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> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 39 | #include <linux/export.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> |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 45 | #include <linux/sysctl.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 46 | #include <linux/kdebug.h> |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 47 | #include <linux/memory.h> |
Masami Hiramatsu | 4554dbc | 2010-02-02 16:49:18 -0500 | [diff] [blame] | 48 | #include <linux/ftrace.h> |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 49 | #include <linux/cpu.h> |
Jason Baron | bf5438fc | 2010-09-17 11:09:00 -0400 | [diff] [blame] | 50 | #include <linux/jump_label.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 51 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 52 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <asm/cacheflush.h> |
| 54 | #include <asm/errno.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 55 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
| 57 | #define KPROBE_HASH_BITS 6 |
| 58 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 59 | |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 60 | |
| 61 | /* |
| 62 | * Some oddball architectures like 64bit powerpc have function descriptors |
| 63 | * so this must be overridable. |
| 64 | */ |
| 65 | #ifndef kprobe_lookup_name |
| 66 | #define kprobe_lookup_name(name, addr) \ |
| 67 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) |
| 68 | #endif |
| 69 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 70 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 72 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 74 | /* NOTE: change this value only with kprobe_mutex held */ |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 75 | static bool kprobes_all_disarmed; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 76 | |
Masami Hiramatsu | 43948f5 | 2010-10-25 22:18:01 +0900 | [diff] [blame] | 77 | /* This protects kprobe_table and optimizing_list */ |
| 78 | static DEFINE_MUTEX(kprobe_mutex); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 79 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 80 | static struct { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 81 | raw_spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 82 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 83 | |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 84 | static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 85 | { |
| 86 | return &(kretprobe_table_locks[hash].lock); |
| 87 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 89 | /* Blacklist -- list of struct kprobe_blacklist_entry */ |
| 90 | static LIST_HEAD(kprobe_blacklist); |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 91 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 92 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 93 | /* |
| 94 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 95 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 96 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 97 | * is a recipe for disaster |
| 98 | */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 99 | struct kprobe_insn_page { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 100 | struct list_head list; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 101 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 102 | struct kprobe_insn_cache *cache; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 103 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 104 | int ngarbage; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 105 | char slot_used[]; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 106 | }; |
| 107 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 108 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
| 109 | (offsetof(struct kprobe_insn_page, slot_used) + \ |
| 110 | (sizeof(char) * (slots))) |
| 111 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 112 | static int slots_per_page(struct kprobe_insn_cache *c) |
| 113 | { |
| 114 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); |
| 115 | } |
| 116 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 117 | enum kprobe_slot_state { |
| 118 | SLOT_CLEAN = 0, |
| 119 | SLOT_DIRTY = 1, |
| 120 | SLOT_USED = 2, |
| 121 | }; |
| 122 | |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 123 | static void *alloc_insn_page(void) |
| 124 | { |
| 125 | return module_alloc(PAGE_SIZE); |
| 126 | } |
| 127 | |
| 128 | static void free_insn_page(void *page) |
| 129 | { |
Rusty Russell | be1f221 | 2015-01-20 09:07:05 +1030 | [diff] [blame] | 130 | module_memfree(page); |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 131 | } |
| 132 | |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 133 | struct kprobe_insn_cache kprobe_insn_slots = { |
| 134 | .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 135 | .alloc = alloc_insn_page, |
| 136 | .free = free_insn_page, |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 137 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
| 138 | .insn_size = MAX_INSN_SIZE, |
| 139 | .nr_garbage = 0, |
| 140 | }; |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 141 | static int collect_garbage_slots(struct kprobe_insn_cache *c); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 142 | |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 143 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 144 | * __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] | 145 | * We allocate an executable page if there's no room on existing ones. |
| 146 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 147 | kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 148 | { |
| 149 | struct kprobe_insn_page *kip; |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 150 | kprobe_opcode_t *slot = NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 151 | |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 152 | mutex_lock(&c->mutex); |
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++; |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 161 | slot = kip->insns + (i * c->insn_size); |
| 162 | goto out; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 163 | } |
| 164 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 165 | /* kip->nused is broken. Fix it. */ |
| 166 | kip->nused = slots_per_page(c); |
| 167 | WARN_ON(1); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 168 | } |
| 169 | } |
| 170 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 171 | /* If there are any garbage slots, collect it and try again. */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 172 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 173 | goto retry; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 174 | |
| 175 | /* All out of space. Need to allocate a new page. */ |
| 176 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 177 | if (!kip) |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 178 | goto out; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 179 | |
| 180 | /* |
| 181 | * Use module_alloc so this page is within +/- 2GB of where the |
| 182 | * kernel image and loaded module images reside. This is required |
| 183 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 184 | */ |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 185 | kip->insns = c->alloc(); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 186 | if (!kip->insns) { |
| 187 | kfree(kip); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 188 | goto out; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 189 | } |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 190 | INIT_LIST_HEAD(&kip->list); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 191 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 192 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 193 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 194 | kip->ngarbage = 0; |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 195 | kip->cache = c; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 196 | list_add(&kip->list, &c->pages); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 197 | slot = kip->insns; |
| 198 | out: |
| 199 | mutex_unlock(&c->mutex); |
| 200 | return slot; |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 201 | } |
| 202 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 203 | /* Return 1 if all garbages are collected, otherwise 0. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 204 | static int collect_one_slot(struct kprobe_insn_page *kip, int idx) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 205 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 206 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 207 | kip->nused--; |
| 208 | if (kip->nused == 0) { |
| 209 | /* |
| 210 | * Page is no longer in use. Free it unless |
| 211 | * it's the last one. We keep the last one |
| 212 | * so as not to have to set it up again the |
| 213 | * next time somebody inserts a probe. |
| 214 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 215 | if (!list_is_singular(&kip->list)) { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 216 | list_del(&kip->list); |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 217 | kip->cache->free(kip->insns); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 218 | kfree(kip); |
| 219 | } |
| 220 | return 1; |
| 221 | } |
| 222 | return 0; |
| 223 | } |
| 224 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 225 | static int collect_garbage_slots(struct kprobe_insn_cache *c) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 226 | { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 227 | struct kprobe_insn_page *kip, *next; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 228 | |
Masami Hiramatsu | 615d0eb | 2010-02-02 16:49:04 -0500 | [diff] [blame] | 229 | /* Ensure no-one is interrupted on the garbages */ |
| 230 | synchronize_sched(); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 231 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 232 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 233 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 234 | if (kip->ngarbage == 0) |
| 235 | continue; |
| 236 | kip->ngarbage = 0; /* we will collect all garbages */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 237 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 238 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 239 | collect_one_slot(kip, i)) |
| 240 | break; |
| 241 | } |
| 242 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 243 | c->nr_garbage = 0; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 244 | return 0; |
| 245 | } |
| 246 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 247 | void __free_insn_slot(struct kprobe_insn_cache *c, |
| 248 | kprobe_opcode_t *slot, int dirty) |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 249 | { |
| 250 | struct kprobe_insn_page *kip; |
| 251 | |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 252 | mutex_lock(&c->mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 253 | list_for_each_entry(kip, &c->pages, list) { |
Masami Hiramatsu | 83ff56f | 2010-03-09 10:22:19 -0500 | [diff] [blame] | 254 | long idx = ((long)slot - (long)kip->insns) / |
| 255 | (c->insn_size * sizeof(kprobe_opcode_t)); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 256 | if (idx >= 0 && idx < slots_per_page(c)) { |
| 257 | WARN_ON(kip->slot_used[idx] != SLOT_USED); |
| 258 | if (dirty) { |
| 259 | kip->slot_used[idx] = SLOT_DIRTY; |
| 260 | kip->ngarbage++; |
| 261 | if (++c->nr_garbage > slots_per_page(c)) |
| 262 | collect_garbage_slots(c); |
| 263 | } else |
| 264 | collect_one_slot(kip, idx); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 265 | goto out; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 266 | } |
| 267 | } |
| 268 | /* Could not free this slot. */ |
| 269 | WARN_ON(1); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 270 | out: |
| 271 | mutex_unlock(&c->mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 272 | } |
| 273 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 274 | #ifdef CONFIG_OPTPROBES |
| 275 | /* For optimized_kprobe buffer */ |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 276 | struct kprobe_insn_cache kprobe_optinsn_slots = { |
| 277 | .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 278 | .alloc = alloc_insn_page, |
| 279 | .free = free_insn_page, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 280 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), |
| 281 | /* .insn_size is initialized later */ |
| 282 | .nr_garbage = 0, |
| 283 | }; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 284 | #endif |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 285 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 286 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 287 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 288 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 289 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 290 | __this_cpu_write(kprobe_instance, kp); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 291 | } |
| 292 | |
| 293 | static inline void reset_kprobe_instance(void) |
| 294 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 295 | __this_cpu_write(kprobe_instance, NULL); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 296 | } |
| 297 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 298 | /* |
| 299 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 300 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 301 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 302 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 303 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 304 | struct kprobe *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | { |
| 306 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 307 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | |
| 309 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 310 | hlist_for_each_entry_rcu(p, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | if (p->addr == addr) |
| 312 | return p; |
| 313 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 314 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | return NULL; |
| 316 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 317 | NOKPROBE_SYMBOL(get_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 319 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 320 | |
| 321 | /* Return true if the kprobe is an aggregator */ |
| 322 | static inline int kprobe_aggrprobe(struct kprobe *p) |
| 323 | { |
| 324 | return p->pre_handler == aggr_pre_handler; |
| 325 | } |
| 326 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 327 | /* Return true(!0) if the kprobe is unused */ |
| 328 | static inline int kprobe_unused(struct kprobe *p) |
| 329 | { |
| 330 | return kprobe_aggrprobe(p) && kprobe_disabled(p) && |
| 331 | list_empty(&p->list); |
| 332 | } |
| 333 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 334 | /* |
| 335 | * Keep all fields in the kprobe consistent |
| 336 | */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 337 | static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 338 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 339 | memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); |
| 340 | memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 341 | } |
| 342 | |
| 343 | #ifdef CONFIG_OPTPROBES |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 344 | /* NOTE: change this value only with kprobe_mutex held */ |
| 345 | static bool kprobes_allow_optimization; |
| 346 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 347 | /* |
| 348 | * Call all pre_handler on the list, but ignores its return value. |
| 349 | * This must be called from arch-dep optimized caller. |
| 350 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 351 | void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 352 | { |
| 353 | struct kprobe *kp; |
| 354 | |
| 355 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 356 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
| 357 | set_kprobe_instance(kp); |
| 358 | kp->pre_handler(kp, regs); |
| 359 | } |
| 360 | reset_kprobe_instance(); |
| 361 | } |
| 362 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 363 | NOKPROBE_SYMBOL(opt_pre_handler); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 364 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 365 | /* Free optimized instructions and optimized_kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 366 | static void free_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 367 | { |
| 368 | struct optimized_kprobe *op; |
| 369 | |
| 370 | op = container_of(p, struct optimized_kprobe, kp); |
| 371 | arch_remove_optimized_kprobe(op); |
| 372 | arch_remove_kprobe(p); |
| 373 | kfree(op); |
| 374 | } |
| 375 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 376 | /* Return true(!0) if the kprobe is ready for optimization. */ |
| 377 | static inline int kprobe_optready(struct kprobe *p) |
| 378 | { |
| 379 | struct optimized_kprobe *op; |
| 380 | |
| 381 | if (kprobe_aggrprobe(p)) { |
| 382 | op = container_of(p, struct optimized_kprobe, kp); |
| 383 | return arch_prepared_optinsn(&op->optinsn); |
| 384 | } |
| 385 | |
| 386 | return 0; |
| 387 | } |
| 388 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 389 | /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ |
| 390 | static inline int kprobe_disarmed(struct kprobe *p) |
| 391 | { |
| 392 | struct optimized_kprobe *op; |
| 393 | |
| 394 | /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ |
| 395 | if (!kprobe_aggrprobe(p)) |
| 396 | return kprobe_disabled(p); |
| 397 | |
| 398 | op = container_of(p, struct optimized_kprobe, kp); |
| 399 | |
| 400 | return kprobe_disabled(p) && list_empty(&op->list); |
| 401 | } |
| 402 | |
| 403 | /* Return true(!0) if the probe is queued on (un)optimizing lists */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 404 | static int kprobe_queued(struct kprobe *p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 405 | { |
| 406 | struct optimized_kprobe *op; |
| 407 | |
| 408 | if (kprobe_aggrprobe(p)) { |
| 409 | op = container_of(p, struct optimized_kprobe, kp); |
| 410 | if (!list_empty(&op->list)) |
| 411 | return 1; |
| 412 | } |
| 413 | return 0; |
| 414 | } |
| 415 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 416 | /* |
| 417 | * Return an optimized kprobe whose optimizing code replaces |
| 418 | * instructions including addr (exclude breakpoint). |
| 419 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 420 | static struct kprobe *get_optimized_kprobe(unsigned long addr) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 421 | { |
| 422 | int i; |
| 423 | struct kprobe *p = NULL; |
| 424 | struct optimized_kprobe *op; |
| 425 | |
| 426 | /* Don't check i == 0, since that is a breakpoint case. */ |
| 427 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) |
| 428 | p = get_kprobe((void *)(addr - i)); |
| 429 | |
| 430 | if (p && kprobe_optready(p)) { |
| 431 | op = container_of(p, struct optimized_kprobe, kp); |
| 432 | if (arch_within_optimized_kprobe(op, addr)) |
| 433 | return p; |
| 434 | } |
| 435 | |
| 436 | return NULL; |
| 437 | } |
| 438 | |
| 439 | /* Optimization staging list, protected by kprobe_mutex */ |
| 440 | static LIST_HEAD(optimizing_list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 441 | static LIST_HEAD(unoptimizing_list); |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 442 | static LIST_HEAD(freeing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 443 | |
| 444 | static void kprobe_optimizer(struct work_struct *work); |
| 445 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); |
| 446 | #define OPTIMIZE_DELAY 5 |
| 447 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 448 | /* |
| 449 | * Optimize (replace a breakpoint with a jump) kprobes listed on |
| 450 | * optimizing_list. |
| 451 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 452 | static void do_optimize_kprobes(void) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 453 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 454 | /* Optimization never be done when disarmed */ |
| 455 | if (kprobes_all_disarmed || !kprobes_allow_optimization || |
| 456 | list_empty(&optimizing_list)) |
| 457 | return; |
| 458 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 459 | /* |
| 460 | * The optimization/unoptimization refers online_cpus via |
| 461 | * stop_machine() and cpu-hotplug modifies online_cpus. |
| 462 | * And same time, text_mutex will be held in cpu-hotplug and here. |
| 463 | * This combination can cause a deadlock (cpu-hotplug try to lock |
| 464 | * text_mutex but stop_machine can not be done because online_cpus |
| 465 | * has been changed) |
| 466 | * To avoid this deadlock, we need to call get_online_cpus() |
| 467 | * for preventing cpu-hotplug outside of text_mutex locking. |
| 468 | */ |
| 469 | get_online_cpus(); |
| 470 | mutex_lock(&text_mutex); |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 471 | arch_optimize_kprobes(&optimizing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 472 | mutex_unlock(&text_mutex); |
| 473 | put_online_cpus(); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 474 | } |
| 475 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 476 | /* |
| 477 | * Unoptimize (replace a jump with a breakpoint and remove the breakpoint |
| 478 | * if need) kprobes listed on unoptimizing_list. |
| 479 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 480 | static void do_unoptimize_kprobes(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 481 | { |
| 482 | struct optimized_kprobe *op, *tmp; |
| 483 | |
| 484 | /* Unoptimization must be done anytime */ |
| 485 | if (list_empty(&unoptimizing_list)) |
| 486 | return; |
| 487 | |
| 488 | /* Ditto to do_optimize_kprobes */ |
| 489 | get_online_cpus(); |
| 490 | mutex_lock(&text_mutex); |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 491 | arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 492 | /* Loop free_list for disarming */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 493 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 494 | /* Disarm probes if marked disabled */ |
| 495 | if (kprobe_disabled(&op->kp)) |
| 496 | arch_disarm_kprobe(&op->kp); |
| 497 | if (kprobe_unused(&op->kp)) { |
| 498 | /* |
| 499 | * Remove unused probes from hash list. After waiting |
| 500 | * for synchronization, these probes are reclaimed. |
| 501 | * (reclaiming is done by do_free_cleaned_kprobes.) |
| 502 | */ |
| 503 | hlist_del_rcu(&op->kp.hlist); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 504 | } else |
| 505 | list_del_init(&op->list); |
| 506 | } |
| 507 | mutex_unlock(&text_mutex); |
| 508 | put_online_cpus(); |
| 509 | } |
| 510 | |
| 511 | /* Reclaim all kprobes on the free_list */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 512 | static void do_free_cleaned_kprobes(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 513 | { |
| 514 | struct optimized_kprobe *op, *tmp; |
| 515 | |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 516 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 517 | BUG_ON(!kprobe_unused(&op->kp)); |
| 518 | list_del_init(&op->list); |
| 519 | free_aggr_kprobe(&op->kp); |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | /* Start optimizer after OPTIMIZE_DELAY passed */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 524 | static void kick_kprobe_optimizer(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 525 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 526 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 527 | } |
| 528 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 529 | /* Kprobe jump optimizer */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 530 | static void kprobe_optimizer(struct work_struct *work) |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 531 | { |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 532 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 533 | /* Lock modules while optimizing kprobes */ |
| 534 | mutex_lock(&module_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 535 | |
| 536 | /* |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 537 | * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) |
| 538 | * kprobes before waiting for quiesence period. |
| 539 | */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 540 | do_unoptimize_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 541 | |
| 542 | /* |
| 543 | * Step 2: Wait for quiesence period to ensure all running interrupts |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 544 | * are done. Because optprobe may modify multiple instructions |
| 545 | * there is a chance that Nth instruction is interrupted. In that |
| 546 | * case, running interrupt can return to 2nd-Nth byte of jump |
| 547 | * instruction. This wait is for avoiding it. |
| 548 | */ |
| 549 | synchronize_sched(); |
| 550 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 551 | /* Step 3: Optimize kprobes after quiesence period */ |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 552 | do_optimize_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 553 | |
| 554 | /* Step 4: Free cleaned kprobes after quiesence period */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 555 | do_free_cleaned_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 556 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 557 | mutex_unlock(&module_mutex); |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 558 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 559 | |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 560 | /* Step 5: Kick optimizer again if needed */ |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 561 | if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 562 | kick_kprobe_optimizer(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 563 | } |
| 564 | |
| 565 | /* Wait for completing optimization and unoptimization */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 566 | static void wait_for_kprobe_optimizer(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 567 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 568 | mutex_lock(&kprobe_mutex); |
| 569 | |
| 570 | while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { |
| 571 | mutex_unlock(&kprobe_mutex); |
| 572 | |
| 573 | /* this will also make optimizing_work execute immmediately */ |
| 574 | flush_delayed_work(&optimizing_work); |
| 575 | /* @optimizing_work might not have been queued yet, relax */ |
| 576 | cpu_relax(); |
| 577 | |
| 578 | mutex_lock(&kprobe_mutex); |
| 579 | } |
| 580 | |
| 581 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 582 | } |
| 583 | |
| 584 | /* Optimize kprobe if p is ready to be optimized */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 585 | static void optimize_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 586 | { |
| 587 | struct optimized_kprobe *op; |
| 588 | |
| 589 | /* Check if the kprobe is disabled or not ready for optimization. */ |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 590 | if (!kprobe_optready(p) || !kprobes_allow_optimization || |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 591 | (kprobe_disabled(p) || kprobes_all_disarmed)) |
| 592 | return; |
| 593 | |
| 594 | /* Both of break_handler and post_handler are not supported. */ |
| 595 | if (p->break_handler || p->post_handler) |
| 596 | return; |
| 597 | |
| 598 | op = container_of(p, struct optimized_kprobe, kp); |
| 599 | |
| 600 | /* Check there is no other kprobes at the optimized instructions */ |
| 601 | if (arch_check_optimized_kprobe(op) < 0) |
| 602 | return; |
| 603 | |
| 604 | /* Check if it is already optimized. */ |
| 605 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) |
| 606 | return; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 607 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 608 | |
| 609 | if (!list_empty(&op->list)) |
| 610 | /* This is under unoptimizing. Just dequeue the probe */ |
| 611 | list_del_init(&op->list); |
| 612 | else { |
| 613 | list_add(&op->list, &optimizing_list); |
| 614 | kick_kprobe_optimizer(); |
| 615 | } |
| 616 | } |
| 617 | |
| 618 | /* Short cut to direct unoptimizing */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 619 | static void force_unoptimize_kprobe(struct optimized_kprobe *op) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 620 | { |
| 621 | get_online_cpus(); |
| 622 | arch_unoptimize_kprobe(op); |
| 623 | put_online_cpus(); |
| 624 | if (kprobe_disabled(&op->kp)) |
| 625 | arch_disarm_kprobe(&op->kp); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 626 | } |
| 627 | |
| 628 | /* Unoptimize a kprobe if p is optimized */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 629 | static void unoptimize_kprobe(struct kprobe *p, bool force) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 630 | { |
| 631 | struct optimized_kprobe *op; |
| 632 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 633 | if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) |
| 634 | return; /* This is not an optprobe nor optimized */ |
| 635 | |
| 636 | op = container_of(p, struct optimized_kprobe, kp); |
| 637 | if (!kprobe_optimized(p)) { |
| 638 | /* Unoptimized or unoptimizing case */ |
| 639 | if (force && !list_empty(&op->list)) { |
| 640 | /* |
| 641 | * Only if this is unoptimizing kprobe and forced, |
| 642 | * forcibly unoptimize it. (No need to unoptimize |
| 643 | * unoptimized kprobe again :) |
| 644 | */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 645 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 646 | force_unoptimize_kprobe(op); |
| 647 | } |
| 648 | return; |
| 649 | } |
| 650 | |
| 651 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
| 652 | if (!list_empty(&op->list)) { |
| 653 | /* Dequeue from the optimization queue */ |
| 654 | list_del_init(&op->list); |
| 655 | return; |
| 656 | } |
| 657 | /* Optimized kprobe case */ |
| 658 | if (force) |
| 659 | /* Forcibly update the code: this is a special case */ |
| 660 | force_unoptimize_kprobe(op); |
| 661 | else { |
| 662 | list_add(&op->list, &unoptimizing_list); |
| 663 | kick_kprobe_optimizer(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 664 | } |
| 665 | } |
| 666 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 667 | /* Cancel unoptimizing for reusing */ |
| 668 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 669 | { |
| 670 | struct optimized_kprobe *op; |
| 671 | |
| 672 | BUG_ON(!kprobe_unused(ap)); |
| 673 | /* |
| 674 | * Unused kprobe MUST be on the way of delayed unoptimizing (means |
| 675 | * there is still a relative jump) and disabled. |
| 676 | */ |
| 677 | op = container_of(ap, struct optimized_kprobe, kp); |
| 678 | if (unlikely(list_empty(&op->list))) |
| 679 | printk(KERN_WARNING "Warning: found a stray unused " |
| 680 | "aggrprobe@%p\n", ap->addr); |
| 681 | /* Enable the probe again */ |
| 682 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 683 | /* Optimize it again (remove from op->list) */ |
| 684 | BUG_ON(!kprobe_optready(ap)); |
| 685 | optimize_kprobe(ap); |
| 686 | } |
| 687 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 688 | /* Remove optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 689 | static void kill_optimized_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 690 | { |
| 691 | struct optimized_kprobe *op; |
| 692 | |
| 693 | op = container_of(p, struct optimized_kprobe, kp); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 694 | if (!list_empty(&op->list)) |
| 695 | /* Dequeue from the (un)optimization queue */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 696 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 697 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 698 | |
| 699 | if (kprobe_unused(p)) { |
| 700 | /* Enqueue if it is unused */ |
| 701 | list_add(&op->list, &freeing_list); |
| 702 | /* |
| 703 | * Remove unused probes from the hash list. After waiting |
| 704 | * for synchronization, this probe is reclaimed. |
| 705 | * (reclaiming is done by do_free_cleaned_kprobes().) |
| 706 | */ |
| 707 | hlist_del_rcu(&op->kp.hlist); |
| 708 | } |
| 709 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 710 | /* Don't touch the code, because it is already freed. */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 711 | arch_remove_optimized_kprobe(op); |
| 712 | } |
| 713 | |
| 714 | /* Try to prepare optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 715 | static void prepare_optimized_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 716 | { |
| 717 | struct optimized_kprobe *op; |
| 718 | |
| 719 | op = container_of(p, struct optimized_kprobe, kp); |
Masami Hiramatsu | cbf6ab5 | 2015-01-05 19:29:32 +0800 | [diff] [blame] | 720 | arch_prepare_optimized_kprobe(op, p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 721 | } |
| 722 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 723 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 724 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 725 | { |
| 726 | struct optimized_kprobe *op; |
| 727 | |
| 728 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); |
| 729 | if (!op) |
| 730 | return NULL; |
| 731 | |
| 732 | INIT_LIST_HEAD(&op->list); |
| 733 | op->kp.addr = p->addr; |
Masami Hiramatsu | cbf6ab5 | 2015-01-05 19:29:32 +0800 | [diff] [blame] | 734 | arch_prepare_optimized_kprobe(op, p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 735 | |
| 736 | return &op->kp; |
| 737 | } |
| 738 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 739 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 740 | |
| 741 | /* |
| 742 | * Prepare an optimized_kprobe and optimize it |
| 743 | * NOTE: p must be a normal registered kprobe |
| 744 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 745 | static void try_to_optimize_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 746 | { |
| 747 | struct kprobe *ap; |
| 748 | struct optimized_kprobe *op; |
| 749 | |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 750 | /* Impossible to optimize ftrace-based kprobe */ |
| 751 | if (kprobe_ftrace(p)) |
| 752 | return; |
| 753 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 754 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 755 | jump_label_lock(); |
| 756 | mutex_lock(&text_mutex); |
| 757 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 758 | ap = alloc_aggr_kprobe(p); |
| 759 | if (!ap) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 760 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 761 | |
| 762 | op = container_of(ap, struct optimized_kprobe, kp); |
| 763 | if (!arch_prepared_optinsn(&op->optinsn)) { |
| 764 | /* If failed to setup optimizing, fallback to kprobe */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 765 | arch_remove_optimized_kprobe(op); |
| 766 | kfree(op); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 767 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 768 | } |
| 769 | |
| 770 | init_aggr_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 771 | optimize_kprobe(ap); /* This just kicks optimizer thread */ |
| 772 | |
| 773 | out: |
| 774 | mutex_unlock(&text_mutex); |
| 775 | jump_label_unlock(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 776 | } |
| 777 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 778 | #ifdef CONFIG_SYSCTL |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 779 | static void optimize_all_kprobes(void) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 780 | { |
| 781 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 782 | struct kprobe *p; |
| 783 | unsigned int i; |
| 784 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 785 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 786 | /* If optimization is already allowed, just return */ |
| 787 | if (kprobes_allow_optimization) |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 788 | goto out; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 789 | |
| 790 | kprobes_allow_optimization = true; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 791 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 792 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 793 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 794 | if (!kprobe_disabled(p)) |
| 795 | optimize_kprobe(p); |
| 796 | } |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 797 | printk(KERN_INFO "Kprobes globally optimized\n"); |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 798 | out: |
| 799 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 800 | } |
| 801 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 802 | static void unoptimize_all_kprobes(void) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 803 | { |
| 804 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 805 | struct kprobe *p; |
| 806 | unsigned int i; |
| 807 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 808 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 809 | /* If optimization is already prohibited, just return */ |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 810 | if (!kprobes_allow_optimization) { |
| 811 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 812 | return; |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 813 | } |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 814 | |
| 815 | kprobes_allow_optimization = false; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 816 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 817 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 818 | hlist_for_each_entry_rcu(p, head, hlist) { |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 819 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 820 | unoptimize_kprobe(p, false); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 821 | } |
| 822 | } |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 823 | mutex_unlock(&kprobe_mutex); |
| 824 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 825 | /* Wait for unoptimizing completion */ |
| 826 | wait_for_kprobe_optimizer(); |
| 827 | printk(KERN_INFO "Kprobes globally unoptimized\n"); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 828 | } |
| 829 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 830 | static DEFINE_MUTEX(kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 831 | int sysctl_kprobes_optimization; |
| 832 | int proc_kprobes_optimization_handler(struct ctl_table *table, int write, |
| 833 | void __user *buffer, size_t *length, |
| 834 | loff_t *ppos) |
| 835 | { |
| 836 | int ret; |
| 837 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 838 | mutex_lock(&kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 839 | sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; |
| 840 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); |
| 841 | |
| 842 | if (sysctl_kprobes_optimization) |
| 843 | optimize_all_kprobes(); |
| 844 | else |
| 845 | unoptimize_all_kprobes(); |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 846 | mutex_unlock(&kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 847 | |
| 848 | return ret; |
| 849 | } |
| 850 | #endif /* CONFIG_SYSCTL */ |
| 851 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 852 | /* Put a breakpoint for a probe. Must be called with text_mutex locked */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 853 | static void __arm_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 854 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 855 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 856 | |
| 857 | /* Check collision with other optimized kprobes */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 858 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 859 | if (unlikely(_p)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 860 | /* Fallback to unoptimized kprobe */ |
| 861 | unoptimize_kprobe(_p, true); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 862 | |
| 863 | arch_arm_kprobe(p); |
| 864 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ |
| 865 | } |
| 866 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 867 | /* Remove the breakpoint of a probe. Must be called with text_mutex locked */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 868 | static void __disarm_kprobe(struct kprobe *p, bool reopt) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 869 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 870 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 871 | |
Wang Nan | 69d54b9 | 2015-02-13 14:40:26 -0800 | [diff] [blame] | 872 | /* Try to unoptimize */ |
| 873 | unoptimize_kprobe(p, kprobes_all_disarmed); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 874 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 875 | if (!kprobe_queued(p)) { |
| 876 | arch_disarm_kprobe(p); |
| 877 | /* If another kprobe was blocked, optimize it. */ |
| 878 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 879 | if (unlikely(_p) && reopt) |
| 880 | optimize_kprobe(_p); |
| 881 | } |
| 882 | /* TODO: reoptimize others after unoptimized this probe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 883 | } |
| 884 | |
| 885 | #else /* !CONFIG_OPTPROBES */ |
| 886 | |
| 887 | #define optimize_kprobe(p) do {} while (0) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 888 | #define unoptimize_kprobe(p, f) do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 889 | #define kill_optimized_kprobe(p) do {} while (0) |
| 890 | #define prepare_optimized_kprobe(p) do {} while (0) |
| 891 | #define try_to_optimize_kprobe(p) do {} while (0) |
| 892 | #define __arm_kprobe(p) arch_arm_kprobe(p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 893 | #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) |
| 894 | #define kprobe_disarmed(p) kprobe_disabled(p) |
| 895 | #define wait_for_kprobe_optimizer() do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 896 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 897 | /* There should be no unused kprobes can be reused without optimization */ |
| 898 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 899 | { |
| 900 | printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); |
| 901 | BUG_ON(kprobe_unused(ap)); |
| 902 | } |
| 903 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 904 | static void free_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 905 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 906 | arch_remove_kprobe(p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 907 | kfree(p); |
| 908 | } |
| 909 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 910 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 911 | { |
| 912 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 913 | } |
| 914 | #endif /* CONFIG_OPTPROBES */ |
| 915 | |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 916 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 917 | static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
Masami Hiramatsu | e525389 | 2012-06-05 19:28:38 +0900 | [diff] [blame] | 918 | .func = kprobe_ftrace_handler, |
Masami Hiramatsu | 1d70be3 | 2014-11-21 05:25:23 -0500 | [diff] [blame] | 919 | .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 920 | }; |
| 921 | static int kprobe_ftrace_enabled; |
| 922 | |
| 923 | /* Must ensure p->addr is really on ftrace */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 924 | static int prepare_kprobe(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 925 | { |
| 926 | if (!kprobe_ftrace(p)) |
| 927 | return arch_prepare_kprobe(p); |
| 928 | |
| 929 | return arch_prepare_kprobe_ftrace(p); |
| 930 | } |
| 931 | |
| 932 | /* Caller must lock kprobe_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 933 | static void arm_kprobe_ftrace(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 934 | { |
| 935 | int ret; |
| 936 | |
| 937 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 938 | (unsigned long)p->addr, 0, 0); |
| 939 | WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 940 | kprobe_ftrace_enabled++; |
| 941 | if (kprobe_ftrace_enabled == 1) { |
| 942 | ret = register_ftrace_function(&kprobe_ftrace_ops); |
| 943 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 944 | } |
| 945 | } |
| 946 | |
| 947 | /* Caller must lock kprobe_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 948 | static void disarm_kprobe_ftrace(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 949 | { |
| 950 | int ret; |
| 951 | |
| 952 | kprobe_ftrace_enabled--; |
| 953 | if (kprobe_ftrace_enabled == 0) { |
| 954 | ret = unregister_ftrace_function(&kprobe_ftrace_ops); |
| 955 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 956 | } |
| 957 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 958 | (unsigned long)p->addr, 1, 0); |
| 959 | WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 960 | } |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 961 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 962 | #define prepare_kprobe(p) arch_prepare_kprobe(p) |
| 963 | #define arm_kprobe_ftrace(p) do {} while (0) |
| 964 | #define disarm_kprobe_ftrace(p) do {} while (0) |
| 965 | #endif |
| 966 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 967 | /* Arm a kprobe with text_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 968 | static void arm_kprobe(struct kprobe *kp) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 969 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 970 | if (unlikely(kprobe_ftrace(kp))) { |
| 971 | arm_kprobe_ftrace(kp); |
| 972 | return; |
| 973 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 974 | /* |
| 975 | * Here, since __arm_kprobe() doesn't use stop_machine(), |
| 976 | * this doesn't cause deadlock on text_mutex. So, we don't |
| 977 | * need get_online_cpus(). |
| 978 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 979 | mutex_lock(&text_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 980 | __arm_kprobe(kp); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 981 | mutex_unlock(&text_mutex); |
| 982 | } |
| 983 | |
| 984 | /* Disarm a kprobe with text_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 985 | static void disarm_kprobe(struct kprobe *kp, bool reopt) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 986 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 987 | if (unlikely(kprobe_ftrace(kp))) { |
| 988 | disarm_kprobe_ftrace(kp); |
| 989 | return; |
| 990 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 991 | /* Ditto */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 992 | mutex_lock(&text_mutex); |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 993 | __disarm_kprobe(kp, reopt); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 994 | mutex_unlock(&text_mutex); |
| 995 | } |
| 996 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 997 | /* |
| 998 | * Aggregate handlers for multiple kprobes support - these handlers |
| 999 | * take care of invoking the individual kprobe handlers on p->list |
| 1000 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1001 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1002 | { |
| 1003 | struct kprobe *kp; |
| 1004 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1005 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1006 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1007 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1008 | if (kp->pre_handler(kp, regs)) |
| 1009 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1010 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1011 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1012 | } |
| 1013 | return 0; |
| 1014 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1015 | NOKPROBE_SYMBOL(aggr_pre_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1016 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1017 | static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 1018 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1019 | { |
| 1020 | struct kprobe *kp; |
| 1021 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1022 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1023 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1024 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1025 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1026 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1027 | } |
| 1028 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1029 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1030 | NOKPROBE_SYMBOL(aggr_post_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1031 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1032 | static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 1033 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1034 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1035 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1036 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1037 | /* |
| 1038 | * if we faulted "during" the execution of a user specified |
| 1039 | * probe handler, invoke just that probe's fault handler |
| 1040 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1041 | if (cur && cur->fault_handler) { |
| 1042 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1043 | return 1; |
| 1044 | } |
| 1045 | return 0; |
| 1046 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1047 | NOKPROBE_SYMBOL(aggr_fault_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1048 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1049 | static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1050 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1051 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1052 | int ret = 0; |
| 1053 | |
| 1054 | if (cur && cur->break_handler) { |
| 1055 | if (cur->break_handler(cur, regs)) |
| 1056 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1057 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1058 | reset_kprobe_instance(); |
| 1059 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1060 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1061 | NOKPROBE_SYMBOL(aggr_break_handler); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1062 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1063 | /* Walks the list and increments nmissed count for multiprobe case */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1064 | void kprobes_inc_nmissed_count(struct kprobe *p) |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1065 | { |
| 1066 | struct kprobe *kp; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1067 | if (!kprobe_aggrprobe(p)) { |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1068 | p->nmissed++; |
| 1069 | } else { |
| 1070 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1071 | kp->nmissed++; |
| 1072 | } |
| 1073 | return; |
| 1074 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1075 | NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1076 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1077 | void recycle_rp_inst(struct kretprobe_instance *ri, |
| 1078 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1079 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1080 | struct kretprobe *rp = ri->rp; |
| 1081 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1082 | /* remove rp inst off the rprobe_inst_table */ |
| 1083 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1084 | INIT_HLIST_NODE(&ri->hlist); |
| 1085 | if (likely(rp)) { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1086 | raw_spin_lock(&rp->lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1087 | hlist_add_head(&ri->hlist, &rp->free_instances); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1088 | raw_spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1089 | } else |
| 1090 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1091 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1092 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1093 | NOKPROBE_SYMBOL(recycle_rp_inst); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1094 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1095 | void kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1096 | struct hlist_head **head, unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1097 | __acquires(hlist_lock) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1098 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1099 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1100 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1101 | |
| 1102 | *head = &kretprobe_inst_table[hash]; |
| 1103 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1104 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1105 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1106 | NOKPROBE_SYMBOL(kretprobe_hash_lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1107 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1108 | static void kretprobe_table_lock(unsigned long hash, |
| 1109 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1110 | __acquires(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1111 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1112 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1113 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1114 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1115 | NOKPROBE_SYMBOL(kretprobe_table_lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1116 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1117 | void kretprobe_hash_unlock(struct task_struct *tsk, |
| 1118 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1119 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1120 | { |
| 1121 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1122 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1123 | |
| 1124 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1125 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1126 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1127 | NOKPROBE_SYMBOL(kretprobe_hash_unlock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1128 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1129 | static void kretprobe_table_unlock(unsigned long hash, |
| 1130 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1131 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1132 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1133 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1134 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1135 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1136 | NOKPROBE_SYMBOL(kretprobe_table_unlock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1137 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1138 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 1139 | * This function is called from finish_task_switch when task tk becomes dead, |
| 1140 | * so that we can recycle any function-return probe instances associated |
| 1141 | * with this task. These left over instances represent probed functions |
| 1142 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1143 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1144 | void kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1145 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1146 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1147 | struct hlist_head *head, empty_rp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1148 | struct hlist_node *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1149 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1150 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1151 | if (unlikely(!kprobes_initialized)) |
| 1152 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 1153 | return; |
| 1154 | |
Ananth N Mavinakayanahalli | d496aab | 2012-01-20 14:34:04 -0800 | [diff] [blame] | 1155 | INIT_HLIST_HEAD(&empty_rp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1156 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 1157 | head = &kretprobe_inst_table[hash]; |
| 1158 | kretprobe_table_lock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1159 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1160 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1161 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1162 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1163 | kretprobe_table_unlock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1164 | hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1165 | hlist_del(&ri->hlist); |
| 1166 | kfree(ri); |
| 1167 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1168 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1169 | NOKPROBE_SYMBOL(kprobe_flush_task); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1170 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1171 | static inline void free_rp_inst(struct kretprobe *rp) |
| 1172 | { |
| 1173 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1174 | struct hlist_node *next; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1175 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1176 | hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1177 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1178 | kfree(ri); |
| 1179 | } |
| 1180 | } |
| 1181 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1182 | static void cleanup_rp_inst(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1183 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1184 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1185 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1186 | struct hlist_node *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1187 | struct hlist_head *head; |
| 1188 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1189 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1190 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 1191 | kretprobe_table_lock(hash, &flags); |
| 1192 | head = &kretprobe_inst_table[hash]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1193 | hlist_for_each_entry_safe(ri, next, head, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1194 | if (ri->rp == rp) |
| 1195 | ri->rp = NULL; |
| 1196 | } |
| 1197 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1198 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1199 | free_rp_inst(rp); |
| 1200 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1201 | NOKPROBE_SYMBOL(cleanup_rp_inst); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1202 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1203 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1204 | * 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] | 1205 | * second jprobe at the address - two jprobes can't coexist |
| 1206 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1207 | static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1208 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1209 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1210 | |
| 1211 | if (p->break_handler || p->post_handler) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1212 | unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1213 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1214 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1215 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1216 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1217 | list_add_tail_rcu(&p->list, &ap->list); |
| 1218 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1219 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1220 | list_add_rcu(&p->list, &ap->list); |
| 1221 | if (p->post_handler && !ap->post_handler) |
| 1222 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1223 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1224 | return 0; |
| 1225 | } |
| 1226 | |
| 1227 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1228 | * Fill in the required fields of the "manager kprobe". Replace the |
| 1229 | * earlier kprobe in the hlist with the manager kprobe |
| 1230 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1231 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1232 | { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1233 | /* Copy p's insn slot to ap */ |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1234 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 1235 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1236 | ap->addr = p->addr; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1237 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1238 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1239 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1240 | /* We don't care the kprobe which has gone. */ |
| 1241 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1242 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1243 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1244 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1245 | |
| 1246 | INIT_LIST_HEAD(&ap->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1247 | INIT_HLIST_NODE(&ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1248 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1249 | list_add_rcu(&p->list, &ap->list); |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 1250 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1251 | } |
| 1252 | |
| 1253 | /* |
| 1254 | * This is the second or subsequent kprobe at the address - handle |
| 1255 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1256 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1257 | static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1258 | { |
| 1259 | int ret = 0; |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1260 | struct kprobe *ap = orig_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1261 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1262 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 1263 | jump_label_lock(); |
| 1264 | /* |
| 1265 | * Get online CPUs to avoid text_mutex deadlock.with stop machine, |
| 1266 | * which is invoked by unoptimize_kprobe() in add_new_kprobe() |
| 1267 | */ |
| 1268 | get_online_cpus(); |
| 1269 | mutex_lock(&text_mutex); |
| 1270 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1271 | if (!kprobe_aggrprobe(orig_p)) { |
| 1272 | /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ |
| 1273 | ap = alloc_aggr_kprobe(orig_p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1274 | if (!ap) { |
| 1275 | ret = -ENOMEM; |
| 1276 | goto out; |
| 1277 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1278 | init_aggr_kprobe(ap, orig_p); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1279 | } else if (kprobe_unused(ap)) |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 1280 | /* This probe is going to die. Rescue it */ |
| 1281 | reuse_unused_kprobe(ap); |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1282 | |
| 1283 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1284 | /* |
| 1285 | * Attempting to insert new probe at the same location that |
| 1286 | * had a probe in the module vaddr area which already |
| 1287 | * freed. So, the instruction slot has already been |
| 1288 | * released. We need a new slot for the new probe. |
| 1289 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1290 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1291 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1292 | /* |
| 1293 | * Even if fail to allocate new slot, don't need to |
| 1294 | * free aggr_probe. It will be used next time, or |
| 1295 | * freed by unregister_kprobe. |
| 1296 | */ |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1297 | goto out; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1298 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1299 | /* Prepare optimized instructions if possible. */ |
| 1300 | prepare_optimized_kprobe(ap); |
| 1301 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1302 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1303 | * Clear gone flag to prevent allocating new slot again, and |
| 1304 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1305 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1306 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 1307 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1308 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1309 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1310 | /* Copy ap's insn slot to p */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1311 | copy_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1312 | ret = add_new_kprobe(ap, p); |
| 1313 | |
| 1314 | out: |
| 1315 | mutex_unlock(&text_mutex); |
| 1316 | put_online_cpus(); |
| 1317 | jump_label_unlock(); |
| 1318 | |
| 1319 | if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 1320 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 1321 | if (!kprobes_all_disarmed) |
| 1322 | /* Arm the breakpoint again. */ |
| 1323 | arm_kprobe(ap); |
| 1324 | } |
| 1325 | return ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1326 | } |
| 1327 | |
Masami Hiramatsu | be8f274 | 2014-04-17 17:16:58 +0900 | [diff] [blame] | 1328 | bool __weak arch_within_kprobe_blacklist(unsigned long addr) |
| 1329 | { |
| 1330 | /* The __kprobes marked functions and entry code must not be probed */ |
| 1331 | return addr >= (unsigned long)__kprobes_text_start && |
| 1332 | addr < (unsigned long)__kprobes_text_end; |
| 1333 | } |
| 1334 | |
Andy Lutomirski | e5779e8 | 2015-07-30 20:32:40 -0700 | [diff] [blame] | 1335 | bool within_kprobe_blacklist(unsigned long addr) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1336 | { |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1337 | struct kprobe_blacklist_entry *ent; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1338 | |
Masami Hiramatsu | be8f274 | 2014-04-17 17:16:58 +0900 | [diff] [blame] | 1339 | if (arch_within_kprobe_blacklist(addr)) |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1340 | return true; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1341 | /* |
| 1342 | * If there exists a kprobe_blacklist, verify and |
| 1343 | * fail any probe registration in the prohibited area |
| 1344 | */ |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1345 | list_for_each_entry(ent, &kprobe_blacklist, list) { |
| 1346 | if (addr >= ent->start_addr && addr < ent->end_addr) |
| 1347 | return true; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1348 | } |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1349 | |
| 1350 | return false; |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1351 | } |
| 1352 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1353 | /* |
| 1354 | * If we have a symbol_name argument, look it up and add the offset field |
| 1355 | * to it. This way, we can specify a relative address to a symbol. |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1356 | * This returns encoded errors if it fails to look up symbol or invalid |
| 1357 | * combination of parameters. |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1358 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1359 | static kprobe_opcode_t *kprobe_addr(struct kprobe *p) |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1360 | { |
| 1361 | kprobe_opcode_t *addr = p->addr; |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1362 | |
| 1363 | if ((p->symbol_name && p->addr) || |
| 1364 | (!p->symbol_name && !p->addr)) |
| 1365 | goto invalid; |
| 1366 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1367 | if (p->symbol_name) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1368 | kprobe_lookup_name(p->symbol_name, addr); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1369 | if (!addr) |
| 1370 | return ERR_PTR(-ENOENT); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1371 | } |
| 1372 | |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1373 | addr = (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 1374 | if (addr) |
| 1375 | return addr; |
| 1376 | |
| 1377 | invalid: |
| 1378 | return ERR_PTR(-EINVAL); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1379 | } |
| 1380 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1381 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1382 | static struct kprobe *__get_valid_kprobe(struct kprobe *p) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1383 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1384 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1385 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1386 | ap = get_kprobe(p->addr); |
| 1387 | if (unlikely(!ap)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1388 | return NULL; |
| 1389 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1390 | if (p != ap) { |
| 1391 | list_for_each_entry_rcu(list_p, &ap->list, list) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1392 | if (list_p == p) |
| 1393 | /* kprobe p is a valid probe */ |
| 1394 | goto valid; |
| 1395 | return NULL; |
| 1396 | } |
| 1397 | valid: |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1398 | return ap; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1399 | } |
| 1400 | |
| 1401 | /* Return error if the kprobe is being re-registered */ |
| 1402 | static inline int check_kprobe_rereg(struct kprobe *p) |
| 1403 | { |
| 1404 | int ret = 0; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1405 | |
| 1406 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1407 | if (__get_valid_kprobe(p)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1408 | ret = -EINVAL; |
| 1409 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1410 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1411 | return ret; |
| 1412 | } |
| 1413 | |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1414 | int __weak arch_check_ftrace_location(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1416 | unsigned long ftrace_addr; |
| 1417 | |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1418 | ftrace_addr = ftrace_location((unsigned long)p->addr); |
| 1419 | if (ftrace_addr) { |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1420 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1421 | /* Given address is not on the instruction boundary */ |
| 1422 | if ((unsigned long)p->addr != ftrace_addr) |
| 1423 | return -EILSEQ; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1424 | p->flags |= KPROBE_FLAG_FTRACE; |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1425 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1426 | return -EINVAL; |
| 1427 | #endif |
| 1428 | } |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1429 | return 0; |
| 1430 | } |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1431 | |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1432 | static int check_kprobe_address_safe(struct kprobe *p, |
| 1433 | struct module **probed_mod) |
| 1434 | { |
| 1435 | int ret; |
| 1436 | |
| 1437 | ret = arch_check_ftrace_location(p); |
| 1438 | if (ret) |
| 1439 | return ret; |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1440 | jump_label_lock(); |
| 1441 | preempt_disable(); |
| 1442 | |
| 1443 | /* Ensure it is not in reserved area nor out of text */ |
| 1444 | if (!kernel_text_address((unsigned long) p->addr) || |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1445 | within_kprobe_blacklist((unsigned long) p->addr) || |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1446 | jump_label_text_reserved(p->addr, p->addr)) { |
| 1447 | ret = -EINVAL; |
| 1448 | goto out; |
| 1449 | } |
| 1450 | |
| 1451 | /* Check if are we probing a module */ |
| 1452 | *probed_mod = __module_text_address((unsigned long) p->addr); |
| 1453 | if (*probed_mod) { |
| 1454 | /* |
| 1455 | * We must hold a refcount of the probed module while updating |
| 1456 | * its code to prohibit unexpected unloading. |
| 1457 | */ |
| 1458 | if (unlikely(!try_module_get(*probed_mod))) { |
| 1459 | ret = -ENOENT; |
| 1460 | goto out; |
| 1461 | } |
| 1462 | |
| 1463 | /* |
| 1464 | * If the module freed .init.text, we couldn't insert |
| 1465 | * kprobes in there. |
| 1466 | */ |
| 1467 | if (within_module_init((unsigned long)p->addr, *probed_mod) && |
| 1468 | (*probed_mod)->state != MODULE_STATE_COMING) { |
| 1469 | module_put(*probed_mod); |
| 1470 | *probed_mod = NULL; |
| 1471 | ret = -ENOENT; |
| 1472 | } |
| 1473 | } |
| 1474 | out: |
| 1475 | preempt_enable(); |
| 1476 | jump_label_unlock(); |
| 1477 | |
| 1478 | return ret; |
| 1479 | } |
| 1480 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1481 | int register_kprobe(struct kprobe *p) |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1482 | { |
| 1483 | int ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1484 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1485 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1486 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1488 | /* Adjust probe address from symbol */ |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1489 | addr = kprobe_addr(p); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1490 | if (IS_ERR(addr)) |
| 1491 | return PTR_ERR(addr); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1492 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 1493 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1494 | ret = check_kprobe_rereg(p); |
| 1495 | if (ret) |
| 1496 | return ret; |
| 1497 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1498 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 1499 | p->flags &= KPROBE_FLAG_DISABLED; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1500 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1501 | INIT_LIST_HEAD(&p->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1502 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1503 | ret = check_kprobe_address_safe(p, &probed_mod); |
| 1504 | if (ret) |
| 1505 | return ret; |
| 1506 | |
| 1507 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1508 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1509 | old_p = get_kprobe(p->addr); |
| 1510 | if (old_p) { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1511 | /* Since this may unoptimize old_p, locking text_mutex. */ |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1512 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | goto out; |
| 1514 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1516 | mutex_lock(&text_mutex); /* Avoiding text modification */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1517 | ret = prepare_kprobe(p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1518 | mutex_unlock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 1519 | if (ret) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1520 | goto out; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1521 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1522 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1523 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1524 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 1525 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1526 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1527 | arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1528 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1529 | /* Try to optimize kprobe */ |
| 1530 | try_to_optimize_kprobe(p); |
| 1531 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 1533 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1534 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1535 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1536 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1537 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | return ret; |
| 1539 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1540 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1542 | /* Check if all probes on the aggrprobe are disabled */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1543 | static int aggr_kprobe_disabled(struct kprobe *ap) |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1544 | { |
| 1545 | struct kprobe *kp; |
| 1546 | |
| 1547 | list_for_each_entry_rcu(kp, &ap->list, list) |
| 1548 | if (!kprobe_disabled(kp)) |
| 1549 | /* |
| 1550 | * There is an active probe on the list. |
| 1551 | * We can't disable this ap. |
| 1552 | */ |
| 1553 | return 0; |
| 1554 | |
| 1555 | return 1; |
| 1556 | } |
| 1557 | |
| 1558 | /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1559 | static struct kprobe *__disable_kprobe(struct kprobe *p) |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1560 | { |
| 1561 | struct kprobe *orig_p; |
| 1562 | |
| 1563 | /* Get an original kprobe for return */ |
| 1564 | orig_p = __get_valid_kprobe(p); |
| 1565 | if (unlikely(orig_p == NULL)) |
| 1566 | return NULL; |
| 1567 | |
| 1568 | if (!kprobe_disabled(p)) { |
| 1569 | /* Disable probe if it is a child probe */ |
| 1570 | if (p != orig_p) |
| 1571 | p->flags |= KPROBE_FLAG_DISABLED; |
| 1572 | |
| 1573 | /* Try to disarm and disable this/parent probe */ |
| 1574 | if (p == orig_p || aggr_kprobe_disabled(orig_p)) { |
Wang Nan | 69d54b9 | 2015-02-13 14:40:26 -0800 | [diff] [blame] | 1575 | /* |
| 1576 | * If kprobes_all_disarmed is set, orig_p |
| 1577 | * should have already been disarmed, so |
| 1578 | * skip unneed disarming process. |
| 1579 | */ |
| 1580 | if (!kprobes_all_disarmed) |
| 1581 | disarm_kprobe(orig_p, true); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1582 | orig_p->flags |= KPROBE_FLAG_DISABLED; |
| 1583 | } |
| 1584 | } |
| 1585 | |
| 1586 | return orig_p; |
| 1587 | } |
| 1588 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1589 | /* |
| 1590 | * Unregister a kprobe without a scheduler synchronization. |
| 1591 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1592 | static int __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1593 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1594 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1595 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1596 | /* Disable kprobe. This will disarm it if needed. */ |
| 1597 | ap = __disable_kprobe(p); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1598 | if (ap == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1599 | return -EINVAL; |
| 1600 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1601 | if (ap == p) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1602 | /* |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1603 | * This probe is an independent(and non-optimized) kprobe |
| 1604 | * (not an aggrprobe). Remove from the hash list. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1605 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1606 | goto disarmed; |
| 1607 | |
| 1608 | /* Following process expects this probe is an aggrprobe */ |
| 1609 | WARN_ON(!kprobe_aggrprobe(ap)); |
| 1610 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1611 | if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) |
| 1612 | /* |
| 1613 | * !disarmed could be happen if the probe is under delayed |
| 1614 | * unoptimizing. |
| 1615 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1616 | goto disarmed; |
| 1617 | else { |
| 1618 | /* If disabling probe has special handlers, update aggrprobe */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1619 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1620 | ap->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1621 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1622 | list_for_each_entry_rcu(list_p, &ap->list, list) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1623 | if ((list_p != p) && (list_p->post_handler)) |
| 1624 | goto noclean; |
| 1625 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1626 | ap->post_handler = NULL; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1627 | } |
| 1628 | noclean: |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1629 | /* |
| 1630 | * Remove from the aggrprobe: this path will do nothing in |
| 1631 | * __unregister_kprobe_bottom(). |
| 1632 | */ |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1633 | list_del_rcu(&p->list); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1634 | if (!kprobe_disabled(ap) && !kprobes_all_disarmed) |
| 1635 | /* |
| 1636 | * Try to optimize this probe again, because post |
| 1637 | * handler may have been changed. |
| 1638 | */ |
| 1639 | optimize_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1640 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1641 | return 0; |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1642 | |
| 1643 | disarmed: |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1644 | BUG_ON(!kprobe_disarmed(ap)); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1645 | hlist_del_rcu(&ap->hlist); |
| 1646 | return 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1647 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1648 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1649 | static void __unregister_kprobe_bottom(struct kprobe *p) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1650 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1651 | struct kprobe *ap; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1652 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1653 | if (list_empty(&p->list)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1654 | /* This is an independent kprobe */ |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 1655 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1656 | else if (list_is_singular(&p->list)) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1657 | /* This is the last child of an aggrprobe */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1658 | ap = list_entry(p->list.next, struct kprobe, list); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1659 | list_del(&p->list); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1660 | free_aggr_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1661 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1662 | /* Otherwise, do nothing. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | } |
| 1664 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1665 | int register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1666 | { |
| 1667 | int i, ret = 0; |
| 1668 | |
| 1669 | if (num <= 0) |
| 1670 | return -EINVAL; |
| 1671 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1672 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1673 | if (ret < 0) { |
| 1674 | if (i > 0) |
| 1675 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1676 | break; |
| 1677 | } |
| 1678 | } |
| 1679 | return ret; |
| 1680 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1681 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1682 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1683 | void unregister_kprobe(struct kprobe *p) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1684 | { |
| 1685 | unregister_kprobes(&p, 1); |
| 1686 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1687 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1688 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1689 | void unregister_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1690 | { |
| 1691 | int i; |
| 1692 | |
| 1693 | if (num <= 0) |
| 1694 | return; |
| 1695 | mutex_lock(&kprobe_mutex); |
| 1696 | for (i = 0; i < num; i++) |
| 1697 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 1698 | kps[i]->addr = NULL; |
| 1699 | mutex_unlock(&kprobe_mutex); |
| 1700 | |
| 1701 | synchronize_sched(); |
| 1702 | for (i = 0; i < num; i++) |
| 1703 | if (kps[i]->addr) |
| 1704 | __unregister_kprobe_bottom(kps[i]); |
| 1705 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1706 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1707 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1708 | static struct notifier_block kprobe_exceptions_nb = { |
| 1709 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 1710 | .priority = 0x7fffffff /* we need to be notified first */ |
| 1711 | }; |
| 1712 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 1713 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 1714 | { |
| 1715 | return (unsigned long)entry; |
| 1716 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1717 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1718 | int register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1719 | { |
| 1720 | struct jprobe *jp; |
| 1721 | int ret = 0, i; |
| 1722 | |
| 1723 | if (num <= 0) |
| 1724 | return -EINVAL; |
| 1725 | for (i = 0; i < num; i++) { |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1726 | unsigned long addr, offset; |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1727 | jp = jps[i]; |
| 1728 | addr = arch_deref_entry_point(jp->entry); |
| 1729 | |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1730 | /* Verify probepoint is a function entry point */ |
| 1731 | if (kallsyms_lookup_size_offset(addr, NULL, &offset) && |
| 1732 | offset == 0) { |
| 1733 | jp->kp.pre_handler = setjmp_pre_handler; |
| 1734 | jp->kp.break_handler = longjmp_break_handler; |
| 1735 | ret = register_kprobe(&jp->kp); |
| 1736 | } else |
| 1737 | ret = -EINVAL; |
Namhyung Kim | edbaadb | 2010-09-15 10:04:26 +0900 | [diff] [blame] | 1738 | |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1739 | if (ret < 0) { |
| 1740 | if (i > 0) |
| 1741 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1742 | break; |
| 1743 | } |
| 1744 | } |
| 1745 | return ret; |
| 1746 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1747 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1748 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1749 | int register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1750 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1751 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1753 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1754 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1755 | void unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1756 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1757 | unregister_jprobes(&jp, 1); |
| 1758 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1759 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1760 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1761 | void unregister_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1762 | { |
| 1763 | int i; |
| 1764 | |
| 1765 | if (num <= 0) |
| 1766 | return; |
| 1767 | mutex_lock(&kprobe_mutex); |
| 1768 | for (i = 0; i < num; i++) |
| 1769 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 1770 | jps[i]->kp.addr = NULL; |
| 1771 | mutex_unlock(&kprobe_mutex); |
| 1772 | |
| 1773 | synchronize_sched(); |
| 1774 | for (i = 0; i < num; i++) { |
| 1775 | if (jps[i]->kp.addr) |
| 1776 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 1777 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1778 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1779 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1780 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1781 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1782 | /* |
| 1783 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 1784 | * hits it will set up the return probe. |
| 1785 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1786 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1787 | { |
| 1788 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1789 | unsigned long hash, flags = 0; |
| 1790 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1791 | |
Masami Hiramatsu | f96f567 | 2014-08-04 03:10:16 +0000 | [diff] [blame] | 1792 | /* |
| 1793 | * To avoid deadlocks, prohibit return probing in NMI contexts, |
| 1794 | * just skip the probe and increase the (inexact) 'nmissed' |
| 1795 | * statistical counter, so that the user is informed that |
| 1796 | * something happened: |
| 1797 | */ |
| 1798 | if (unlikely(in_nmi())) { |
| 1799 | rp->nmissed++; |
| 1800 | return 0; |
| 1801 | } |
| 1802 | |
| 1803 | /* 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] | 1804 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1805 | raw_spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1806 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1807 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1808 | struct kretprobe_instance, hlist); |
| 1809 | hlist_del(&ri->hlist); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1810 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1811 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1812 | ri->rp = rp; |
| 1813 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1814 | |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1815 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
| 1816 | raw_spin_lock_irqsave(&rp->lock, flags); |
| 1817 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 1818 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1819 | return 0; |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1820 | } |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1821 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1822 | arch_prepare_kretprobe(ri, regs); |
| 1823 | |
| 1824 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1825 | INIT_HLIST_NODE(&ri->hlist); |
| 1826 | kretprobe_table_lock(hash, &flags); |
| 1827 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 1828 | kretprobe_table_unlock(hash, &flags); |
| 1829 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1830 | rp->nmissed++; |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1831 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1832 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1833 | return 0; |
| 1834 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1835 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1836 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1837 | int register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1838 | { |
| 1839 | int ret = 0; |
| 1840 | struct kretprobe_instance *inst; |
| 1841 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1842 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1843 | |
| 1844 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1845 | addr = kprobe_addr(&rp->kp); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1846 | if (IS_ERR(addr)) |
| 1847 | return PTR_ERR(addr); |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1848 | |
| 1849 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1850 | if (kretprobe_blacklist[i].addr == addr) |
| 1851 | return -EINVAL; |
| 1852 | } |
| 1853 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1854 | |
| 1855 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1856 | rp->kp.post_handler = NULL; |
| 1857 | rp->kp.fault_handler = NULL; |
| 1858 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1859 | |
| 1860 | /* Pre-allocate memory for max kretprobe instances */ |
| 1861 | if (rp->maxactive <= 0) { |
| 1862 | #ifdef CONFIG_PREEMPT |
Heiko Carstens | c2ef666 | 2009-12-21 13:02:24 +0100 | [diff] [blame] | 1863 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1864 | #else |
Ananth N Mavinakayanahalli | 4dae560 | 2009-10-30 19:23:10 +0530 | [diff] [blame] | 1865 | rp->maxactive = num_possible_cpus(); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1866 | #endif |
| 1867 | } |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1868 | raw_spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1869 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1870 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1871 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1872 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1873 | if (inst == NULL) { |
| 1874 | free_rp_inst(rp); |
| 1875 | return -ENOMEM; |
| 1876 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1877 | INIT_HLIST_NODE(&inst->hlist); |
| 1878 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1879 | } |
| 1880 | |
| 1881 | rp->nmissed = 0; |
| 1882 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1883 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1884 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1885 | free_rp_inst(rp); |
| 1886 | return ret; |
| 1887 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1888 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1889 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1890 | int register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1891 | { |
| 1892 | int ret = 0, i; |
| 1893 | |
| 1894 | if (num <= 0) |
| 1895 | return -EINVAL; |
| 1896 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1897 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1898 | if (ret < 0) { |
| 1899 | if (i > 0) |
| 1900 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1901 | break; |
| 1902 | } |
| 1903 | } |
| 1904 | return ret; |
| 1905 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1906 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1907 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1908 | void unregister_kretprobe(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1909 | { |
| 1910 | unregister_kretprobes(&rp, 1); |
| 1911 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1912 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1913 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1914 | void unregister_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1915 | { |
| 1916 | int i; |
| 1917 | |
| 1918 | if (num <= 0) |
| 1919 | return; |
| 1920 | mutex_lock(&kprobe_mutex); |
| 1921 | for (i = 0; i < num; i++) |
| 1922 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1923 | rps[i]->kp.addr = NULL; |
| 1924 | mutex_unlock(&kprobe_mutex); |
| 1925 | |
| 1926 | synchronize_sched(); |
| 1927 | for (i = 0; i < num; i++) { |
| 1928 | if (rps[i]->kp.addr) { |
| 1929 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1930 | cleanup_rp_inst(rps[i]); |
| 1931 | } |
| 1932 | } |
| 1933 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1934 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1935 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1936 | #else /* CONFIG_KRETPROBES */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1937 | int register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1938 | { |
| 1939 | return -ENOSYS; |
| 1940 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1941 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1942 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1943 | int register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1944 | { |
| 1945 | return -ENOSYS; |
| 1946 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1947 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1948 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1949 | void unregister_kretprobe(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1950 | { |
| 1951 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1952 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1953 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1954 | void unregister_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1955 | { |
| 1956 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1957 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1958 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1959 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1960 | { |
| 1961 | return 0; |
| 1962 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1963 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1964 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1965 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1966 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1967 | /* Set the kprobe gone and remove its instruction buffer. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1968 | static void kill_kprobe(struct kprobe *p) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1969 | { |
| 1970 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1971 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1972 | p->flags |= KPROBE_FLAG_GONE; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1973 | if (kprobe_aggrprobe(p)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1974 | /* |
| 1975 | * If this is an aggr_kprobe, we have to list all the |
| 1976 | * chained probes and mark them GONE. |
| 1977 | */ |
| 1978 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1979 | kp->flags |= KPROBE_FLAG_GONE; |
| 1980 | p->post_handler = NULL; |
| 1981 | p->break_handler = NULL; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1982 | kill_optimized_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1983 | } |
| 1984 | /* |
| 1985 | * Here, we can remove insn_slot safely, because no thread calls |
| 1986 | * the original probed function (which will be freed soon) any more. |
| 1987 | */ |
| 1988 | arch_remove_kprobe(p); |
| 1989 | } |
| 1990 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1991 | /* Disable one kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1992 | int disable_kprobe(struct kprobe *kp) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1993 | { |
| 1994 | int ret = 0; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1995 | |
| 1996 | mutex_lock(&kprobe_mutex); |
| 1997 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1998 | /* Disable this kprobe */ |
| 1999 | if (__disable_kprobe(kp) == NULL) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2000 | ret = -EINVAL; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2001 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2002 | mutex_unlock(&kprobe_mutex); |
| 2003 | return ret; |
| 2004 | } |
| 2005 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 2006 | |
| 2007 | /* Enable one kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2008 | int enable_kprobe(struct kprobe *kp) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2009 | { |
| 2010 | int ret = 0; |
| 2011 | struct kprobe *p; |
| 2012 | |
| 2013 | mutex_lock(&kprobe_mutex); |
| 2014 | |
| 2015 | /* Check whether specified probe is valid. */ |
| 2016 | p = __get_valid_kprobe(kp); |
| 2017 | if (unlikely(p == NULL)) { |
| 2018 | ret = -EINVAL; |
| 2019 | goto out; |
| 2020 | } |
| 2021 | |
| 2022 | if (kprobe_gone(kp)) { |
| 2023 | /* This kprobe has gone, we couldn't enable it. */ |
| 2024 | ret = -EINVAL; |
| 2025 | goto out; |
| 2026 | } |
| 2027 | |
| 2028 | if (p != kp) |
| 2029 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 2030 | |
| 2031 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { |
| 2032 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 2033 | arm_kprobe(p); |
| 2034 | } |
| 2035 | out: |
| 2036 | mutex_unlock(&kprobe_mutex); |
| 2037 | return ret; |
| 2038 | } |
| 2039 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 2040 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2041 | void dump_kprobe(struct kprobe *kp) |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 2042 | { |
| 2043 | printk(KERN_WARNING "Dumping kprobe:\n"); |
| 2044 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", |
| 2045 | kp->symbol_name, kp->addr, kp->offset); |
| 2046 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2047 | NOKPROBE_SYMBOL(dump_kprobe); |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 2048 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2049 | /* |
| 2050 | * Lookup and populate the kprobe_blacklist. |
| 2051 | * |
| 2052 | * Unlike the kretprobe blacklist, we'll need to determine |
| 2053 | * the range of addresses that belong to the said functions, |
| 2054 | * since a kprobe need not necessarily be at the beginning |
| 2055 | * of a function. |
| 2056 | */ |
| 2057 | static int __init populate_kprobe_blacklist(unsigned long *start, |
| 2058 | unsigned long *end) |
| 2059 | { |
| 2060 | unsigned long *iter; |
| 2061 | struct kprobe_blacklist_entry *ent; |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2062 | unsigned long entry, offset = 0, size = 0; |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2063 | |
| 2064 | for (iter = start; iter < end; iter++) { |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2065 | entry = arch_deref_entry_point((void *)*iter); |
| 2066 | |
| 2067 | if (!kernel_text_address(entry) || |
| 2068 | !kallsyms_lookup_size_offset(entry, &size, &offset)) { |
| 2069 | pr_err("Failed to find blacklist at %p\n", |
| 2070 | (void *)entry); |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2071 | continue; |
| 2072 | } |
| 2073 | |
| 2074 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); |
| 2075 | if (!ent) |
| 2076 | return -ENOMEM; |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2077 | ent->start_addr = entry; |
| 2078 | ent->end_addr = entry + size; |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2079 | INIT_LIST_HEAD(&ent->list); |
| 2080 | list_add_tail(&ent->list, &kprobe_blacklist); |
| 2081 | } |
| 2082 | return 0; |
| 2083 | } |
| 2084 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2085 | /* Module notifier call back, checking kprobes on the module */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2086 | static int kprobes_module_callback(struct notifier_block *nb, |
| 2087 | unsigned long val, void *data) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2088 | { |
| 2089 | struct module *mod = data; |
| 2090 | struct hlist_head *head; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2091 | struct kprobe *p; |
| 2092 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2093 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2094 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2095 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2096 | return NOTIFY_DONE; |
| 2097 | |
| 2098 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2099 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 2100 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 2101 | * notified, only .init.text section would be freed. We need to |
| 2102 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2103 | */ |
| 2104 | mutex_lock(&kprobe_mutex); |
| 2105 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2106 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2107 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2108 | if (within_module_init((unsigned long)p->addr, mod) || |
| 2109 | (checkcore && |
| 2110 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2111 | /* |
| 2112 | * The vaddr this probe is installed will soon |
| 2113 | * be vfreed buy not synced to disk. Hence, |
| 2114 | * disarming the breakpoint isn't needed. |
| 2115 | */ |
| 2116 | kill_kprobe(p); |
| 2117 | } |
| 2118 | } |
| 2119 | mutex_unlock(&kprobe_mutex); |
| 2120 | return NOTIFY_DONE; |
| 2121 | } |
| 2122 | |
| 2123 | static struct notifier_block kprobe_module_nb = { |
| 2124 | .notifier_call = kprobes_module_callback, |
| 2125 | .priority = 0 |
| 2126 | }; |
| 2127 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2128 | /* Markers of _kprobe_blacklist section */ |
| 2129 | extern unsigned long __start_kprobe_blacklist[]; |
| 2130 | extern unsigned long __stop_kprobe_blacklist[]; |
| 2131 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2132 | static int __init init_kprobes(void) |
| 2133 | { |
| 2134 | int i, err = 0; |
| 2135 | |
| 2136 | /* FIXME allocate the probe table, currently defined statically */ |
| 2137 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2138 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2139 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2140 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 2141 | raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2142 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2144 | err = populate_kprobe_blacklist(__start_kprobe_blacklist, |
| 2145 | __stop_kprobe_blacklist); |
| 2146 | if (err) { |
| 2147 | pr_err("kprobes: failed to populate blacklist: %d\n", err); |
| 2148 | pr_err("Please take care of using kprobes.\n"); |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 2149 | } |
| 2150 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 2151 | if (kretprobe_blacklist_size) { |
| 2152 | /* lookup the function address from its name */ |
| 2153 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 2154 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 2155 | kretprobe_blacklist[i].addr); |
| 2156 | if (!kretprobe_blacklist[i].addr) |
| 2157 | printk("kretprobe: lookup failed: %s\n", |
| 2158 | kretprobe_blacklist[i].name); |
| 2159 | } |
| 2160 | } |
| 2161 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2162 | #if defined(CONFIG_OPTPROBES) |
| 2163 | #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2164 | /* Init kprobe_optinsn_slots */ |
| 2165 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; |
| 2166 | #endif |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2167 | /* By default, kprobes can be optimized */ |
| 2168 | kprobes_allow_optimization = true; |
| 2169 | #endif |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2170 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2171 | /* By default, kprobes are armed */ |
| 2172 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2173 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 2174 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2175 | if (!err) |
| 2176 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2177 | if (!err) |
| 2178 | err = register_module_notifier(&kprobe_module_nb); |
| 2179 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 2180 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2181 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 2182 | if (!err) |
| 2183 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2184 | return err; |
| 2185 | } |
| 2186 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2187 | #ifdef CONFIG_DEBUG_FS |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2188 | static void report_probe(struct seq_file *pi, struct kprobe *p, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2189 | const char *sym, int offset, char *modname, struct kprobe *pp) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2190 | { |
| 2191 | char *kprobe_type; |
| 2192 | |
| 2193 | if (p->pre_handler == pre_handler_kretprobe) |
| 2194 | kprobe_type = "r"; |
| 2195 | else if (p->pre_handler == setjmp_pre_handler) |
| 2196 | kprobe_type = "j"; |
| 2197 | else |
| 2198 | kprobe_type = "k"; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2199 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2200 | if (sym) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2201 | seq_printf(pi, "%p %s %s+0x%x %s ", |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2202 | p->addr, kprobe_type, sym, offset, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2203 | (modname ? modname : " ")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2204 | else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2205 | seq_printf(pi, "%p %s %p ", |
| 2206 | p->addr, kprobe_type, p->addr); |
| 2207 | |
| 2208 | if (!pp) |
| 2209 | pp = p; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2210 | seq_printf(pi, "%s%s%s%s\n", |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2211 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 2212 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2213 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), |
| 2214 | (kprobe_ftrace(pp) ? "[FTRACE]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2215 | } |
| 2216 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2217 | static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2218 | { |
| 2219 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 2220 | } |
| 2221 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2222 | static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2223 | { |
| 2224 | (*pos)++; |
| 2225 | if (*pos >= KPROBE_TABLE_SIZE) |
| 2226 | return NULL; |
| 2227 | return pos; |
| 2228 | } |
| 2229 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2230 | static void kprobe_seq_stop(struct seq_file *f, void *v) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2231 | { |
| 2232 | /* Nothing to do */ |
| 2233 | } |
| 2234 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2235 | static int show_kprobe_addr(struct seq_file *pi, void *v) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2236 | { |
| 2237 | struct hlist_head *head; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2238 | struct kprobe *p, *kp; |
| 2239 | const char *sym = NULL; |
| 2240 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2241 | unsigned long offset = 0; |
Joe Mario | ab76786 | 2013-11-12 15:10:23 -0800 | [diff] [blame] | 2242 | char *modname, namebuf[KSYM_NAME_LEN]; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2243 | |
| 2244 | head = &kprobe_table[i]; |
| 2245 | preempt_disable(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2246 | hlist_for_each_entry_rcu(p, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2247 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2248 | &offset, &modname, namebuf); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2249 | if (kprobe_aggrprobe(p)) { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2250 | list_for_each_entry_rcu(kp, &p->list, list) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2251 | report_probe(pi, kp, sym, offset, modname, p); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2252 | } else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2253 | report_probe(pi, p, sym, offset, modname, NULL); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2254 | } |
| 2255 | preempt_enable(); |
| 2256 | return 0; |
| 2257 | } |
| 2258 | |
James Morris | 88e9d34 | 2009-09-22 16:43:43 -0700 | [diff] [blame] | 2259 | static const struct seq_operations kprobes_seq_ops = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2260 | .start = kprobe_seq_start, |
| 2261 | .next = kprobe_seq_next, |
| 2262 | .stop = kprobe_seq_stop, |
| 2263 | .show = show_kprobe_addr |
| 2264 | }; |
| 2265 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2266 | static int kprobes_open(struct inode *inode, struct file *filp) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2267 | { |
| 2268 | return seq_open(filp, &kprobes_seq_ops); |
| 2269 | } |
| 2270 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2271 | static const struct file_operations debugfs_kprobes_operations = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2272 | .open = kprobes_open, |
| 2273 | .read = seq_read, |
| 2274 | .llseek = seq_lseek, |
| 2275 | .release = seq_release, |
| 2276 | }; |
| 2277 | |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2278 | /* kprobes/blacklist -- shows which functions can not be probed */ |
| 2279 | static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) |
| 2280 | { |
| 2281 | return seq_list_start(&kprobe_blacklist, *pos); |
| 2282 | } |
| 2283 | |
| 2284 | static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) |
| 2285 | { |
| 2286 | return seq_list_next(v, &kprobe_blacklist, pos); |
| 2287 | } |
| 2288 | |
| 2289 | static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) |
| 2290 | { |
| 2291 | struct kprobe_blacklist_entry *ent = |
| 2292 | list_entry(v, struct kprobe_blacklist_entry, list); |
| 2293 | |
| 2294 | seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, |
| 2295 | (void *)ent->end_addr, (void *)ent->start_addr); |
| 2296 | return 0; |
| 2297 | } |
| 2298 | |
| 2299 | static const struct seq_operations kprobe_blacklist_seq_ops = { |
| 2300 | .start = kprobe_blacklist_seq_start, |
| 2301 | .next = kprobe_blacklist_seq_next, |
| 2302 | .stop = kprobe_seq_stop, /* Reuse void function */ |
| 2303 | .show = kprobe_blacklist_seq_show, |
| 2304 | }; |
| 2305 | |
| 2306 | static int kprobe_blacklist_open(struct inode *inode, struct file *filp) |
| 2307 | { |
| 2308 | return seq_open(filp, &kprobe_blacklist_seq_ops); |
| 2309 | } |
| 2310 | |
| 2311 | static const struct file_operations debugfs_kprobe_blacklist_ops = { |
| 2312 | .open = kprobe_blacklist_open, |
| 2313 | .read = seq_read, |
| 2314 | .llseek = seq_lseek, |
| 2315 | .release = seq_release, |
| 2316 | }; |
| 2317 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2318 | static void arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2319 | { |
| 2320 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2321 | struct kprobe *p; |
| 2322 | unsigned int i; |
| 2323 | |
| 2324 | mutex_lock(&kprobe_mutex); |
| 2325 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2326 | /* If kprobes are armed, just return */ |
| 2327 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2328 | goto already_enabled; |
| 2329 | |
Wang Nan | 977ad48 | 2015-02-13 14:40:24 -0800 | [diff] [blame] | 2330 | /* |
| 2331 | * optimize_kprobe() called by arm_kprobe() checks |
| 2332 | * kprobes_all_disarmed, so set kprobes_all_disarmed before |
| 2333 | * arm_kprobe. |
| 2334 | */ |
| 2335 | kprobes_all_disarmed = false; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2336 | /* Arming kprobes doesn't optimize kprobe itself */ |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2337 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2338 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2339 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2340 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2341 | arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2342 | } |
| 2343 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2344 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 2345 | |
| 2346 | already_enabled: |
| 2347 | mutex_unlock(&kprobe_mutex); |
| 2348 | return; |
| 2349 | } |
| 2350 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2351 | static void disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2352 | { |
| 2353 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2354 | struct kprobe *p; |
| 2355 | unsigned int i; |
| 2356 | |
| 2357 | mutex_lock(&kprobe_mutex); |
| 2358 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2359 | /* If kprobes are already disarmed, just return */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2360 | if (kprobes_all_disarmed) { |
| 2361 | mutex_unlock(&kprobe_mutex); |
| 2362 | return; |
| 2363 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2364 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2365 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2366 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2367 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2368 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2369 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2370 | hlist_for_each_entry_rcu(p, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2371 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2372 | disarm_kprobe(p, false); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2373 | } |
| 2374 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2375 | mutex_unlock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2376 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2377 | /* Wait for disarming all kprobes by optimizer */ |
| 2378 | wait_for_kprobe_optimizer(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2379 | } |
| 2380 | |
| 2381 | /* |
| 2382 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 2383 | * when the bool state is switched. We can reuse that facility when |
| 2384 | * available |
| 2385 | */ |
| 2386 | static ssize_t read_enabled_file_bool(struct file *file, |
| 2387 | char __user *user_buf, size_t count, loff_t *ppos) |
| 2388 | { |
| 2389 | char buf[3]; |
| 2390 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2391 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2392 | buf[0] = '1'; |
| 2393 | else |
| 2394 | buf[0] = '0'; |
| 2395 | buf[1] = '\n'; |
| 2396 | buf[2] = 0x00; |
| 2397 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 2398 | } |
| 2399 | |
| 2400 | static ssize_t write_enabled_file_bool(struct file *file, |
| 2401 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 2402 | { |
| 2403 | char buf[32]; |
Stephen Boyd | efeb156 | 2012-01-12 17:17:11 -0800 | [diff] [blame] | 2404 | size_t buf_size; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2405 | |
| 2406 | buf_size = min(count, (sizeof(buf)-1)); |
| 2407 | if (copy_from_user(buf, user_buf, buf_size)) |
| 2408 | return -EFAULT; |
| 2409 | |
Mathias Krause | 10fb46d | 2013-07-03 15:05:39 -0700 | [diff] [blame] | 2410 | buf[buf_size] = '\0'; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2411 | switch (buf[0]) { |
| 2412 | case 'y': |
| 2413 | case 'Y': |
| 2414 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2415 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2416 | break; |
| 2417 | case 'n': |
| 2418 | case 'N': |
| 2419 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2420 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2421 | break; |
Mathias Krause | 10fb46d | 2013-07-03 15:05:39 -0700 | [diff] [blame] | 2422 | default: |
| 2423 | return -EINVAL; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2424 | } |
| 2425 | |
| 2426 | return count; |
| 2427 | } |
| 2428 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2429 | static const struct file_operations fops_kp = { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2430 | .read = read_enabled_file_bool, |
| 2431 | .write = write_enabled_file_bool, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 2432 | .llseek = default_llseek, |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2433 | }; |
| 2434 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2435 | static int __init debugfs_kprobe_init(void) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2436 | { |
| 2437 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2438 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2439 | |
| 2440 | dir = debugfs_create_dir("kprobes", NULL); |
| 2441 | if (!dir) |
| 2442 | return -ENOMEM; |
| 2443 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 2444 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2445 | &debugfs_kprobes_operations); |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2446 | if (!file) |
| 2447 | goto error; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2448 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2449 | file = debugfs_create_file("enabled", 0600, dir, |
| 2450 | &value, &fops_kp); |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2451 | if (!file) |
| 2452 | goto error; |
| 2453 | |
| 2454 | file = debugfs_create_file("blacklist", 0444, dir, NULL, |
| 2455 | &debugfs_kprobe_blacklist_ops); |
| 2456 | if (!file) |
| 2457 | goto error; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2458 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2459 | return 0; |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2460 | |
| 2461 | error: |
| 2462 | debugfs_remove(dir); |
| 2463 | return -ENOMEM; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2464 | } |
| 2465 | |
| 2466 | late_initcall(debugfs_kprobe_init); |
| 2467 | #endif /* CONFIG_DEBUG_FS */ |
| 2468 | |
| 2469 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2470 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2471 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2472 | EXPORT_SYMBOL_GPL(jprobe_return); |