Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Kernel Probes (KProbes) |
| 3 | * kernel/kprobes.c |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 18 | * |
| 19 | * Copyright (C) IBM Corporation, 2002, 2004 |
| 20 | * |
| 21 | * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel |
| 22 | * Probes initial implementation (includes suggestions from |
| 23 | * Rusty Russell). |
| 24 | * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with |
| 25 | * hlists and exceptions notifier as suggested by Andi Kleen. |
| 26 | * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes |
| 27 | * interface to access function arguments. |
| 28 | * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes |
| 29 | * exceptions notifier to be first on the priority list. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 30 | * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston |
| 31 | * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| 32 | * <prasanna@in.ibm.com> added function-return probes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | */ |
| 34 | #include <linux/kprobes.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <linux/hash.h> |
| 36 | #include <linux/init.h> |
Tim Schmielau | 4e57b68 | 2005-10-30 15:03:48 -0800 | [diff] [blame] | 37 | #include <linux/slab.h> |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 38 | #include <linux/stddef.h> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 39 | #include <linux/export.h> |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 40 | #include <linux/moduleloader.h> |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 41 | #include <linux/kallsyms.h> |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 42 | #include <linux/freezer.h> |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 43 | #include <linux/seq_file.h> |
| 44 | #include <linux/debugfs.h> |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 45 | #include <linux/sysctl.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 46 | #include <linux/kdebug.h> |
Mathieu Desnoyers | 4460fda | 2009-03-06 10:36:38 -0500 | [diff] [blame] | 47 | #include <linux/memory.h> |
Masami Hiramatsu | 4554dbc | 2010-02-02 16:49:18 -0500 | [diff] [blame] | 48 | #include <linux/ftrace.h> |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 49 | #include <linux/cpu.h> |
Jason Baron | bf5438fc | 2010-09-17 11:09:00 -0400 | [diff] [blame] | 50 | #include <linux/jump_label.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 51 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 52 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <asm/cacheflush.h> |
| 54 | #include <asm/errno.h> |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 55 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
| 57 | #define KPROBE_HASH_BITS 6 |
| 58 | #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
| 59 | |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 60 | |
| 61 | /* |
| 62 | * Some oddball architectures like 64bit powerpc have function descriptors |
| 63 | * so this must be overridable. |
| 64 | */ |
| 65 | #ifndef kprobe_lookup_name |
| 66 | #define kprobe_lookup_name(name, addr) \ |
| 67 | addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) |
| 68 | #endif |
| 69 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 70 | static int kprobes_initialized; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 72 | static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 74 | /* NOTE: change this value only with kprobe_mutex held */ |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 75 | static bool kprobes_all_disarmed; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 76 | |
Masami Hiramatsu | 43948f5 | 2010-10-25 22:18:01 +0900 | [diff] [blame] | 77 | /* This protects kprobe_table and optimizing_list */ |
| 78 | static DEFINE_MUTEX(kprobe_mutex); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 79 | static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 80 | static struct { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 81 | raw_spinlock_t lock ____cacheline_aligned_in_smp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 82 | } kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
| 83 | |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 84 | static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 85 | { |
| 86 | return &(kretprobe_table_locks[hash].lock); |
| 87 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 89 | /* |
| 90 | * Normally, functions that we'd want to prohibit kprobes in, are marked |
| 91 | * __kprobes. But, there are cases where such functions already belong to |
| 92 | * a different section (__sched for preempt_schedule) |
| 93 | * |
| 94 | * For such cases, we now have a blacklist |
| 95 | */ |
Daniel Guilak | 544304b | 2008-07-10 09:38:19 -0700 | [diff] [blame] | 96 | static struct kprobe_blackpoint kprobe_blacklist[] = { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 97 | {"preempt_schedule",}, |
Masami Hiramatsu | 65e234e | 2009-08-27 13:23:32 -0400 | [diff] [blame] | 98 | {"native_get_debugreg",}, |
Masami Hiramatsu | a00e817 | 2009-09-08 12:47:55 -0400 | [diff] [blame] | 99 | {"irq_entries_start",}, |
| 100 | {"common_interrupt",}, |
Masami Hiramatsu | 5ecaafd | 2010-02-05 01:24:34 -0500 | [diff] [blame] | 101 | {"mcount",}, /* mcount can be called from everywhere */ |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 102 | {NULL} /* Terminator */ |
| 103 | }; |
| 104 | |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 105 | #ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 106 | /* |
| 107 | * kprobe->ainsn.insn points to the copy of the instruction to be |
| 108 | * single-stepped. x86_64, POWER4 and above have no-exec support and |
| 109 | * stepping on the instruction on a vmalloced/kmalloced/data page |
| 110 | * is a recipe for disaster |
| 111 | */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 112 | struct kprobe_insn_page { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 113 | struct list_head list; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 114 | kprobe_opcode_t *insns; /* Page of instruction slots */ |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 115 | int nused; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 116 | int ngarbage; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 117 | char slot_used[]; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 118 | }; |
| 119 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 120 | #define KPROBE_INSN_PAGE_SIZE(slots) \ |
| 121 | (offsetof(struct kprobe_insn_page, slot_used) + \ |
| 122 | (sizeof(char) * (slots))) |
| 123 | |
| 124 | struct kprobe_insn_cache { |
| 125 | struct list_head pages; /* list of kprobe_insn_page */ |
| 126 | size_t insn_size; /* size of instruction slot */ |
| 127 | int nr_garbage; |
| 128 | }; |
| 129 | |
| 130 | static int slots_per_page(struct kprobe_insn_cache *c) |
| 131 | { |
| 132 | return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); |
| 133 | } |
| 134 | |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 135 | enum kprobe_slot_state { |
| 136 | SLOT_CLEAN = 0, |
| 137 | SLOT_DIRTY = 1, |
| 138 | SLOT_USED = 2, |
| 139 | }; |
| 140 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 141 | static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */ |
| 142 | static struct kprobe_insn_cache kprobe_insn_slots = { |
| 143 | .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), |
| 144 | .insn_size = MAX_INSN_SIZE, |
| 145 | .nr_garbage = 0, |
| 146 | }; |
| 147 | static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 148 | |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 149 | /** |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 150 | * __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] | 151 | * We allocate an executable page if there's no room on existing ones. |
| 152 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 153 | static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 154 | { |
| 155 | struct kprobe_insn_page *kip; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 156 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 157 | retry: |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 158 | list_for_each_entry(kip, &c->pages, list) { |
| 159 | if (kip->nused < slots_per_page(c)) { |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 160 | int i; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 161 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 162 | if (kip->slot_used[i] == SLOT_CLEAN) { |
| 163 | kip->slot_used[i] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 164 | kip->nused++; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 165 | return kip->insns + (i * c->insn_size); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 166 | } |
| 167 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 168 | /* kip->nused is broken. Fix it. */ |
| 169 | kip->nused = slots_per_page(c); |
| 170 | WARN_ON(1); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 171 | } |
| 172 | } |
| 173 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 174 | /* If there are any garbage slots, collect it and try again. */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 175 | if (c->nr_garbage && collect_garbage_slots(c) == 0) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 176 | goto retry; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 177 | |
| 178 | /* All out of space. Need to allocate a new page. */ |
| 179 | kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 180 | if (!kip) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 181 | return NULL; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 182 | |
| 183 | /* |
| 184 | * Use module_alloc so this page is within +/- 2GB of where the |
| 185 | * kernel image and loaded module images reside. This is required |
| 186 | * so x86_64 can correctly handle the %rip-relative fixups. |
| 187 | */ |
| 188 | kip->insns = module_alloc(PAGE_SIZE); |
| 189 | if (!kip->insns) { |
| 190 | kfree(kip); |
| 191 | return NULL; |
| 192 | } |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 193 | INIT_LIST_HEAD(&kip->list); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 194 | memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 195 | kip->slot_used[0] = SLOT_USED; |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 196 | kip->nused = 1; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 197 | kip->ngarbage = 0; |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 198 | list_add(&kip->list, &c->pages); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 199 | return kip->insns; |
| 200 | } |
| 201 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 202 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 203 | kprobe_opcode_t __kprobes *get_insn_slot(void) |
| 204 | { |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 205 | kprobe_opcode_t *ret = NULL; |
| 206 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 207 | mutex_lock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 208 | ret = __get_insn_slot(&kprobe_insn_slots); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 209 | mutex_unlock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 210 | |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 211 | return ret; |
| 212 | } |
| 213 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 214 | /* Return 1 if all garbages are collected, otherwise 0. */ |
| 215 | static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) |
| 216 | { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 217 | kip->slot_used[idx] = SLOT_CLEAN; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 218 | kip->nused--; |
| 219 | if (kip->nused == 0) { |
| 220 | /* |
| 221 | * Page is no longer in use. Free it unless |
| 222 | * it's the last one. We keep the last one |
| 223 | * so as not to have to set it up again the |
| 224 | * next time somebody inserts a probe. |
| 225 | */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 226 | if (!list_is_singular(&kip->list)) { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 227 | list_del(&kip->list); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 228 | module_free(NULL, kip->insns); |
| 229 | kfree(kip); |
| 230 | } |
| 231 | return 1; |
| 232 | } |
| 233 | return 0; |
| 234 | } |
| 235 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 236 | static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c) |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 237 | { |
Masami Hiramatsu | c5cb5a2 | 2009-06-30 17:08:14 -0400 | [diff] [blame] | 238 | struct kprobe_insn_page *kip, *next; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 239 | |
Masami Hiramatsu | 615d0eb | 2010-02-02 16:49:04 -0500 | [diff] [blame] | 240 | /* Ensure no-one is interrupted on the garbages */ |
| 241 | synchronize_sched(); |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 242 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 243 | list_for_each_entry_safe(kip, next, &c->pages, list) { |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 244 | int i; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 245 | if (kip->ngarbage == 0) |
| 246 | continue; |
| 247 | kip->ngarbage = 0; /* we will collect all garbages */ |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 248 | for (i = 0; i < slots_per_page(c); i++) { |
Masami Hiramatsu | ab40c5c | 2007-01-30 14:36:06 -0800 | [diff] [blame] | 249 | if (kip->slot_used[i] == SLOT_DIRTY && |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 250 | collect_one_slot(kip, i)) |
| 251 | break; |
| 252 | } |
| 253 | } |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 254 | c->nr_garbage = 0; |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 255 | return 0; |
| 256 | } |
| 257 | |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 258 | static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, |
| 259 | kprobe_opcode_t *slot, int dirty) |
| 260 | { |
| 261 | struct kprobe_insn_page *kip; |
| 262 | |
| 263 | list_for_each_entry(kip, &c->pages, list) { |
Masami Hiramatsu | 83ff56f | 2010-03-09 10:22:19 -0500 | [diff] [blame] | 264 | long idx = ((long)slot - (long)kip->insns) / |
| 265 | (c->insn_size * sizeof(kprobe_opcode_t)); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 266 | if (idx >= 0 && idx < slots_per_page(c)) { |
| 267 | WARN_ON(kip->slot_used[idx] != SLOT_USED); |
| 268 | if (dirty) { |
| 269 | kip->slot_used[idx] = SLOT_DIRTY; |
| 270 | kip->ngarbage++; |
| 271 | if (++c->nr_garbage > slots_per_page(c)) |
| 272 | collect_garbage_slots(c); |
| 273 | } else |
| 274 | collect_one_slot(kip, idx); |
| 275 | return; |
| 276 | } |
| 277 | } |
| 278 | /* Could not free this slot. */ |
| 279 | WARN_ON(1); |
| 280 | } |
| 281 | |
Masami Hiramatsu | b4c6c34 | 2006-12-06 20:38:11 -0800 | [diff] [blame] | 282 | void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 283 | { |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 284 | mutex_lock(&kprobe_insn_mutex); |
Masami Hiramatsu | 4610ee1 | 2010-02-25 08:33:59 -0500 | [diff] [blame] | 285 | __free_insn_slot(&kprobe_insn_slots, slot, dirty); |
Masami Hiramatsu | 1294156 | 2009-01-06 14:41:50 -0800 | [diff] [blame] | 286 | mutex_unlock(&kprobe_insn_mutex); |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 287 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 288 | #ifdef CONFIG_OPTPROBES |
| 289 | /* For optimized_kprobe buffer */ |
| 290 | static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */ |
| 291 | static struct kprobe_insn_cache kprobe_optinsn_slots = { |
| 292 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), |
| 293 | /* .insn_size is initialized later */ |
| 294 | .nr_garbage = 0, |
| 295 | }; |
| 296 | /* Get a slot for optimized_kprobe buffer */ |
| 297 | kprobe_opcode_t __kprobes *get_optinsn_slot(void) |
| 298 | { |
| 299 | kprobe_opcode_t *ret = NULL; |
| 300 | |
| 301 | mutex_lock(&kprobe_optinsn_mutex); |
| 302 | ret = __get_insn_slot(&kprobe_optinsn_slots); |
| 303 | mutex_unlock(&kprobe_optinsn_mutex); |
| 304 | |
| 305 | return ret; |
| 306 | } |
| 307 | |
| 308 | void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty) |
| 309 | { |
| 310 | mutex_lock(&kprobe_optinsn_mutex); |
| 311 | __free_insn_slot(&kprobe_optinsn_slots, slot, dirty); |
| 312 | mutex_unlock(&kprobe_optinsn_mutex); |
| 313 | } |
| 314 | #endif |
Anil S Keshavamurthy | 2d14e39 | 2006-01-09 20:52:41 -0800 | [diff] [blame] | 315 | #endif |
Ananth N Mavinakayanahalli | 9ec4b1f | 2005-06-27 15:17:01 -0700 | [diff] [blame] | 316 | |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 317 | /* We have preemption disabled.. so it is safe to use __ versions */ |
| 318 | static inline void set_kprobe_instance(struct kprobe *kp) |
| 319 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 320 | __this_cpu_write(kprobe_instance, kp); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 321 | } |
| 322 | |
| 323 | static inline void reset_kprobe_instance(void) |
| 324 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 325 | __this_cpu_write(kprobe_instance, NULL); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 326 | } |
| 327 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 328 | /* |
| 329 | * This routine is called either: |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 330 | * - under the kprobe_mutex - during kprobe_[un]register() |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 331 | * OR |
Ananth N Mavinakayanahalli | d217d54 | 2005-11-07 01:00:14 -0800 | [diff] [blame] | 332 | * - with preemption disabled - from arch/xxx/kernel/kprobes.c |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 333 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 334 | struct kprobe __kprobes *get_kprobe(void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | { |
| 336 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 337 | struct kprobe *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | |
| 339 | head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 340 | hlist_for_each_entry_rcu(p, head, hlist) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | if (p->addr == addr) |
| 342 | return p; |
| 343 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 344 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | return NULL; |
| 346 | } |
| 347 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 348 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
| 349 | |
| 350 | /* Return true if the kprobe is an aggregator */ |
| 351 | static inline int kprobe_aggrprobe(struct kprobe *p) |
| 352 | { |
| 353 | return p->pre_handler == aggr_pre_handler; |
| 354 | } |
| 355 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 356 | /* Return true(!0) if the kprobe is unused */ |
| 357 | static inline int kprobe_unused(struct kprobe *p) |
| 358 | { |
| 359 | return kprobe_aggrprobe(p) && kprobe_disabled(p) && |
| 360 | list_empty(&p->list); |
| 361 | } |
| 362 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 363 | /* |
| 364 | * Keep all fields in the kprobe consistent |
| 365 | */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 366 | static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 367 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 368 | memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); |
| 369 | memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 370 | } |
| 371 | |
| 372 | #ifdef CONFIG_OPTPROBES |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 373 | /* NOTE: change this value only with kprobe_mutex held */ |
| 374 | static bool kprobes_allow_optimization; |
| 375 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 376 | /* |
| 377 | * Call all pre_handler on the list, but ignores its return value. |
| 378 | * This must be called from arch-dep optimized caller. |
| 379 | */ |
| 380 | void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
| 381 | { |
| 382 | struct kprobe *kp; |
| 383 | |
| 384 | list_for_each_entry_rcu(kp, &p->list, list) { |
| 385 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
| 386 | set_kprobe_instance(kp); |
| 387 | kp->pre_handler(kp, regs); |
| 388 | } |
| 389 | reset_kprobe_instance(); |
| 390 | } |
| 391 | } |
| 392 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 393 | /* Free optimized instructions and optimized_kprobe */ |
| 394 | static __kprobes void free_aggr_kprobe(struct kprobe *p) |
| 395 | { |
| 396 | struct optimized_kprobe *op; |
| 397 | |
| 398 | op = container_of(p, struct optimized_kprobe, kp); |
| 399 | arch_remove_optimized_kprobe(op); |
| 400 | arch_remove_kprobe(p); |
| 401 | kfree(op); |
| 402 | } |
| 403 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 404 | /* Return true(!0) if the kprobe is ready for optimization. */ |
| 405 | static inline int kprobe_optready(struct kprobe *p) |
| 406 | { |
| 407 | struct optimized_kprobe *op; |
| 408 | |
| 409 | if (kprobe_aggrprobe(p)) { |
| 410 | op = container_of(p, struct optimized_kprobe, kp); |
| 411 | return arch_prepared_optinsn(&op->optinsn); |
| 412 | } |
| 413 | |
| 414 | return 0; |
| 415 | } |
| 416 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 417 | /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ |
| 418 | static inline int kprobe_disarmed(struct kprobe *p) |
| 419 | { |
| 420 | struct optimized_kprobe *op; |
| 421 | |
| 422 | /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ |
| 423 | if (!kprobe_aggrprobe(p)) |
| 424 | return kprobe_disabled(p); |
| 425 | |
| 426 | op = container_of(p, struct optimized_kprobe, kp); |
| 427 | |
| 428 | return kprobe_disabled(p) && list_empty(&op->list); |
| 429 | } |
| 430 | |
| 431 | /* Return true(!0) if the probe is queued on (un)optimizing lists */ |
| 432 | static int __kprobes kprobe_queued(struct kprobe *p) |
| 433 | { |
| 434 | struct optimized_kprobe *op; |
| 435 | |
| 436 | if (kprobe_aggrprobe(p)) { |
| 437 | op = container_of(p, struct optimized_kprobe, kp); |
| 438 | if (!list_empty(&op->list)) |
| 439 | return 1; |
| 440 | } |
| 441 | return 0; |
| 442 | } |
| 443 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 444 | /* |
| 445 | * Return an optimized kprobe whose optimizing code replaces |
| 446 | * instructions including addr (exclude breakpoint). |
| 447 | */ |
Namhyung Kim | 6376b22 | 2010-09-15 10:04:28 +0900 | [diff] [blame] | 448 | static struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 449 | { |
| 450 | int i; |
| 451 | struct kprobe *p = NULL; |
| 452 | struct optimized_kprobe *op; |
| 453 | |
| 454 | /* Don't check i == 0, since that is a breakpoint case. */ |
| 455 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) |
| 456 | p = get_kprobe((void *)(addr - i)); |
| 457 | |
| 458 | if (p && kprobe_optready(p)) { |
| 459 | op = container_of(p, struct optimized_kprobe, kp); |
| 460 | if (arch_within_optimized_kprobe(op, addr)) |
| 461 | return p; |
| 462 | } |
| 463 | |
| 464 | return NULL; |
| 465 | } |
| 466 | |
| 467 | /* Optimization staging list, protected by kprobe_mutex */ |
| 468 | static LIST_HEAD(optimizing_list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 469 | static LIST_HEAD(unoptimizing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 470 | |
| 471 | static void kprobe_optimizer(struct work_struct *work); |
| 472 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); |
| 473 | #define OPTIMIZE_DELAY 5 |
| 474 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 475 | /* |
| 476 | * Optimize (replace a breakpoint with a jump) kprobes listed on |
| 477 | * optimizing_list. |
| 478 | */ |
| 479 | static __kprobes void do_optimize_kprobes(void) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 480 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 481 | /* Optimization never be done when disarmed */ |
| 482 | if (kprobes_all_disarmed || !kprobes_allow_optimization || |
| 483 | list_empty(&optimizing_list)) |
| 484 | return; |
| 485 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 486 | /* |
| 487 | * The optimization/unoptimization refers online_cpus via |
| 488 | * stop_machine() and cpu-hotplug modifies online_cpus. |
| 489 | * And same time, text_mutex will be held in cpu-hotplug and here. |
| 490 | * This combination can cause a deadlock (cpu-hotplug try to lock |
| 491 | * text_mutex but stop_machine can not be done because online_cpus |
| 492 | * has been changed) |
| 493 | * To avoid this deadlock, we need to call get_online_cpus() |
| 494 | * for preventing cpu-hotplug outside of text_mutex locking. |
| 495 | */ |
| 496 | get_online_cpus(); |
| 497 | mutex_lock(&text_mutex); |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 498 | arch_optimize_kprobes(&optimizing_list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 499 | mutex_unlock(&text_mutex); |
| 500 | put_online_cpus(); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 501 | } |
| 502 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 503 | /* |
| 504 | * Unoptimize (replace a jump with a breakpoint and remove the breakpoint |
| 505 | * if need) kprobes listed on unoptimizing_list. |
| 506 | */ |
| 507 | static __kprobes void do_unoptimize_kprobes(struct list_head *free_list) |
| 508 | { |
| 509 | struct optimized_kprobe *op, *tmp; |
| 510 | |
| 511 | /* Unoptimization must be done anytime */ |
| 512 | if (list_empty(&unoptimizing_list)) |
| 513 | return; |
| 514 | |
| 515 | /* Ditto to do_optimize_kprobes */ |
| 516 | get_online_cpus(); |
| 517 | mutex_lock(&text_mutex); |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 518 | arch_unoptimize_kprobes(&unoptimizing_list, free_list); |
| 519 | /* Loop free_list for disarming */ |
| 520 | list_for_each_entry_safe(op, tmp, free_list, list) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 521 | /* Disarm probes if marked disabled */ |
| 522 | if (kprobe_disabled(&op->kp)) |
| 523 | arch_disarm_kprobe(&op->kp); |
| 524 | if (kprobe_unused(&op->kp)) { |
| 525 | /* |
| 526 | * Remove unused probes from hash list. After waiting |
| 527 | * for synchronization, these probes are reclaimed. |
| 528 | * (reclaiming is done by do_free_cleaned_kprobes.) |
| 529 | */ |
| 530 | hlist_del_rcu(&op->kp.hlist); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 531 | } else |
| 532 | list_del_init(&op->list); |
| 533 | } |
| 534 | mutex_unlock(&text_mutex); |
| 535 | put_online_cpus(); |
| 536 | } |
| 537 | |
| 538 | /* Reclaim all kprobes on the free_list */ |
| 539 | static __kprobes void do_free_cleaned_kprobes(struct list_head *free_list) |
| 540 | { |
| 541 | struct optimized_kprobe *op, *tmp; |
| 542 | |
| 543 | list_for_each_entry_safe(op, tmp, free_list, list) { |
| 544 | BUG_ON(!kprobe_unused(&op->kp)); |
| 545 | list_del_init(&op->list); |
| 546 | free_aggr_kprobe(&op->kp); |
| 547 | } |
| 548 | } |
| 549 | |
| 550 | /* Start optimizer after OPTIMIZE_DELAY passed */ |
| 551 | static __kprobes void kick_kprobe_optimizer(void) |
| 552 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 553 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 554 | } |
| 555 | |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 556 | /* Kprobe jump optimizer */ |
| 557 | static __kprobes void kprobe_optimizer(struct work_struct *work) |
| 558 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 559 | LIST_HEAD(free_list); |
| 560 | |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 561 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 562 | /* Lock modules while optimizing kprobes */ |
| 563 | mutex_lock(&module_mutex); |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 564 | |
| 565 | /* |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 566 | * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) |
| 567 | * kprobes before waiting for quiesence period. |
| 568 | */ |
| 569 | do_unoptimize_kprobes(&free_list); |
| 570 | |
| 571 | /* |
| 572 | * Step 2: Wait for quiesence period to ensure all running interrupts |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 573 | * are done. Because optprobe may modify multiple instructions |
| 574 | * there is a chance that Nth instruction is interrupted. In that |
| 575 | * case, running interrupt can return to 2nd-Nth byte of jump |
| 576 | * instruction. This wait is for avoiding it. |
| 577 | */ |
| 578 | synchronize_sched(); |
| 579 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 580 | /* Step 3: Optimize kprobes after quiesence period */ |
Masami Hiramatsu | 61f4e13 | 2010-12-03 18:54:03 +0900 | [diff] [blame] | 581 | do_optimize_kprobes(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 582 | |
| 583 | /* Step 4: Free cleaned kprobes after quiesence period */ |
| 584 | do_free_cleaned_kprobes(&free_list); |
| 585 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 586 | mutex_unlock(&module_mutex); |
Steven Rostedt | 72ef379 | 2012-06-05 19:28:14 +0900 | [diff] [blame] | 587 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 588 | |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 589 | /* Step 5: Kick optimizer again if needed */ |
Masami Hiramatsu | f984ba4 | 2010-12-03 18:54:34 +0900 | [diff] [blame] | 590 | if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
Masami Hiramatsu | cd7ebe2 | 2010-12-03 18:54:28 +0900 | [diff] [blame] | 591 | kick_kprobe_optimizer(); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 592 | } |
| 593 | |
| 594 | /* Wait for completing optimization and unoptimization */ |
| 595 | static __kprobes void wait_for_kprobe_optimizer(void) |
| 596 | { |
Tejun Heo | ad72b3b | 2012-12-21 17:57:00 -0800 | [diff] [blame] | 597 | mutex_lock(&kprobe_mutex); |
| 598 | |
| 599 | while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { |
| 600 | mutex_unlock(&kprobe_mutex); |
| 601 | |
| 602 | /* this will also make optimizing_work execute immmediately */ |
| 603 | flush_delayed_work(&optimizing_work); |
| 604 | /* @optimizing_work might not have been queued yet, relax */ |
| 605 | cpu_relax(); |
| 606 | |
| 607 | mutex_lock(&kprobe_mutex); |
| 608 | } |
| 609 | |
| 610 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 611 | } |
| 612 | |
| 613 | /* Optimize kprobe if p is ready to be optimized */ |
| 614 | static __kprobes void optimize_kprobe(struct kprobe *p) |
| 615 | { |
| 616 | struct optimized_kprobe *op; |
| 617 | |
| 618 | /* Check if the kprobe is disabled or not ready for optimization. */ |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 619 | if (!kprobe_optready(p) || !kprobes_allow_optimization || |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 620 | (kprobe_disabled(p) || kprobes_all_disarmed)) |
| 621 | return; |
| 622 | |
| 623 | /* Both of break_handler and post_handler are not supported. */ |
| 624 | if (p->break_handler || p->post_handler) |
| 625 | return; |
| 626 | |
| 627 | op = container_of(p, struct optimized_kprobe, kp); |
| 628 | |
| 629 | /* Check there is no other kprobes at the optimized instructions */ |
| 630 | if (arch_check_optimized_kprobe(op) < 0) |
| 631 | return; |
| 632 | |
| 633 | /* Check if it is already optimized. */ |
| 634 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) |
| 635 | return; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 636 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 637 | |
| 638 | if (!list_empty(&op->list)) |
| 639 | /* This is under unoptimizing. Just dequeue the probe */ |
| 640 | list_del_init(&op->list); |
| 641 | else { |
| 642 | list_add(&op->list, &optimizing_list); |
| 643 | kick_kprobe_optimizer(); |
| 644 | } |
| 645 | } |
| 646 | |
| 647 | /* Short cut to direct unoptimizing */ |
| 648 | static __kprobes void force_unoptimize_kprobe(struct optimized_kprobe *op) |
| 649 | { |
| 650 | get_online_cpus(); |
| 651 | arch_unoptimize_kprobe(op); |
| 652 | put_online_cpus(); |
| 653 | if (kprobe_disabled(&op->kp)) |
| 654 | arch_disarm_kprobe(&op->kp); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 655 | } |
| 656 | |
| 657 | /* Unoptimize a kprobe if p is optimized */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 658 | static __kprobes void unoptimize_kprobe(struct kprobe *p, bool force) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 659 | { |
| 660 | struct optimized_kprobe *op; |
| 661 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 662 | if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) |
| 663 | return; /* This is not an optprobe nor optimized */ |
| 664 | |
| 665 | op = container_of(p, struct optimized_kprobe, kp); |
| 666 | if (!kprobe_optimized(p)) { |
| 667 | /* Unoptimized or unoptimizing case */ |
| 668 | if (force && !list_empty(&op->list)) { |
| 669 | /* |
| 670 | * Only if this is unoptimizing kprobe and forced, |
| 671 | * forcibly unoptimize it. (No need to unoptimize |
| 672 | * unoptimized kprobe again :) |
| 673 | */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 674 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 675 | force_unoptimize_kprobe(op); |
| 676 | } |
| 677 | return; |
| 678 | } |
| 679 | |
| 680 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
| 681 | if (!list_empty(&op->list)) { |
| 682 | /* Dequeue from the optimization queue */ |
| 683 | list_del_init(&op->list); |
| 684 | return; |
| 685 | } |
| 686 | /* Optimized kprobe case */ |
| 687 | if (force) |
| 688 | /* Forcibly update the code: this is a special case */ |
| 689 | force_unoptimize_kprobe(op); |
| 690 | else { |
| 691 | list_add(&op->list, &unoptimizing_list); |
| 692 | kick_kprobe_optimizer(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 693 | } |
| 694 | } |
| 695 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 696 | /* Cancel unoptimizing for reusing */ |
| 697 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 698 | { |
| 699 | struct optimized_kprobe *op; |
| 700 | |
| 701 | BUG_ON(!kprobe_unused(ap)); |
| 702 | /* |
| 703 | * Unused kprobe MUST be on the way of delayed unoptimizing (means |
| 704 | * there is still a relative jump) and disabled. |
| 705 | */ |
| 706 | op = container_of(ap, struct optimized_kprobe, kp); |
| 707 | if (unlikely(list_empty(&op->list))) |
| 708 | printk(KERN_WARNING "Warning: found a stray unused " |
| 709 | "aggrprobe@%p\n", ap->addr); |
| 710 | /* Enable the probe again */ |
| 711 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 712 | /* Optimize it again (remove from op->list) */ |
| 713 | BUG_ON(!kprobe_optready(ap)); |
| 714 | optimize_kprobe(ap); |
| 715 | } |
| 716 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 717 | /* Remove optimized instructions */ |
| 718 | static void __kprobes kill_optimized_kprobe(struct kprobe *p) |
| 719 | { |
| 720 | struct optimized_kprobe *op; |
| 721 | |
| 722 | op = container_of(p, struct optimized_kprobe, kp); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 723 | if (!list_empty(&op->list)) |
| 724 | /* Dequeue from the (un)optimization queue */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 725 | list_del_init(&op->list); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 726 | |
| 727 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
| 728 | /* Don't touch the code, because it is already freed. */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 729 | arch_remove_optimized_kprobe(op); |
| 730 | } |
| 731 | |
| 732 | /* Try to prepare optimized instructions */ |
| 733 | static __kprobes void prepare_optimized_kprobe(struct kprobe *p) |
| 734 | { |
| 735 | struct optimized_kprobe *op; |
| 736 | |
| 737 | op = container_of(p, struct optimized_kprobe, kp); |
| 738 | arch_prepare_optimized_kprobe(op); |
| 739 | } |
| 740 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 741 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
| 742 | static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
| 743 | { |
| 744 | struct optimized_kprobe *op; |
| 745 | |
| 746 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); |
| 747 | if (!op) |
| 748 | return NULL; |
| 749 | |
| 750 | INIT_LIST_HEAD(&op->list); |
| 751 | op->kp.addr = p->addr; |
| 752 | arch_prepare_optimized_kprobe(op); |
| 753 | |
| 754 | return &op->kp; |
| 755 | } |
| 756 | |
| 757 | static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
| 758 | |
| 759 | /* |
| 760 | * Prepare an optimized_kprobe and optimize it |
| 761 | * NOTE: p must be a normal registered kprobe |
| 762 | */ |
| 763 | static __kprobes void try_to_optimize_kprobe(struct kprobe *p) |
| 764 | { |
| 765 | struct kprobe *ap; |
| 766 | struct optimized_kprobe *op; |
| 767 | |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 768 | /* Impossible to optimize ftrace-based kprobe */ |
| 769 | if (kprobe_ftrace(p)) |
| 770 | return; |
| 771 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 772 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 773 | jump_label_lock(); |
| 774 | mutex_lock(&text_mutex); |
| 775 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 776 | ap = alloc_aggr_kprobe(p); |
| 777 | if (!ap) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 778 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 779 | |
| 780 | op = container_of(ap, struct optimized_kprobe, kp); |
| 781 | if (!arch_prepared_optinsn(&op->optinsn)) { |
| 782 | /* If failed to setup optimizing, fallback to kprobe */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 783 | arch_remove_optimized_kprobe(op); |
| 784 | kfree(op); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 785 | goto out; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 786 | } |
| 787 | |
| 788 | init_aggr_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 789 | optimize_kprobe(ap); /* This just kicks optimizer thread */ |
| 790 | |
| 791 | out: |
| 792 | mutex_unlock(&text_mutex); |
| 793 | jump_label_unlock(); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 794 | } |
| 795 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 796 | #ifdef CONFIG_SYSCTL |
Masami Hiramatsu | 43948f5 | 2010-10-25 22:18:01 +0900 | [diff] [blame] | 797 | /* This should be called with kprobe_mutex locked */ |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 798 | static void __kprobes optimize_all_kprobes(void) |
| 799 | { |
| 800 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 801 | struct kprobe *p; |
| 802 | unsigned int i; |
| 803 | |
| 804 | /* If optimization is already allowed, just return */ |
| 805 | if (kprobes_allow_optimization) |
| 806 | return; |
| 807 | |
| 808 | kprobes_allow_optimization = true; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 809 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 810 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 811 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 812 | if (!kprobe_disabled(p)) |
| 813 | optimize_kprobe(p); |
| 814 | } |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 815 | printk(KERN_INFO "Kprobes globally optimized\n"); |
| 816 | } |
| 817 | |
Masami Hiramatsu | 43948f5 | 2010-10-25 22:18:01 +0900 | [diff] [blame] | 818 | /* This should be called with kprobe_mutex locked */ |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 819 | static void __kprobes unoptimize_all_kprobes(void) |
| 820 | { |
| 821 | struct hlist_head *head; |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 822 | struct kprobe *p; |
| 823 | unsigned int i; |
| 824 | |
| 825 | /* If optimization is already prohibited, just return */ |
| 826 | if (!kprobes_allow_optimization) |
| 827 | return; |
| 828 | |
| 829 | kprobes_allow_optimization = false; |
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)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 834 | unoptimize_kprobe(p, false); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 835 | } |
| 836 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 837 | /* Wait for unoptimizing completion */ |
| 838 | wait_for_kprobe_optimizer(); |
| 839 | printk(KERN_INFO "Kprobes globally unoptimized\n"); |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 840 | } |
| 841 | |
| 842 | int sysctl_kprobes_optimization; |
| 843 | int proc_kprobes_optimization_handler(struct ctl_table *table, int write, |
| 844 | void __user *buffer, size_t *length, |
| 845 | loff_t *ppos) |
| 846 | { |
| 847 | int ret; |
| 848 | |
| 849 | mutex_lock(&kprobe_mutex); |
| 850 | sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; |
| 851 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); |
| 852 | |
| 853 | if (sysctl_kprobes_optimization) |
| 854 | optimize_all_kprobes(); |
| 855 | else |
| 856 | unoptimize_all_kprobes(); |
| 857 | mutex_unlock(&kprobe_mutex); |
| 858 | |
| 859 | return ret; |
| 860 | } |
| 861 | #endif /* CONFIG_SYSCTL */ |
| 862 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 863 | /* Put a breakpoint for a probe. Must be called with text_mutex locked */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 864 | static void __kprobes __arm_kprobe(struct kprobe *p) |
| 865 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 866 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 867 | |
| 868 | /* Check collision with other optimized kprobes */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 869 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 870 | if (unlikely(_p)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 871 | /* Fallback to unoptimized kprobe */ |
| 872 | unoptimize_kprobe(_p, true); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 873 | |
| 874 | arch_arm_kprobe(p); |
| 875 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ |
| 876 | } |
| 877 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 878 | /* Remove the breakpoint of a probe. Must be called with text_mutex locked */ |
| 879 | static void __kprobes __disarm_kprobe(struct kprobe *p, bool reopt) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 880 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 881 | struct kprobe *_p; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 882 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 883 | unoptimize_kprobe(p, false); /* Try to unoptimize */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 884 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 885 | if (!kprobe_queued(p)) { |
| 886 | arch_disarm_kprobe(p); |
| 887 | /* If another kprobe was blocked, optimize it. */ |
| 888 | _p = get_optimized_kprobe((unsigned long)p->addr); |
| 889 | if (unlikely(_p) && reopt) |
| 890 | optimize_kprobe(_p); |
| 891 | } |
| 892 | /* TODO: reoptimize others after unoptimized this probe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 893 | } |
| 894 | |
| 895 | #else /* !CONFIG_OPTPROBES */ |
| 896 | |
| 897 | #define optimize_kprobe(p) do {} while (0) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 898 | #define unoptimize_kprobe(p, f) do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 899 | #define kill_optimized_kprobe(p) do {} while (0) |
| 900 | #define prepare_optimized_kprobe(p) do {} while (0) |
| 901 | #define try_to_optimize_kprobe(p) do {} while (0) |
| 902 | #define __arm_kprobe(p) arch_arm_kprobe(p) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 903 | #define __disarm_kprobe(p, o) arch_disarm_kprobe(p) |
| 904 | #define kprobe_disarmed(p) kprobe_disabled(p) |
| 905 | #define wait_for_kprobe_optimizer() do {} while (0) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 906 | |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 907 | /* There should be no unused kprobes can be reused without optimization */ |
| 908 | static void reuse_unused_kprobe(struct kprobe *ap) |
| 909 | { |
| 910 | printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); |
| 911 | BUG_ON(kprobe_unused(ap)); |
| 912 | } |
| 913 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 914 | static __kprobes void free_aggr_kprobe(struct kprobe *p) |
| 915 | { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 916 | arch_remove_kprobe(p); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 917 | kfree(p); |
| 918 | } |
| 919 | |
| 920 | static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
| 921 | { |
| 922 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); |
| 923 | } |
| 924 | #endif /* CONFIG_OPTPROBES */ |
| 925 | |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 926 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 927 | static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
Masami Hiramatsu | e525389 | 2012-06-05 19:28:38 +0900 | [diff] [blame] | 928 | .func = kprobe_ftrace_handler, |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 929 | .flags = FTRACE_OPS_FL_SAVE_REGS, |
| 930 | }; |
| 931 | static int kprobe_ftrace_enabled; |
| 932 | |
| 933 | /* Must ensure p->addr is really on ftrace */ |
| 934 | static int __kprobes prepare_kprobe(struct kprobe *p) |
| 935 | { |
| 936 | if (!kprobe_ftrace(p)) |
| 937 | return arch_prepare_kprobe(p); |
| 938 | |
| 939 | return arch_prepare_kprobe_ftrace(p); |
| 940 | } |
| 941 | |
| 942 | /* Caller must lock kprobe_mutex */ |
| 943 | static void __kprobes arm_kprobe_ftrace(struct kprobe *p) |
| 944 | { |
| 945 | int ret; |
| 946 | |
| 947 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 948 | (unsigned long)p->addr, 0, 0); |
| 949 | WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 950 | kprobe_ftrace_enabled++; |
| 951 | if (kprobe_ftrace_enabled == 1) { |
| 952 | ret = register_ftrace_function(&kprobe_ftrace_ops); |
| 953 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 954 | } |
| 955 | } |
| 956 | |
| 957 | /* Caller must lock kprobe_mutex */ |
| 958 | static void __kprobes disarm_kprobe_ftrace(struct kprobe *p) |
| 959 | { |
| 960 | int ret; |
| 961 | |
| 962 | kprobe_ftrace_enabled--; |
| 963 | if (kprobe_ftrace_enabled == 0) { |
| 964 | ret = unregister_ftrace_function(&kprobe_ftrace_ops); |
| 965 | WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret); |
| 966 | } |
| 967 | ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, |
| 968 | (unsigned long)p->addr, 1, 0); |
| 969 | WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret); |
| 970 | } |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 971 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 972 | #define prepare_kprobe(p) arch_prepare_kprobe(p) |
| 973 | #define arm_kprobe_ftrace(p) do {} while (0) |
| 974 | #define disarm_kprobe_ftrace(p) do {} while (0) |
| 975 | #endif |
| 976 | |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 977 | /* Arm a kprobe with text_mutex */ |
| 978 | static void __kprobes arm_kprobe(struct kprobe *kp) |
| 979 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 980 | if (unlikely(kprobe_ftrace(kp))) { |
| 981 | arm_kprobe_ftrace(kp); |
| 982 | return; |
| 983 | } |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 984 | /* |
| 985 | * Here, since __arm_kprobe() doesn't use stop_machine(), |
| 986 | * this doesn't cause deadlock on text_mutex. So, we don't |
| 987 | * need get_online_cpus(). |
| 988 | */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 989 | mutex_lock(&text_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 990 | __arm_kprobe(kp); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 991 | mutex_unlock(&text_mutex); |
| 992 | } |
| 993 | |
| 994 | /* Disarm a kprobe with text_mutex */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 995 | static void __kprobes disarm_kprobe(struct kprobe *kp, bool reopt) |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 996 | { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 997 | if (unlikely(kprobe_ftrace(kp))) { |
| 998 | disarm_kprobe_ftrace(kp); |
| 999 | return; |
| 1000 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1001 | /* Ditto */ |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1002 | mutex_lock(&text_mutex); |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1003 | __disarm_kprobe(kp, reopt); |
Masami Hiramatsu | 201517a | 2009-05-07 16:31:26 -0400 | [diff] [blame] | 1004 | mutex_unlock(&text_mutex); |
| 1005 | } |
| 1006 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1007 | /* |
| 1008 | * Aggregate handlers for multiple kprobes support - these handlers |
| 1009 | * take care of invoking the individual kprobe handlers on p->list |
| 1010 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1011 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1012 | { |
| 1013 | struct kprobe *kp; |
| 1014 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1015 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1016 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1017 | set_kprobe_instance(kp); |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1018 | if (kp->pre_handler(kp, regs)) |
| 1019 | return 1; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1020 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1021 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1022 | } |
| 1023 | return 0; |
| 1024 | } |
| 1025 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1026 | static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, |
| 1027 | unsigned long flags) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1028 | { |
| 1029 | struct kprobe *kp; |
| 1030 | |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1031 | list_for_each_entry_rcu(kp, &p->list, list) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1032 | if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1033 | set_kprobe_instance(kp); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1034 | kp->post_handler(kp, regs, flags); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1035 | reset_kprobe_instance(); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1036 | } |
| 1037 | } |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1038 | } |
| 1039 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1040 | static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, |
| 1041 | int trapnr) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1042 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1043 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1044 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1045 | /* |
| 1046 | * if we faulted "during" the execution of a user specified |
| 1047 | * probe handler, invoke just that probe's fault handler |
| 1048 | */ |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1049 | if (cur && cur->fault_handler) { |
| 1050 | if (cur->fault_handler(cur, regs, trapnr)) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1051 | return 1; |
| 1052 | } |
| 1053 | return 0; |
| 1054 | } |
| 1055 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1056 | static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1057 | { |
Christoph Lameter | b76834b | 2010-12-06 11:16:25 -0600 | [diff] [blame] | 1058 | struct kprobe *cur = __this_cpu_read(kprobe_instance); |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1059 | int ret = 0; |
| 1060 | |
| 1061 | if (cur && cur->break_handler) { |
| 1062 | if (cur->break_handler(cur, regs)) |
| 1063 | ret = 1; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1064 | } |
Ananth N Mavinakayanahalli | e658452 | 2005-11-07 01:00:07 -0800 | [diff] [blame] | 1065 | reset_kprobe_instance(); |
| 1066 | return ret; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1067 | } |
| 1068 | |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1069 | /* Walks the list and increments nmissed count for multiprobe case */ |
| 1070 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
| 1071 | { |
| 1072 | struct kprobe *kp; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1073 | if (!kprobe_aggrprobe(p)) { |
Keshavamurthy Anil S | bf8d5c5 | 2005-12-12 00:37:34 -0800 | [diff] [blame] | 1074 | p->nmissed++; |
| 1075 | } else { |
| 1076 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1077 | kp->nmissed++; |
| 1078 | } |
| 1079 | return; |
| 1080 | } |
| 1081 | |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1082 | void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, |
| 1083 | struct hlist_head *head) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1084 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1085 | struct kretprobe *rp = ri->rp; |
| 1086 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1087 | /* remove rp inst off the rprobe_inst_table */ |
| 1088 | hlist_del(&ri->hlist); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1089 | INIT_HLIST_NODE(&ri->hlist); |
| 1090 | if (likely(rp)) { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1091 | raw_spin_lock(&rp->lock); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1092 | hlist_add_head(&ri->hlist, &rp->free_instances); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1093 | raw_spin_unlock(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1094 | } else |
| 1095 | /* Unregistering */ |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1096 | hlist_add_head(&ri->hlist, head); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1097 | } |
| 1098 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 1099 | void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1100 | struct hlist_head **head, unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1101 | __acquires(hlist_lock) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1102 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1103 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1104 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1105 | |
| 1106 | *head = &kretprobe_inst_table[hash]; |
| 1107 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1108 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1109 | } |
| 1110 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 1111 | static void __kprobes kretprobe_table_lock(unsigned long hash, |
| 1112 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1113 | __acquires(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1114 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1115 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1116 | raw_spin_lock_irqsave(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1117 | } |
| 1118 | |
Masami Hiramatsu | 017c39b | 2009-01-06 14:41:51 -0800 | [diff] [blame] | 1119 | void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, |
| 1120 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1121 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1122 | { |
| 1123 | unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1124 | raw_spinlock_t *hlist_lock; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1125 | |
| 1126 | hlist_lock = kretprobe_table_lock_ptr(hash); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1127 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1128 | } |
| 1129 | |
Namhyung Kim | 6376b22 | 2010-09-15 10:04:28 +0900 | [diff] [blame] | 1130 | static void __kprobes kretprobe_table_unlock(unsigned long hash, |
| 1131 | unsigned long *flags) |
Namhyung Kim | 635c17c | 2010-09-15 10:04:30 +0900 | [diff] [blame] | 1132 | __releases(hlist_lock) |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1133 | { |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1134 | raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); |
| 1135 | raw_spin_unlock_irqrestore(hlist_lock, *flags); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1136 | } |
| 1137 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1138 | /* |
bibo mao | c6fd91f | 2006-03-26 01:38:20 -0800 | [diff] [blame] | 1139 | * This function is called from finish_task_switch when task tk becomes dead, |
| 1140 | * so that we can recycle any function-return probe instances associated |
| 1141 | * with this task. These left over instances represent probed functions |
| 1142 | * that have been called but will never return. |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1143 | */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1144 | void __kprobes kprobe_flush_task(struct task_struct *tk) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1145 | { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1146 | struct kretprobe_instance *ri; |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1147 | struct hlist_head *head, empty_rp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1148 | struct hlist_node *tmp; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1149 | unsigned long hash, flags = 0; |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 1150 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1151 | if (unlikely(!kprobes_initialized)) |
| 1152 | /* Early boot. kretprobe_table_locks not yet initialized. */ |
| 1153 | return; |
| 1154 | |
Ananth N Mavinakayanahalli | d496aab | 2012-01-20 14:34:04 -0800 | [diff] [blame] | 1155 | INIT_HLIST_HEAD(&empty_rp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1156 | hash = hash_ptr(tk, KPROBE_HASH_BITS); |
| 1157 | head = &kretprobe_inst_table[hash]; |
| 1158 | kretprobe_table_lock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1159 | hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1160 | if (ri->task == tk) |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1161 | recycle_rp_inst(ri, &empty_rp); |
bibo,mao | 62c27be | 2006-10-02 02:17:33 -0700 | [diff] [blame] | 1162 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1163 | kretprobe_table_unlock(hash, &flags); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1164 | hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
bibo,mao | 99219a3 | 2006-10-02 02:17:35 -0700 | [diff] [blame] | 1165 | hlist_del(&ri->hlist); |
| 1166 | kfree(ri); |
| 1167 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1168 | } |
| 1169 | |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1170 | static inline void free_rp_inst(struct kretprobe *rp) |
| 1171 | { |
| 1172 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1173 | struct hlist_node *next; |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1174 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1175 | hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1176 | hlist_del(&ri->hlist); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1177 | kfree(ri); |
| 1178 | } |
| 1179 | } |
| 1180 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1181 | static void __kprobes cleanup_rp_inst(struct kretprobe *rp) |
| 1182 | { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1183 | unsigned long flags, hash; |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1184 | struct kretprobe_instance *ri; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1185 | struct hlist_node *next; |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1186 | struct hlist_head *head; |
| 1187 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1188 | /* No race here */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1189 | for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { |
| 1190 | kretprobe_table_lock(hash, &flags); |
| 1191 | head = &kretprobe_inst_table[hash]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 1192 | hlist_for_each_entry_safe(ri, next, head, hlist) { |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1193 | if (ri->rp == rp) |
| 1194 | ri->rp = NULL; |
| 1195 | } |
| 1196 | kretprobe_table_unlock(hash, &flags); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1197 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1198 | free_rp_inst(rp); |
| 1199 | } |
| 1200 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1201 | /* |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1202 | * 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] | 1203 | * second jprobe at the address - two jprobes can't coexist |
| 1204 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1205 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1206 | { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1207 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1208 | |
| 1209 | if (p->break_handler || p->post_handler) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1210 | unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1211 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1212 | if (p->break_handler) { |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1213 | if (ap->break_handler) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1214 | return -EEXIST; |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1215 | list_add_tail_rcu(&p->list, &ap->list); |
| 1216 | ap->break_handler = aggr_break_handler; |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1217 | } else |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1218 | list_add_rcu(&p->list, &ap->list); |
| 1219 | if (p->post_handler && !ap->post_handler) |
| 1220 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1221 | |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1222 | return 0; |
| 1223 | } |
| 1224 | |
| 1225 | /* |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1226 | * Fill in the required fields of the "manager kprobe". Replace the |
| 1227 | * earlier kprobe in the hlist with the manager kprobe |
| 1228 | */ |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1229 | static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1230 | { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1231 | /* Copy p's insn slot to ap */ |
Prasanna S Panchamukhi | 8b0914e | 2005-06-23 00:09:41 -0700 | [diff] [blame] | 1232 | copy_kprobe(p, ap); |
bibo, mao | a9ad965 | 2006-07-30 03:03:26 -0700 | [diff] [blame] | 1233 | flush_insn_slot(ap); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1234 | ap->addr = p->addr; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1235 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1236 | ap->pre_handler = aggr_pre_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1237 | ap->fault_handler = aggr_fault_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1238 | /* We don't care the kprobe which has gone. */ |
| 1239 | if (p->post_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1240 | ap->post_handler = aggr_post_handler; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1241 | if (p->break_handler && !kprobe_gone(p)) |
mao, bibo | 3672165 | 2006-06-26 00:25:22 -0700 | [diff] [blame] | 1242 | ap->break_handler = aggr_break_handler; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1243 | |
| 1244 | INIT_LIST_HEAD(&ap->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1245 | INIT_HLIST_NODE(&ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1246 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1247 | list_add_rcu(&p->list, &ap->list); |
Keshavamurthy Anil S | adad0f3 | 2005-12-12 00:37:12 -0800 | [diff] [blame] | 1248 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1249 | } |
| 1250 | |
| 1251 | /* |
| 1252 | * This is the second or subsequent kprobe at the address - handle |
| 1253 | * the intricacies |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1254 | */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1255 | static int __kprobes register_aggr_kprobe(struct kprobe *orig_p, |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1256 | struct kprobe *p) |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1257 | { |
| 1258 | int ret = 0; |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1259 | struct kprobe *ap = orig_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1260 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1261 | /* For preparing optimization, jump_label_text_reserved() is called */ |
| 1262 | jump_label_lock(); |
| 1263 | /* |
| 1264 | * Get online CPUs to avoid text_mutex deadlock.with stop machine, |
| 1265 | * which is invoked by unoptimize_kprobe() in add_new_kprobe() |
| 1266 | */ |
| 1267 | get_online_cpus(); |
| 1268 | mutex_lock(&text_mutex); |
| 1269 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1270 | if (!kprobe_aggrprobe(orig_p)) { |
| 1271 | /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ |
| 1272 | ap = alloc_aggr_kprobe(orig_p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1273 | if (!ap) { |
| 1274 | ret = -ENOMEM; |
| 1275 | goto out; |
| 1276 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1277 | init_aggr_kprobe(ap, orig_p); |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1278 | } else if (kprobe_unused(ap)) |
Masami Hiramatsu | 0490cd1 | 2010-12-03 18:54:16 +0900 | [diff] [blame] | 1279 | /* This probe is going to die. Rescue it */ |
| 1280 | reuse_unused_kprobe(ap); |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1281 | |
| 1282 | if (kprobe_gone(ap)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1283 | /* |
| 1284 | * Attempting to insert new probe at the same location that |
| 1285 | * had a probe in the module vaddr area which already |
| 1286 | * freed. So, the instruction slot has already been |
| 1287 | * released. We need a new slot for the new probe. |
| 1288 | */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1289 | ret = arch_prepare_kprobe(ap); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1290 | if (ret) |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1291 | /* |
| 1292 | * Even if fail to allocate new slot, don't need to |
| 1293 | * free aggr_probe. It will be used next time, or |
| 1294 | * freed by unregister_kprobe. |
| 1295 | */ |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1296 | goto out; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1297 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1298 | /* Prepare optimized instructions if possible. */ |
| 1299 | prepare_optimized_kprobe(ap); |
| 1300 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1301 | /* |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1302 | * Clear gone flag to prevent allocating new slot again, and |
| 1303 | * set disabled flag because it is not armed yet. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1304 | */ |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1305 | ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) |
| 1306 | | KPROBE_FLAG_DISABLED; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1307 | } |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1308 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1309 | /* Copy ap's insn slot to p */ |
Masami Hiramatsu | b918e5e | 2009-04-06 19:00:58 -0700 | [diff] [blame] | 1310 | copy_kprobe(ap, p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1311 | ret = add_new_kprobe(ap, p); |
| 1312 | |
| 1313 | out: |
| 1314 | mutex_unlock(&text_mutex); |
| 1315 | put_online_cpus(); |
| 1316 | jump_label_unlock(); |
| 1317 | |
| 1318 | if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { |
| 1319 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
| 1320 | if (!kprobes_all_disarmed) |
| 1321 | /* Arm the breakpoint again. */ |
| 1322 | arm_kprobe(ap); |
| 1323 | } |
| 1324 | return ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1325 | } |
| 1326 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1327 | static int __kprobes in_kprobes_functions(unsigned long addr) |
| 1328 | { |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1329 | struct kprobe_blackpoint *kb; |
| 1330 | |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 1331 | if (addr >= (unsigned long)__kprobes_text_start && |
| 1332 | addr < (unsigned long)__kprobes_text_end) |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1333 | return -EINVAL; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 1334 | /* |
| 1335 | * If there exists a kprobe_blacklist, verify and |
| 1336 | * fail any probe registration in the prohibited area |
| 1337 | */ |
| 1338 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 1339 | if (kb->start_addr) { |
| 1340 | if (addr >= kb->start_addr && |
| 1341 | addr < (kb->start_addr + kb->range)) |
| 1342 | return -EINVAL; |
| 1343 | } |
| 1344 | } |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1345 | return 0; |
| 1346 | } |
| 1347 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1348 | /* |
| 1349 | * If we have a symbol_name argument, look it up and add the offset field |
| 1350 | * 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] | 1351 | * This returns encoded errors if it fails to look up symbol or invalid |
| 1352 | * combination of parameters. |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1353 | */ |
| 1354 | static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) |
| 1355 | { |
| 1356 | kprobe_opcode_t *addr = p->addr; |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1357 | |
| 1358 | if ((p->symbol_name && p->addr) || |
| 1359 | (!p->symbol_name && !p->addr)) |
| 1360 | goto invalid; |
| 1361 | |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1362 | if (p->symbol_name) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1363 | kprobe_lookup_name(p->symbol_name, addr); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1364 | if (!addr) |
| 1365 | return ERR_PTR(-ENOENT); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1366 | } |
| 1367 | |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1368 | addr = (kprobe_opcode_t *)(((char *)addr) + p->offset); |
| 1369 | if (addr) |
| 1370 | return addr; |
| 1371 | |
| 1372 | invalid: |
| 1373 | return ERR_PTR(-EINVAL); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1374 | } |
| 1375 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1376 | /* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
| 1377 | static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) |
| 1378 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1379 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1380 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1381 | ap = get_kprobe(p->addr); |
| 1382 | if (unlikely(!ap)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1383 | return NULL; |
| 1384 | |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1385 | if (p != ap) { |
| 1386 | list_for_each_entry_rcu(list_p, &ap->list, list) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1387 | if (list_p == p) |
| 1388 | /* kprobe p is a valid probe */ |
| 1389 | goto valid; |
| 1390 | return NULL; |
| 1391 | } |
| 1392 | valid: |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1393 | return ap; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1394 | } |
| 1395 | |
| 1396 | /* Return error if the kprobe is being re-registered */ |
| 1397 | static inline int check_kprobe_rereg(struct kprobe *p) |
| 1398 | { |
| 1399 | int ret = 0; |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1400 | |
| 1401 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1402 | if (__get_valid_kprobe(p)) |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1403 | ret = -EINVAL; |
| 1404 | mutex_unlock(&kprobe_mutex); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1405 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1406 | return ret; |
| 1407 | } |
| 1408 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1409 | static __kprobes int check_kprobe_address_safe(struct kprobe *p, |
| 1410 | struct module **probed_mod) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1411 | { |
| 1412 | int ret = 0; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1413 | unsigned long ftrace_addr; |
| 1414 | |
| 1415 | /* |
| 1416 | * If the address is located on a ftrace nop, set the |
| 1417 | * breakpoint to the following instruction. |
| 1418 | */ |
| 1419 | ftrace_addr = ftrace_location((unsigned long)p->addr); |
| 1420 | if (ftrace_addr) { |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1421 | #ifdef CONFIG_KPROBES_ON_FTRACE |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1422 | /* Given address is not on the instruction boundary */ |
| 1423 | if ((unsigned long)p->addr != ftrace_addr) |
| 1424 | return -EILSEQ; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1425 | p->flags |= KPROBE_FLAG_FTRACE; |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 1426 | #else /* !CONFIG_KPROBES_ON_FTRACE */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1427 | return -EINVAL; |
| 1428 | #endif |
| 1429 | } |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1430 | |
| 1431 | jump_label_lock(); |
| 1432 | preempt_disable(); |
| 1433 | |
| 1434 | /* Ensure it is not in reserved area nor out of text */ |
| 1435 | if (!kernel_text_address((unsigned long) p->addr) || |
| 1436 | in_kprobes_functions((unsigned long) p->addr) || |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1437 | jump_label_text_reserved(p->addr, p->addr)) { |
| 1438 | ret = -EINVAL; |
| 1439 | goto out; |
| 1440 | } |
| 1441 | |
| 1442 | /* Check if are we probing a module */ |
| 1443 | *probed_mod = __module_text_address((unsigned long) p->addr); |
| 1444 | if (*probed_mod) { |
| 1445 | /* |
| 1446 | * We must hold a refcount of the probed module while updating |
| 1447 | * its code to prohibit unexpected unloading. |
| 1448 | */ |
| 1449 | if (unlikely(!try_module_get(*probed_mod))) { |
| 1450 | ret = -ENOENT; |
| 1451 | goto out; |
| 1452 | } |
| 1453 | |
| 1454 | /* |
| 1455 | * If the module freed .init.text, we couldn't insert |
| 1456 | * kprobes in there. |
| 1457 | */ |
| 1458 | if (within_module_init((unsigned long)p->addr, *probed_mod) && |
| 1459 | (*probed_mod)->state != MODULE_STATE_COMING) { |
| 1460 | module_put(*probed_mod); |
| 1461 | *probed_mod = NULL; |
| 1462 | ret = -ENOENT; |
| 1463 | } |
| 1464 | } |
| 1465 | out: |
| 1466 | preempt_enable(); |
| 1467 | jump_label_unlock(); |
| 1468 | |
| 1469 | return ret; |
| 1470 | } |
| 1471 | |
| 1472 | int __kprobes register_kprobe(struct kprobe *p) |
| 1473 | { |
| 1474 | int ret; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1475 | struct kprobe *old_p; |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1476 | struct module *probed_mod; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1477 | kprobe_opcode_t *addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1479 | /* Adjust probe address from symbol */ |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1480 | addr = kprobe_addr(p); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1481 | if (IS_ERR(addr)) |
| 1482 | return PTR_ERR(addr); |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1483 | p->addr = addr; |
Ananth N Mavinakayanahalli | 3a872d8 | 2006-10-02 02:17:30 -0700 | [diff] [blame] | 1484 | |
Ananth N Mavinakayanahalli | 1f0ab40 | 2009-09-15 10:43:07 +0530 | [diff] [blame] | 1485 | ret = check_kprobe_rereg(p); |
| 1486 | if (ret) |
| 1487 | return ret; |
| 1488 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1489 | /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ |
| 1490 | p->flags &= KPROBE_FLAG_DISABLED; |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1491 | p->nmissed = 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1492 | INIT_LIST_HEAD(&p->list); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1493 | |
Masami Hiramatsu | f7fa6ef0 | 2012-06-05 19:28:20 +0900 | [diff] [blame] | 1494 | ret = check_kprobe_address_safe(p, &probed_mod); |
| 1495 | if (ret) |
| 1496 | return ret; |
| 1497 | |
| 1498 | mutex_lock(&kprobe_mutex); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1499 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1500 | old_p = get_kprobe(p->addr); |
| 1501 | if (old_p) { |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1502 | /* Since this may unoptimize old_p, locking text_mutex. */ |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1503 | ret = register_aggr_kprobe(old_p, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1504 | goto out; |
| 1505 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1506 | |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1507 | mutex_lock(&text_mutex); /* Avoiding text modification */ |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1508 | ret = prepare_kprobe(p); |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1509 | mutex_unlock(&text_mutex); |
Christoph Hellwig | 6f716ac | 2007-05-08 00:34:13 -0700 | [diff] [blame] | 1510 | if (ret) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1511 | goto out; |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1512 | |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1513 | INIT_HLIST_NODE(&p->hlist); |
Ananth N Mavinakayanahalli | 3516a46 | 2005-11-07 01:00:13 -0800 | [diff] [blame] | 1514 | hlist_add_head_rcu(&p->hlist, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
| 1516 | |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1517 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
Masami Hiramatsu | 2576428 | 2012-06-05 19:28:26 +0900 | [diff] [blame] | 1518 | arm_kprobe(p); |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 1519 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1520 | /* Try to optimize kprobe */ |
| 1521 | try_to_optimize_kprobe(p); |
| 1522 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1523 | out: |
Ingo Molnar | 7a7d1cf | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 1524 | mutex_unlock(&kprobe_mutex); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1525 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1526 | if (probed_mod) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1527 | module_put(probed_mod); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1528 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1529 | return ret; |
| 1530 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1531 | EXPORT_SYMBOL_GPL(register_kprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1533 | /* Check if all probes on the aggrprobe are disabled */ |
| 1534 | static int __kprobes aggr_kprobe_disabled(struct kprobe *ap) |
| 1535 | { |
| 1536 | struct kprobe *kp; |
| 1537 | |
| 1538 | list_for_each_entry_rcu(kp, &ap->list, list) |
| 1539 | if (!kprobe_disabled(kp)) |
| 1540 | /* |
| 1541 | * There is an active probe on the list. |
| 1542 | * We can't disable this ap. |
| 1543 | */ |
| 1544 | return 0; |
| 1545 | |
| 1546 | return 1; |
| 1547 | } |
| 1548 | |
| 1549 | /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ |
| 1550 | static struct kprobe *__kprobes __disable_kprobe(struct kprobe *p) |
| 1551 | { |
| 1552 | struct kprobe *orig_p; |
| 1553 | |
| 1554 | /* Get an original kprobe for return */ |
| 1555 | orig_p = __get_valid_kprobe(p); |
| 1556 | if (unlikely(orig_p == NULL)) |
| 1557 | return NULL; |
| 1558 | |
| 1559 | if (!kprobe_disabled(p)) { |
| 1560 | /* Disable probe if it is a child probe */ |
| 1561 | if (p != orig_p) |
| 1562 | p->flags |= KPROBE_FLAG_DISABLED; |
| 1563 | |
| 1564 | /* Try to disarm and disable this/parent probe */ |
| 1565 | if (p == orig_p || aggr_kprobe_disabled(orig_p)) { |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 1566 | disarm_kprobe(orig_p, true); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1567 | orig_p->flags |= KPROBE_FLAG_DISABLED; |
| 1568 | } |
| 1569 | } |
| 1570 | |
| 1571 | return orig_p; |
| 1572 | } |
| 1573 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1574 | /* |
| 1575 | * Unregister a kprobe without a scheduler synchronization. |
| 1576 | */ |
| 1577 | static int __kprobes __unregister_kprobe_top(struct kprobe *p) |
Keshavamurthy Anil S | df019b1 | 2006-01-11 12:17:41 -0800 | [diff] [blame] | 1578 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1579 | struct kprobe *ap, *list_p; |
Ananth N Mavinakayanahalli | 64f562c | 2005-05-05 16:15:42 -0700 | [diff] [blame] | 1580 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1581 | /* Disable kprobe. This will disarm it if needed. */ |
| 1582 | ap = __disable_kprobe(p); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1583 | if (ap == NULL) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1584 | return -EINVAL; |
| 1585 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1586 | if (ap == p) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1587 | /* |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1588 | * This probe is an independent(and non-optimized) kprobe |
| 1589 | * (not an aggrprobe). Remove from the hash list. |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 1590 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1591 | goto disarmed; |
| 1592 | |
| 1593 | /* Following process expects this probe is an aggrprobe */ |
| 1594 | WARN_ON(!kprobe_aggrprobe(ap)); |
| 1595 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1596 | if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) |
| 1597 | /* |
| 1598 | * !disarmed could be happen if the probe is under delayed |
| 1599 | * unoptimizing. |
| 1600 | */ |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1601 | goto disarmed; |
| 1602 | else { |
| 1603 | /* If disabling probe has special handlers, update aggrprobe */ |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1604 | if (p->break_handler && !kprobe_gone(p)) |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1605 | ap->break_handler = NULL; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1606 | if (p->post_handler && !kprobe_gone(p)) { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1607 | list_for_each_entry_rcu(list_p, &ap->list, list) { |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1608 | if ((list_p != p) && (list_p->post_handler)) |
| 1609 | goto noclean; |
| 1610 | } |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1611 | ap->post_handler = NULL; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1612 | } |
| 1613 | noclean: |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1614 | /* |
| 1615 | * Remove from the aggrprobe: this path will do nothing in |
| 1616 | * __unregister_kprobe_bottom(). |
| 1617 | */ |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1618 | list_del_rcu(&p->list); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1619 | if (!kprobe_disabled(ap) && !kprobes_all_disarmed) |
| 1620 | /* |
| 1621 | * Try to optimize this probe again, because post |
| 1622 | * handler may have been changed. |
| 1623 | */ |
| 1624 | optimize_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1625 | } |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1626 | return 0; |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1627 | |
| 1628 | disarmed: |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1629 | BUG_ON(!kprobe_disarmed(ap)); |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1630 | hlist_del_rcu(&ap->hlist); |
| 1631 | return 0; |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1632 | } |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1633 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1634 | static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) |
| 1635 | { |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1636 | struct kprobe *ap; |
Mao, Bibo | b3e55c7 | 2005-12-12 00:37:00 -0800 | [diff] [blame] | 1637 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1638 | if (list_empty(&p->list)) |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1639 | /* This is an independent kprobe */ |
Ananth N Mavinakayanahalli | 0498b63 | 2006-01-09 20:52:46 -0800 | [diff] [blame] | 1640 | arch_remove_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1641 | else if (list_is_singular(&p->list)) { |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1642 | /* This is the last child of an aggrprobe */ |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1643 | ap = list_entry(p->list.next, struct kprobe, list); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1644 | list_del(&p->list); |
Masami Hiramatsu | 6d8e40a | 2010-12-03 18:53:50 +0900 | [diff] [blame] | 1645 | free_aggr_kprobe(ap); |
Anil S Keshavamurthy | 49a2a1b | 2006-01-09 20:52:43 -0800 | [diff] [blame] | 1646 | } |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 1647 | /* Otherwise, do nothing. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | } |
| 1649 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1650 | int __kprobes register_kprobes(struct kprobe **kps, int num) |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1651 | { |
| 1652 | int i, ret = 0; |
| 1653 | |
| 1654 | if (num <= 0) |
| 1655 | return -EINVAL; |
| 1656 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1657 | ret = register_kprobe(kps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1658 | if (ret < 0) { |
| 1659 | if (i > 0) |
| 1660 | unregister_kprobes(kps, i); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1661 | break; |
| 1662 | } |
| 1663 | } |
| 1664 | return ret; |
| 1665 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1666 | EXPORT_SYMBOL_GPL(register_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1667 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1668 | void __kprobes unregister_kprobe(struct kprobe *p) |
| 1669 | { |
| 1670 | unregister_kprobes(&p, 1); |
| 1671 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1672 | EXPORT_SYMBOL_GPL(unregister_kprobe); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1673 | |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1674 | void __kprobes unregister_kprobes(struct kprobe **kps, int num) |
| 1675 | { |
| 1676 | int i; |
| 1677 | |
| 1678 | if (num <= 0) |
| 1679 | return; |
| 1680 | mutex_lock(&kprobe_mutex); |
| 1681 | for (i = 0; i < num; i++) |
| 1682 | if (__unregister_kprobe_top(kps[i]) < 0) |
| 1683 | kps[i]->addr = NULL; |
| 1684 | mutex_unlock(&kprobe_mutex); |
| 1685 | |
| 1686 | synchronize_sched(); |
| 1687 | for (i = 0; i < num; i++) |
| 1688 | if (kps[i]->addr) |
| 1689 | __unregister_kprobe_bottom(kps[i]); |
| 1690 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1691 | EXPORT_SYMBOL_GPL(unregister_kprobes); |
Masami Hiramatsu | 9861668 | 2008-04-28 02:14:28 -0700 | [diff] [blame] | 1692 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1693 | static struct notifier_block kprobe_exceptions_nb = { |
| 1694 | .notifier_call = kprobe_exceptions_notify, |
Anil S Keshavamurthy | 3d5631e | 2006-06-26 00:25:28 -0700 | [diff] [blame] | 1695 | .priority = 0x7fffffff /* we need to be notified first */ |
| 1696 | }; |
| 1697 | |
Michael Ellerman | 3d7e338 | 2007-07-19 01:48:11 -0700 | [diff] [blame] | 1698 | unsigned long __weak arch_deref_entry_point(void *entry) |
| 1699 | { |
| 1700 | return (unsigned long)entry; |
| 1701 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1702 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1703 | int __kprobes register_jprobes(struct jprobe **jps, int num) |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1704 | { |
| 1705 | struct jprobe *jp; |
| 1706 | int ret = 0, i; |
| 1707 | |
| 1708 | if (num <= 0) |
| 1709 | return -EINVAL; |
| 1710 | for (i = 0; i < num; i++) { |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1711 | unsigned long addr, offset; |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1712 | jp = jps[i]; |
| 1713 | addr = arch_deref_entry_point(jp->entry); |
| 1714 | |
Namhyung Kim | 05662bd | 2010-09-15 10:04:27 +0900 | [diff] [blame] | 1715 | /* Verify probepoint is a function entry point */ |
| 1716 | if (kallsyms_lookup_size_offset(addr, NULL, &offset) && |
| 1717 | offset == 0) { |
| 1718 | jp->kp.pre_handler = setjmp_pre_handler; |
| 1719 | jp->kp.break_handler = longjmp_break_handler; |
| 1720 | ret = register_kprobe(&jp->kp); |
| 1721 | } else |
| 1722 | ret = -EINVAL; |
Namhyung Kim | edbaadb | 2010-09-15 10:04:26 +0900 | [diff] [blame] | 1723 | |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1724 | if (ret < 0) { |
| 1725 | if (i > 0) |
| 1726 | unregister_jprobes(jps, i); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1727 | break; |
| 1728 | } |
| 1729 | } |
| 1730 | return ret; |
| 1731 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1732 | EXPORT_SYMBOL_GPL(register_jprobes); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1733 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1734 | int __kprobes register_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1735 | { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1736 | return register_jprobes(&jp, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1737 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1738 | EXPORT_SYMBOL_GPL(register_jprobe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1739 | |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1740 | void __kprobes unregister_jprobe(struct jprobe *jp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | { |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1742 | unregister_jprobes(&jp, 1); |
| 1743 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1744 | EXPORT_SYMBOL_GPL(unregister_jprobe); |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1745 | |
Masami Hiramatsu | 26b31c1 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1746 | void __kprobes unregister_jprobes(struct jprobe **jps, int num) |
| 1747 | { |
| 1748 | int i; |
| 1749 | |
| 1750 | if (num <= 0) |
| 1751 | return; |
| 1752 | mutex_lock(&kprobe_mutex); |
| 1753 | for (i = 0; i < num; i++) |
| 1754 | if (__unregister_kprobe_top(&jps[i]->kp) < 0) |
| 1755 | jps[i]->kp.addr = NULL; |
| 1756 | mutex_unlock(&kprobe_mutex); |
| 1757 | |
| 1758 | synchronize_sched(); |
| 1759 | for (i = 0; i < num; i++) { |
| 1760 | if (jps[i]->kp.addr) |
| 1761 | __unregister_kprobe_bottom(&jps[i]->kp); |
| 1762 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1763 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1764 | EXPORT_SYMBOL_GPL(unregister_jprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1765 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1766 | #ifdef CONFIG_KRETPROBES |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1767 | /* |
| 1768 | * This kprobe pre_handler is registered with every kretprobe. When probe |
| 1769 | * hits it will set up the return probe. |
| 1770 | */ |
| 1771 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1772 | struct pt_regs *regs) |
| 1773 | { |
| 1774 | struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1775 | unsigned long hash, flags = 0; |
| 1776 | struct kretprobe_instance *ri; |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1777 | |
| 1778 | /*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] | 1779 | hash = hash_ptr(current, KPROBE_HASH_BITS); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1780 | raw_spin_lock_irqsave(&rp->lock, flags); |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1781 | if (!hlist_empty(&rp->free_instances)) { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1782 | ri = hlist_entry(rp->free_instances.first, |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1783 | struct kretprobe_instance, hlist); |
| 1784 | hlist_del(&ri->hlist); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1785 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1786 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1787 | ri->rp = rp; |
| 1788 | ri->task = current; |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1789 | |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1790 | if (rp->entry_handler && rp->entry_handler(ri, regs)) { |
| 1791 | raw_spin_lock_irqsave(&rp->lock, flags); |
| 1792 | hlist_add_head(&ri->hlist, &rp->free_instances); |
| 1793 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1794 | return 0; |
Jiang Liu | 55ca614 | 2012-02-03 15:37:16 -0800 | [diff] [blame] | 1795 | } |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1796 | |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1797 | arch_prepare_kretprobe(ri, regs); |
| 1798 | |
| 1799 | /* XXX(hch): why is there no hlist_move_head? */ |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1800 | INIT_HLIST_NODE(&ri->hlist); |
| 1801 | kretprobe_table_lock(hash, &flags); |
| 1802 | hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); |
| 1803 | kretprobe_table_unlock(hash, &flags); |
| 1804 | } else { |
Christoph Hellwig | 4c4308c | 2007-05-08 00:34:14 -0700 | [diff] [blame] | 1805 | rp->nmissed++; |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1806 | raw_spin_unlock_irqrestore(&rp->lock, flags); |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1807 | } |
Adrian Bunk | e65cefe | 2006-02-03 03:03:42 -0800 | [diff] [blame] | 1808 | return 0; |
| 1809 | } |
| 1810 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1811 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1812 | { |
| 1813 | int ret = 0; |
| 1814 | struct kretprobe_instance *inst; |
| 1815 | int i; |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1816 | void *addr; |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1817 | |
| 1818 | if (kretprobe_blacklist_size) { |
Masami Hiramatsu | b2a5cd6 | 2008-03-04 14:29:44 -0800 | [diff] [blame] | 1819 | addr = kprobe_addr(&rp->kp); |
Masami Hiramatsu | bc81d48 | 2011-06-27 16:26:50 +0900 | [diff] [blame] | 1820 | if (IS_ERR(addr)) |
| 1821 | return PTR_ERR(addr); |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 1822 | |
| 1823 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 1824 | if (kretprobe_blacklist[i].addr == addr) |
| 1825 | return -EINVAL; |
| 1826 | } |
| 1827 | } |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1828 | |
| 1829 | rp->kp.pre_handler = pre_handler_kretprobe; |
Ananth N Mavinakayanahalli | 7522a84 | 2006-04-20 02:43:11 -0700 | [diff] [blame] | 1830 | rp->kp.post_handler = NULL; |
| 1831 | rp->kp.fault_handler = NULL; |
| 1832 | rp->kp.break_handler = NULL; |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1833 | |
| 1834 | /* Pre-allocate memory for max kretprobe instances */ |
| 1835 | if (rp->maxactive <= 0) { |
| 1836 | #ifdef CONFIG_PREEMPT |
Heiko Carstens | c2ef666 | 2009-12-21 13:02:24 +0100 | [diff] [blame] | 1837 | rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1838 | #else |
Ananth N Mavinakayanahalli | 4dae560 | 2009-10-30 19:23:10 +0530 | [diff] [blame] | 1839 | rp->maxactive = num_possible_cpus(); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1840 | #endif |
| 1841 | } |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 1842 | raw_spin_lock_init(&rp->lock); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1843 | INIT_HLIST_HEAD(&rp->free_instances); |
| 1844 | for (i = 0; i < rp->maxactive; i++) { |
Abhishek Sagar | f47cd9b | 2008-02-06 01:38:22 -0800 | [diff] [blame] | 1845 | inst = kmalloc(sizeof(struct kretprobe_instance) + |
| 1846 | rp->data_size, GFP_KERNEL); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1847 | if (inst == NULL) { |
| 1848 | free_rp_inst(rp); |
| 1849 | return -ENOMEM; |
| 1850 | } |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 1851 | INIT_HLIST_NODE(&inst->hlist); |
| 1852 | hlist_add_head(&inst->hlist, &rp->free_instances); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1853 | } |
| 1854 | |
| 1855 | rp->nmissed = 0; |
| 1856 | /* Establish function entry probe point */ |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1857 | ret = register_kprobe(&rp->kp); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1858 | if (ret != 0) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1859 | free_rp_inst(rp); |
| 1860 | return ret; |
| 1861 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1862 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1863 | |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1864 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1865 | { |
| 1866 | int ret = 0, i; |
| 1867 | |
| 1868 | if (num <= 0) |
| 1869 | return -EINVAL; |
| 1870 | for (i = 0; i < num; i++) { |
Masami Hiramatsu | 49ad2fd | 2009-01-06 14:41:53 -0800 | [diff] [blame] | 1871 | ret = register_kretprobe(rps[i]); |
Masami Hiramatsu | 67dddaa | 2008-06-12 15:21:35 -0700 | [diff] [blame] | 1872 | if (ret < 0) { |
| 1873 | if (i > 0) |
| 1874 | unregister_kretprobes(rps, i); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1875 | break; |
| 1876 | } |
| 1877 | } |
| 1878 | return ret; |
| 1879 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1880 | EXPORT_SYMBOL_GPL(register_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1881 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1882 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1883 | { |
| 1884 | unregister_kretprobes(&rp, 1); |
| 1885 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1886 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1887 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1888 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1889 | { |
| 1890 | int i; |
| 1891 | |
| 1892 | if (num <= 0) |
| 1893 | return; |
| 1894 | mutex_lock(&kprobe_mutex); |
| 1895 | for (i = 0; i < num; i++) |
| 1896 | if (__unregister_kprobe_top(&rps[i]->kp) < 0) |
| 1897 | rps[i]->kp.addr = NULL; |
| 1898 | mutex_unlock(&kprobe_mutex); |
| 1899 | |
| 1900 | synchronize_sched(); |
| 1901 | for (i = 0; i < num; i++) { |
| 1902 | if (rps[i]->kp.addr) { |
| 1903 | __unregister_kprobe_bottom(&rps[i]->kp); |
| 1904 | cleanup_rp_inst(rps[i]); |
| 1905 | } |
| 1906 | } |
| 1907 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1908 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1909 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1910 | #else /* CONFIG_KRETPROBES */ |
Prasanna S Panchamukhi | d0aaff9 | 2005-09-06 15:19:26 -0700 | [diff] [blame] | 1911 | int __kprobes register_kretprobe(struct kretprobe *rp) |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1912 | { |
| 1913 | return -ENOSYS; |
| 1914 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1915 | EXPORT_SYMBOL_GPL(register_kretprobe); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1916 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1917 | int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
| 1918 | { |
| 1919 | return -ENOSYS; |
| 1920 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1921 | EXPORT_SYMBOL_GPL(register_kretprobes); |
| 1922 | |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1923 | void __kprobes unregister_kretprobe(struct kretprobe *rp) |
| 1924 | { |
| 1925 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1926 | EXPORT_SYMBOL_GPL(unregister_kretprobe); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1927 | |
| 1928 | void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) |
| 1929 | { |
| 1930 | } |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 1931 | EXPORT_SYMBOL_GPL(unregister_kretprobes); |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1932 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1933 | static int __kprobes pre_handler_kretprobe(struct kprobe *p, |
| 1934 | struct pt_regs *regs) |
| 1935 | { |
| 1936 | return 0; |
| 1937 | } |
Masami Hiramatsu | 4a296e0 | 2008-04-28 02:14:29 -0700 | [diff] [blame] | 1938 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 1939 | #endif /* CONFIG_KRETPROBES */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 1940 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1941 | /* Set the kprobe gone and remove its instruction buffer. */ |
| 1942 | static void __kprobes kill_kprobe(struct kprobe *p) |
| 1943 | { |
| 1944 | struct kprobe *kp; |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 1945 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1946 | p->flags |= KPROBE_FLAG_GONE; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1947 | if (kprobe_aggrprobe(p)) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1948 | /* |
| 1949 | * If this is an aggr_kprobe, we have to list all the |
| 1950 | * chained probes and mark them GONE. |
| 1951 | */ |
| 1952 | list_for_each_entry_rcu(kp, &p->list, list) |
| 1953 | kp->flags |= KPROBE_FLAG_GONE; |
| 1954 | p->post_handler = NULL; |
| 1955 | p->break_handler = NULL; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 1956 | kill_optimized_kprobe(p); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 1957 | } |
| 1958 | /* |
| 1959 | * Here, we can remove insn_slot safely, because no thread calls |
| 1960 | * the original probed function (which will be freed soon) any more. |
| 1961 | */ |
| 1962 | arch_remove_kprobe(p); |
| 1963 | } |
| 1964 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1965 | /* Disable one kprobe */ |
| 1966 | int __kprobes disable_kprobe(struct kprobe *kp) |
| 1967 | { |
| 1968 | int ret = 0; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1969 | |
| 1970 | mutex_lock(&kprobe_mutex); |
| 1971 | |
Masami Hiramatsu | 6f0f1dd | 2010-12-03 18:53:57 +0900 | [diff] [blame] | 1972 | /* Disable this kprobe */ |
| 1973 | if (__disable_kprobe(kp) == NULL) |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1974 | ret = -EINVAL; |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1975 | |
Masami Hiramatsu | c061482 | 2010-04-27 18:33:12 -0400 | [diff] [blame] | 1976 | mutex_unlock(&kprobe_mutex); |
| 1977 | return ret; |
| 1978 | } |
| 1979 | EXPORT_SYMBOL_GPL(disable_kprobe); |
| 1980 | |
| 1981 | /* Enable one kprobe */ |
| 1982 | int __kprobes enable_kprobe(struct kprobe *kp) |
| 1983 | { |
| 1984 | int ret = 0; |
| 1985 | struct kprobe *p; |
| 1986 | |
| 1987 | mutex_lock(&kprobe_mutex); |
| 1988 | |
| 1989 | /* Check whether specified probe is valid. */ |
| 1990 | p = __get_valid_kprobe(kp); |
| 1991 | if (unlikely(p == NULL)) { |
| 1992 | ret = -EINVAL; |
| 1993 | goto out; |
| 1994 | } |
| 1995 | |
| 1996 | if (kprobe_gone(kp)) { |
| 1997 | /* This kprobe has gone, we couldn't enable it. */ |
| 1998 | ret = -EINVAL; |
| 1999 | goto out; |
| 2000 | } |
| 2001 | |
| 2002 | if (p != kp) |
| 2003 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
| 2004 | |
| 2005 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { |
| 2006 | p->flags &= ~KPROBE_FLAG_DISABLED; |
| 2007 | arm_kprobe(p); |
| 2008 | } |
| 2009 | out: |
| 2010 | mutex_unlock(&kprobe_mutex); |
| 2011 | return ret; |
| 2012 | } |
| 2013 | EXPORT_SYMBOL_GPL(enable_kprobe); |
| 2014 | |
Frederic Weisbecker | 24851d2 | 2009-08-26 23:38:30 +0200 | [diff] [blame] | 2015 | void __kprobes dump_kprobe(struct kprobe *kp) |
| 2016 | { |
| 2017 | printk(KERN_WARNING "Dumping kprobe:\n"); |
| 2018 | printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", |
| 2019 | kp->symbol_name, kp->addr, kp->offset); |
| 2020 | } |
| 2021 | |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2022 | /* Module notifier call back, checking kprobes on the module */ |
| 2023 | static int __kprobes kprobes_module_callback(struct notifier_block *nb, |
| 2024 | unsigned long val, void *data) |
| 2025 | { |
| 2026 | struct module *mod = data; |
| 2027 | struct hlist_head *head; |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2028 | struct kprobe *p; |
| 2029 | unsigned int i; |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2030 | int checkcore = (val == MODULE_STATE_GOING); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2031 | |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2032 | if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2033 | return NOTIFY_DONE; |
| 2034 | |
| 2035 | /* |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2036 | * When MODULE_STATE_GOING was notified, both of module .text and |
| 2037 | * .init.text sections would be freed. When MODULE_STATE_LIVE was |
| 2038 | * notified, only .init.text section would be freed. We need to |
| 2039 | * disable kprobes which have been inserted in the sections. |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2040 | */ |
| 2041 | mutex_lock(&kprobe_mutex); |
| 2042 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2043 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2044 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | f24659d | 2009-01-06 14:41:55 -0800 | [diff] [blame] | 2045 | if (within_module_init((unsigned long)p->addr, mod) || |
| 2046 | (checkcore && |
| 2047 | within_module_core((unsigned long)p->addr, mod))) { |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2048 | /* |
| 2049 | * The vaddr this probe is installed will soon |
| 2050 | * be vfreed buy not synced to disk. Hence, |
| 2051 | * disarming the breakpoint isn't needed. |
| 2052 | */ |
| 2053 | kill_kprobe(p); |
| 2054 | } |
| 2055 | } |
| 2056 | mutex_unlock(&kprobe_mutex); |
| 2057 | return NOTIFY_DONE; |
| 2058 | } |
| 2059 | |
| 2060 | static struct notifier_block kprobe_module_nb = { |
| 2061 | .notifier_call = kprobes_module_callback, |
| 2062 | .priority = 0 |
| 2063 | }; |
| 2064 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2065 | static int __init init_kprobes(void) |
| 2066 | { |
| 2067 | int i, err = 0; |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 2068 | unsigned long offset = 0, size = 0; |
| 2069 | char *modname, namebuf[128]; |
| 2070 | const char *symbol_name; |
| 2071 | void *addr; |
| 2072 | struct kprobe_blackpoint *kb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2073 | |
| 2074 | /* FIXME allocate the probe table, currently defined statically */ |
| 2075 | /* initialize all list heads */ |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2076 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2077 | INIT_HLIST_HEAD(&kprobe_table[i]); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2078 | INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
Thomas Gleixner | ec484608 | 2009-07-25 16:09:17 +0200 | [diff] [blame] | 2079 | raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
Hien Nguyen | b94cce9 | 2005-06-23 00:09:19 -0700 | [diff] [blame] | 2080 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2081 | |
Srinivasa Ds | 3d8d996 | 2008-04-28 02:14:26 -0700 | [diff] [blame] | 2082 | /* |
| 2083 | * Lookup and populate the kprobe_blacklist. |
| 2084 | * |
| 2085 | * Unlike the kretprobe blacklist, we'll need to determine |
| 2086 | * the range of addresses that belong to the said functions, |
| 2087 | * since a kprobe need not necessarily be at the beginning |
| 2088 | * of a function. |
| 2089 | */ |
| 2090 | for (kb = kprobe_blacklist; kb->name != NULL; kb++) { |
| 2091 | kprobe_lookup_name(kb->name, addr); |
| 2092 | if (!addr) |
| 2093 | continue; |
| 2094 | |
| 2095 | kb->start_addr = (unsigned long)addr; |
| 2096 | symbol_name = kallsyms_lookup(kb->start_addr, |
| 2097 | &size, &offset, &modname, namebuf); |
| 2098 | if (!symbol_name) |
| 2099 | kb->range = 0; |
| 2100 | else |
| 2101 | kb->range = size; |
| 2102 | } |
| 2103 | |
Masami Hiramatsu | f438d91 | 2007-10-16 01:27:49 -0700 | [diff] [blame] | 2104 | if (kretprobe_blacklist_size) { |
| 2105 | /* lookup the function address from its name */ |
| 2106 | for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
| 2107 | kprobe_lookup_name(kretprobe_blacklist[i].name, |
| 2108 | kretprobe_blacklist[i].addr); |
| 2109 | if (!kretprobe_blacklist[i].addr) |
| 2110 | printk("kretprobe: lookup failed: %s\n", |
| 2111 | kretprobe_blacklist[i].name); |
| 2112 | } |
| 2113 | } |
| 2114 | |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2115 | #if defined(CONFIG_OPTPROBES) |
| 2116 | #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2117 | /* Init kprobe_optinsn_slots */ |
| 2118 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; |
| 2119 | #endif |
Masami Hiramatsu | b2be84d | 2010-02-25 08:34:15 -0500 | [diff] [blame] | 2120 | /* By default, kprobes can be optimized */ |
| 2121 | kprobes_allow_optimization = true; |
| 2122 | #endif |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2123 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2124 | /* By default, kprobes are armed */ |
| 2125 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2126 | |
Rusty Lynch | 6772926 | 2005-07-05 18:54:50 -0700 | [diff] [blame] | 2127 | err = arch_init_kprobes(); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2128 | if (!err) |
| 2129 | err = register_die_notifier(&kprobe_exceptions_nb); |
Masami Hiramatsu | e8386a0 | 2009-01-06 14:41:52 -0800 | [diff] [blame] | 2130 | if (!err) |
| 2131 | err = register_module_notifier(&kprobe_module_nb); |
| 2132 | |
Srinivasa D S | ef53d9c | 2008-07-25 01:46:04 -0700 | [diff] [blame] | 2133 | kprobes_initialized = (err == 0); |
Rusty Lynch | 802eae7 | 2005-06-27 15:17:08 -0700 | [diff] [blame] | 2134 | |
Ananth N Mavinakayanahalli | 8c1c935 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 2135 | if (!err) |
| 2136 | init_test_probes(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2137 | return err; |
| 2138 | } |
| 2139 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2140 | #ifdef CONFIG_DEBUG_FS |
| 2141 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2142 | const char *sym, int offset, char *modname, struct kprobe *pp) |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2143 | { |
| 2144 | char *kprobe_type; |
| 2145 | |
| 2146 | if (p->pre_handler == pre_handler_kretprobe) |
| 2147 | kprobe_type = "r"; |
| 2148 | else if (p->pre_handler == setjmp_pre_handler) |
| 2149 | kprobe_type = "j"; |
| 2150 | else |
| 2151 | kprobe_type = "k"; |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2152 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2153 | if (sym) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2154 | seq_printf(pi, "%p %s %s+0x%x %s ", |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2155 | p->addr, kprobe_type, sym, offset, |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2156 | (modname ? modname : " ")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2157 | else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2158 | seq_printf(pi, "%p %s %p ", |
| 2159 | p->addr, kprobe_type, p->addr); |
| 2160 | |
| 2161 | if (!pp) |
| 2162 | pp = p; |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2163 | seq_printf(pi, "%s%s%s%s\n", |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2164 | (kprobe_gone(p) ? "[GONE]" : ""), |
| 2165 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2166 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), |
| 2167 | (kprobe_ftrace(pp) ? "[FTRACE]" : "")); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2168 | } |
| 2169 | |
| 2170 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
| 2171 | { |
| 2172 | return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; |
| 2173 | } |
| 2174 | |
| 2175 | static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
| 2176 | { |
| 2177 | (*pos)++; |
| 2178 | if (*pos >= KPROBE_TABLE_SIZE) |
| 2179 | return NULL; |
| 2180 | return pos; |
| 2181 | } |
| 2182 | |
| 2183 | static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) |
| 2184 | { |
| 2185 | /* Nothing to do */ |
| 2186 | } |
| 2187 | |
| 2188 | static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) |
| 2189 | { |
| 2190 | struct hlist_head *head; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2191 | struct kprobe *p, *kp; |
| 2192 | const char *sym = NULL; |
| 2193 | unsigned int i = *(loff_t *) v; |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2194 | unsigned long offset = 0; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2195 | char *modname, namebuf[128]; |
| 2196 | |
| 2197 | head = &kprobe_table[i]; |
| 2198 | preempt_disable(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2199 | hlist_for_each_entry_rcu(p, head, hlist) { |
Alexey Dobriyan | ffb4512 | 2007-05-08 00:28:41 -0700 | [diff] [blame] | 2200 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2201 | &offset, &modname, namebuf); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2202 | if (kprobe_aggrprobe(p)) { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2203 | list_for_each_entry_rcu(kp, &p->list, list) |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2204 | report_probe(pi, kp, sym, offset, modname, p); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2205 | } else |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2206 | report_probe(pi, p, sym, offset, modname, NULL); |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2207 | } |
| 2208 | preempt_enable(); |
| 2209 | return 0; |
| 2210 | } |
| 2211 | |
James Morris | 88e9d34 | 2009-09-22 16:43:43 -0700 | [diff] [blame] | 2212 | static const struct seq_operations kprobes_seq_ops = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2213 | .start = kprobe_seq_start, |
| 2214 | .next = kprobe_seq_next, |
| 2215 | .stop = kprobe_seq_stop, |
| 2216 | .show = show_kprobe_addr |
| 2217 | }; |
| 2218 | |
| 2219 | static int __kprobes kprobes_open(struct inode *inode, struct file *filp) |
| 2220 | { |
| 2221 | return seq_open(filp, &kprobes_seq_ops); |
| 2222 | } |
| 2223 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2224 | static const struct file_operations debugfs_kprobes_operations = { |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2225 | .open = kprobes_open, |
| 2226 | .read = seq_read, |
| 2227 | .llseek = seq_lseek, |
| 2228 | .release = seq_release, |
| 2229 | }; |
| 2230 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2231 | static void __kprobes arm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2232 | { |
| 2233 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2234 | struct kprobe *p; |
| 2235 | unsigned int i; |
| 2236 | |
| 2237 | mutex_lock(&kprobe_mutex); |
| 2238 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2239 | /* If kprobes are armed, just return */ |
| 2240 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2241 | goto already_enabled; |
| 2242 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2243 | /* Arming kprobes doesn't optimize kprobe itself */ |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2244 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2245 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2246 | hlist_for_each_entry_rcu(p, head, hlist) |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2247 | if (!kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2248 | arm_kprobe(p); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2249 | } |
| 2250 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2251 | kprobes_all_disarmed = false; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2252 | printk(KERN_INFO "Kprobes globally enabled\n"); |
| 2253 | |
| 2254 | already_enabled: |
| 2255 | mutex_unlock(&kprobe_mutex); |
| 2256 | return; |
| 2257 | } |
| 2258 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2259 | static void __kprobes disarm_all_kprobes(void) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2260 | { |
| 2261 | struct hlist_head *head; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2262 | struct kprobe *p; |
| 2263 | unsigned int i; |
| 2264 | |
| 2265 | mutex_lock(&kprobe_mutex); |
| 2266 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2267 | /* If kprobes are already disarmed, just return */ |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2268 | if (kprobes_all_disarmed) { |
| 2269 | mutex_unlock(&kprobe_mutex); |
| 2270 | return; |
| 2271 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2272 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2273 | kprobes_all_disarmed = true; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2274 | printk(KERN_INFO "Kprobes globally disabled\n"); |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 2275 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2276 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
| 2277 | head = &kprobe_table[i]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 2278 | hlist_for_each_entry_rcu(p, head, hlist) { |
Masami Hiramatsu | de5bd88 | 2009-04-06 19:01:02 -0700 | [diff] [blame] | 2279 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
Masami Hiramatsu | ae6aa16 | 2012-06-05 19:28:32 +0900 | [diff] [blame] | 2280 | disarm_kprobe(p, false); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2281 | } |
| 2282 | } |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2283 | mutex_unlock(&kprobe_mutex); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2284 | |
Masami Hiramatsu | 6274de4 | 2010-12-03 18:54:09 +0900 | [diff] [blame] | 2285 | /* Wait for disarming all kprobes by optimizer */ |
| 2286 | wait_for_kprobe_optimizer(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2287 | } |
| 2288 | |
| 2289 | /* |
| 2290 | * XXX: The debugfs bool file interface doesn't allow for callbacks |
| 2291 | * when the bool state is switched. We can reuse that facility when |
| 2292 | * available |
| 2293 | */ |
| 2294 | static ssize_t read_enabled_file_bool(struct file *file, |
| 2295 | char __user *user_buf, size_t count, loff_t *ppos) |
| 2296 | { |
| 2297 | char buf[3]; |
| 2298 | |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2299 | if (!kprobes_all_disarmed) |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2300 | buf[0] = '1'; |
| 2301 | else |
| 2302 | buf[0] = '0'; |
| 2303 | buf[1] = '\n'; |
| 2304 | buf[2] = 0x00; |
| 2305 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 2306 | } |
| 2307 | |
| 2308 | static ssize_t write_enabled_file_bool(struct file *file, |
| 2309 | const char __user *user_buf, size_t count, loff_t *ppos) |
| 2310 | { |
| 2311 | char buf[32]; |
Stephen Boyd | efeb156 | 2012-01-12 17:17:11 -0800 | [diff] [blame] | 2312 | size_t buf_size; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2313 | |
| 2314 | buf_size = min(count, (sizeof(buf)-1)); |
| 2315 | if (copy_from_user(buf, user_buf, buf_size)) |
| 2316 | return -EFAULT; |
| 2317 | |
| 2318 | switch (buf[0]) { |
| 2319 | case 'y': |
| 2320 | case 'Y': |
| 2321 | case '1': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2322 | arm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2323 | break; |
| 2324 | case 'n': |
| 2325 | case 'N': |
| 2326 | case '0': |
Masami Hiramatsu | e579abe | 2009-04-06 19:01:01 -0700 | [diff] [blame] | 2327 | disarm_all_kprobes(); |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2328 | break; |
| 2329 | } |
| 2330 | |
| 2331 | return count; |
| 2332 | } |
| 2333 | |
Alexey Dobriyan | 828c095 | 2009-10-01 15:43:56 -0700 | [diff] [blame] | 2334 | static const struct file_operations fops_kp = { |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2335 | .read = read_enabled_file_bool, |
| 2336 | .write = write_enabled_file_bool, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 2337 | .llseek = default_llseek, |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2338 | }; |
| 2339 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2340 | static int __kprobes debugfs_kprobe_init(void) |
| 2341 | { |
| 2342 | struct dentry *dir, *file; |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2343 | unsigned int value = 1; |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2344 | |
| 2345 | dir = debugfs_create_dir("kprobes", NULL); |
| 2346 | if (!dir) |
| 2347 | return -ENOMEM; |
| 2348 | |
Randy Dunlap | e386979 | 2007-05-08 00:27:01 -0700 | [diff] [blame] | 2349 | file = debugfs_create_file("list", 0444, dir, NULL, |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2350 | &debugfs_kprobes_operations); |
| 2351 | if (!file) { |
| 2352 | debugfs_remove(dir); |
| 2353 | return -ENOMEM; |
| 2354 | } |
| 2355 | |
Ananth N Mavinakayanahalli | bf8f6e5b | 2007-05-08 00:34:16 -0700 | [diff] [blame] | 2356 | file = debugfs_create_file("enabled", 0600, dir, |
| 2357 | &value, &fops_kp); |
| 2358 | if (!file) { |
| 2359 | debugfs_remove(dir); |
| 2360 | return -ENOMEM; |
| 2361 | } |
| 2362 | |
Srinivasa Ds | 346fd59 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 2363 | return 0; |
| 2364 | } |
| 2365 | |
| 2366 | late_initcall(debugfs_kprobe_init); |
| 2367 | #endif /* CONFIG_DEBUG_FS */ |
| 2368 | |
| 2369 | module_init(init_kprobes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2370 | |
Masami Hiramatsu | 99081ab | 2009-04-06 19:00:59 -0700 | [diff] [blame] | 2371 | /* defined in arch/.../kernel/kprobes.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2372 | EXPORT_SYMBOL_GPL(jprobe_return); |