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 | |
Christoph Hellwig | bfd45be | 2016-10-11 13:52:22 -0700 | [diff] [blame] | 52 | #include <asm/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <asm/cacheflush.h> |
| 54 | #include <asm/errno.h> |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 55 | #include <linux/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 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 61 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 63 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 65 | /* NOTE: change this value only with kprobe_mutex held */ |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 66 | static bool kprobes_all_disarmed; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 67 | |
Masami Hiramatsu | 43948f5 | 2010-10-25 22:18:01 +0900 | [diff] [blame] | 68 | /* This protects kprobe_table and optimizing_list */ |
| 69 | static DEFINE_MUTEX(kprobe_mutex); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 70 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 71 | static struct { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 72 | raw_spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 73 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 74 | |
Naveen N. Rao | 290e307 | 2017-04-19 18:21:01 +0530 | [diff] [blame] | 75 | kprobe_opcode_t * __weak kprobe_lookup_name(const char *name, |
| 76 | unsigned int __unused) |
Naveen N. Rao | 49e0b46 | 2017-04-19 18:21:00 +0530 | [diff] [blame] | 77 | { |
| 78 | return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); |
| 79 | } |
| 80 | |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 81 | static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 82 | { |
| 83 | return &(kretprobe_table_locks[hash].lock); |
| 84 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 86 | /* Blacklist -- list of struct kprobe_blacklist_entry */ |
| 87 | static LIST_HEAD(kprobe_blacklist); |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 88 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 89 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 90 | /* |
| 91 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 92 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 93 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 94 | * is a recipe for disaster |
| 95 | */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 96 | struct kprobe_insn_page { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 97 | struct list_head list; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 98 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 99 | struct kprobe_insn_cache *cache; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 100 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 101 | int ngarbage; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 102 | char slot_used[]; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 103 | }; |
| 104 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 105 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
| 106 | (offsetof(struct kprobe_insn_page, slot_used) + \ |
| 107 | (sizeof(char) * (slots))) |
| 108 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 109 | static int slots_per_page(struct kprobe_insn_cache *c) |
| 110 | { |
| 111 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); |
| 112 | } |
| 113 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 114 | enum kprobe_slot_state { |
| 115 | SLOT_CLEAN = 0, |
| 116 | SLOT_DIRTY = 1, |
| 117 | SLOT_USED = 2, |
| 118 | }; |
| 119 | |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 120 | static void *alloc_insn_page(void) |
| 121 | { |
| 122 | return module_alloc(PAGE_SIZE); |
| 123 | } |
| 124 | |
| 125 | static void free_insn_page(void *page) |
| 126 | { |
Rusty Russell | be1f221 | 2015-01-20 09:07:05 +1030 | [diff] [blame] | 127 | module_memfree(page); |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 128 | } |
| 129 | |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 130 | struct kprobe_insn_cache kprobe_insn_slots = { |
| 131 | .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 132 | .alloc = alloc_insn_page, |
| 133 | .free = free_insn_page, |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 134 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
| 135 | .insn_size = MAX_INSN_SIZE, |
| 136 | .nr_garbage = 0, |
| 137 | }; |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 138 | static int collect_garbage_slots(struct kprobe_insn_cache *c); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 139 | |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 140 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 141 | * __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] | 142 | * We allocate an executable page if there's no room on existing ones. |
| 143 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 144 | kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 145 | { |
| 146 | struct kprobe_insn_page *kip; |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 147 | kprobe_opcode_t *slot = NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 148 | |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 149 | /* Since the slot array is not protected by rcu, we need a mutex */ |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 150 | mutex_lock(&c->mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 151 | retry: |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 152 | rcu_read_lock(); |
| 153 | list_for_each_entry_rcu(kip, &c->pages, list) { |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 154 | if (kip->nused < slots_per_page(c)) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 155 | int i; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 156 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 157 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 158 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 159 | kip->nused++; |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 160 | slot = kip->insns + (i * c->insn_size); |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 161 | rcu_read_unlock(); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 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 | } |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 170 | rcu_read_unlock(); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 171 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 172 | /* If there are any garbage slots, collect it and try again. */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 173 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 174 | goto retry; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 175 | |
| 176 | /* All out of space. Need to allocate a new page. */ |
| 177 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 178 | if (!kip) |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 179 | goto out; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 180 | |
| 181 | /* |
| 182 | * Use module_alloc so this page is within +/- 2GB of where the |
| 183 | * kernel image and loaded module images reside. This is required |
| 184 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 185 | */ |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 186 | kip->insns = c->alloc(); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 187 | if (!kip->insns) { |
| 188 | kfree(kip); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 189 | goto out; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 190 | } |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 191 | INIT_LIST_HEAD(&kip->list); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 192 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 193 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 194 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 195 | kip->ngarbage = 0; |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 196 | kip->cache = c; |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 197 | list_add_rcu(&kip->list, &c->pages); |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 198 | slot = kip->insns; |
| 199 | out: |
| 200 | mutex_unlock(&c->mutex); |
| 201 | return slot; |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 202 | } |
| 203 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 204 | /* Return 1 if all garbages are collected, otherwise 0. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 205 | static int collect_one_slot(struct kprobe_insn_page *kip, int idx) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 206 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 207 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 208 | kip->nused--; |
| 209 | if (kip->nused == 0) { |
| 210 | /* |
| 211 | * Page is no longer in use. Free it unless |
| 212 | * it's the last one. We keep the last one |
| 213 | * so as not to have to set it up again the |
| 214 | * next time somebody inserts a probe. |
| 215 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 216 | if (!list_is_singular(&kip->list)) { |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 217 | list_del_rcu(&kip->list); |
| 218 | synchronize_rcu(); |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 219 | kip->cache->free(kip->insns); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 220 | kfree(kip); |
| 221 | } |
| 222 | return 1; |
| 223 | } |
| 224 | return 0; |
| 225 | } |
| 226 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 227 | static int collect_garbage_slots(struct kprobe_insn_cache *c) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 228 | { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 229 | struct kprobe_insn_page *kip, *next; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 230 | |
Masami Hiramatsu | 615d0eb | 2010-02-02 16:49:04 -0500 | [diff] [blame] | 231 | /* Ensure no-one is interrupted on the garbages */ |
| 232 | synchronize_sched(); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 233 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 234 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 235 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 236 | if (kip->ngarbage == 0) |
| 237 | continue; |
| 238 | kip->ngarbage = 0; /* we will collect all garbages */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 239 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 240 | if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i)) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 241 | break; |
| 242 | } |
| 243 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 244 | c->nr_garbage = 0; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 245 | return 0; |
| 246 | } |
| 247 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 248 | void __free_insn_slot(struct kprobe_insn_cache *c, |
| 249 | kprobe_opcode_t *slot, int dirty) |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 250 | { |
| 251 | struct kprobe_insn_page *kip; |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 252 | long idx; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 253 | |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 254 | mutex_lock(&c->mutex); |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 255 | rcu_read_lock(); |
| 256 | list_for_each_entry_rcu(kip, &c->pages, list) { |
| 257 | idx = ((long)slot - (long)kip->insns) / |
| 258 | (c->insn_size * sizeof(kprobe_opcode_t)); |
| 259 | if (idx >= 0 && idx < slots_per_page(c)) |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 260 | goto out; |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 261 | } |
| 262 | /* Could not find this slot. */ |
| 263 | WARN_ON(1); |
| 264 | kip = NULL; |
| 265 | out: |
| 266 | rcu_read_unlock(); |
| 267 | /* Mark and sweep: this may sleep */ |
| 268 | if (kip) { |
| 269 | /* Check double free */ |
| 270 | WARN_ON(kip->slot_used[idx] != SLOT_USED); |
| 271 | if (dirty) { |
| 272 | kip->slot_used[idx] = SLOT_DIRTY; |
| 273 | kip->ngarbage++; |
| 274 | if (++c->nr_garbage > slots_per_page(c)) |
| 275 | collect_garbage_slots(c); |
| 276 | } else { |
| 277 | collect_one_slot(kip, idx); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 278 | } |
| 279 | } |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 280 | mutex_unlock(&c->mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 281 | } |
| 282 | |
Masami Hiramatsu | 5b48562 | 2017-01-08 23:58:09 +0900 | [diff] [blame] | 283 | /* |
| 284 | * Check given address is on the page of kprobe instruction slots. |
| 285 | * This will be used for checking whether the address on a stack |
| 286 | * is on a text area or not. |
| 287 | */ |
| 288 | bool __is_insn_slot_addr(struct kprobe_insn_cache *c, unsigned long addr) |
| 289 | { |
| 290 | struct kprobe_insn_page *kip; |
| 291 | bool ret = false; |
| 292 | |
| 293 | rcu_read_lock(); |
| 294 | list_for_each_entry_rcu(kip, &c->pages, list) { |
| 295 | if (addr >= (unsigned long)kip->insns && |
| 296 | addr < (unsigned long)kip->insns + PAGE_SIZE) { |
| 297 | ret = true; |
| 298 | break; |
| 299 | } |
| 300 | } |
| 301 | rcu_read_unlock(); |
| 302 | |
| 303 | return ret; |
| 304 | } |
| 305 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 306 | #ifdef CONFIG_OPTPROBES |
| 307 | /* For optimized_kprobe buffer */ |
Heiko Carstens | c802d64 | 2013-09-11 14:24:11 -0700 | [diff] [blame] | 308 | struct kprobe_insn_cache kprobe_optinsn_slots = { |
| 309 | .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), |
Heiko Carstens | af96397 | 2013-09-11 14:24:13 -0700 | [diff] [blame] | 310 | .alloc = alloc_insn_page, |
| 311 | .free = free_insn_page, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 312 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), |
| 313 | /* .insn_size is initialized later */ |
| 314 | .nr_garbage = 0, |
| 315 | }; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 316 | #endif |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 317 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 318 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 319 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 320 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 321 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 322 | __this_cpu_write(kprobe_instance, kp); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 323 | } |
| 324 | |
| 325 | static inline void reset_kprobe_instance(void) |
| 326 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 327 | __this_cpu_write(kprobe_instance, NULL); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 328 | } |
| 329 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 330 | /* |
| 331 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 332 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 333 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 334 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 335 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 336 | struct kprobe *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | { |
| 338 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 339 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | |
| 341 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 342 | hlist_for_each_entry_rcu(p, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | if (p->addr == addr) |
| 344 | return p; |
| 345 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 346 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | return NULL; |
| 348 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 349 | NOKPROBE_SYMBOL(get_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 351 | static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 352 | |
| 353 | /* Return true if the kprobe is an aggregator */ |
| 354 | static inline int kprobe_aggrprobe(struct kprobe *p) |
| 355 | { |
| 356 | return p->pre_handler == aggr_pre_handler; |
| 357 | } |
| 358 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 359 | /* Return true(!0) if the kprobe is unused */ |
| 360 | static inline int kprobe_unused(struct kprobe *p) |
| 361 | { |
| 362 | return kprobe_aggrprobe(p) && kprobe_disabled(p) && |
| 363 | list_empty(&p->list); |
| 364 | } |
| 365 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 366 | /* |
| 367 | * Keep all fields in the kprobe consistent |
| 368 | */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 369 | static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 370 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 371 | memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); |
| 372 | memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 373 | } |
| 374 | |
| 375 | #ifdef CONFIG_OPTPROBES |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 376 | /* NOTE: change this value only with kprobe_mutex held */ |
| 377 | static bool kprobes_allow_optimization; |
| 378 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 379 | /* |
| 380 | * Call all pre_handler on the list, but ignores its return value. |
| 381 | * This must be called from arch-dep optimized caller. |
| 382 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 383 | void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 384 | { |
| 385 | struct kprobe *kp; |
| 386 | |
| 387 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 388 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
| 389 | set_kprobe_instance(kp); |
| 390 | kp->pre_handler(kp, regs); |
| 391 | } |
| 392 | reset_kprobe_instance(); |
| 393 | } |
| 394 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 395 | NOKPROBE_SYMBOL(opt_pre_handler); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 396 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 397 | /* Free optimized instructions and optimized_kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 398 | static void free_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 399 | { |
| 400 | struct optimized_kprobe *op; |
| 401 | |
| 402 | op = container_of(p, struct optimized_kprobe, kp); |
| 403 | arch_remove_optimized_kprobe(op); |
| 404 | arch_remove_kprobe(p); |
| 405 | kfree(op); |
| 406 | } |
| 407 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 408 | /* Return true(!0) if the kprobe is ready for optimization. */ |
| 409 | static inline int kprobe_optready(struct kprobe *p) |
| 410 | { |
| 411 | struct optimized_kprobe *op; |
| 412 | |
| 413 | if (kprobe_aggrprobe(p)) { |
| 414 | op = container_of(p, struct optimized_kprobe, kp); |
| 415 | return arch_prepared_optinsn(&op->optinsn); |
| 416 | } |
| 417 | |
| 418 | return 0; |
| 419 | } |
| 420 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 421 | /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ |
| 422 | static inline int kprobe_disarmed(struct kprobe *p) |
| 423 | { |
| 424 | struct optimized_kprobe *op; |
| 425 | |
| 426 | /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ |
| 427 | if (!kprobe_aggrprobe(p)) |
| 428 | return kprobe_disabled(p); |
| 429 | |
| 430 | op = container_of(p, struct optimized_kprobe, kp); |
| 431 | |
| 432 | return kprobe_disabled(p) && list_empty(&op->list); |
| 433 | } |
| 434 | |
| 435 | /* Return true(!0) if the probe is queued on (un)optimizing lists */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 436 | static int kprobe_queued(struct kprobe *p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 437 | { |
| 438 | struct optimized_kprobe *op; |
| 439 | |
| 440 | if (kprobe_aggrprobe(p)) { |
| 441 | op = container_of(p, struct optimized_kprobe, kp); |
| 442 | if (!list_empty(&op->list)) |
| 443 | return 1; |
| 444 | } |
| 445 | return 0; |
| 446 | } |
| 447 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 448 | /* |
| 449 | * Return an optimized kprobe whose optimizing code replaces |
| 450 | * instructions including addr (exclude breakpoint). |
| 451 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 452 | static struct kprobe *get_optimized_kprobe(unsigned long addr) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 453 | { |
| 454 | int i; |
| 455 | struct kprobe *p = NULL; |
| 456 | struct optimized_kprobe *op; |
| 457 | |
| 458 | /* Don't check i == 0, since that is a breakpoint case. */ |
| 459 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) |
| 460 | p = get_kprobe((void *)(addr - i)); |
| 461 | |
| 462 | if (p && kprobe_optready(p)) { |
| 463 | op = container_of(p, struct optimized_kprobe, kp); |
| 464 | if (arch_within_optimized_kprobe(op, addr)) |
| 465 | return p; |
| 466 | } |
| 467 | |
| 468 | return NULL; |
| 469 | } |
| 470 | |
| 471 | /* Optimization staging list, protected by kprobe_mutex */ |
| 472 | static LIST_HEAD(optimizing_list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 473 | static LIST_HEAD(unoptimizing_list); |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 474 | static LIST_HEAD(freeing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 475 | |
| 476 | static void kprobe_optimizer(struct work_struct *work); |
| 477 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); |
| 478 | #define OPTIMIZE_DELAY 5 |
| 479 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 480 | /* |
| 481 | * Optimize (replace a breakpoint with a jump) kprobes listed on |
| 482 | * optimizing_list. |
| 483 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 484 | static void do_optimize_kprobes(void) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 485 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 486 | /* Optimization never be done when disarmed */ |
| 487 | if (kprobes_all_disarmed || !kprobes_allow_optimization || |
| 488 | list_empty(&optimizing_list)) |
| 489 | return; |
| 490 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 491 | /* |
| 492 | * The optimization/unoptimization refers online_cpus via |
| 493 | * stop_machine() and cpu-hotplug modifies online_cpus. |
| 494 | * And same time, text_mutex will be held in cpu-hotplug and here. |
| 495 | * This combination can cause a deadlock (cpu-hotplug try to lock |
| 496 | * text_mutex but stop_machine can not be done because online_cpus |
| 497 | * has been changed) |
| 498 | * To avoid this deadlock, we need to call get_online_cpus() |
| 499 | * for preventing cpu-hotplug outside of text_mutex locking. |
| 500 | */ |
| 501 | get_online_cpus(); |
| 502 | mutex_lock(&text_mutex); |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 503 | arch_optimize_kprobes(&optimizing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 504 | mutex_unlock(&text_mutex); |
| 505 | put_online_cpus(); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 506 | } |
| 507 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 508 | /* |
| 509 | * Unoptimize (replace a jump with a breakpoint and remove the breakpoint |
| 510 | * if need) kprobes listed on unoptimizing_list. |
| 511 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 512 | static void do_unoptimize_kprobes(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 513 | { |
| 514 | struct optimized_kprobe *op, *tmp; |
| 515 | |
| 516 | /* Unoptimization must be done anytime */ |
| 517 | if (list_empty(&unoptimizing_list)) |
| 518 | return; |
| 519 | |
| 520 | /* Ditto to do_optimize_kprobes */ |
| 521 | get_online_cpus(); |
| 522 | mutex_lock(&text_mutex); |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 523 | arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 524 | /* Loop free_list for disarming */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 525 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 526 | /* Disarm probes if marked disabled */ |
| 527 | if (kprobe_disabled(&op->kp)) |
| 528 | arch_disarm_kprobe(&op->kp); |
| 529 | if (kprobe_unused(&op->kp)) { |
| 530 | /* |
| 531 | * Remove unused probes from hash list. After waiting |
| 532 | * for synchronization, these probes are reclaimed. |
| 533 | * (reclaiming is done by do_free_cleaned_kprobes.) |
| 534 | */ |
| 535 | hlist_del_rcu(&op->kp.hlist); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 536 | } else |
| 537 | list_del_init(&op->list); |
| 538 | } |
| 539 | mutex_unlock(&text_mutex); |
| 540 | put_online_cpus(); |
| 541 | } |
| 542 | |
| 543 | /* Reclaim all kprobes on the free_list */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 544 | static void do_free_cleaned_kprobes(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 545 | { |
| 546 | struct optimized_kprobe *op, *tmp; |
| 547 | |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 548 | list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 549 | BUG_ON(!kprobe_unused(&op->kp)); |
| 550 | list_del_init(&op->list); |
| 551 | free_aggr_kprobe(&op->kp); |
| 552 | } |
| 553 | } |
| 554 | |
| 555 | /* Start optimizer after OPTIMIZE_DELAY passed */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 556 | static void kick_kprobe_optimizer(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 557 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 558 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 559 | } |
| 560 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 561 | /* Kprobe jump optimizer */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 562 | static void kprobe_optimizer(struct work_struct *work) |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 563 | { |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 564 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 565 | /* Lock modules while optimizing kprobes */ |
| 566 | mutex_lock(&module_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 567 | |
| 568 | /* |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 569 | * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) |
| 570 | * kprobes before waiting for quiesence period. |
| 571 | */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 572 | do_unoptimize_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 573 | |
| 574 | /* |
| 575 | * Step 2: Wait for quiesence period to ensure all running interrupts |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 576 | * are done. Because optprobe may modify multiple instructions |
| 577 | * there is a chance that Nth instruction is interrupted. In that |
| 578 | * case, running interrupt can return to 2nd-Nth byte of jump |
| 579 | * instruction. This wait is for avoiding it. |
| 580 | */ |
| 581 | synchronize_sched(); |
| 582 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 583 | /* Step 3: Optimize kprobes after quiesence period */ |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 584 | do_optimize_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 585 | |
| 586 | /* Step 4: Free cleaned kprobes after quiesence period */ |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 587 | do_free_cleaned_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 588 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 589 | mutex_unlock(&module_mutex); |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 590 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 591 | |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 592 | /* Step 5: Kick optimizer again if needed */ |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 593 | if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 594 | kick_kprobe_optimizer(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 595 | } |
| 596 | |
| 597 | /* Wait for completing optimization and unoptimization */ |
Thomas Gleixner | 30e7d89 | 2017-05-17 10:19:49 +0200 | [diff] [blame] | 598 | void wait_for_kprobe_optimizer(void) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 599 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 600 | mutex_lock(&kprobe_mutex); |
| 601 | |
| 602 | while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { |
| 603 | mutex_unlock(&kprobe_mutex); |
| 604 | |
| 605 | /* this will also make optimizing_work execute immmediately */ |
| 606 | flush_delayed_work(&optimizing_work); |
| 607 | /* @optimizing_work might not have been queued yet, relax */ |
| 608 | cpu_relax(); |
| 609 | |
| 610 | mutex_lock(&kprobe_mutex); |
| 611 | } |
| 612 | |
| 613 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 614 | } |
| 615 | |
| 616 | /* Optimize kprobe if p is ready to be optimized */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 617 | static void optimize_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 618 | { |
| 619 | struct optimized_kprobe *op; |
| 620 | |
| 621 | /* Check if the kprobe is disabled or not ready for optimization. */ |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 622 | if (!kprobe_optready(p) || !kprobes_allow_optimization || |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 623 | (kprobe_disabled(p) || kprobes_all_disarmed)) |
| 624 | return; |
| 625 | |
| 626 | /* Both of break_handler and post_handler are not supported. */ |
| 627 | if (p->break_handler || p->post_handler) |
| 628 | return; |
| 629 | |
| 630 | op = container_of(p, struct optimized_kprobe, kp); |
| 631 | |
| 632 | /* Check there is no other kprobes at the optimized instructions */ |
| 633 | if (arch_check_optimized_kprobe(op) < 0) |
| 634 | return; |
| 635 | |
| 636 | /* Check if it is already optimized. */ |
| 637 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) |
| 638 | return; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 639 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 640 | |
| 641 | if (!list_empty(&op->list)) |
| 642 | /* This is under unoptimizing. Just dequeue the probe */ |
| 643 | list_del_init(&op->list); |
| 644 | else { |
| 645 | list_add(&op->list, &optimizing_list); |
| 646 | kick_kprobe_optimizer(); |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | /* Short cut to direct unoptimizing */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 651 | static void force_unoptimize_kprobe(struct optimized_kprobe *op) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 652 | { |
| 653 | get_online_cpus(); |
| 654 | arch_unoptimize_kprobe(op); |
| 655 | put_online_cpus(); |
| 656 | if (kprobe_disabled(&op->kp)) |
| 657 | arch_disarm_kprobe(&op->kp); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 658 | } |
| 659 | |
| 660 | /* Unoptimize a kprobe if p is optimized */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 661 | static void unoptimize_kprobe(struct kprobe *p, bool force) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 662 | { |
| 663 | struct optimized_kprobe *op; |
| 664 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 665 | if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) |
| 666 | return; /* This is not an optprobe nor optimized */ |
| 667 | |
| 668 | op = container_of(p, struct optimized_kprobe, kp); |
| 669 | if (!kprobe_optimized(p)) { |
| 670 | /* Unoptimized or unoptimizing case */ |
| 671 | if (force && !list_empty(&op->list)) { |
| 672 | /* |
| 673 | * Only if this is unoptimizing kprobe and forced, |
| 674 | * forcibly unoptimize it. (No need to unoptimize |
| 675 | * unoptimized kprobe again :) |
| 676 | */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 677 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 678 | force_unoptimize_kprobe(op); |
| 679 | } |
| 680 | return; |
| 681 | } |
| 682 | |
| 683 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
| 684 | if (!list_empty(&op->list)) { |
| 685 | /* Dequeue from the optimization queue */ |
| 686 | list_del_init(&op->list); |
| 687 | return; |
| 688 | } |
| 689 | /* Optimized kprobe case */ |
| 690 | if (force) |
| 691 | /* Forcibly update the code: this is a special case */ |
| 692 | force_unoptimize_kprobe(op); |
| 693 | else { |
| 694 | list_add(&op->list, &unoptimizing_list); |
| 695 | kick_kprobe_optimizer(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 696 | } |
| 697 | } |
| 698 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 699 | /* Cancel unoptimizing for reusing */ |
| 700 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 701 | { |
| 702 | struct optimized_kprobe *op; |
| 703 | |
| 704 | BUG_ON(!kprobe_unused(ap)); |
| 705 | /* |
| 706 | * Unused kprobe MUST be on the way of delayed unoptimizing (means |
| 707 | * there is still a relative jump) and disabled. |
| 708 | */ |
| 709 | op = container_of(ap, struct optimized_kprobe, kp); |
| 710 | if (unlikely(list_empty(&op->list))) |
| 711 | printk(KERN_WARNING "Warning: found a stray unused " |
| 712 | "aggrprobe@%p\n", ap->addr); |
| 713 | /* Enable the probe again */ |
| 714 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 715 | /* Optimize it again (remove from op->list) */ |
| 716 | BUG_ON(!kprobe_optready(ap)); |
| 717 | optimize_kprobe(ap); |
| 718 | } |
| 719 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 720 | /* Remove optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 721 | static void kill_optimized_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 722 | { |
| 723 | struct optimized_kprobe *op; |
| 724 | |
| 725 | op = container_of(p, struct optimized_kprobe, kp); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 726 | if (!list_empty(&op->list)) |
| 727 | /* Dequeue from the (un)optimization queue */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 728 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 729 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
Masami Hiramatsu | 7b959fc | 2013-05-22 18:34:09 +0900 | [diff] [blame] | 730 | |
| 731 | if (kprobe_unused(p)) { |
| 732 | /* Enqueue if it is unused */ |
| 733 | list_add(&op->list, &freeing_list); |
| 734 | /* |
| 735 | * Remove unused probes from the hash list. After waiting |
| 736 | * for synchronization, this probe is reclaimed. |
| 737 | * (reclaiming is done by do_free_cleaned_kprobes().) |
| 738 | */ |
| 739 | hlist_del_rcu(&op->kp.hlist); |
| 740 | } |
| 741 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 742 | /* Don't touch the code, because it is already freed. */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 743 | arch_remove_optimized_kprobe(op); |
| 744 | } |
| 745 | |
Masami Hiramatsu | a460246 | 2017-04-19 18:22:25 +0530 | [diff] [blame] | 746 | static inline |
| 747 | void __prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) |
| 748 | { |
| 749 | if (!kprobe_ftrace(p)) |
| 750 | arch_prepare_optimized_kprobe(op, p); |
| 751 | } |
| 752 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 753 | /* Try to prepare optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 754 | static void prepare_optimized_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 755 | { |
| 756 | struct optimized_kprobe *op; |
| 757 | |
| 758 | op = container_of(p, struct optimized_kprobe, kp); |
Masami Hiramatsu | a460246 | 2017-04-19 18:22:25 +0530 | [diff] [blame] | 759 | __prepare_optimized_kprobe(op, p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 760 | } |
| 761 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 762 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 763 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 764 | { |
| 765 | struct optimized_kprobe *op; |
| 766 | |
| 767 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); |
| 768 | if (!op) |
| 769 | return NULL; |
| 770 | |
| 771 | INIT_LIST_HEAD(&op->list); |
| 772 | op->kp.addr = p->addr; |
Masami Hiramatsu | a460246 | 2017-04-19 18:22:25 +0530 | [diff] [blame] | 773 | __prepare_optimized_kprobe(op, p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 774 | |
| 775 | return &op->kp; |
| 776 | } |
| 777 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 778 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 779 | |
| 780 | /* |
| 781 | * Prepare an optimized_kprobe and optimize it |
| 782 | * NOTE: p must be a normal registered kprobe |
| 783 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 784 | static void try_to_optimize_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 785 | { |
| 786 | struct kprobe *ap; |
| 787 | struct optimized_kprobe *op; |
| 788 | |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 789 | /* Impossible to optimize ftrace-based kprobe */ |
| 790 | if (kprobe_ftrace(p)) |
| 791 | return; |
| 792 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 793 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 794 | jump_label_lock(); |
| 795 | mutex_lock(&text_mutex); |
| 796 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 797 | ap = alloc_aggr_kprobe(p); |
| 798 | if (!ap) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 799 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 800 | |
| 801 | op = container_of(ap, struct optimized_kprobe, kp); |
| 802 | if (!arch_prepared_optinsn(&op->optinsn)) { |
| 803 | /* If failed to setup optimizing, fallback to kprobe */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 804 | arch_remove_optimized_kprobe(op); |
| 805 | kfree(op); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 806 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 807 | } |
| 808 | |
| 809 | init_aggr_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 810 | optimize_kprobe(ap); /* This just kicks optimizer thread */ |
| 811 | |
| 812 | out: |
| 813 | mutex_unlock(&text_mutex); |
| 814 | jump_label_unlock(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 815 | } |
| 816 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 817 | #ifdef CONFIG_SYSCTL |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 818 | static void optimize_all_kprobes(void) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 819 | { |
| 820 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 821 | struct kprobe *p; |
| 822 | unsigned int i; |
| 823 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 824 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 825 | /* If optimization is already allowed, just return */ |
| 826 | if (kprobes_allow_optimization) |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 827 | goto out; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 828 | |
| 829 | kprobes_allow_optimization = true; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 830 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 831 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 832 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 833 | if (!kprobe_disabled(p)) |
| 834 | optimize_kprobe(p); |
| 835 | } |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 836 | printk(KERN_INFO "Kprobes globally optimized\n"); |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 837 | out: |
| 838 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 839 | } |
| 840 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 841 | static void unoptimize_all_kprobes(void) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 842 | { |
| 843 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 844 | struct kprobe *p; |
| 845 | unsigned int i; |
| 846 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 847 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 848 | /* If optimization is already prohibited, just return */ |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 849 | if (!kprobes_allow_optimization) { |
| 850 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 851 | return; |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 852 | } |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 853 | |
| 854 | kprobes_allow_optimization = false; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 855 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 856 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 857 | hlist_for_each_entry_rcu(p, head, hlist) { |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 858 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 859 | unoptimize_kprobe(p, false); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 860 | } |
| 861 | } |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 862 | mutex_unlock(&kprobe_mutex); |
| 863 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 864 | /* Wait for unoptimizing completion */ |
| 865 | wait_for_kprobe_optimizer(); |
| 866 | printk(KERN_INFO "Kprobes globally unoptimized\n"); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 867 | } |
| 868 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 869 | static DEFINE_MUTEX(kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 870 | int sysctl_kprobes_optimization; |
| 871 | int proc_kprobes_optimization_handler(struct ctl_table *table, int write, |
| 872 | void __user *buffer, size_t *length, |
| 873 | loff_t *ppos) |
| 874 | { |
| 875 | int ret; |
| 876 | |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 877 | mutex_lock(&kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 878 | sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; |
| 879 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); |
| 880 | |
| 881 | if (sysctl_kprobes_optimization) |
| 882 | optimize_all_kprobes(); |
| 883 | else |
| 884 | unoptimize_all_kprobes(); |
Masami Hiramatsu | 5c51543 | 2013-04-18 18:33:18 +0900 | [diff] [blame] | 885 | mutex_unlock(&kprobe_sysctl_mutex); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 886 | |
| 887 | return ret; |
| 888 | } |
| 889 | #endif /* CONFIG_SYSCTL */ |
| 890 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 891 | /* 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] | 892 | static void __arm_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 893 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 894 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 895 | |
| 896 | /* Check collision with other optimized kprobes */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 897 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 898 | if (unlikely(_p)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 899 | /* Fallback to unoptimized kprobe */ |
| 900 | unoptimize_kprobe(_p, true); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 901 | |
| 902 | arch_arm_kprobe(p); |
| 903 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ |
| 904 | } |
| 905 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 906 | /* 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] | 907 | static void __disarm_kprobe(struct kprobe *p, bool reopt) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 908 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 909 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 910 | |
Wang Nan | 69d54b9 | 2015-02-13 14:40:26 -0800 | [diff] [blame] | 911 | /* Try to unoptimize */ |
| 912 | unoptimize_kprobe(p, kprobes_all_disarmed); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 913 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 914 | if (!kprobe_queued(p)) { |
| 915 | arch_disarm_kprobe(p); |
| 916 | /* If another kprobe was blocked, optimize it. */ |
| 917 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 918 | if (unlikely(_p) && reopt) |
| 919 | optimize_kprobe(_p); |
| 920 | } |
| 921 | /* TODO: reoptimize others after unoptimized this probe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 922 | } |
| 923 | |
| 924 | #else /* !CONFIG_OPTPROBES */ |
| 925 | |
| 926 | #define optimize_kprobe(p) do {} while (0) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 927 | #define unoptimize_kprobe(p, f) do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 928 | #define kill_optimized_kprobe(p) do {} while (0) |
| 929 | #define prepare_optimized_kprobe(p) do {} while (0) |
| 930 | #define try_to_optimize_kprobe(p) do {} while (0) |
| 931 | #define __arm_kprobe(p) arch_arm_kprobe(p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 932 | #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) |
| 933 | #define kprobe_disarmed(p) kprobe_disabled(p) |
| 934 | #define wait_for_kprobe_optimizer() do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 935 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 936 | /* There should be no unused kprobes can be reused without optimization */ |
| 937 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 938 | { |
| 939 | printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); |
| 940 | BUG_ON(kprobe_unused(ap)); |
| 941 | } |
| 942 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 943 | static void free_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 944 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 945 | arch_remove_kprobe(p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 946 | kfree(p); |
| 947 | } |
| 948 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 949 | static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 950 | { |
| 951 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 952 | } |
| 953 | #endif /* CONFIG_OPTPROBES */ |
| 954 | |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 955 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 956 | static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
Masami Hiramatsu | e525389 | 2012-06-05 19:28:38 +0900 | [diff] [blame] | 957 | .func = kprobe_ftrace_handler, |
Masami Hiramatsu | 1d70be3 | 2014-11-21 05:25:23 -0500 | [diff] [blame] | 958 | .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 959 | }; |
| 960 | static int kprobe_ftrace_enabled; |
| 961 | |
| 962 | /* Must ensure p->addr is really on ftrace */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 963 | static int prepare_kprobe(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 964 | { |
| 965 | if (!kprobe_ftrace(p)) |
| 966 | return arch_prepare_kprobe(p); |
| 967 | |
| 968 | return arch_prepare_kprobe_ftrace(p); |
| 969 | } |
| 970 | |
| 971 | /* Caller must lock kprobe_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 972 | static void arm_kprobe_ftrace(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 973 | { |
| 974 | int ret; |
| 975 | |
| 976 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 977 | (unsigned long)p->addr, 0, 0); |
| 978 | WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 979 | kprobe_ftrace_enabled++; |
| 980 | if (kprobe_ftrace_enabled == 1) { |
| 981 | ret = register_ftrace_function(&kprobe_ftrace_ops); |
| 982 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 983 | } |
| 984 | } |
| 985 | |
| 986 | /* Caller must lock kprobe_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 987 | static void disarm_kprobe_ftrace(struct kprobe *p) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 988 | { |
| 989 | int ret; |
| 990 | |
| 991 | kprobe_ftrace_enabled--; |
| 992 | if (kprobe_ftrace_enabled == 0) { |
| 993 | ret = unregister_ftrace_function(&kprobe_ftrace_ops); |
| 994 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 995 | } |
| 996 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 997 | (unsigned long)p->addr, 1, 0); |
| 998 | WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 999 | } |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1000 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1001 | #define prepare_kprobe(p) arch_prepare_kprobe(p) |
| 1002 | #define arm_kprobe_ftrace(p) do {} while (0) |
| 1003 | #define disarm_kprobe_ftrace(p) do {} while (0) |
| 1004 | #endif |
| 1005 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1006 | /* Arm a kprobe with text_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1007 | static void arm_kprobe(struct kprobe *kp) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1008 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1009 | if (unlikely(kprobe_ftrace(kp))) { |
| 1010 | arm_kprobe_ftrace(kp); |
| 1011 | return; |
| 1012 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1013 | /* |
| 1014 | * Here, since __arm_kprobe() doesn't use stop_machine(), |
| 1015 | * this doesn't cause deadlock on text_mutex. So, we don't |
| 1016 | * need get_online_cpus(). |
| 1017 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1018 | mutex_lock(&text_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1019 | __arm_kprobe(kp); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1020 | mutex_unlock(&text_mutex); |
| 1021 | } |
| 1022 | |
| 1023 | /* Disarm a kprobe with text_mutex */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1024 | static void disarm_kprobe(struct kprobe *kp, bool reopt) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1025 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1026 | if (unlikely(kprobe_ftrace(kp))) { |
| 1027 | disarm_kprobe_ftrace(kp); |
| 1028 | return; |
| 1029 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1030 | /* Ditto */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1031 | mutex_lock(&text_mutex); |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1032 | __disarm_kprobe(kp, reopt); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1033 | mutex_unlock(&text_mutex); |
| 1034 | } |
| 1035 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1036 | /* |
| 1037 | * Aggregate handlers for multiple kprobes support - these handlers |
| 1038 | * take care of invoking the individual kprobe handlers on p->list |
| 1039 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1040 | 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] | 1041 | { |
| 1042 | struct kprobe *kp; |
| 1043 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1044 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1045 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1046 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1047 | if (kp->pre_handler(kp, regs)) |
| 1048 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1049 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1050 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1051 | } |
| 1052 | return 0; |
| 1053 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1054 | NOKPROBE_SYMBOL(aggr_pre_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1055 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1056 | static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 1057 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1058 | { |
| 1059 | struct kprobe *kp; |
| 1060 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1061 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1062 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1063 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1064 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1065 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1066 | } |
| 1067 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1068 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1069 | NOKPROBE_SYMBOL(aggr_post_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1070 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1071 | static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 1072 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1073 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1074 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1075 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1076 | /* |
| 1077 | * if we faulted "during" the execution of a user specified |
| 1078 | * probe handler, invoke just that probe's fault handler |
| 1079 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1080 | if (cur && cur->fault_handler) { |
| 1081 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1082 | return 1; |
| 1083 | } |
| 1084 | return 0; |
| 1085 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1086 | NOKPROBE_SYMBOL(aggr_fault_handler); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1087 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1088 | 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] | 1089 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1090 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1091 | int ret = 0; |
| 1092 | |
| 1093 | if (cur && cur->break_handler) { |
| 1094 | if (cur->break_handler(cur, regs)) |
| 1095 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1096 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1097 | reset_kprobe_instance(); |
| 1098 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1099 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1100 | NOKPROBE_SYMBOL(aggr_break_handler); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1101 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1102 | /* Walks the list and increments nmissed count for multiprobe case */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1103 | void kprobes_inc_nmissed_count(struct kprobe *p) |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1104 | { |
| 1105 | struct kprobe *kp; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1106 | if (!kprobe_aggrprobe(p)) { |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1107 | p->nmissed++; |
| 1108 | } else { |
| 1109 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1110 | kp->nmissed++; |
| 1111 | } |
| 1112 | return; |
| 1113 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1114 | NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1115 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1116 | void recycle_rp_inst(struct kretprobe_instance *ri, |
| 1117 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1118 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1119 | struct kretprobe *rp = ri->rp; |
| 1120 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1121 | /* remove rp inst off the rprobe_inst_table */ |
| 1122 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1123 | INIT_HLIST_NODE(&ri->hlist); |
| 1124 | if (likely(rp)) { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1125 | raw_spin_lock(&rp->lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1126 | hlist_add_head(&ri->hlist, &rp->free_instances); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1127 | raw_spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1128 | } else |
| 1129 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1130 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1131 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1132 | NOKPROBE_SYMBOL(recycle_rp_inst); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1133 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1134 | void kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1135 | struct hlist_head **head, unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1136 | __acquires(hlist_lock) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1137 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1138 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1139 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1140 | |
| 1141 | *head = &kretprobe_inst_table[hash]; |
| 1142 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1143 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1144 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1145 | NOKPROBE_SYMBOL(kretprobe_hash_lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1146 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1147 | static void kretprobe_table_lock(unsigned long hash, |
| 1148 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1149 | __acquires(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1150 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1151 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1152 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1153 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1154 | NOKPROBE_SYMBOL(kretprobe_table_lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1155 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1156 | void kretprobe_hash_unlock(struct task_struct *tsk, |
| 1157 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1158 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1159 | { |
| 1160 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1161 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1162 | |
| 1163 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1164 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1165 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1166 | NOKPROBE_SYMBOL(kretprobe_hash_unlock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1167 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1168 | static void kretprobe_table_unlock(unsigned long hash, |
| 1169 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1170 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1171 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1172 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1173 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1174 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1175 | NOKPROBE_SYMBOL(kretprobe_table_unlock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1176 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1177 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 1178 | * This function is called from finish_task_switch when task tk becomes dead, |
| 1179 | * so that we can recycle any function-return probe instances associated |
| 1180 | * with this task. These left over instances represent probed functions |
| 1181 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1182 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1183 | void kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1184 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1185 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1186 | struct hlist_head *head, empty_rp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1187 | struct hlist_node *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1188 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1189 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1190 | if (unlikely(!kprobes_initialized)) |
| 1191 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 1192 | return; |
| 1193 | |
Ananth N Mavinakayanahalli | d496aab | 2012-01-20 14:34:04 -0800 | [diff] [blame] | 1194 | INIT_HLIST_HEAD(&empty_rp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1195 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 1196 | head = &kretprobe_inst_table[hash]; |
| 1197 | kretprobe_table_lock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1198 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1199 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1200 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1201 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1202 | kretprobe_table_unlock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1203 | hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1204 | hlist_del(&ri->hlist); |
| 1205 | kfree(ri); |
| 1206 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1207 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1208 | NOKPROBE_SYMBOL(kprobe_flush_task); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1209 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1210 | static inline void free_rp_inst(struct kretprobe *rp) |
| 1211 | { |
| 1212 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1213 | struct hlist_node *next; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1214 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1215 | hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1216 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1217 | kfree(ri); |
| 1218 | } |
| 1219 | } |
| 1220 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1221 | static void cleanup_rp_inst(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1222 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1223 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1224 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1225 | struct hlist_node *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1226 | struct hlist_head *head; |
| 1227 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1228 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1229 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 1230 | kretprobe_table_lock(hash, &flags); |
| 1231 | head = &kretprobe_inst_table[hash]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1232 | hlist_for_each_entry_safe(ri, next, head, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1233 | if (ri->rp == rp) |
| 1234 | ri->rp = NULL; |
| 1235 | } |
| 1236 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1237 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1238 | free_rp_inst(rp); |
| 1239 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1240 | NOKPROBE_SYMBOL(cleanup_rp_inst); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1241 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1242 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1243 | * 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] | 1244 | * second jprobe at the address - two jprobes can't coexist |
| 1245 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1246 | static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1247 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1248 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1249 | |
| 1250 | if (p->break_handler || p->post_handler) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1251 | unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1252 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1253 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1254 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1255 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1256 | list_add_tail_rcu(&p->list, &ap->list); |
| 1257 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1258 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1259 | list_add_rcu(&p->list, &ap->list); |
| 1260 | if (p->post_handler && !ap->post_handler) |
| 1261 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1262 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1263 | return 0; |
| 1264 | } |
| 1265 | |
| 1266 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1267 | * Fill in the required fields of the "manager kprobe". Replace the |
| 1268 | * earlier kprobe in the hlist with the manager kprobe |
| 1269 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1270 | static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1271 | { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1272 | /* Copy p's insn slot to ap */ |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1273 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 1274 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1275 | ap->addr = p->addr; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1276 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1277 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1278 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1279 | /* We don't care the kprobe which has gone. */ |
| 1280 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1281 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1282 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1283 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1284 | |
| 1285 | INIT_LIST_HEAD(&ap->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1286 | INIT_HLIST_NODE(&ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1287 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1288 | list_add_rcu(&p->list, &ap->list); |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 1289 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1290 | } |
| 1291 | |
| 1292 | /* |
| 1293 | * This is the second or subsequent kprobe at the address - handle |
| 1294 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1295 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1296 | 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] | 1297 | { |
| 1298 | int ret = 0; |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1299 | struct kprobe *ap = orig_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1300 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1301 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 1302 | jump_label_lock(); |
| 1303 | /* |
| 1304 | * Get online CPUs to avoid text_mutex deadlock.with stop machine, |
| 1305 | * which is invoked by unoptimize_kprobe() in add_new_kprobe() |
| 1306 | */ |
| 1307 | get_online_cpus(); |
| 1308 | mutex_lock(&text_mutex); |
| 1309 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1310 | if (!kprobe_aggrprobe(orig_p)) { |
| 1311 | /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ |
| 1312 | ap = alloc_aggr_kprobe(orig_p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1313 | if (!ap) { |
| 1314 | ret = -ENOMEM; |
| 1315 | goto out; |
| 1316 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1317 | init_aggr_kprobe(ap, orig_p); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1318 | } else if (kprobe_unused(ap)) |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 1319 | /* This probe is going to die. Rescue it */ |
| 1320 | reuse_unused_kprobe(ap); |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1321 | |
| 1322 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1323 | /* |
| 1324 | * Attempting to insert new probe at the same location that |
| 1325 | * had a probe in the module vaddr area which already |
| 1326 | * freed. So, the instruction slot has already been |
| 1327 | * released. We need a new slot for the new probe. |
| 1328 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1329 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1330 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1331 | /* |
| 1332 | * Even if fail to allocate new slot, don't need to |
| 1333 | * free aggr_probe. It will be used next time, or |
| 1334 | * freed by unregister_kprobe. |
| 1335 | */ |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1336 | goto out; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1337 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1338 | /* Prepare optimized instructions if possible. */ |
| 1339 | prepare_optimized_kprobe(ap); |
| 1340 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1341 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1342 | * Clear gone flag to prevent allocating new slot again, and |
| 1343 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1344 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1345 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 1346 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1347 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1348 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1349 | /* Copy ap's insn slot to p */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1350 | copy_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1351 | ret = add_new_kprobe(ap, p); |
| 1352 | |
| 1353 | out: |
| 1354 | mutex_unlock(&text_mutex); |
| 1355 | put_online_cpus(); |
| 1356 | jump_label_unlock(); |
| 1357 | |
| 1358 | if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 1359 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 1360 | if (!kprobes_all_disarmed) |
| 1361 | /* Arm the breakpoint again. */ |
| 1362 | arm_kprobe(ap); |
| 1363 | } |
| 1364 | return ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1365 | } |
| 1366 | |
Masami Hiramatsu | be8f274 | 2014-04-17 17:16:58 +0900 | [diff] [blame] | 1367 | bool __weak arch_within_kprobe_blacklist(unsigned long addr) |
| 1368 | { |
| 1369 | /* The __kprobes marked functions and entry code must not be probed */ |
| 1370 | return addr >= (unsigned long)__kprobes_text_start && |
| 1371 | addr < (unsigned long)__kprobes_text_end; |
| 1372 | } |
| 1373 | |
Andy Lutomirski | e5779e8 | 2015-07-30 20:32:40 -0700 | [diff] [blame] | 1374 | bool within_kprobe_blacklist(unsigned long addr) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1375 | { |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1376 | struct kprobe_blacklist_entry *ent; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1377 | |
Masami Hiramatsu | be8f274 | 2014-04-17 17:16:58 +0900 | [diff] [blame] | 1378 | if (arch_within_kprobe_blacklist(addr)) |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1379 | return true; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1380 | /* |
| 1381 | * If there exists a kprobe_blacklist, verify and |
| 1382 | * fail any probe registration in the prohibited area |
| 1383 | */ |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1384 | list_for_each_entry(ent, &kprobe_blacklist, list) { |
| 1385 | if (addr >= ent->start_addr && addr < ent->end_addr) |
| 1386 | return true; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1387 | } |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1388 | |
| 1389 | return false; |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1390 | } |
| 1391 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1392 | /* |
| 1393 | * If we have a symbol_name argument, look it up and add the offset field |
| 1394 | * 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] | 1395 | * This returns encoded errors if it fails to look up symbol or invalid |
| 1396 | * combination of parameters. |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1397 | */ |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1398 | static kprobe_opcode_t *_kprobe_addr(kprobe_opcode_t *addr, |
| 1399 | const char *symbol_name, unsigned int offset) |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1400 | { |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1401 | if ((symbol_name && addr) || (!symbol_name && !addr)) |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1402 | goto invalid; |
| 1403 | |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1404 | if (symbol_name) { |
Linus Torvalds | 7246f60 | 2017-05-05 11:36:44 -0700 | [diff] [blame] | 1405 | addr = kprobe_lookup_name(symbol_name, offset); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1406 | if (!addr) |
| 1407 | return ERR_PTR(-ENOENT); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1408 | } |
| 1409 | |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1410 | addr = (kprobe_opcode_t *)(((char *)addr) + offset); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1411 | if (addr) |
| 1412 | return addr; |
| 1413 | |
| 1414 | invalid: |
| 1415 | return ERR_PTR(-EINVAL); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1416 | } |
| 1417 | |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1418 | static kprobe_opcode_t *kprobe_addr(struct kprobe *p) |
| 1419 | { |
| 1420 | return _kprobe_addr(p->addr, p->symbol_name, p->offset); |
| 1421 | } |
| 1422 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1423 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1424 | static struct kprobe *__get_valid_kprobe(struct kprobe *p) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1425 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1426 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1427 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1428 | ap = get_kprobe(p->addr); |
| 1429 | if (unlikely(!ap)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1430 | return NULL; |
| 1431 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1432 | if (p != ap) { |
| 1433 | list_for_each_entry_rcu(list_p, &ap->list, list) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1434 | if (list_p == p) |
| 1435 | /* kprobe p is a valid probe */ |
| 1436 | goto valid; |
| 1437 | return NULL; |
| 1438 | } |
| 1439 | valid: |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1440 | return ap; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1441 | } |
| 1442 | |
| 1443 | /* Return error if the kprobe is being re-registered */ |
| 1444 | static inline int check_kprobe_rereg(struct kprobe *p) |
| 1445 | { |
| 1446 | int ret = 0; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1447 | |
| 1448 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1449 | if (__get_valid_kprobe(p)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1450 | ret = -EINVAL; |
| 1451 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1452 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1453 | return ret; |
| 1454 | } |
| 1455 | |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1456 | int __weak arch_check_ftrace_location(struct kprobe *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1457 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1458 | unsigned long ftrace_addr; |
| 1459 | |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1460 | ftrace_addr = ftrace_location((unsigned long)p->addr); |
| 1461 | if (ftrace_addr) { |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1462 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1463 | /* Given address is not on the instruction boundary */ |
| 1464 | if ((unsigned long)p->addr != ftrace_addr) |
| 1465 | return -EILSEQ; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1466 | p->flags |= KPROBE_FLAG_FTRACE; |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1467 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1468 | return -EINVAL; |
| 1469 | #endif |
| 1470 | } |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1471 | return 0; |
| 1472 | } |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1473 | |
Heiko Carstens | f7f242f | 2014-10-15 12:17:34 +0200 | [diff] [blame] | 1474 | static int check_kprobe_address_safe(struct kprobe *p, |
| 1475 | struct module **probed_mod) |
| 1476 | { |
| 1477 | int ret; |
| 1478 | |
| 1479 | ret = arch_check_ftrace_location(p); |
| 1480 | if (ret) |
| 1481 | return ret; |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1482 | jump_label_lock(); |
| 1483 | preempt_disable(); |
| 1484 | |
| 1485 | /* Ensure it is not in reserved area nor out of text */ |
| 1486 | if (!kernel_text_address((unsigned long) p->addr) || |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 1487 | within_kprobe_blacklist((unsigned long) p->addr) || |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1488 | jump_label_text_reserved(p->addr, p->addr)) { |
| 1489 | ret = -EINVAL; |
| 1490 | goto out; |
| 1491 | } |
| 1492 | |
| 1493 | /* Check if are we probing a module */ |
| 1494 | *probed_mod = __module_text_address((unsigned long) p->addr); |
| 1495 | if (*probed_mod) { |
| 1496 | /* |
| 1497 | * We must hold a refcount of the probed module while updating |
| 1498 | * its code to prohibit unexpected unloading. |
| 1499 | */ |
| 1500 | if (unlikely(!try_module_get(*probed_mod))) { |
| 1501 | ret = -ENOENT; |
| 1502 | goto out; |
| 1503 | } |
| 1504 | |
| 1505 | /* |
| 1506 | * If the module freed .init.text, we couldn't insert |
| 1507 | * kprobes in there. |
| 1508 | */ |
| 1509 | if (within_module_init((unsigned long)p->addr, *probed_mod) && |
| 1510 | (*probed_mod)->state != MODULE_STATE_COMING) { |
| 1511 | module_put(*probed_mod); |
| 1512 | *probed_mod = NULL; |
| 1513 | ret = -ENOENT; |
| 1514 | } |
| 1515 | } |
| 1516 | out: |
| 1517 | preempt_enable(); |
| 1518 | jump_label_unlock(); |
| 1519 | |
| 1520 | return ret; |
| 1521 | } |
| 1522 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1523 | int register_kprobe(struct kprobe *p) |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1524 | { |
| 1525 | int ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1526 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1527 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1528 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1529 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1530 | /* Adjust probe address from symbol */ |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1531 | addr = kprobe_addr(p); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1532 | if (IS_ERR(addr)) |
| 1533 | return PTR_ERR(addr); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1534 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 1535 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1536 | ret = check_kprobe_rereg(p); |
| 1537 | if (ret) |
| 1538 | return ret; |
| 1539 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1540 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 1541 | p->flags &= KPROBE_FLAG_DISABLED; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1542 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1543 | INIT_LIST_HEAD(&p->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1544 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1545 | ret = check_kprobe_address_safe(p, &probed_mod); |
| 1546 | if (ret) |
| 1547 | return ret; |
| 1548 | |
| 1549 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1550 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1551 | old_p = get_kprobe(p->addr); |
| 1552 | if (old_p) { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1553 | /* Since this may unoptimize old_p, locking text_mutex. */ |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1554 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | goto out; |
| 1556 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1557 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1558 | mutex_lock(&text_mutex); /* Avoiding text modification */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1559 | ret = prepare_kprobe(p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1560 | mutex_unlock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 1561 | if (ret) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1562 | goto out; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1563 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1564 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1565 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1566 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 1567 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1568 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1569 | arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1570 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1571 | /* Try to optimize kprobe */ |
| 1572 | try_to_optimize_kprobe(p); |
| 1573 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1574 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 1575 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1576 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1577 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1578 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1580 | return ret; |
| 1581 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1582 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1583 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1584 | /* Check if all probes on the aggrprobe are disabled */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1585 | static int aggr_kprobe_disabled(struct kprobe *ap) |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1586 | { |
| 1587 | struct kprobe *kp; |
| 1588 | |
| 1589 | list_for_each_entry_rcu(kp, &ap->list, list) |
| 1590 | if (!kprobe_disabled(kp)) |
| 1591 | /* |
| 1592 | * There is an active probe on the list. |
| 1593 | * We can't disable this ap. |
| 1594 | */ |
| 1595 | return 0; |
| 1596 | |
| 1597 | return 1; |
| 1598 | } |
| 1599 | |
| 1600 | /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1601 | static struct kprobe *__disable_kprobe(struct kprobe *p) |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1602 | { |
| 1603 | struct kprobe *orig_p; |
| 1604 | |
| 1605 | /* Get an original kprobe for return */ |
| 1606 | orig_p = __get_valid_kprobe(p); |
| 1607 | if (unlikely(orig_p == NULL)) |
| 1608 | return NULL; |
| 1609 | |
| 1610 | if (!kprobe_disabled(p)) { |
| 1611 | /* Disable probe if it is a child probe */ |
| 1612 | if (p != orig_p) |
| 1613 | p->flags |= KPROBE_FLAG_DISABLED; |
| 1614 | |
| 1615 | /* Try to disarm and disable this/parent probe */ |
| 1616 | if (p == orig_p || aggr_kprobe_disabled(orig_p)) { |
Wang Nan | 69d54b9 | 2015-02-13 14:40:26 -0800 | [diff] [blame] | 1617 | /* |
| 1618 | * If kprobes_all_disarmed is set, orig_p |
| 1619 | * should have already been disarmed, so |
| 1620 | * skip unneed disarming process. |
| 1621 | */ |
| 1622 | if (!kprobes_all_disarmed) |
| 1623 | disarm_kprobe(orig_p, true); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1624 | orig_p->flags |= KPROBE_FLAG_DISABLED; |
| 1625 | } |
| 1626 | } |
| 1627 | |
| 1628 | return orig_p; |
| 1629 | } |
| 1630 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1631 | /* |
| 1632 | * Unregister a kprobe without a scheduler synchronization. |
| 1633 | */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1634 | static int __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1635 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1636 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1637 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1638 | /* Disable kprobe. This will disarm it if needed. */ |
| 1639 | ap = __disable_kprobe(p); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1640 | if (ap == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1641 | return -EINVAL; |
| 1642 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1643 | if (ap == p) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1644 | /* |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1645 | * This probe is an independent(and non-optimized) kprobe |
| 1646 | * (not an aggrprobe). Remove from the hash list. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1647 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1648 | goto disarmed; |
| 1649 | |
| 1650 | /* Following process expects this probe is an aggrprobe */ |
| 1651 | WARN_ON(!kprobe_aggrprobe(ap)); |
| 1652 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1653 | if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) |
| 1654 | /* |
| 1655 | * !disarmed could be happen if the probe is under delayed |
| 1656 | * unoptimizing. |
| 1657 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1658 | goto disarmed; |
| 1659 | else { |
| 1660 | /* If disabling probe has special handlers, update aggrprobe */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1661 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1662 | ap->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1663 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1664 | list_for_each_entry_rcu(list_p, &ap->list, list) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1665 | if ((list_p != p) && (list_p->post_handler)) |
| 1666 | goto noclean; |
| 1667 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1668 | ap->post_handler = NULL; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1669 | } |
| 1670 | noclean: |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1671 | /* |
| 1672 | * Remove from the aggrprobe: this path will do nothing in |
| 1673 | * __unregister_kprobe_bottom(). |
| 1674 | */ |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1675 | list_del_rcu(&p->list); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1676 | if (!kprobe_disabled(ap) && !kprobes_all_disarmed) |
| 1677 | /* |
| 1678 | * Try to optimize this probe again, because post |
| 1679 | * handler may have been changed. |
| 1680 | */ |
| 1681 | optimize_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1682 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1683 | return 0; |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1684 | |
| 1685 | disarmed: |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1686 | BUG_ON(!kprobe_disarmed(ap)); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1687 | hlist_del_rcu(&ap->hlist); |
| 1688 | return 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1689 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1690 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1691 | static void __unregister_kprobe_bottom(struct kprobe *p) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1692 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1693 | struct kprobe *ap; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1694 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1695 | if (list_empty(&p->list)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1696 | /* This is an independent kprobe */ |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 1697 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1698 | else if (list_is_singular(&p->list)) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1699 | /* This is the last child of an aggrprobe */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1700 | ap = list_entry(p->list.next, struct kprobe, list); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1701 | list_del(&p->list); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1702 | free_aggr_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1703 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1704 | /* Otherwise, do nothing. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1705 | } |
| 1706 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1707 | int register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1708 | { |
| 1709 | int i, ret = 0; |
| 1710 | |
| 1711 | if (num <= 0) |
| 1712 | return -EINVAL; |
| 1713 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1714 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1715 | if (ret < 0) { |
| 1716 | if (i > 0) |
| 1717 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1718 | break; |
| 1719 | } |
| 1720 | } |
| 1721 | return ret; |
| 1722 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1723 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1724 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1725 | void unregister_kprobe(struct kprobe *p) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1726 | { |
| 1727 | unregister_kprobes(&p, 1); |
| 1728 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1729 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1730 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1731 | void unregister_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1732 | { |
| 1733 | int i; |
| 1734 | |
| 1735 | if (num <= 0) |
| 1736 | return; |
| 1737 | mutex_lock(&kprobe_mutex); |
| 1738 | for (i = 0; i < num; i++) |
| 1739 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 1740 | kps[i]->addr = NULL; |
| 1741 | mutex_unlock(&kprobe_mutex); |
| 1742 | |
| 1743 | synchronize_sched(); |
| 1744 | for (i = 0; i < num; i++) |
| 1745 | if (kps[i]->addr) |
| 1746 | __unregister_kprobe_bottom(kps[i]); |
| 1747 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1748 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1749 | |
Naveen N. Rao | 5f6bee3 | 2017-03-08 22:34:15 +0530 | [diff] [blame] | 1750 | int __weak kprobe_exceptions_notify(struct notifier_block *self, |
| 1751 | unsigned long val, void *data) |
Naveen N. Rao | fc62d02 | 2017-02-08 01:24:14 +0530 | [diff] [blame] | 1752 | { |
| 1753 | return NOTIFY_DONE; |
| 1754 | } |
Naveen N. Rao | 5f6bee3 | 2017-03-08 22:34:15 +0530 | [diff] [blame] | 1755 | NOKPROBE_SYMBOL(kprobe_exceptions_notify); |
Naveen N. Rao | fc62d02 | 2017-02-08 01:24:14 +0530 | [diff] [blame] | 1756 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1757 | static struct notifier_block kprobe_exceptions_nb = { |
| 1758 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 1759 | .priority = 0x7fffffff /* we need to be notified first */ |
| 1760 | }; |
| 1761 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 1762 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 1763 | { |
| 1764 | return (unsigned long)entry; |
| 1765 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1766 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1767 | int register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1768 | { |
| 1769 | struct jprobe *jp; |
| 1770 | int ret = 0, i; |
| 1771 | |
| 1772 | if (num <= 0) |
| 1773 | return -EINVAL; |
| 1774 | for (i = 0; i < num; i++) { |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1775 | unsigned long addr, offset; |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1776 | jp = jps[i]; |
| 1777 | addr = arch_deref_entry_point(jp->entry); |
| 1778 | |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1779 | /* Verify probepoint is a function entry point */ |
| 1780 | if (kallsyms_lookup_size_offset(addr, NULL, &offset) && |
| 1781 | offset == 0) { |
| 1782 | jp->kp.pre_handler = setjmp_pre_handler; |
| 1783 | jp->kp.break_handler = longjmp_break_handler; |
| 1784 | ret = register_kprobe(&jp->kp); |
| 1785 | } else |
| 1786 | ret = -EINVAL; |
Namhyung Kim | edbaadb | 2010-09-15 10:04:26 +0900 | [diff] [blame] | 1787 | |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1788 | if (ret < 0) { |
| 1789 | if (i > 0) |
| 1790 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1791 | break; |
| 1792 | } |
| 1793 | } |
| 1794 | return ret; |
| 1795 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1796 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1797 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1798 | int register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1800 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1801 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1802 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1803 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1804 | void unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1806 | unregister_jprobes(&jp, 1); |
| 1807 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1808 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1809 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1810 | void unregister_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1811 | { |
| 1812 | int i; |
| 1813 | |
| 1814 | if (num <= 0) |
| 1815 | return; |
| 1816 | mutex_lock(&kprobe_mutex); |
| 1817 | for (i = 0; i < num; i++) |
| 1818 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 1819 | jps[i]->kp.addr = NULL; |
| 1820 | mutex_unlock(&kprobe_mutex); |
| 1821 | |
| 1822 | synchronize_sched(); |
| 1823 | for (i = 0; i < num; i++) { |
| 1824 | if (jps[i]->kp.addr) |
| 1825 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 1826 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1828 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1829 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1830 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1831 | /* |
| 1832 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 1833 | * hits it will set up the return probe. |
| 1834 | */ |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1835 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1836 | { |
| 1837 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1838 | unsigned long hash, flags = 0; |
| 1839 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1840 | |
Masami Hiramatsu | f96f567 | 2014-08-04 03:10:16 +0000 | [diff] [blame] | 1841 | /* |
| 1842 | * To avoid deadlocks, prohibit return probing in NMI contexts, |
| 1843 | * just skip the probe and increase the (inexact) 'nmissed' |
| 1844 | * statistical counter, so that the user is informed that |
| 1845 | * something happened: |
| 1846 | */ |
| 1847 | if (unlikely(in_nmi())) { |
| 1848 | rp->nmissed++; |
| 1849 | return 0; |
| 1850 | } |
| 1851 | |
| 1852 | /* 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] | 1853 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1854 | raw_spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1855 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1856 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1857 | struct kretprobe_instance, hlist); |
| 1858 | hlist_del(&ri->hlist); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1859 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1860 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1861 | ri->rp = rp; |
| 1862 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1863 | |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1864 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
| 1865 | raw_spin_lock_irqsave(&rp->lock, flags); |
| 1866 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 1867 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1868 | return 0; |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1869 | } |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1870 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1871 | arch_prepare_kretprobe(ri, regs); |
| 1872 | |
| 1873 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1874 | INIT_HLIST_NODE(&ri->hlist); |
| 1875 | kretprobe_table_lock(hash, &flags); |
| 1876 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 1877 | kretprobe_table_unlock(hash, &flags); |
| 1878 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1879 | rp->nmissed++; |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1880 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1881 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1882 | return 0; |
| 1883 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 1884 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1885 | |
Naveen N. Rao | 90ec5e8 | 2017-02-22 19:23:37 +0530 | [diff] [blame] | 1886 | bool __weak arch_function_offset_within_entry(unsigned long offset) |
| 1887 | { |
| 1888 | return !offset; |
| 1889 | } |
| 1890 | |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1891 | bool function_offset_within_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset) |
| 1892 | { |
| 1893 | kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset); |
| 1894 | |
| 1895 | if (IS_ERR(kp_addr)) |
| 1896 | return false; |
| 1897 | |
| 1898 | if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) || |
| 1899 | !arch_function_offset_within_entry(offset)) |
| 1900 | return false; |
| 1901 | |
| 1902 | return true; |
| 1903 | } |
| 1904 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1905 | int register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1906 | { |
| 1907 | int ret = 0; |
| 1908 | struct kretprobe_instance *inst; |
| 1909 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1910 | void *addr; |
Naveen N. Rao | 90ec5e8 | 2017-02-22 19:23:37 +0530 | [diff] [blame] | 1911 | |
Naveen N. Rao | 1d585e7 | 2017-03-08 13:56:06 +0530 | [diff] [blame] | 1912 | if (!function_offset_within_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset)) |
Naveen N. Rao | 90ec5e8 | 2017-02-22 19:23:37 +0530 | [diff] [blame] | 1913 | return -EINVAL; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1914 | |
| 1915 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1916 | addr = kprobe_addr(&rp->kp); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1917 | if (IS_ERR(addr)) |
| 1918 | return PTR_ERR(addr); |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1919 | |
| 1920 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1921 | if (kretprobe_blacklist[i].addr == addr) |
| 1922 | return -EINVAL; |
| 1923 | } |
| 1924 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1925 | |
| 1926 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1927 | rp->kp.post_handler = NULL; |
| 1928 | rp->kp.fault_handler = NULL; |
| 1929 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1930 | |
| 1931 | /* Pre-allocate memory for max kretprobe instances */ |
| 1932 | if (rp->maxactive <= 0) { |
| 1933 | #ifdef CONFIG_PREEMPT |
Heiko Carstens | c2ef666 | 2009-12-21 13:02:24 +0100 | [diff] [blame] | 1934 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1935 | #else |
Ananth N Mavinakayanahalli | 4dae560 | 2009-10-30 19:23:10 +0530 | [diff] [blame] | 1936 | rp->maxactive = num_possible_cpus(); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1937 | #endif |
| 1938 | } |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1939 | raw_spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1940 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1941 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1942 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1943 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1944 | if (inst == NULL) { |
| 1945 | free_rp_inst(rp); |
| 1946 | return -ENOMEM; |
| 1947 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1948 | INIT_HLIST_NODE(&inst->hlist); |
| 1949 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1950 | } |
| 1951 | |
| 1952 | rp->nmissed = 0; |
| 1953 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1954 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1955 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1956 | free_rp_inst(rp); |
| 1957 | return ret; |
| 1958 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1959 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1960 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1961 | int register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1962 | { |
| 1963 | int ret = 0, i; |
| 1964 | |
| 1965 | if (num <= 0) |
| 1966 | return -EINVAL; |
| 1967 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1968 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1969 | if (ret < 0) { |
| 1970 | if (i > 0) |
| 1971 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1972 | break; |
| 1973 | } |
| 1974 | } |
| 1975 | return ret; |
| 1976 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1977 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1978 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1979 | void unregister_kretprobe(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1980 | { |
| 1981 | unregister_kretprobes(&rp, 1); |
| 1982 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1983 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1984 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 1985 | void unregister_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1986 | { |
| 1987 | int i; |
| 1988 | |
| 1989 | if (num <= 0) |
| 1990 | return; |
| 1991 | mutex_lock(&kprobe_mutex); |
| 1992 | for (i = 0; i < num; i++) |
| 1993 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1994 | rps[i]->kp.addr = NULL; |
| 1995 | mutex_unlock(&kprobe_mutex); |
| 1996 | |
| 1997 | synchronize_sched(); |
| 1998 | for (i = 0; i < num; i++) { |
| 1999 | if (rps[i]->kp.addr) { |
| 2000 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 2001 | cleanup_rp_inst(rps[i]); |
| 2002 | } |
| 2003 | } |
| 2004 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2005 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2006 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 2007 | #else /* CONFIG_KRETPROBES */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2008 | int register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2009 | { |
| 2010 | return -ENOSYS; |
| 2011 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2012 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2013 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2014 | int register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2015 | { |
| 2016 | return -ENOSYS; |
| 2017 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2018 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 2019 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2020 | void unregister_kretprobe(struct kretprobe *rp) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2021 | { |
| 2022 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2023 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2024 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2025 | void unregister_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2026 | { |
| 2027 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2028 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2029 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2030 | static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2031 | { |
| 2032 | return 0; |
| 2033 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2034 | NOKPROBE_SYMBOL(pre_handler_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 2035 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 2036 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2037 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2038 | /* Set the kprobe gone and remove its instruction buffer. */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2039 | static void kill_kprobe(struct kprobe *p) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2040 | { |
| 2041 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2042 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2043 | p->flags |= KPROBE_FLAG_GONE; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2044 | if (kprobe_aggrprobe(p)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2045 | /* |
| 2046 | * If this is an aggr_kprobe, we have to list all the |
| 2047 | * chained probes and mark them GONE. |
| 2048 | */ |
| 2049 | list_for_each_entry_rcu(kp, &p->list, list) |
| 2050 | kp->flags |= KPROBE_FLAG_GONE; |
| 2051 | p->post_handler = NULL; |
| 2052 | p->break_handler = NULL; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2053 | kill_optimized_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2054 | } |
| 2055 | /* |
| 2056 | * Here, we can remove insn_slot safely, because no thread calls |
| 2057 | * the original probed function (which will be freed soon) any more. |
| 2058 | */ |
| 2059 | arch_remove_kprobe(p); |
| 2060 | } |
| 2061 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2062 | /* Disable one kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2063 | int disable_kprobe(struct kprobe *kp) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2064 | { |
| 2065 | int ret = 0; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2066 | |
| 2067 | mutex_lock(&kprobe_mutex); |
| 2068 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 2069 | /* Disable this kprobe */ |
| 2070 | if (__disable_kprobe(kp) == NULL) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2071 | ret = -EINVAL; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2072 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2073 | mutex_unlock(&kprobe_mutex); |
| 2074 | return ret; |
| 2075 | } |
| 2076 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 2077 | |
| 2078 | /* Enable one kprobe */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2079 | int enable_kprobe(struct kprobe *kp) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 2080 | { |
| 2081 | int ret = 0; |
| 2082 | struct kprobe *p; |
| 2083 | |
| 2084 | mutex_lock(&kprobe_mutex); |
| 2085 | |
| 2086 | /* Check whether specified probe is valid. */ |
| 2087 | p = __get_valid_kprobe(kp); |
| 2088 | if (unlikely(p == NULL)) { |
| 2089 | ret = -EINVAL; |
| 2090 | goto out; |
| 2091 | } |
| 2092 | |
| 2093 | if (kprobe_gone(kp)) { |
| 2094 | /* This kprobe has gone, we couldn't enable it. */ |
| 2095 | ret = -EINVAL; |
| 2096 | goto out; |
| 2097 | } |
| 2098 | |
| 2099 | if (p != kp) |
| 2100 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 2101 | |
| 2102 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { |
| 2103 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 2104 | arm_kprobe(p); |
| 2105 | } |
| 2106 | out: |
| 2107 | mutex_unlock(&kprobe_mutex); |
| 2108 | return ret; |
| 2109 | } |
| 2110 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 2111 | |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2112 | void dump_kprobe(struct kprobe *kp) |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 2113 | { |
| 2114 | printk(KERN_WARNING "Dumping kprobe:\n"); |
| 2115 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", |
| 2116 | kp->symbol_name, kp->addr, kp->offset); |
| 2117 | } |
Masami Hiramatsu | 820aede | 2014-04-17 17:18:21 +0900 | [diff] [blame] | 2118 | NOKPROBE_SYMBOL(dump_kprobe); |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 2119 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2120 | /* |
| 2121 | * Lookup and populate the kprobe_blacklist. |
| 2122 | * |
| 2123 | * Unlike the kretprobe blacklist, we'll need to determine |
| 2124 | * the range of addresses that belong to the said functions, |
| 2125 | * since a kprobe need not necessarily be at the beginning |
| 2126 | * of a function. |
| 2127 | */ |
| 2128 | static int __init populate_kprobe_blacklist(unsigned long *start, |
| 2129 | unsigned long *end) |
| 2130 | { |
| 2131 | unsigned long *iter; |
| 2132 | struct kprobe_blacklist_entry *ent; |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2133 | unsigned long entry, offset = 0, size = 0; |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2134 | |
| 2135 | for (iter = start; iter < end; iter++) { |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2136 | entry = arch_deref_entry_point((void *)*iter); |
| 2137 | |
| 2138 | if (!kernel_text_address(entry) || |
| 2139 | !kallsyms_lookup_size_offset(entry, &size, &offset)) { |
| 2140 | pr_err("Failed to find blacklist at %p\n", |
| 2141 | (void *)entry); |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2142 | continue; |
| 2143 | } |
| 2144 | |
| 2145 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); |
| 2146 | if (!ent) |
| 2147 | return -ENOMEM; |
Masami Hiramatsu | d81b425 | 2014-07-17 11:44:11 +0000 | [diff] [blame] | 2148 | ent->start_addr = entry; |
| 2149 | ent->end_addr = entry + size; |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2150 | INIT_LIST_HEAD(&ent->list); |
| 2151 | list_add_tail(&ent->list, &kprobe_blacklist); |
| 2152 | } |
| 2153 | return 0; |
| 2154 | } |
| 2155 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2156 | /* Module notifier call back, checking kprobes on the module */ |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2157 | static int kprobes_module_callback(struct notifier_block *nb, |
| 2158 | unsigned long val, void *data) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2159 | { |
| 2160 | struct module *mod = data; |
| 2161 | struct hlist_head *head; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2162 | struct kprobe *p; |
| 2163 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2164 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2165 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2166 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2167 | return NOTIFY_DONE; |
| 2168 | |
| 2169 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2170 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 2171 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 2172 | * notified, only .init.text section would be freed. We need to |
| 2173 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2174 | */ |
| 2175 | mutex_lock(&kprobe_mutex); |
| 2176 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2177 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2178 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2179 | if (within_module_init((unsigned long)p->addr, mod) || |
| 2180 | (checkcore && |
| 2181 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2182 | /* |
| 2183 | * The vaddr this probe is installed will soon |
| 2184 | * be vfreed buy not synced to disk. Hence, |
| 2185 | * disarming the breakpoint isn't needed. |
Steven Rostedt (VMware) | 545a028 | 2017-05-16 14:58:35 -0400 | [diff] [blame] | 2186 | * |
| 2187 | * Note, this will also move any optimized probes |
| 2188 | * that are pending to be removed from their |
| 2189 | * corresponding lists to the freeing_list and |
| 2190 | * will not be touched by the delayed |
| 2191 | * kprobe_optimizer work handler. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2192 | */ |
| 2193 | kill_kprobe(p); |
| 2194 | } |
| 2195 | } |
| 2196 | mutex_unlock(&kprobe_mutex); |
| 2197 | return NOTIFY_DONE; |
| 2198 | } |
| 2199 | |
| 2200 | static struct notifier_block kprobe_module_nb = { |
| 2201 | .notifier_call = kprobes_module_callback, |
| 2202 | .priority = 0 |
| 2203 | }; |
| 2204 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2205 | /* Markers of _kprobe_blacklist section */ |
| 2206 | extern unsigned long __start_kprobe_blacklist[]; |
| 2207 | extern unsigned long __stop_kprobe_blacklist[]; |
| 2208 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | static int __init init_kprobes(void) |
| 2210 | { |
| 2211 | int i, err = 0; |
| 2212 | |
| 2213 | /* FIXME allocate the probe table, currently defined statically */ |
| 2214 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2215 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2216 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2217 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 2218 | raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2219 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2220 | |
Masami Hiramatsu | 376e242 | 2014-04-17 17:17:05 +0900 | [diff] [blame] | 2221 | err = populate_kprobe_blacklist(__start_kprobe_blacklist, |
| 2222 | __stop_kprobe_blacklist); |
| 2223 | if (err) { |
| 2224 | pr_err("kprobes: failed to populate blacklist: %d\n", err); |
| 2225 | pr_err("Please take care of using kprobes.\n"); |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 2226 | } |
| 2227 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 2228 | if (kretprobe_blacklist_size) { |
| 2229 | /* lookup the function address from its name */ |
| 2230 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
Naveen N. Rao | 49e0b46 | 2017-04-19 18:21:00 +0530 | [diff] [blame] | 2231 | kretprobe_blacklist[i].addr = |
Naveen N. Rao | 290e307 | 2017-04-19 18:21:01 +0530 | [diff] [blame] | 2232 | kprobe_lookup_name(kretprobe_blacklist[i].name, 0); |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 2233 | if (!kretprobe_blacklist[i].addr) |
| 2234 | printk("kretprobe: lookup failed: %s\n", |
| 2235 | kretprobe_blacklist[i].name); |
| 2236 | } |
| 2237 | } |
| 2238 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2239 | #if defined(CONFIG_OPTPROBES) |
| 2240 | #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2241 | /* Init kprobe_optinsn_slots */ |
| 2242 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; |
| 2243 | #endif |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2244 | /* By default, kprobes can be optimized */ |
| 2245 | kprobes_allow_optimization = true; |
| 2246 | #endif |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2247 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2248 | /* By default, kprobes are armed */ |
| 2249 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2250 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 2251 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2252 | if (!err) |
| 2253 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2254 | if (!err) |
| 2255 | err = register_module_notifier(&kprobe_module_nb); |
| 2256 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 2257 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2258 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 2259 | if (!err) |
| 2260 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2261 | return err; |
| 2262 | } |
| 2263 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2264 | #ifdef CONFIG_DEBUG_FS |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2265 | static void report_probe(struct seq_file *pi, struct kprobe *p, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2266 | const char *sym, int offset, char *modname, struct kprobe *pp) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2267 | { |
| 2268 | char *kprobe_type; |
| 2269 | |
| 2270 | if (p->pre_handler == pre_handler_kretprobe) |
| 2271 | kprobe_type = "r"; |
| 2272 | else if (p->pre_handler == setjmp_pre_handler) |
| 2273 | kprobe_type = "j"; |
| 2274 | else |
| 2275 | kprobe_type = "k"; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2276 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2277 | if (sym) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2278 | seq_printf(pi, "%p %s %s+0x%x %s ", |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2279 | p->addr, kprobe_type, sym, offset, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2280 | (modname ? modname : " ")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2281 | else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2282 | seq_printf(pi, "%p %s %p ", |
| 2283 | p->addr, kprobe_type, p->addr); |
| 2284 | |
| 2285 | if (!pp) |
| 2286 | pp = p; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2287 | seq_printf(pi, "%s%s%s%s\n", |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2288 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 2289 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2290 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), |
| 2291 | (kprobe_ftrace(pp) ? "[FTRACE]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2292 | } |
| 2293 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2294 | static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2295 | { |
| 2296 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 2297 | } |
| 2298 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2299 | 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] | 2300 | { |
| 2301 | (*pos)++; |
| 2302 | if (*pos >= KPROBE_TABLE_SIZE) |
| 2303 | return NULL; |
| 2304 | return pos; |
| 2305 | } |
| 2306 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2307 | static void kprobe_seq_stop(struct seq_file *f, void *v) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2308 | { |
| 2309 | /* Nothing to do */ |
| 2310 | } |
| 2311 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2312 | static int show_kprobe_addr(struct seq_file *pi, void *v) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2313 | { |
| 2314 | struct hlist_head *head; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2315 | struct kprobe *p, *kp; |
| 2316 | const char *sym = NULL; |
| 2317 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2318 | unsigned long offset = 0; |
Joe Mario | ab76786 | 2013-11-12 15:10:23 -0800 | [diff] [blame] | 2319 | char *modname, namebuf[KSYM_NAME_LEN]; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2320 | |
| 2321 | head = &kprobe_table[i]; |
| 2322 | preempt_disable(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2323 | hlist_for_each_entry_rcu(p, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2324 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2325 | &offset, &modname, namebuf); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2326 | if (kprobe_aggrprobe(p)) { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2327 | list_for_each_entry_rcu(kp, &p->list, list) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2328 | report_probe(pi, kp, sym, offset, modname, p); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2329 | } else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2330 | report_probe(pi, p, sym, offset, modname, NULL); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2331 | } |
| 2332 | preempt_enable(); |
| 2333 | return 0; |
| 2334 | } |
| 2335 | |
James Morris | 88e9d34 | 2009-09-22 16:43:43 -0700 | [diff] [blame] | 2336 | static const struct seq_operations kprobes_seq_ops = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2337 | .start = kprobe_seq_start, |
| 2338 | .next = kprobe_seq_next, |
| 2339 | .stop = kprobe_seq_stop, |
| 2340 | .show = show_kprobe_addr |
| 2341 | }; |
| 2342 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2343 | static int kprobes_open(struct inode *inode, struct file *filp) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2344 | { |
| 2345 | return seq_open(filp, &kprobes_seq_ops); |
| 2346 | } |
| 2347 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2348 | static const struct file_operations debugfs_kprobes_operations = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2349 | .open = kprobes_open, |
| 2350 | .read = seq_read, |
| 2351 | .llseek = seq_lseek, |
| 2352 | .release = seq_release, |
| 2353 | }; |
| 2354 | |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2355 | /* kprobes/blacklist -- shows which functions can not be probed */ |
| 2356 | static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) |
| 2357 | { |
| 2358 | return seq_list_start(&kprobe_blacklist, *pos); |
| 2359 | } |
| 2360 | |
| 2361 | static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) |
| 2362 | { |
| 2363 | return seq_list_next(v, &kprobe_blacklist, pos); |
| 2364 | } |
| 2365 | |
| 2366 | static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) |
| 2367 | { |
| 2368 | struct kprobe_blacklist_entry *ent = |
| 2369 | list_entry(v, struct kprobe_blacklist_entry, list); |
| 2370 | |
| 2371 | seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, |
| 2372 | (void *)ent->end_addr, (void *)ent->start_addr); |
| 2373 | return 0; |
| 2374 | } |
| 2375 | |
| 2376 | static const struct seq_operations kprobe_blacklist_seq_ops = { |
| 2377 | .start = kprobe_blacklist_seq_start, |
| 2378 | .next = kprobe_blacklist_seq_next, |
| 2379 | .stop = kprobe_seq_stop, /* Reuse void function */ |
| 2380 | .show = kprobe_blacklist_seq_show, |
| 2381 | }; |
| 2382 | |
| 2383 | static int kprobe_blacklist_open(struct inode *inode, struct file *filp) |
| 2384 | { |
| 2385 | return seq_open(filp, &kprobe_blacklist_seq_ops); |
| 2386 | } |
| 2387 | |
| 2388 | static const struct file_operations debugfs_kprobe_blacklist_ops = { |
| 2389 | .open = kprobe_blacklist_open, |
| 2390 | .read = seq_read, |
| 2391 | .llseek = seq_lseek, |
| 2392 | .release = seq_release, |
| 2393 | }; |
| 2394 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2395 | static void arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2396 | { |
| 2397 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2398 | struct kprobe *p; |
| 2399 | unsigned int i; |
| 2400 | |
| 2401 | mutex_lock(&kprobe_mutex); |
| 2402 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2403 | /* If kprobes are armed, just return */ |
| 2404 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2405 | goto already_enabled; |
| 2406 | |
Wang Nan | 977ad48 | 2015-02-13 14:40:24 -0800 | [diff] [blame] | 2407 | /* |
| 2408 | * optimize_kprobe() called by arm_kprobe() checks |
| 2409 | * kprobes_all_disarmed, so set kprobes_all_disarmed before |
| 2410 | * arm_kprobe. |
| 2411 | */ |
| 2412 | kprobes_all_disarmed = false; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2413 | /* Arming kprobes doesn't optimize kprobe itself */ |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2414 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2415 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2416 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2417 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2418 | arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2419 | } |
| 2420 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2421 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 2422 | |
| 2423 | already_enabled: |
| 2424 | mutex_unlock(&kprobe_mutex); |
| 2425 | return; |
| 2426 | } |
| 2427 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2428 | static void disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2429 | { |
| 2430 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2431 | struct kprobe *p; |
| 2432 | unsigned int i; |
| 2433 | |
| 2434 | mutex_lock(&kprobe_mutex); |
| 2435 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2436 | /* If kprobes are already disarmed, just return */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2437 | if (kprobes_all_disarmed) { |
| 2438 | mutex_unlock(&kprobe_mutex); |
| 2439 | return; |
| 2440 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2441 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2442 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2443 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2444 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2445 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2446 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2447 | hlist_for_each_entry_rcu(p, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2448 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2449 | disarm_kprobe(p, false); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2450 | } |
| 2451 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2452 | mutex_unlock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2453 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2454 | /* Wait for disarming all kprobes by optimizer */ |
| 2455 | wait_for_kprobe_optimizer(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2456 | } |
| 2457 | |
| 2458 | /* |
| 2459 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 2460 | * when the bool state is switched. We can reuse that facility when |
| 2461 | * available |
| 2462 | */ |
| 2463 | static ssize_t read_enabled_file_bool(struct file *file, |
| 2464 | char __user *user_buf, size_t count, loff_t *ppos) |
| 2465 | { |
| 2466 | char buf[3]; |
| 2467 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2468 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2469 | buf[0] = '1'; |
| 2470 | else |
| 2471 | buf[0] = '0'; |
| 2472 | buf[1] = '\n'; |
| 2473 | buf[2] = 0x00; |
| 2474 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 2475 | } |
| 2476 | |
| 2477 | static ssize_t write_enabled_file_bool(struct file *file, |
| 2478 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 2479 | { |
| 2480 | char buf[32]; |
Stephen Boyd | efeb156 | 2012-01-12 17:17:11 -0800 | [diff] [blame] | 2481 | size_t buf_size; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2482 | |
| 2483 | buf_size = min(count, (sizeof(buf)-1)); |
| 2484 | if (copy_from_user(buf, user_buf, buf_size)) |
| 2485 | return -EFAULT; |
| 2486 | |
Mathias Krause | 10fb46d | 2013-07-03 15:05:39 -0700 | [diff] [blame] | 2487 | buf[buf_size] = '\0'; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2488 | switch (buf[0]) { |
| 2489 | case 'y': |
| 2490 | case 'Y': |
| 2491 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2492 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2493 | break; |
| 2494 | case 'n': |
| 2495 | case 'N': |
| 2496 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2497 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2498 | break; |
Mathias Krause | 10fb46d | 2013-07-03 15:05:39 -0700 | [diff] [blame] | 2499 | default: |
| 2500 | return -EINVAL; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2501 | } |
| 2502 | |
| 2503 | return count; |
| 2504 | } |
| 2505 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2506 | static const struct file_operations fops_kp = { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2507 | .read = read_enabled_file_bool, |
| 2508 | .write = write_enabled_file_bool, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 2509 | .llseek = default_llseek, |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2510 | }; |
| 2511 | |
Masami Hiramatsu | 55479f6 | 2014-04-17 17:17:54 +0900 | [diff] [blame] | 2512 | static int __init debugfs_kprobe_init(void) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2513 | { |
| 2514 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2515 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2516 | |
| 2517 | dir = debugfs_create_dir("kprobes", NULL); |
| 2518 | if (!dir) |
| 2519 | return -ENOMEM; |
| 2520 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 2521 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2522 | &debugfs_kprobes_operations); |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2523 | if (!file) |
| 2524 | goto error; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2525 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2526 | file = debugfs_create_file("enabled", 0600, dir, |
| 2527 | &value, &fops_kp); |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2528 | if (!file) |
| 2529 | goto error; |
| 2530 | |
| 2531 | file = debugfs_create_file("blacklist", 0444, dir, NULL, |
| 2532 | &debugfs_kprobe_blacklist_ops); |
| 2533 | if (!file) |
| 2534 | goto error; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2535 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2536 | return 0; |
Masami Hiramatsu | 6372474 | 2014-04-17 17:18:49 +0900 | [diff] [blame] | 2537 | |
| 2538 | error: |
| 2539 | debugfs_remove(dir); |
| 2540 | return -ENOMEM; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2541 | } |
| 2542 | |
| 2543 | late_initcall(debugfs_kprobe_init); |
| 2544 | #endif /* CONFIG_DEBUG_FS */ |
| 2545 | |
| 2546 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2547 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2548 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2549 | EXPORT_SYMBOL_GPL(jprobe_return); |