555 | |
| 556 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 557 | * Fill in the required fields of the "manager kprobe". Replace the |
| 558 | * earlier kprobe in the hlist with the manager kprobe |
| 559 | */ |
| 560 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
| 561 | { |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 562 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 563 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 564 | ap->addr = p->addr; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 565 | ap->flags = p->flags; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 566 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 567 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 568 | /* We don't care the kprobe which has gone. */ |
| 569 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 570 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 571 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 572 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 573 | |
| 574 | INIT_LIST_HEAD(&ap->list); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 575 | list_add_rcu(&p->list, &ap->list); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 576 | |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 577 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 578 | } |
| 579 | |
| 580 | /* |
| 581 | * This is the second or subsequent kprobe at the address - handle |
| 582 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 583 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 584 | static int __kprobes register_aggr_kprobe(struct kprobe *old_p, |
| 585 | struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 586 | { |
| 587 | int ret = 0; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 588 | struct kprobe *ap = old_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 589 | |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 590 | if (old_p->pre_handler != aggr_pre_handler) { |
| 591 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ |
| 592 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 593 | if (!ap) |
| 594 | return -ENOMEM; |
| 595 | add_aggr_kprobe(ap, old_p); |
| 596 | } |
| 597 | |
| 598 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 599 | /* |
| 600 | * Attempting to insert new probe at the same location that |
| 601 | * had a probe in the module vaddr area which already |
| 602 | * freed. So, the instruction slot has already been |
| 603 | * released. We need a new slot for the new probe. |
| 604 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 605 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 606 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 607 | /* |
| 608 | * Even if fail to allocate new slot, don't need to |
| 609 | * free aggr_probe. It will be used next time, or |
| 610 | * freed by unregister_kprobe. |
| 611 | */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 612 | return ret; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 613 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 614 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 615 | * Clear gone flag to prevent allocating new slot again, and |
| 616 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 617 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 618 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 619 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 620 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 621 | |
| 622 | copy_kprobe(ap, p); |
| 623 | return add_new_kprobe(ap, p); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 624 | } |
| 625 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 626 | /* Try to disable aggr_kprobe, and return 1 if succeeded.*/ |
| 627 | static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) |
| 628 | { |
| 629 | struct kprobe *kp; |
| 630 | |
| 631 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 632 | if (!kprobe_disabled(kp)) |
| 633 | /* |
| 634 | * There is an active probe on the list. |
| 635 | * We can't disable aggr_kprobe. |
| 636 | */ |
| 637 | return 0; |
| 638 | } |
| 639 | p->flags |= KPROBE_FLAG_DISABLED; |
| 640 | return 1; |
| 641 | } |
| 642 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 643 | static int __kprobes in_kprobes_functions(unsigned long addr) |
| 644 | { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 645 | struct kprobe_blackpoint *kb; |
| 646 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 647 | if (addr >= (unsigned long)__kprobes_text_start && |
| 648 | addr < (unsigned long)__kprobes_text_end) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 649 | return -EINVAL; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 650 | /* |
| 651 | * If there exists a kprobe_blacklist, verify and |
| 652 | * fail any probe registration in the prohibited area |
| 653 | */ |
| 654 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 655 | if (kb->start_addr) { |
| 656 | if (addr >= kb->start_addr && |
| 657 | addr < (kb->start_addr + kb->range)) |
| 658 | return -EINVAL; |
| 659 | } |
| 660 | } |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 661 | return 0; |
| 662 | } |
| 663 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 664 | /* |
| 665 | * If we have a symbol_name argument, look it up and add the offset field |
| 666 | * to it. This way, we can specify a relative address to a symbol. |
| 667 | */ |
| 668 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) |
| 669 | { |
| 670 | kprobe_opcode_t *addr = p->addr; |
| 671 | if (p->symbol_name) { |
| 672 | if (addr) |
| 673 | return NULL; |
| 674 | kprobe_lookup_name(p->symbol_name, addr); |
| 675 | } |
| 676 | |
| 677 | if (!addr) |
| 678 | return NULL; |
| 679 | return (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 680 | } |
| 681 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 682 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
| 683 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) |
| 684 | { |
| 685 | struct kprobe *old_p, *list_p; |
| 686 | |
| 687 | old_p = get_kprobe(p->addr); |
| 688 | if (unlikely(!old_p)) |
| 689 | return NULL; |
| 690 | |
| 691 | if (p != old_p) { |
| 692 | list_for_each_entry_rcu(list_p, &old_p->list, list) |
| 693 | if (list_p == p) |
| 694 | /* kprobe p is a valid probe */ |
| 695 | goto valid; |
| 696 | return NULL; |
| 697 | } |
| 698 | valid: |
| 699 | return old_p; |
| 700 | } |
| 701 | |
| 702 | /* Return error if the kprobe is being re-registered */ |
| 703 | static inline int check_kprobe_rereg(struct kprobe *p) |
| 704 | { |
| 705 | int ret = 0; |
| 706 | struct kprobe *old_p; |
| 707 | |
| 708 | mutex_lock(&kprobe_mutex); |
| 709 | old_p = __get_valid_kprobe(p); |
| 710 | if (old_p) |
| 711 | ret = -EINVAL; |
| 712 | mutex_unlock(&kprobe_mutex); |
| 713 | return ret; |
| 714 | } |
| 715 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 716 | int __kprobes register_kprobe(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | { |
| 718 | int ret = 0; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 719 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 720 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 721 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 723 | addr = kprobe_addr(p); |
| 724 | if (!addr) |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 725 | return -EINVAL; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 726 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 727 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 728 | ret = check_kprobe_rereg(p); |
| 729 | if (ret) |
| 730 | return ret; |
| 731 | |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 732 | preempt_disable(); |
Masami Hiramatsu | ec30c5f | 2009-07-28 19:47:23 -0400 | [diff] [blame] | 733 | if (!kernel_text_address((unsigned long) p->addr) || |
Masami Hiramatsu | 4554dbc | 2010-02-02 16:49:18 -0500 | [diff] [blame] | 734 | in_kprobes_functions((unsigned long) p->addr) || |
| 735 | ftrace_text_reserved(p->addr, p->addr)) { |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 736 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 737 | return -EINVAL; |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 738 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 739 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 740 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 741 | p->flags &= KPROBE_FLAG_DISABLED; |
| 742 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 743 | /* |
| 744 | * Check if are we probing a module. |
| 745 | */ |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 746 | probed_mod = __module_text_address((unsigned long) p->addr); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 747 | if (probed_mod) { |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 748 | /* |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 749 | * We must hold a refcount of the probed module while updating |
| 750 | * its code to prohibit unexpected unloading. |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 751 | */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 752 | if (unlikely(!try_module_get(probed_mod))) { |
| 753 | preempt_enable(); |
| 754 | return -EINVAL; |
| 755 | } |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 756 | /* |
| 757 | * If the module freed .init.text, we couldn't insert |
| 758 | * kprobes in there. |
| 759 | */ |
| 760 | if (within_module_init((unsigned long)p->addr, probed_mod) && |
| 761 | probed_mod->state != MODULE_STATE_COMING) { |
| 762 | module_put(probed_mod); |
| 763 | preempt_enable(); |
| 764 | return -EINVAL; |
| 765 | } |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 766 | } |
Masami Hiramatsu | a189d03 | 2008-11-12 13:26:51 -0800 | [diff] [blame] | 767 | preempt_enable(); |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 768 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 769 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 770 | INIT_LIST_HEAD(&p->list); |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 771 | mutex_lock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 772 | old_p = get_kprobe(p->addr); |
| 773 | if (old_p) { |
| 774 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | goto out; |
| 776 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 778 | mutex_lock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 779 | ret = arch_prepare_kprobe(p); |
| 780 | if (ret) |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 781 | goto out_unlock_text; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 782 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 783 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 784 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 786 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 787 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 788 | arch_arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 789 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 790 | out_unlock_text: |
| 791 | mutex_unlock(&text_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 793 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 794 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 795 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 796 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 797 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | return ret; |
| 799 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 800 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 802 | /* |
| 803 | * Unregister a kprobe without a scheduler synchronization. |
| 804 | */ |
| 805 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 806 | { |
Keshavamurthy Anil S | f709b12 | 2006-01-09 20:52:44 -0800 | [diff] [blame] | 807 | struct kprobe *old_p, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 808 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 809 | old_p = __get_valid_kprobe(p); |
| 810 | if (old_p == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 811 | return -EINVAL; |
| 812 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 813 | if (old_p == p || |
| 814 | (old_p->pre_handler == aggr_pre_handler && |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 815 | list_is_singular(&old_p->list))) { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 816 | /* |
| 817 | * Only probe on the hash list. Disarm only if kprobes are |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 818 | * enabled and not gone - otherwise, the breakpoint would |
| 819 | * already have been removed. We save on flushing icache. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 820 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 821 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
| 822 | disarm_kprobe(p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 823 | hlist_del_rcu(&old_p->hlist); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 824 | } else { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 825 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 826 | old_p->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 827 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 828 | list_for_each_entry_rcu(list_p, &old_p->list, list) { |
| 829 | if ((list_p != p) && (list_p->post_handler)) |
| 830 | goto noclean; |
| 831 | } |
| 832 | old_p->post_handler = NULL; |
| 833 | } |
| 834 | noclean: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 835 | list_del_rcu(&p->list); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 836 | if (!kprobe_disabled(old_p)) { |
| 837 | try_to_disable_aggr_kprobe(old_p); |
| 838 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 839 | disarm_kprobe(old_p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 840 | } |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 841 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 842 | return 0; |
| 843 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 844 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 845 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
| 846 | { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 847 | struct kprobe *old_p; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 848 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 849 | if (list_empty(&p->list)) |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 850 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 851 | else if (list_is_singular(&p->list)) { |
| 852 | /* "p" is the last child of an aggr_kprobe */ |
| 853 | old_p = list_entry(p->list.next, struct kprobe, list); |
| 854 | list_del(&p->list); |
| 855 | arch_remove_kprobe(old_p); |
| 856 | kfree(old_p); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 857 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | } |
| 859 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 860 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 861 | { |
| 862 | int i, ret = 0; |
| 863 | |
| 864 | if (num <= 0) |
| 865 | return -EINVAL; |
| 866 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 867 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 868 | if (ret < 0) { |
| 869 | if (i > 0) |
| 870 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 871 | break; |
| 872 | } |
| 873 | } |
| 874 | return ret; |
| 875 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 876 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 877 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 878 | void __kprobes unregister_kprobe(struct kprobe *p) |
| 879 | { |
| 880 | unregister_kprobes(&p, 1); |
| 881 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 882 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 883 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 884 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
| 885 | { |
| 886 | int i; |
| 887 | |
| 888 | if (num <= 0) |
| 889 | return; |
| 890 | mutex_lock(&kprobe_mutex); |
| 891 | for (i = 0; i < num; i++) |
| 892 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 893 | kps[i]->addr = NULL; |
| 894 | mutex_unlock(&kprobe_mutex); |
| 895 | |
| 896 | synchronize_sched(); |
| 897 | for (i = 0; i < num; i++) |
| 898 | if (kps[i]->addr) |
| 899 | __unregister_kprobe_bottom(kps[i]); |
| 900 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 901 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 902 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | static struct notifier_block kprobe_exceptions_nb = { |
| 904 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 905 | .priority = 0x7fffffff /* we need to be notified first */ |
| 906 | }; |
| 907 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 908 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 909 | { |
| 910 | return (unsigned long)entry; |
| 911 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 913 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 914 | { |
| 915 | struct jprobe *jp; |
| 916 | int ret = 0, i; |
| 917 | |
| 918 | if (num <= 0) |
| 919 | return -EINVAL; |
| 920 | for (i = 0; i < num; i++) { |
| 921 | unsigned long addr; |
| 922 | jp = jps[i]; |
| 923 | addr = arch_deref_entry_point(jp->entry); |
| 924 | |
| 925 | if (!kernel_text_address(addr)) |
| 926 | ret = -EINVAL; |
| 927 | else { |
| 928 | /* Todo: Verify probepoint is a function entry point */ |
| 929 | jp->kp.pre_handler = setjmp_pre_handler; |
| 930 | jp->kp.break_handler = longjmp_break_handler; |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 931 | ret = register_kprobe(&jp->kp); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 932 | } |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 933 | if (ret < 0) { |
| 934 | if (i > 0) |
| 935 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 936 | break; |
| 937 | } |
| 938 | } |
| 939 | return ret; |
| 940 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 941 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 942 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 943 | int __kprobes register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 945 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 947 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 949 | void __kprobes unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 951 | unregister_jprobes(&jp, 1); |
| 952 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 953 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 954 | |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 955 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
| 956 | { |
| 957 | int i; |
| 958 | |
| 959 | if (num <= 0) |
| 960 | return; |
| 961 | mutex_lock(&kprobe_mutex); |
| 962 | for (i = 0; i < num; i++) |
| 963 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 964 | jps[i]->kp.addr = NULL; |
| 965 | mutex_unlock(&kprobe_mutex); |
| 966 | |
| 967 | synchronize_sched(); |
| 968 | for (i = 0; i < num; i++) { |
| 969 | if (jps[i]->kp.addr) |
| 970 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 971 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 973 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 975 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 976 | /* |
| 977 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 978 | * hits it will set up the return probe. |
| 979 | */ |
| 980 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 981 | struct pt_regs *regs) |
| 982 | { |
| 983 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 984 | unsigned long hash, flags = 0; |
| 985 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 986 | |
| 987 | /*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] | 988 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
| 989 | spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 990 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 991 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 992 | struct kretprobe_instance, hlist); |
| 993 | hlist_del(&ri->hlist); |
| 994 | spin_unlock_irqrestore(&rp->lock, flags); |
| 995 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 996 | ri->rp = rp; |
| 997 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 998 | |
Ananth N Mavinakayanahalli | f02b862 | 2009-03-18 17:06:21 +0530 | [diff] [blame] | 999 | if (rp->entry_handler && rp->entry_handler(ri, regs)) |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1000 | return 0; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1001 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1002 | arch_prepare_kretprobe(ri, regs); |
| 1003 | |
| 1004 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1005 | INIT_HLIST_NODE(&ri->hlist); |
| 1006 | kretprobe_table_lock(hash, &flags); |
| 1007 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 1008 | kretprobe_table_unlock(hash, &flags); |
| 1009 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1010 | rp->nmissed++; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1011 | spin_unlock_irqrestore(&rp->lock, flags); |
| 1012 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1013 | return 0; |
| 1014 | } |
| 1015 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1016 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1017 | { |
| 1018 | int ret = 0; |
| 1019 | struct kretprobe_instance *inst; |
| 1020 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1021 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1022 | |
| 1023 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1024 | addr = kprobe_addr(&rp->kp); |
| 1025 | if (!addr) |
| 1026 | return -EINVAL; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1027 | |
| 1028 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1029 | if (kretprobe_blacklist[i].addr == addr) |
| 1030 | return -EINVAL; |
| 1031 | } |
| 1032 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1033 | |
| 1034 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1035 | rp->kp.post_handler = NULL; |
| 1036 | rp->kp.fault_handler = NULL; |
| 1037 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1038 | |
| 1039 | /* Pre-allocate memory for max kretprobe instances */ |
| 1040 | if (rp->maxactive <= 0) { |
| 1041 | #ifdef CONFIG_PREEMPT |
Heiko Carstens | c2ef666 | 2009-12-21 13:02:24 +0100 | [diff] [blame] | 1042 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1043 | #else |
Ananth N Mavinakayanahalli | 4dae560 | 2009-10-30 19:23:10 +0530 | [diff] [blame] | 1044 | rp->maxactive = num_possible_cpus(); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1045 | #endif |
| 1046 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1047 | spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1048 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1049 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1050 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1051 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1052 | if (inst == NULL) { |
| 1053 | free_rp_inst(rp); |
| 1054 | return -ENOMEM; |
| 1055 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1056 | INIT_HLIST_NODE(&inst->hlist); |
| 1057 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1058 | } |
| 1059 | |
| 1060 | rp->nmissed = 0; |
| 1061 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1062 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1063 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1064 | free_rp_inst(rp); |
| 1065 | return ret; |
| 1066 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1067 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1068 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1069 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1070 | { |
| 1071 | int ret = 0, i; |
| 1072 | |
| 1073 | if (num <= 0) |
| 1074 | return -EINVAL; |
| 1075 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1076 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1077 | if (ret < 0) { |
| 1078 | if (i > 0) |
| 1079 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1080 | break; |
| 1081 | } |
| 1082 | } |
| 1083 | return ret; |
| 1084 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1085 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1086 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1087 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1088 | { |
| 1089 | unregister_kretprobes(&rp, 1); |
| 1090 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1091 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1092 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1093 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1094 | { |
| 1095 | int i; |
| 1096 | |
| 1097 | if (num <= 0) |
| 1098 | return; |
| 1099 | mutex_lock(&kprobe_mutex); |
| 1100 | for (i = 0; i < num; i++) |
| 1101 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1102 | rps[i]->kp.addr = NULL; |
| 1103 | mutex_unlock(&kprobe_mutex); |
| 1104 | |
| 1105 | synchronize_sched(); |
| 1106 | for (i = 0; i < num; i++) { |
| 1107 | if (rps[i]->kp.addr) { |
| 1108 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1109 | cleanup_rp_inst(rps[i]); |
| 1110 | } |
| 1111 | } |
| 1112 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1113 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1114 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1115 | #else /* CONFIG_KRETPROBES */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1116 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1117 | { |
| 1118 | return -ENOSYS; |
| 1119 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1120 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1121 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1122 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
| 1123 | { |
| 1124 | return -ENOSYS; |
| 1125 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1126 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1127 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1128 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1129 | { |
| 1130 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1131 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1132 | |
| 1133 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1134 | { |
| 1135 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1136 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1137 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1138 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1139 | struct pt_regs *regs) |
| 1140 | { |
| 1141 | return 0; |
| 1142 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1143 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1144 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1145 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1146 | /* Set the kprobe gone and remove its instruction buffer. */ |
| 1147 | static void __kprobes kill_kprobe(struct kprobe *p) |
| 1148 | { |
| 1149 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1150 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1151 | p->flags |= KPROBE_FLAG_GONE; |
| 1152 | if (p->pre_handler == aggr_pre_handler) { |
| 1153 | /* |
| 1154 | * If this is an aggr_kprobe, we have to list all the |
| 1155 | * chained probes and mark them GONE. |
| 1156 | */ |
| 1157 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1158 | kp->flags |= KPROBE_FLAG_GONE; |
| 1159 | p->post_handler = NULL; |
| 1160 | p->break_handler = NULL; |
| 1161 | } |
| 1162 | /* |
| 1163 | * Here, we can remove insn_slot safely, because no thread calls |
| 1164 | * the original probed function (which will be freed soon) any more. |
| 1165 | */ |
| 1166 | arch_remove_kprobe(p); |
| 1167 | } |
| 1168 | |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 1169 | void __kprobes dump_kprobe(struct kprobe *kp) |
| 1170 | { |
| 1171 | printk(KERN_WARNING "Dumping kprobe:\n"); |
| 1172 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", |
| 1173 | kp->symbol_name, kp->addr, kp->offset); |
| 1174 | } |
| 1175 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1176 | /* Module notifier call back, checking kprobes on the module */ |
| 1177 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, |
| 1178 | unsigned long val, void *data) |
| 1179 | { |
| 1180 | struct module *mod = data; |
| 1181 | struct hlist_head *head; |
| 1182 | struct hlist_node *node; |
| 1183 | struct kprobe *p; |
| 1184 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1185 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1186 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1187 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1188 | return NOTIFY_DONE; |
| 1189 | |
| 1190 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1191 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 1192 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 1193 | * notified, only .init.text section would be freed. We need to |
| 1194 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1195 | */ |
| 1196 | mutex_lock(&kprobe_mutex); |
| 1197 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1198 | head = &kprobe_table[i]; |
| 1199 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 1200 | if (within_module_init((unsigned long)p->addr, mod) || |
| 1201 | (checkcore && |
| 1202 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1203 | /* |
| 1204 | * The vaddr this probe is installed will soon |
| 1205 | * be vfreed buy not synced to disk. Hence, |
| 1206 | * disarming the breakpoint isn't needed. |
| 1207 | */ |
| 1208 | kill_kprobe(p); |
| 1209 | } |
| 1210 | } |
| 1211 | mutex_unlock(&kprobe_mutex); |
| 1212 | return NOTIFY_DONE; |
| 1213 | } |
| 1214 | |
| 1215 | static struct notifier_block kprobe_module_nb = { |
| 1216 | .notifier_call = kprobes_module_callback, |
| 1217 | .priority = 0 |
| 1218 | }; |
| 1219 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | static int __init init_kprobes(void) |
| 1221 | { |
| 1222 | int i, err = 0; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1223 | unsigned long offset = 0, size = 0; |
| 1224 | char *modname, namebuf[128]; |
| 1225 | const char *symbol_name; |
| 1226 | void *addr; |
| 1227 | struct kprobe_blackpoint *kb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | |
| 1229 | /* FIXME allocate the probe table, currently defined statically */ |
| 1230 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1231 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1233 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1234 | spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1235 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1237 | /* |
| 1238 | * Lookup and populate the kprobe_blacklist. |
| 1239 | * |
| 1240 | * Unlike the kretprobe blacklist, we'll need to determine |
| 1241 | * the range of addresses that belong to the said functions, |
| 1242 | * since a kprobe need not necessarily be at the beginning |
| 1243 | * of a function. |
| 1244 | */ |
| 1245 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 1246 | kprobe_lookup_name(kb->name, addr); |
| 1247 | if (!addr) |
| 1248 | continue; |
| 1249 | |
| 1250 | kb->start_addr = (unsigned long)addr; |
| 1251 | symbol_name = kallsyms_lookup(kb->start_addr, |
| 1252 | &size, &offset, &modname, namebuf); |
| 1253 | if (!symbol_name) |
| 1254 | kb->range = 0; |
| 1255 | else |
| 1256 | kb->range = size; |
| 1257 | } |
| 1258 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1259 | if (kretprobe_blacklist_size) { |
| 1260 | /* lookup the function address from its name */ |
| 1261 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1262 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 1263 | kretprobe_blacklist[i].addr); |
| 1264 | if (!kretprobe_blacklist[i].addr) |
| 1265 | printk("kretprobe: lookup failed: %s\n", |
| 1266 | kretprobe_blacklist[i].name); |
| 1267 | } |
| 1268 | } |
| 1269 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1270 | /* By default, kprobes are armed */ |
| 1271 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1272 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 1273 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1274 | if (!err) |
| 1275 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1276 | if (!err) |
| 1277 | err = register_module_notifier(&kprobe_module_nb); |
| 1278 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1279 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1280 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 1281 | if (!err) |
| 1282 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | return err; |
| 1284 | } |
| 1285 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1286 | #ifdef CONFIG_DEBUG_FS |
| 1287 | 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] | 1288 | const char *sym, int offset,char *modname) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1289 | { |
| 1290 | char *kprobe_type; |
| 1291 | |
| 1292 | if (p->pre_handler == pre_handler_kretprobe) |
| 1293 | kprobe_type = "r"; |
| 1294 | else if (p->pre_handler == setjmp_pre_handler) |
| 1295 | kprobe_type = "j"; |
| 1296 | else |
| 1297 | kprobe_type = "k"; |
| 1298 | if (sym) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1299 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", |
| 1300 | p->addr, kprobe_type, sym, offset, |
| 1301 | (modname ? modname : " "), |
| 1302 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1303 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1304 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1305 | else |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1306 | seq_printf(pi, "%p %s %p %s%s\n", |
| 1307 | p->addr, kprobe_type, p->addr, |
| 1308 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 1309 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? |
| 1310 | "[DISABLED]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1311 | } |
| 1312 | |
| 1313 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
| 1314 | { |
| 1315 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 1316 | } |
| 1317 | |
| 1318 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
| 1319 | { |
| 1320 | (*pos)++; |
| 1321 | if (*pos >= KPROBE_TABLE_SIZE) |
| 1322 | return NULL; |
| 1323 | return pos; |
| 1324 | } |
| 1325 | |
| 1326 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) |
| 1327 | { |
| 1328 | /* Nothing to do */ |
| 1329 | } |
| 1330 | |
| 1331 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) |
| 1332 | { |
| 1333 | struct hlist_head *head; |
| 1334 | struct hlist_node *node; |
| 1335 | struct kprobe *p, *kp; |
| 1336 | const char *sym = NULL; |
| 1337 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1338 | unsigned long offset = 0; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1339 | char *modname, namebuf[128]; |
| 1340 | |
| 1341 | head = &kprobe_table[i]; |
| 1342 | preempt_disable(); |
| 1343 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 1344 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1345 | &offset, &modname, namebuf); |
| 1346 | if (p->pre_handler == aggr_pre_handler) { |
| 1347 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1348 | report_probe(pi, kp, sym, offset, modname); |
| 1349 | } else |
| 1350 | report_probe(pi, p, sym, offset, modname); |
| 1351 | } |
| 1352 | preempt_enable(); |
| 1353 | return 0; |
| 1354 | } |
| 1355 | |
James Morris | 88e9d34 | 2009-09-22 16:43:43 -0700 | [diff] [blame] | 1356 | static const struct seq_operations kprobes_seq_ops = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1357 | .start = kprobe_seq_start, |
| 1358 | .next = kprobe_seq_next, |
| 1359 | .stop = kprobe_seq_stop, |
| 1360 | .show = show_kprobe_addr |
| 1361 | }; |
| 1362 | |
| 1363 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) |
| 1364 | { |
| 1365 | return seq_open(filp, &kprobes_seq_ops); |
| 1366 | } |
| 1367 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 1368 | static const struct file_operations debugfs_kprobes_operations = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1369 | .open = kprobes_open, |
| 1370 | .read = seq_read, |
| 1371 | .llseek = seq_lseek, |
| 1372 | .release = seq_release, |
| 1373 | }; |
| 1374 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1375 | /* Disable one kprobe */ |
| 1376 | int __kprobes disable_kprobe(struct kprobe *kp) |
| 1377 | { |
| 1378 | int ret = 0; |
| 1379 | struct kprobe *p; |
| 1380 | |
| 1381 | mutex_lock(&kprobe_mutex); |
| 1382 | |
| 1383 | /* Check whether specified probe is valid. */ |
| 1384 | p = __get_valid_kprobe(kp); |
| 1385 | if (unlikely(p == NULL)) { |
| 1386 | ret = -EINVAL; |
| 1387 | goto out; |
| 1388 | } |
| 1389 | |
| 1390 | /* If the probe is already disabled (or gone), just return */ |
| 1391 | if (kprobe_disabled(kp)) |
| 1392 | goto out; |
| 1393 | |
| 1394 | kp->flags |= KPROBE_FLAG_DISABLED; |
| 1395 | if (p != kp) |
| 1396 | /* When kp != p, p is always enabled. */ |
| 1397 | try_to_disable_aggr_kprobe(p); |
| 1398 | |
| 1399 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1400 | disarm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1401 | out: |
| 1402 | mutex_unlock(&kprobe_mutex); |
| 1403 | return ret; |
| 1404 | } |
| 1405 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 1406 | |
| 1407 | /* Enable one kprobe */ |
| 1408 | int __kprobes enable_kprobe(struct kprobe *kp) |
| 1409 | { |
| 1410 | int ret = 0; |
| 1411 | struct kprobe *p; |
| 1412 | |
| 1413 | mutex_lock(&kprobe_mutex); |
| 1414 | |
| 1415 | /* Check whether specified probe is valid. */ |
| 1416 | p = __get_valid_kprobe(kp); |
| 1417 | if (unlikely(p == NULL)) { |
| 1418 | ret = -EINVAL; |
| 1419 | goto out; |
| 1420 | } |
| 1421 | |
| 1422 | if (kprobe_gone(kp)) { |
| 1423 | /* This kprobe has gone, we couldn't enable it. */ |
| 1424 | ret = -EINVAL; |
| 1425 | goto out; |
| 1426 | } |
| 1427 | |
| 1428 | if (!kprobes_all_disarmed && kprobe_disabled(p)) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1429 | arm_kprobe(p); |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1430 | |
| 1431 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 1432 | if (p != kp) |
| 1433 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 1434 | out: |
| 1435 | mutex_unlock(&kprobe_mutex); |
| 1436 | return ret; |
| 1437 | } |
| 1438 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 1439 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1440 | static void __kprobes arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1441 | { |
| 1442 | struct hlist_head *head; |
| 1443 | struct hlist_node *node; |
| 1444 | struct kprobe *p; |
| 1445 | unsigned int i; |
| 1446 | |
| 1447 | mutex_lock(&kprobe_mutex); |
| 1448 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1449 | /* If kprobes are armed, just return */ |
| 1450 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1451 | goto already_enabled; |
| 1452 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1453 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1454 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1455 | head = &kprobe_table[i]; |
| 1456 | hlist_for_each_entry_rcu(p, node, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1457 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1458 | arch_arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1459 | } |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1460 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1461 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1462 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1463 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 1464 | |
| 1465 | already_enabled: |
| 1466 | mutex_unlock(&kprobe_mutex); |
| 1467 | return; |
| 1468 | } |
| 1469 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1470 | static void __kprobes disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1471 | { |
| 1472 | struct hlist_head *head; |
| 1473 | struct hlist_node *node; |
| 1474 | struct kprobe *p; |
| 1475 | unsigned int i; |
| 1476 | |
| 1477 | mutex_lock(&kprobe_mutex); |
| 1478 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1479 | /* If kprobes are already disarmed, just return */ |
| 1480 | if (kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1481 | goto already_disabled; |
| 1482 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1483 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1484 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1485 | mutex_lock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1486 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 1487 | head = &kprobe_table[i]; |
| 1488 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1489 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1490 | arch_disarm_kprobe(p); |
| 1491 | } |
| 1492 | } |
| 1493 | |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 1494 | mutex_unlock(&text_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1495 | mutex_unlock(&kprobe_mutex); |
| 1496 | /* Allow all currently running kprobes to complete */ |
| 1497 | synchronize_sched(); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1498 | return; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1499 | |
| 1500 | already_disabled: |
| 1501 | mutex_unlock(&kprobe_mutex); |
| 1502 | return; |
| 1503 | } |
| 1504 | |
| 1505 | /* |
| 1506 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 1507 | * when the bool state is switched. We can reuse that facility when |
| 1508 | * available |
| 1509 | */ |
| 1510 | static ssize_t read_enabled_file_bool(struct file *file, |
| 1511 | char __user *user_buf, size_t count, loff_t *ppos) |
| 1512 | { |
| 1513 | char buf[3]; |
| 1514 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1515 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1516 | buf[0] = '1'; |
| 1517 | else |
| 1518 | buf[0] = '0'; |
| 1519 | buf[1] = '\n'; |
| 1520 | buf[2] = 0x00; |
| 1521 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 1522 | } |
| 1523 | |
| 1524 | static ssize_t write_enabled_file_bool(struct file *file, |
| 1525 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 1526 | { |
| 1527 | char buf[32]; |
| 1528 | int buf_size; |
| 1529 | |
| 1530 | buf_size = min(count, (sizeof(buf)-1)); |
| 1531 | if (copy_from_user(buf, user_buf, buf_size)) |
| 1532 | return -EFAULT; |
| 1533 | |
| 1534 | switch (buf[0]) { |
| 1535 | case 'y': |
| 1536 | case 'Y': |
| 1537 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1538 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1539 | break; |
| 1540 | case 'n': |
| 1541 | case 'N': |
| 1542 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 1543 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1544 | break; |
| 1545 | } |
| 1546 | |
| 1547 | return count; |
| 1548 | } |
| 1549 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 1550 | static const struct file_operations fops_kp = { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1551 | .read = read_enabled_file_bool, |
| 1552 | .write = write_enabled_file_bool, |
| 1553 | }; |
| 1554 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1555 | static int __kprobes debugfs_kprobe_init(void) |
| 1556 | { |
| 1557 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1558 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1559 | |
| 1560 | dir = debugfs_create_dir("kprobes", NULL); |
| 1561 | if (!dir) |
| 1562 | return -ENOMEM; |
| 1563 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 1564 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1565 | &debugfs_kprobes_operations); |
| 1566 | if (!file) { |
| 1567 | debugfs_remove(dir); |
| 1568 | return -ENOMEM; |
| 1569 | } |
| 1570 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1571 | file = debugfs_create_file("enabled", 0600, dir, |
| 1572 | &value, &fops_kp); |
| 1573 | if (!file) { |
| 1574 | debugfs_remove(dir); |
| 1575 | return -ENOMEM; |
| 1576 | } |
| 1577 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1578 | return 0; |
| 1579 | } |
| 1580 | |
| 1581 | late_initcall(debugfs_kprobe_init); |
| 1582 | #endif /* CONFIG_DEBUG_FS */ |
| 1583 | |
| 1584 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1585 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1586 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1587 | EXPORT_SYMBOL_GPL(jprobe_return); |