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kernel/kprobes.c
62.6 KB
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/* * Kernel Probes (KProbes) * kernel/kprobes.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright (C) IBM Corporation, 2002, 2004 * * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel * Probes initial implementation (includes suggestions from * Rusty Russell). * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with * hlists and exceptions notifier as suggested by Andi Kleen. * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes * interface to access function arguments. * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes * exceptions notifier to be first on the priority list. |
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* 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi * <prasanna@in.ibm.com> added function-return probes. |
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*/ #include <linux/kprobes.h> |
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#include <linux/hash.h> #include <linux/init.h> |
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#include <linux/slab.h> |
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#include <linux/stddef.h> |
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#include <linux/export.h> |
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#include <linux/moduleloader.h> |
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#include <linux/kallsyms.h> |
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#include <linux/freezer.h> |
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#include <linux/seq_file.h> #include <linux/debugfs.h> |
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#include <linux/sysctl.h> |
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#include <linux/kdebug.h> |
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#include <linux/memory.h> |
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#include <linux/ftrace.h> |
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#include <linux/cpu.h> |
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#include <linux/jump_label.h> |
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#include <asm/sections.h> |
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#include <asm/cacheflush.h> #include <asm/errno.h> |
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#include <linux/uaccess.h> |
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#define KPROBE_HASH_BITS 6 #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
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static int kprobes_initialized; |
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static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; |
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static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; |
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/* NOTE: change this value only with kprobe_mutex held */ |
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static bool kprobes_all_disarmed; |
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/* This protects kprobe_table and optimizing_list */ static DEFINE_MUTEX(kprobe_mutex); |
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static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
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static struct { |
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raw_spinlock_t lock ____cacheline_aligned_in_smp; |
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} kretprobe_table_locks[KPROBE_TABLE_SIZE]; |
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kprobe_opcode_t * __weak kprobe_lookup_name(const char *name, unsigned int __unused) |
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{ return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); } |
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static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) |
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{ return &(kretprobe_table_locks[hash].lock); } |
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/* Blacklist -- list of struct kprobe_blacklist_entry */ static LIST_HEAD(kprobe_blacklist); |
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#ifdef __ARCH_WANT_KPROBES_INSN_SLOT |
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/* * kprobe->ainsn.insn points to the copy of the instruction to be * single-stepped. x86_64, POWER4 and above have no-exec support and * stepping on the instruction on a vmalloced/kmalloced/data page * is a recipe for disaster */ |
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struct kprobe_insn_page { |
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struct list_head list; |
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kprobe_opcode_t *insns; /* Page of instruction slots */ |
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struct kprobe_insn_cache *cache; |
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int nused; |
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int ngarbage; |
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char slot_used[]; |
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}; |
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#define KPROBE_INSN_PAGE_SIZE(slots) \ (offsetof(struct kprobe_insn_page, slot_used) + \ (sizeof(char) * (slots))) |
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static int slots_per_page(struct kprobe_insn_cache *c) { return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t)); } |
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enum kprobe_slot_state { SLOT_CLEAN = 0, SLOT_DIRTY = 1, SLOT_USED = 2, }; |
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static void *alloc_insn_page(void) { return module_alloc(PAGE_SIZE); } |
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void __weak free_insn_page(void *page) |
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{ |
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module_memfree(page); |
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} |
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struct kprobe_insn_cache kprobe_insn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex), |
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.alloc = alloc_insn_page, .free = free_insn_page, |
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.pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, }; |
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static int collect_garbage_slots(struct kprobe_insn_cache *c); |
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/** |
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* __get_insn_slot() - Find a slot on an executable page for an instruction. |
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* We allocate an executable page if there's no room on existing ones. */ |
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kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) |
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{ struct kprobe_insn_page *kip; |
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kprobe_opcode_t *slot = NULL; |
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|
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/* Since the slot array is not protected by rcu, we need a mutex */ |
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mutex_lock(&c->mutex); |
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retry: |
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rcu_read_lock(); list_for_each_entry_rcu(kip, &c->pages, list) { |
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if (kip->nused < slots_per_page(c)) { |
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int i; |
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for (i = 0; i < slots_per_page(c); i++) { |
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if (kip->slot_used[i] == SLOT_CLEAN) { kip->slot_used[i] = SLOT_USED; |
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kip->nused++; |
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slot = kip->insns + (i * c->insn_size); |
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rcu_read_unlock(); |
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goto out; |
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} } |
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/* kip->nused is broken. Fix it. */ kip->nused = slots_per_page(c); WARN_ON(1); |
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} } |
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rcu_read_unlock(); |
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/* If there are any garbage slots, collect it and try again. */ |
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if (c->nr_garbage && collect_garbage_slots(c) == 0) |
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goto retry; |
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/* All out of space. Need to allocate a new page. */ kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL); |
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if (!kip) |
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goto out; |
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/* * Use module_alloc so this page is within +/- 2GB of where the * kernel image and loaded module images reside. This is required * so x86_64 can correctly handle the %rip-relative fixups. */ |
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kip->insns = c->alloc(); |
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if (!kip->insns) { kfree(kip); |
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goto out; |
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} |
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INIT_LIST_HEAD(&kip->list); |
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memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c)); |
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kip->slot_used[0] = SLOT_USED; |
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kip->nused = 1; |
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kip->ngarbage = 0; |
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kip->cache = c; |
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list_add_rcu(&kip->list, &c->pages); |
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slot = kip->insns; out: mutex_unlock(&c->mutex); return slot; |
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} |
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/* Return 1 if all garbages are collected, otherwise 0. */ |
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static int collect_one_slot(struct kprobe_insn_page *kip, int idx) |
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{ |
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kip->slot_used[idx] = SLOT_CLEAN; |
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kip->nused--; if (kip->nused == 0) { /* * Page is no longer in use. Free it unless * it's the last one. We keep the last one * so as not to have to set it up again the * next time somebody inserts a probe. */ |
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if (!list_is_singular(&kip->list)) { |
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list_del_rcu(&kip->list); synchronize_rcu(); |
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kip->cache->free(kip->insns); |
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kfree(kip); } return 1; } return 0; } |
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static int collect_garbage_slots(struct kprobe_insn_cache *c) |
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{ |
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struct kprobe_insn_page *kip, *next; |
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/* Ensure no-one is interrupted on the garbages */ synchronize_sched(); |
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list_for_each_entry_safe(kip, next, &c->pages, list) { |
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int i; |
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if (kip->ngarbage == 0) continue; kip->ngarbage = 0; /* we will collect all garbages */ |
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for (i = 0; i < slots_per_page(c); i++) { |
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if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i)) |
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break; } } |
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c->nr_garbage = 0; |
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return 0; } |
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void __free_insn_slot(struct kprobe_insn_cache *c, kprobe_opcode_t *slot, int dirty) |
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{ struct kprobe_insn_page *kip; |
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long idx; |
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mutex_lock(&c->mutex); |
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rcu_read_lock(); list_for_each_entry_rcu(kip, &c->pages, list) { idx = ((long)slot - (long)kip->insns) / (c->insn_size * sizeof(kprobe_opcode_t)); if (idx >= 0 && idx < slots_per_page(c)) |
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goto out; |
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} |
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/* Could not find this slot. */ |
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WARN_ON(1); |
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kip = NULL; |
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out: |
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rcu_read_unlock(); /* Mark and sweep: this may sleep */ if (kip) { /* Check double free */ WARN_ON(kip->slot_used[idx] != SLOT_USED); if (dirty) { kip->slot_used[idx] = SLOT_DIRTY; kip->ngarbage++; if (++c->nr_garbage > slots_per_page(c)) collect_garbage_slots(c); } else { collect_one_slot(kip, idx); } } |
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mutex_unlock(&c->mutex); |
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} |
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/* * Check given address is on the page of kprobe instruction slots. * This will be used for checking whether the address on a stack * is on a text area or not. */ bool __is_insn_slot_addr(struct kprobe_insn_cache *c, unsigned long addr) { struct kprobe_insn_page *kip; bool ret = false; rcu_read_lock(); list_for_each_entry_rcu(kip, &c->pages, list) { if (addr >= (unsigned long)kip->insns && addr < (unsigned long)kip->insns + PAGE_SIZE) { ret = true; break; } } rcu_read_unlock(); return ret; } |
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#ifdef CONFIG_OPTPROBES /* For optimized_kprobe buffer */ |
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struct kprobe_insn_cache kprobe_optinsn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex), |
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.alloc = alloc_insn_page, .free = free_insn_page, |
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.pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */ .nr_garbage = 0, }; |
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#endif |
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#endif |
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/* We have preemption disabled.. so it is safe to use __ versions */ static inline void set_kprobe_instance(struct kprobe *kp) { |
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__this_cpu_write(kprobe_instance, kp); |
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} static inline void reset_kprobe_instance(void) { |
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__this_cpu_write(kprobe_instance, NULL); |
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} |
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/* * This routine is called either: |
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* - under the kprobe_mutex - during kprobe_[un]register() |
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* OR |
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* - with preemption disabled - from arch/xxx/kernel/kprobes.c |
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*/ |
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struct kprobe *get_kprobe(void *addr) |
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{ struct hlist_head *head; |
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struct kprobe *p; |
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head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)]; |
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hlist_for_each_entry_rcu(p, head, hlist) { |
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if (p->addr == addr) return p; } |
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return NULL; } |
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NOKPROBE_SYMBOL(get_kprobe); |
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static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); |
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/* Return true if the kprobe is an aggregator */ static inline int kprobe_aggrprobe(struct kprobe *p) { return p->pre_handler == aggr_pre_handler; } |
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/* Return true(!0) if the kprobe is unused */ static inline int kprobe_unused(struct kprobe *p) { return kprobe_aggrprobe(p) && kprobe_disabled(p) && list_empty(&p->list); } |
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/* * Keep all fields in the kprobe consistent */ |
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static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p) |
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{ |
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memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t)); memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn)); |
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} #ifdef CONFIG_OPTPROBES |
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/* NOTE: change this value only with kprobe_mutex held */ static bool kprobes_allow_optimization; |
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/* * Call all pre_handler on the list, but ignores its return value. * This must be called from arch-dep optimized caller. */ |
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void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) |
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{ struct kprobe *kp; list_for_each_entry_rcu(kp, &p->list, list) { if (kp->pre_handler && likely(!kprobe_disabled(kp))) { set_kprobe_instance(kp); kp->pre_handler(kp, regs); } reset_kprobe_instance(); } } |
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NOKPROBE_SYMBOL(opt_pre_handler); |
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/* Free optimized instructions and optimized_kprobe */ |
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static void free_aggr_kprobe(struct kprobe *p) |
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{ struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); arch_remove_optimized_kprobe(op); arch_remove_kprobe(p); kfree(op); } |
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/* Return true(!0) if the kprobe is ready for optimization. */ static inline int kprobe_optready(struct kprobe *p) { struct optimized_kprobe *op; if (kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); return arch_prepared_optinsn(&op->optinsn); } return 0; } |
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/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */ static inline int kprobe_disarmed(struct kprobe *p) { struct optimized_kprobe *op; /* If kprobe is not aggr/opt probe, just return kprobe is disabled */ if (!kprobe_aggrprobe(p)) return kprobe_disabled(p); op = container_of(p, struct optimized_kprobe, kp); return kprobe_disabled(p) && list_empty(&op->list); } /* Return true(!0) if the probe is queued on (un)optimizing lists */ |
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static int kprobe_queued(struct kprobe *p) |
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{ struct optimized_kprobe *op; if (kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) return 1; } return 0; } |
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/* * Return an optimized kprobe whose optimizing code replaces * instructions including addr (exclude breakpoint). */ |
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static struct kprobe *get_optimized_kprobe(unsigned long addr) |
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{ int i; struct kprobe *p = NULL; struct optimized_kprobe *op; /* Don't check i == 0, since that is a breakpoint case. */ for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) p = get_kprobe((void *)(addr - i)); if (p && kprobe_optready(p)) { op = container_of(p, struct optimized_kprobe, kp); if (arch_within_optimized_kprobe(op, addr)) return p; } return NULL; } /* Optimization staging list, protected by kprobe_mutex */ static LIST_HEAD(optimizing_list); |
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static LIST_HEAD(unoptimizing_list); |
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static LIST_HEAD(freeing_list); |
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static void kprobe_optimizer(struct work_struct *work); static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); #define OPTIMIZE_DELAY 5 |
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/* * Optimize (replace a breakpoint with a jump) kprobes listed on * optimizing_list. */ |
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static void do_optimize_kprobes(void) |
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{ |
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/* * The optimization/unoptimization refers online_cpus via * stop_machine() and cpu-hotplug modifies online_cpus. * And same time, text_mutex will be held in cpu-hotplug and here. * This combination can cause a deadlock (cpu-hotplug try to lock * text_mutex but stop_machine can not be done because online_cpus * has been changed) |
2d1e38f56
|
472 |
* To avoid this deadlock, caller must have locked cpu hotplug |
afd66255b
|
473 474 |
* for preventing cpu-hotplug outside of text_mutex locking. */ |
2d1e38f56
|
475 476 477 478 479 480 |
lockdep_assert_cpus_held(); /* Optimization never be done when disarmed */ if (kprobes_all_disarmed || !kprobes_allow_optimization || list_empty(&optimizing_list)) return; |
afd66255b
|
481 |
mutex_lock(&text_mutex); |
cd7ebe229
|
482 |
arch_optimize_kprobes(&optimizing_list); |
afd66255b
|
483 |
mutex_unlock(&text_mutex); |
61f4e13ff
|
484 |
} |
6274de498
|
485 486 487 488 |
/* * Unoptimize (replace a jump with a breakpoint and remove the breakpoint * if need) kprobes listed on unoptimizing_list. */ |
55479f647
|
489 |
static void do_unoptimize_kprobes(void) |
6274de498
|
490 491 |
{ struct optimized_kprobe *op, *tmp; |
2d1e38f56
|
492 493 |
/* See comment in do_optimize_kprobes() */ lockdep_assert_cpus_held(); |
6274de498
|
494 495 496 |
/* Unoptimization must be done anytime */ if (list_empty(&unoptimizing_list)) return; |
6274de498
|
497 |
mutex_lock(&text_mutex); |
7b959fc58
|
498 |
arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list); |
f984ba4eb
|
499 |
/* Loop free_list for disarming */ |
7b959fc58
|
500 |
list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
6274de498
|
501 502 503 504 505 506 507 508 509 510 |
/* Disarm probes if marked disabled */ if (kprobe_disabled(&op->kp)) arch_disarm_kprobe(&op->kp); if (kprobe_unused(&op->kp)) { /* * Remove unused probes from hash list. After waiting * for synchronization, these probes are reclaimed. * (reclaiming is done by do_free_cleaned_kprobes.) */ hlist_del_rcu(&op->kp.hlist); |
6274de498
|
511 512 513 514 |
} else list_del_init(&op->list); } mutex_unlock(&text_mutex); |
6274de498
|
515 516 517 |
} /* Reclaim all kprobes on the free_list */ |
55479f647
|
518 |
static void do_free_cleaned_kprobes(void) |
6274de498
|
519 520 |
{ struct optimized_kprobe *op, *tmp; |
7b959fc58
|
521 |
list_for_each_entry_safe(op, tmp, &freeing_list, list) { |
6274de498
|
522 523 524 525 526 527 528 |
BUG_ON(!kprobe_unused(&op->kp)); list_del_init(&op->list); free_aggr_kprobe(&op->kp); } } /* Start optimizer after OPTIMIZE_DELAY passed */ |
55479f647
|
529 |
static void kick_kprobe_optimizer(void) |
6274de498
|
530 |
{ |
ad72b3bea
|
531 |
schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); |
6274de498
|
532 |
} |
61f4e13ff
|
533 |
/* Kprobe jump optimizer */ |
55479f647
|
534 |
static void kprobe_optimizer(struct work_struct *work) |
61f4e13ff
|
535 |
{ |
72ef3794c
|
536 |
mutex_lock(&kprobe_mutex); |
2d1e38f56
|
537 |
cpus_read_lock(); |
61f4e13ff
|
538 539 |
/* Lock modules while optimizing kprobes */ mutex_lock(&module_mutex); |
61f4e13ff
|
540 541 |
/* |
6274de498
|
542 543 544 |
* Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) * kprobes before waiting for quiesence period. */ |
7b959fc58
|
545 |
do_unoptimize_kprobes(); |
6274de498
|
546 547 548 |
/* * Step 2: Wait for quiesence period to ensure all running interrupts |
61f4e13ff
|
549 550 551 552 553 554 |
* are done. Because optprobe may modify multiple instructions * there is a chance that Nth instruction is interrupted. In that * case, running interrupt can return to 2nd-Nth byte of jump * instruction. This wait is for avoiding it. */ synchronize_sched(); |
6274de498
|
555 |
/* Step 3: Optimize kprobes after quiesence period */ |
61f4e13ff
|
556 |
do_optimize_kprobes(); |
6274de498
|
557 558 |
/* Step 4: Free cleaned kprobes after quiesence period */ |
7b959fc58
|
559 |
do_free_cleaned_kprobes(); |
6274de498
|
560 |
|
afd66255b
|
561 |
mutex_unlock(&module_mutex); |
2d1e38f56
|
562 |
cpus_read_unlock(); |
72ef3794c
|
563 |
mutex_unlock(&kprobe_mutex); |
6274de498
|
564 |
|
cd7ebe229
|
565 |
/* Step 5: Kick optimizer again if needed */ |
f984ba4eb
|
566 |
if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) |
cd7ebe229
|
567 |
kick_kprobe_optimizer(); |
6274de498
|
568 569 570 |
} /* Wait for completing optimization and unoptimization */ |
30e7d894c
|
571 |
void wait_for_kprobe_optimizer(void) |
6274de498
|
572 |
{ |
ad72b3bea
|
573 574 575 576 577 578 579 580 581 582 583 584 585 586 |
mutex_lock(&kprobe_mutex); while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) { mutex_unlock(&kprobe_mutex); /* this will also make optimizing_work execute immmediately */ flush_delayed_work(&optimizing_work); /* @optimizing_work might not have been queued yet, relax */ cpu_relax(); mutex_lock(&kprobe_mutex); } mutex_unlock(&kprobe_mutex); |
afd66255b
|
587 588 589 |
} /* Optimize kprobe if p is ready to be optimized */ |
55479f647
|
590 |
static void optimize_kprobe(struct kprobe *p) |
afd66255b
|
591 592 593 594 |
{ struct optimized_kprobe *op; /* Check if the kprobe is disabled or not ready for optimization. */ |
b2be84df9
|
595 |
if (!kprobe_optready(p) || !kprobes_allow_optimization || |
afd66255b
|
596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 |
(kprobe_disabled(p) || kprobes_all_disarmed)) return; /* Both of break_handler and post_handler are not supported. */ if (p->break_handler || p->post_handler) return; op = container_of(p, struct optimized_kprobe, kp); /* Check there is no other kprobes at the optimized instructions */ if (arch_check_optimized_kprobe(op) < 0) return; /* Check if it is already optimized. */ if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) return; |
afd66255b
|
612 |
op->kp.flags |= KPROBE_FLAG_OPTIMIZED; |
6274de498
|
613 614 615 616 617 618 619 620 621 622 623 |
if (!list_empty(&op->list)) /* This is under unoptimizing. Just dequeue the probe */ list_del_init(&op->list); else { list_add(&op->list, &optimizing_list); kick_kprobe_optimizer(); } } /* Short cut to direct unoptimizing */ |
55479f647
|
624 |
static void force_unoptimize_kprobe(struct optimized_kprobe *op) |
6274de498
|
625 |
{ |
2d1e38f56
|
626 |
lockdep_assert_cpus_held(); |
6274de498
|
627 |
arch_unoptimize_kprobe(op); |
6274de498
|
628 629 |
if (kprobe_disabled(&op->kp)) arch_disarm_kprobe(&op->kp); |
afd66255b
|
630 631 632 |
} /* Unoptimize a kprobe if p is optimized */ |
55479f647
|
633 |
static void unoptimize_kprobe(struct kprobe *p, bool force) |
afd66255b
|
634 635 |
{ struct optimized_kprobe *op; |
6274de498
|
636 637 638 639 640 641 642 643 644 645 646 647 |
if (!kprobe_aggrprobe(p) || kprobe_disarmed(p)) return; /* This is not an optprobe nor optimized */ op = container_of(p, struct optimized_kprobe, kp); if (!kprobe_optimized(p)) { /* Unoptimized or unoptimizing case */ if (force && !list_empty(&op->list)) { /* * Only if this is unoptimizing kprobe and forced, * forcibly unoptimize it. (No need to unoptimize * unoptimized kprobe again :) */ |
afd66255b
|
648 |
list_del_init(&op->list); |
6274de498
|
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 |
force_unoptimize_kprobe(op); } return; } op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; if (!list_empty(&op->list)) { /* Dequeue from the optimization queue */ list_del_init(&op->list); return; } /* Optimized kprobe case */ if (force) /* Forcibly update the code: this is a special case */ force_unoptimize_kprobe(op); else { list_add(&op->list, &unoptimizing_list); kick_kprobe_optimizer(); |
afd66255b
|
667 668 |
} } |
0490cd1f9
|
669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 |
/* Cancel unoptimizing for reusing */ static void reuse_unused_kprobe(struct kprobe *ap) { struct optimized_kprobe *op; BUG_ON(!kprobe_unused(ap)); /* * Unused kprobe MUST be on the way of delayed unoptimizing (means * there is still a relative jump) and disabled. */ op = container_of(ap, struct optimized_kprobe, kp); if (unlikely(list_empty(&op->list))) printk(KERN_WARNING "Warning: found a stray unused " "aggrprobe@%p ", ap->addr); /* Enable the probe again */ ap->flags &= ~KPROBE_FLAG_DISABLED; /* Optimize it again (remove from op->list) */ BUG_ON(!kprobe_optready(ap)); optimize_kprobe(ap); } |
afd66255b
|
690 |
/* Remove optimized instructions */ |
55479f647
|
691 |
static void kill_optimized_kprobe(struct kprobe *p) |
afd66255b
|
692 693 694 695 |
{ struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); |
6274de498
|
696 697 |
if (!list_empty(&op->list)) /* Dequeue from the (un)optimization queue */ |
afd66255b
|
698 |
list_del_init(&op->list); |
6274de498
|
699 |
op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; |
7b959fc58
|
700 701 702 703 704 705 706 707 708 709 710 |
if (kprobe_unused(p)) { /* Enqueue if it is unused */ list_add(&op->list, &freeing_list); /* * Remove unused probes from the hash list. After waiting * for synchronization, this probe is reclaimed. * (reclaiming is done by do_free_cleaned_kprobes().) */ hlist_del_rcu(&op->kp.hlist); } |
6274de498
|
711 |
/* Don't touch the code, because it is already freed. */ |
afd66255b
|
712 713 |
arch_remove_optimized_kprobe(op); } |
a460246c7
|
714 715 716 717 718 719 |
static inline void __prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) { if (!kprobe_ftrace(p)) arch_prepare_optimized_kprobe(op, p); } |
afd66255b
|
720 |
/* Try to prepare optimized instructions */ |
55479f647
|
721 |
static void prepare_optimized_kprobe(struct kprobe *p) |
afd66255b
|
722 723 724 725 |
{ struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); |
a460246c7
|
726 |
__prepare_optimized_kprobe(op, p); |
afd66255b
|
727 |
} |
afd66255b
|
728 |
/* Allocate new optimized_kprobe and try to prepare optimized instructions */ |
55479f647
|
729 |
static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255b
|
730 731 732 733 734 735 736 737 738 |
{ struct optimized_kprobe *op; op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); if (!op) return NULL; INIT_LIST_HEAD(&op->list); op->kp.addr = p->addr; |
a460246c7
|
739 |
__prepare_optimized_kprobe(op, p); |
afd66255b
|
740 741 742 |
return &op->kp; } |
55479f647
|
743 |
static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); |
afd66255b
|
744 745 746 747 748 |
/* * Prepare an optimized_kprobe and optimize it * NOTE: p must be a normal registered kprobe */ |
55479f647
|
749 |
static void try_to_optimize_kprobe(struct kprobe *p) |
afd66255b
|
750 751 752 |
{ struct kprobe *ap; struct optimized_kprobe *op; |
ae6aa16fd
|
753 754 755 |
/* Impossible to optimize ftrace-based kprobe */ if (kprobe_ftrace(p)) return; |
25764288d
|
756 |
/* For preparing optimization, jump_label_text_reserved() is called */ |
2d1e38f56
|
757 |
cpus_read_lock(); |
25764288d
|
758 759 |
jump_label_lock(); mutex_lock(&text_mutex); |
afd66255b
|
760 761 |
ap = alloc_aggr_kprobe(p); if (!ap) |
25764288d
|
762 |
goto out; |
afd66255b
|
763 764 765 766 |
op = container_of(ap, struct optimized_kprobe, kp); if (!arch_prepared_optinsn(&op->optinsn)) { /* If failed to setup optimizing, fallback to kprobe */ |
6274de498
|
767 768 |
arch_remove_optimized_kprobe(op); kfree(op); |
25764288d
|
769 |
goto out; |
afd66255b
|
770 771 772 |
} init_aggr_kprobe(ap, p); |
25764288d
|
773 774 775 776 777 |
optimize_kprobe(ap); /* This just kicks optimizer thread */ out: mutex_unlock(&text_mutex); jump_label_unlock(); |
2d1e38f56
|
778 |
cpus_read_unlock(); |
afd66255b
|
779 |
} |
b2be84df9
|
780 |
#ifdef CONFIG_SYSCTL |
55479f647
|
781 |
static void optimize_all_kprobes(void) |
b2be84df9
|
782 783 |
{ struct hlist_head *head; |
b2be84df9
|
784 785 |
struct kprobe *p; unsigned int i; |
5c51543b0
|
786 |
mutex_lock(&kprobe_mutex); |
b2be84df9
|
787 788 |
/* If optimization is already allowed, just return */ if (kprobes_allow_optimization) |
5c51543b0
|
789 |
goto out; |
b2be84df9
|
790 |
|
2d1e38f56
|
791 |
cpus_read_lock(); |
b2be84df9
|
792 |
kprobes_allow_optimization = true; |
b2be84df9
|
793 794 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; |
b67bfe0d4
|
795 |
hlist_for_each_entry_rcu(p, head, hlist) |
b2be84df9
|
796 797 798 |
if (!kprobe_disabled(p)) optimize_kprobe(p); } |
2d1e38f56
|
799 |
cpus_read_unlock(); |
b2be84df9
|
800 801 |
printk(KERN_INFO "Kprobes globally optimized "); |
5c51543b0
|
802 803 |
out: mutex_unlock(&kprobe_mutex); |
b2be84df9
|
804 |
} |
55479f647
|
805 |
static void unoptimize_all_kprobes(void) |
b2be84df9
|
806 807 |
{ struct hlist_head *head; |
b2be84df9
|
808 809 |
struct kprobe *p; unsigned int i; |
5c51543b0
|
810 |
mutex_lock(&kprobe_mutex); |
b2be84df9
|
811 |
/* If optimization is already prohibited, just return */ |
5c51543b0
|
812 813 |
if (!kprobes_allow_optimization) { mutex_unlock(&kprobe_mutex); |
b2be84df9
|
814 |
return; |
5c51543b0
|
815 |
} |
b2be84df9
|
816 |
|
2d1e38f56
|
817 |
cpus_read_lock(); |
b2be84df9
|
818 |
kprobes_allow_optimization = false; |
b2be84df9
|
819 820 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; |
b67bfe0d4
|
821 |
hlist_for_each_entry_rcu(p, head, hlist) { |
b2be84df9
|
822 |
if (!kprobe_disabled(p)) |
6274de498
|
823 |
unoptimize_kprobe(p, false); |
b2be84df9
|
824 825 |
} } |
2d1e38f56
|
826 |
cpus_read_unlock(); |
5c51543b0
|
827 |
mutex_unlock(&kprobe_mutex); |
6274de498
|
828 829 830 831 |
/* Wait for unoptimizing completion */ wait_for_kprobe_optimizer(); printk(KERN_INFO "Kprobes globally unoptimized "); |
b2be84df9
|
832 |
} |
5c51543b0
|
833 |
static DEFINE_MUTEX(kprobe_sysctl_mutex); |
b2be84df9
|
834 835 836 837 838 839 |
int sysctl_kprobes_optimization; int proc_kprobes_optimization_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { int ret; |
5c51543b0
|
840 |
mutex_lock(&kprobe_sysctl_mutex); |
b2be84df9
|
841 842 843 844 845 846 847 |
sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; ret = proc_dointvec_minmax(table, write, buffer, length, ppos); if (sysctl_kprobes_optimization) optimize_all_kprobes(); else unoptimize_all_kprobes(); |
5c51543b0
|
848 |
mutex_unlock(&kprobe_sysctl_mutex); |
b2be84df9
|
849 850 851 852 |
return ret; } #endif /* CONFIG_SYSCTL */ |
6274de498
|
853 |
/* Put a breakpoint for a probe. Must be called with text_mutex locked */ |
55479f647
|
854 |
static void __arm_kprobe(struct kprobe *p) |
afd66255b
|
855 |
{ |
6d8e40a85
|
856 |
struct kprobe *_p; |
afd66255b
|
857 858 |
/* Check collision with other optimized kprobes */ |
6d8e40a85
|
859 860 |
_p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p)) |
6274de498
|
861 862 |
/* Fallback to unoptimized kprobe */ unoptimize_kprobe(_p, true); |
afd66255b
|
863 864 865 866 |
arch_arm_kprobe(p); optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ } |
6274de498
|
867 |
/* Remove the breakpoint of a probe. Must be called with text_mutex locked */ |
55479f647
|
868 |
static void __disarm_kprobe(struct kprobe *p, bool reopt) |
afd66255b
|
869 |
{ |
6d8e40a85
|
870 |
struct kprobe *_p; |
afd66255b
|
871 |
|
69d54b916
|
872 873 |
/* Try to unoptimize */ unoptimize_kprobe(p, kprobes_all_disarmed); |
afd66255b
|
874 |
|
6274de498
|
875 876 877 878 879 880 881 882 |
if (!kprobe_queued(p)) { arch_disarm_kprobe(p); /* If another kprobe was blocked, optimize it. */ _p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(_p) && reopt) optimize_kprobe(_p); } /* TODO: reoptimize others after unoptimized this probe */ |
afd66255b
|
883 884 885 886 887 |
} #else /* !CONFIG_OPTPROBES */ #define optimize_kprobe(p) do {} while (0) |
6274de498
|
888 |
#define unoptimize_kprobe(p, f) do {} while (0) |
afd66255b
|
889 890 891 892 |
#define kill_optimized_kprobe(p) do {} while (0) #define prepare_optimized_kprobe(p) do {} while (0) #define try_to_optimize_kprobe(p) do {} while (0) #define __arm_kprobe(p) arch_arm_kprobe(p) |
6274de498
|
893 894 895 |
#define __disarm_kprobe(p, o) arch_disarm_kprobe(p) #define kprobe_disarmed(p) kprobe_disabled(p) #define wait_for_kprobe_optimizer() do {} while (0) |
afd66255b
|
896 |
|
0490cd1f9
|
897 898 899 900 901 902 903 |
/* There should be no unused kprobes can be reused without optimization */ static void reuse_unused_kprobe(struct kprobe *ap) { printk(KERN_ERR "Error: There should be no unused kprobe here. "); BUG_ON(kprobe_unused(ap)); } |
55479f647
|
904 |
static void free_aggr_kprobe(struct kprobe *p) |
afd66255b
|
905 |
{ |
6274de498
|
906 |
arch_remove_kprobe(p); |
afd66255b
|
907 908 |
kfree(p); } |
55479f647
|
909 |
static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) |
afd66255b
|
910 911 912 913 |
{ return kzalloc(sizeof(struct kprobe), GFP_KERNEL); } #endif /* CONFIG_OPTPROBES */ |
e7dbfe349
|
914 |
#ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16fd
|
915 |
static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { |
e52538965
|
916 |
.func = kprobe_ftrace_handler, |
1d70be34d
|
917 |
.flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, |
ae6aa16fd
|
918 919 920 921 |
}; static int kprobe_ftrace_enabled; /* Must ensure p->addr is really on ftrace */ |
55479f647
|
922 |
static int prepare_kprobe(struct kprobe *p) |
ae6aa16fd
|
923 924 925 926 927 928 929 930 |
{ if (!kprobe_ftrace(p)) return arch_prepare_kprobe(p); return arch_prepare_kprobe_ftrace(p); } /* Caller must lock kprobe_mutex */ |
55479f647
|
931 |
static void arm_kprobe_ftrace(struct kprobe *p) |
ae6aa16fd
|
932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 |
{ int ret; ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 0, 0); WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d) ", p->addr, ret); kprobe_ftrace_enabled++; if (kprobe_ftrace_enabled == 1) { ret = register_ftrace_function(&kprobe_ftrace_ops); WARN(ret < 0, "Failed to init kprobe-ftrace (%d) ", ret); } } /* Caller must lock kprobe_mutex */ |
55479f647
|
948 |
static void disarm_kprobe_ftrace(struct kprobe *p) |
ae6aa16fd
|
949 950 951 952 953 954 955 956 957 958 959 960 961 962 |
{ int ret; kprobe_ftrace_enabled--; if (kprobe_ftrace_enabled == 0) { ret = unregister_ftrace_function(&kprobe_ftrace_ops); WARN(ret < 0, "Failed to init kprobe-ftrace (%d) ", ret); } ret = ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0); WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d) ", p->addr, ret); } |
e7dbfe349
|
963 |
#else /* !CONFIG_KPROBES_ON_FTRACE */ |
ae6aa16fd
|
964 965 966 967 |
#define prepare_kprobe(p) arch_prepare_kprobe(p) #define arm_kprobe_ftrace(p) do {} while (0) #define disarm_kprobe_ftrace(p) do {} while (0) #endif |
201517a7f
|
968 |
/* Arm a kprobe with text_mutex */ |
55479f647
|
969 |
static void arm_kprobe(struct kprobe *kp) |
201517a7f
|
970 |
{ |
ae6aa16fd
|
971 972 973 974 |
if (unlikely(kprobe_ftrace(kp))) { arm_kprobe_ftrace(kp); return; } |
2d1e38f56
|
975 |
cpus_read_lock(); |
201517a7f
|
976 |
mutex_lock(&text_mutex); |
afd66255b
|
977 |
__arm_kprobe(kp); |
201517a7f
|
978 |
mutex_unlock(&text_mutex); |
2d1e38f56
|
979 |
cpus_read_unlock(); |
201517a7f
|
980 981 982 |
} /* Disarm a kprobe with text_mutex */ |
55479f647
|
983 |
static void disarm_kprobe(struct kprobe *kp, bool reopt) |
201517a7f
|
984 |
{ |
ae6aa16fd
|
985 986 987 988 |
if (unlikely(kprobe_ftrace(kp))) { disarm_kprobe_ftrace(kp); return; } |
2d1e38f56
|
989 990 |
cpus_read_lock(); |
201517a7f
|
991 |
mutex_lock(&text_mutex); |
ae6aa16fd
|
992 |
__disarm_kprobe(kp, reopt); |
201517a7f
|
993 |
mutex_unlock(&text_mutex); |
2d1e38f56
|
994 |
cpus_read_unlock(); |
201517a7f
|
995 |
} |
64f562c6d
|
996 997 998 999 |
/* * Aggregate handlers for multiple kprobes support - these handlers * take care of invoking the individual kprobe handlers on p->list */ |
820aede02
|
1000 |
static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6d
|
1001 1002 |
{ struct kprobe *kp; |
3516a4604
|
1003 |
list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d5
|
1004 |
if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e65845235
|
1005 |
set_kprobe_instance(kp); |
8b0914ea7
|
1006 1007 |
if (kp->pre_handler(kp, regs)) return 1; |
64f562c6d
|
1008 |
} |
e65845235
|
1009 |
reset_kprobe_instance(); |
64f562c6d
|
1010 1011 1012 |
} return 0; } |
820aede02
|
1013 |
NOKPROBE_SYMBOL(aggr_pre_handler); |
64f562c6d
|
1014 |
|
820aede02
|
1015 1016 |
static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, unsigned long flags) |
64f562c6d
|
1017 1018 |
{ struct kprobe *kp; |
3516a4604
|
1019 |
list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d5
|
1020 |
if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e65845235
|
1021 |
set_kprobe_instance(kp); |
64f562c6d
|
1022 |
kp->post_handler(kp, regs, flags); |
e65845235
|
1023 |
reset_kprobe_instance(); |
64f562c6d
|
1024 1025 |
} } |
64f562c6d
|
1026 |
} |
820aede02
|
1027 |
NOKPROBE_SYMBOL(aggr_post_handler); |
64f562c6d
|
1028 |
|
820aede02
|
1029 1030 |
static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, int trapnr) |
64f562c6d
|
1031 |
{ |
b76834bc1
|
1032 |
struct kprobe *cur = __this_cpu_read(kprobe_instance); |
e65845235
|
1033 |
|
64f562c6d
|
1034 1035 1036 1037 |
/* * if we faulted "during" the execution of a user specified * probe handler, invoke just that probe's fault handler */ |
e65845235
|
1038 1039 |
if (cur && cur->fault_handler) { if (cur->fault_handler(cur, regs, trapnr)) |
64f562c6d
|
1040 1041 1042 1043 |
return 1; } return 0; } |
820aede02
|
1044 |
NOKPROBE_SYMBOL(aggr_fault_handler); |
64f562c6d
|
1045 |
|
820aede02
|
1046 |
static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
8b0914ea7
|
1047 |
{ |
b76834bc1
|
1048 |
struct kprobe *cur = __this_cpu_read(kprobe_instance); |
e65845235
|
1049 1050 1051 1052 1053 |
int ret = 0; if (cur && cur->break_handler) { if (cur->break_handler(cur, regs)) ret = 1; |
8b0914ea7
|
1054 |
} |
e65845235
|
1055 1056 |
reset_kprobe_instance(); return ret; |
8b0914ea7
|
1057 |
} |
820aede02
|
1058 |
NOKPROBE_SYMBOL(aggr_break_handler); |
8b0914ea7
|
1059 |
|
bf8d5c52c
|
1060 |
/* Walks the list and increments nmissed count for multiprobe case */ |
820aede02
|
1061 |
void kprobes_inc_nmissed_count(struct kprobe *p) |
bf8d5c52c
|
1062 1063 |
{ struct kprobe *kp; |
afd66255b
|
1064 |
if (!kprobe_aggrprobe(p)) { |
bf8d5c52c
|
1065 1066 1067 1068 1069 1070 1071 |
p->nmissed++; } else { list_for_each_entry_rcu(kp, &p->list, list) kp->nmissed++; } return; } |
820aede02
|
1072 |
NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); |
bf8d5c52c
|
1073 |
|
820aede02
|
1074 1075 |
void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head) |
b94cce926
|
1076 |
{ |
ef53d9c5e
|
1077 |
struct kretprobe *rp = ri->rp; |
b94cce926
|
1078 1079 |
/* remove rp inst off the rprobe_inst_table */ hlist_del(&ri->hlist); |
ef53d9c5e
|
1080 1081 |
INIT_HLIST_NODE(&ri->hlist); if (likely(rp)) { |
ec484608c
|
1082 |
raw_spin_lock(&rp->lock); |
ef53d9c5e
|
1083 |
hlist_add_head(&ri->hlist, &rp->free_instances); |
ec484608c
|
1084 |
raw_spin_unlock(&rp->lock); |
b94cce926
|
1085 1086 |
} else /* Unregistering */ |
99219a3fb
|
1087 |
hlist_add_head(&ri->hlist, head); |
b94cce926
|
1088 |
} |
820aede02
|
1089 |
NOKPROBE_SYMBOL(recycle_rp_inst); |
b94cce926
|
1090 |
|
820aede02
|
1091 |
void kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5e
|
1092 |
struct hlist_head **head, unsigned long *flags) |
635c17c2b
|
1093 |
__acquires(hlist_lock) |
ef53d9c5e
|
1094 1095 |
{ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
ec484608c
|
1096 |
raw_spinlock_t *hlist_lock; |
ef53d9c5e
|
1097 1098 1099 |
*head = &kretprobe_inst_table[hash]; hlist_lock = kretprobe_table_lock_ptr(hash); |
ec484608c
|
1100 |
raw_spin_lock_irqsave(hlist_lock, *flags); |
ef53d9c5e
|
1101 |
} |
820aede02
|
1102 |
NOKPROBE_SYMBOL(kretprobe_hash_lock); |
ef53d9c5e
|
1103 |
|
820aede02
|
1104 1105 |
static void kretprobe_table_lock(unsigned long hash, unsigned long *flags) |
635c17c2b
|
1106 |
__acquires(hlist_lock) |
b94cce926
|
1107 |
{ |
ec484608c
|
1108 1109 |
raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_lock_irqsave(hlist_lock, *flags); |
ef53d9c5e
|
1110 |
} |
820aede02
|
1111 |
NOKPROBE_SYMBOL(kretprobe_table_lock); |
ef53d9c5e
|
1112 |
|
820aede02
|
1113 1114 |
void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags) |
635c17c2b
|
1115 |
__releases(hlist_lock) |
ef53d9c5e
|
1116 1117 |
{ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); |
ec484608c
|
1118 |
raw_spinlock_t *hlist_lock; |
ef53d9c5e
|
1119 1120 |
hlist_lock = kretprobe_table_lock_ptr(hash); |
ec484608c
|
1121 |
raw_spin_unlock_irqrestore(hlist_lock, *flags); |
ef53d9c5e
|
1122 |
} |
820aede02
|
1123 |
NOKPROBE_SYMBOL(kretprobe_hash_unlock); |
ef53d9c5e
|
1124 |
|
820aede02
|
1125 1126 |
static void kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
635c17c2b
|
1127 |
__releases(hlist_lock) |
ef53d9c5e
|
1128 |
{ |
ec484608c
|
1129 1130 |
raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_unlock_irqrestore(hlist_lock, *flags); |
b94cce926
|
1131 |
} |
820aede02
|
1132 |
NOKPROBE_SYMBOL(kretprobe_table_unlock); |
b94cce926
|
1133 |
|
b94cce926
|
1134 |
/* |
c6fd91f0b
|
1135 1136 1137 1138 |
* This function is called from finish_task_switch when task tk becomes dead, * so that we can recycle any function-return probe instances associated * with this task. These left over instances represent probed functions * that have been called but will never return. |
b94cce926
|
1139 |
*/ |
820aede02
|
1140 |
void kprobe_flush_task(struct task_struct *tk) |
b94cce926
|
1141 |
{ |
62c27be0d
|
1142 |
struct kretprobe_instance *ri; |
99219a3fb
|
1143 |
struct hlist_head *head, empty_rp; |
b67bfe0d4
|
1144 |
struct hlist_node *tmp; |
ef53d9c5e
|
1145 |
unsigned long hash, flags = 0; |
802eae7c8
|
1146 |
|
ef53d9c5e
|
1147 1148 1149 |
if (unlikely(!kprobes_initialized)) /* Early boot. kretprobe_table_locks not yet initialized. */ return; |
d496aab56
|
1150 |
INIT_HLIST_HEAD(&empty_rp); |
ef53d9c5e
|
1151 1152 1153 |
hash = hash_ptr(tk, KPROBE_HASH_BITS); head = &kretprobe_inst_table[hash]; kretprobe_table_lock(hash, &flags); |
b67bfe0d4
|
1154 |
hlist_for_each_entry_safe(ri, tmp, head, hlist) { |
62c27be0d
|
1155 |
if (ri->task == tk) |
99219a3fb
|
1156 |
recycle_rp_inst(ri, &empty_rp); |
62c27be0d
|
1157 |
} |
ef53d9c5e
|
1158 |
kretprobe_table_unlock(hash, &flags); |
b67bfe0d4
|
1159 |
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { |
99219a3fb
|
1160 1161 1162 |
hlist_del(&ri->hlist); kfree(ri); } |
b94cce926
|
1163 |
} |
820aede02
|
1164 |
NOKPROBE_SYMBOL(kprobe_flush_task); |
b94cce926
|
1165 |
|
b94cce926
|
1166 1167 1168 |
static inline void free_rp_inst(struct kretprobe *rp) { struct kretprobe_instance *ri; |
b67bfe0d4
|
1169 |
struct hlist_node *next; |
4c4308cb9
|
1170 |
|
b67bfe0d4
|
1171 |
hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) { |
ef53d9c5e
|
1172 |
hlist_del(&ri->hlist); |
b94cce926
|
1173 1174 1175 |
kfree(ri); } } |
820aede02
|
1176 |
static void cleanup_rp_inst(struct kretprobe *rp) |
4a296e07c
|
1177 |
{ |
ef53d9c5e
|
1178 |
unsigned long flags, hash; |
4a296e07c
|
1179 |
struct kretprobe_instance *ri; |
b67bfe0d4
|
1180 |
struct hlist_node *next; |
ef53d9c5e
|
1181 |
struct hlist_head *head; |
4a296e07c
|
1182 |
/* No race here */ |
ef53d9c5e
|
1183 1184 1185 |
for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { kretprobe_table_lock(hash, &flags); head = &kretprobe_inst_table[hash]; |
b67bfe0d4
|
1186 |
hlist_for_each_entry_safe(ri, next, head, hlist) { |
ef53d9c5e
|
1187 1188 1189 1190 |
if (ri->rp == rp) ri->rp = NULL; } kretprobe_table_unlock(hash, &flags); |
4a296e07c
|
1191 |
} |
4a296e07c
|
1192 1193 |
free_rp_inst(rp); } |
820aede02
|
1194 |
NOKPROBE_SYMBOL(cleanup_rp_inst); |
4a296e07c
|
1195 |
|
64f562c6d
|
1196 |
/* |
b918e5e60
|
1197 |
* Add the new probe to ap->list. Fail if this is the |
8b0914ea7
|
1198 1199 |
* second jprobe at the address - two jprobes can't coexist */ |
55479f647
|
1200 |
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea7
|
1201 |
{ |
de5bd88d5
|
1202 |
BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
afd66255b
|
1203 1204 |
if (p->break_handler || p->post_handler) |
6274de498
|
1205 |
unoptimize_kprobe(ap, true); /* Fall back to normal kprobe */ |
afd66255b
|
1206 |
|
8b0914ea7
|
1207 |
if (p->break_handler) { |
b918e5e60
|
1208 |
if (ap->break_handler) |
367216567
|
1209 |
return -EEXIST; |
b918e5e60
|
1210 1211 |
list_add_tail_rcu(&p->list, &ap->list); ap->break_handler = aggr_break_handler; |
8b0914ea7
|
1212 |
} else |
b918e5e60
|
1213 1214 1215 |
list_add_rcu(&p->list, &ap->list); if (p->post_handler && !ap->post_handler) ap->post_handler = aggr_post_handler; |
de5bd88d5
|
1216 |
|
8b0914ea7
|
1217 1218 1219 1220 |
return 0; } /* |
64f562c6d
|
1221 1222 1223 |
* Fill in the required fields of the "manager kprobe". Replace the * earlier kprobe in the hlist with the manager kprobe */ |
55479f647
|
1224 |
static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
64f562c6d
|
1225 |
{ |
afd66255b
|
1226 |
/* Copy p's insn slot to ap */ |
8b0914ea7
|
1227 |
copy_kprobe(p, ap); |
a9ad965ea
|
1228 |
flush_insn_slot(ap); |
64f562c6d
|
1229 |
ap->addr = p->addr; |
afd66255b
|
1230 |
ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
64f562c6d
|
1231 |
ap->pre_handler = aggr_pre_handler; |
64f562c6d
|
1232 |
ap->fault_handler = aggr_fault_handler; |
e8386a0cb
|
1233 1234 |
/* We don't care the kprobe which has gone. */ if (p->post_handler && !kprobe_gone(p)) |
367216567
|
1235 |
ap->post_handler = aggr_post_handler; |
e8386a0cb
|
1236 |
if (p->break_handler && !kprobe_gone(p)) |
367216567
|
1237 |
ap->break_handler = aggr_break_handler; |
64f562c6d
|
1238 1239 |
INIT_LIST_HEAD(&ap->list); |
afd66255b
|
1240 |
INIT_HLIST_NODE(&ap->hlist); |
64f562c6d
|
1241 |
|
afd66255b
|
1242 |
list_add_rcu(&p->list, &ap->list); |
adad0f331
|
1243 |
hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6d
|
1244 1245 1246 1247 1248 |
} /* * This is the second or subsequent kprobe at the address - handle * the intricacies |
64f562c6d
|
1249 |
*/ |
55479f647
|
1250 |
static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) |
64f562c6d
|
1251 1252 |
{ int ret = 0; |
6d8e40a85
|
1253 |
struct kprobe *ap = orig_p; |
64f562c6d
|
1254 |
|
2d1e38f56
|
1255 |
cpus_read_lock(); |
25764288d
|
1256 1257 |
/* For preparing optimization, jump_label_text_reserved() is called */ jump_label_lock(); |
25764288d
|
1258 |
mutex_lock(&text_mutex); |
6d8e40a85
|
1259 1260 1261 |
if (!kprobe_aggrprobe(orig_p)) { /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */ ap = alloc_aggr_kprobe(orig_p); |
25764288d
|
1262 1263 1264 1265 |
if (!ap) { ret = -ENOMEM; goto out; } |
6d8e40a85
|
1266 |
init_aggr_kprobe(ap, orig_p); |
6274de498
|
1267 |
} else if (kprobe_unused(ap)) |
0490cd1f9
|
1268 1269 |
/* This probe is going to die. Rescue it */ reuse_unused_kprobe(ap); |
b918e5e60
|
1270 1271 |
if (kprobe_gone(ap)) { |
e8386a0cb
|
1272 1273 1274 1275 1276 1277 |
/* * Attempting to insert new probe at the same location that * had a probe in the module vaddr area which already * freed. So, the instruction slot has already been * released. We need a new slot for the new probe. */ |
b918e5e60
|
1278 |
ret = arch_prepare_kprobe(ap); |
e8386a0cb
|
1279 |
if (ret) |
b918e5e60
|
1280 1281 1282 1283 1284 |
/* * Even if fail to allocate new slot, don't need to * free aggr_probe. It will be used next time, or * freed by unregister_kprobe. */ |
25764288d
|
1285 |
goto out; |
de5bd88d5
|
1286 |
|
afd66255b
|
1287 1288 |
/* Prepare optimized instructions if possible. */ prepare_optimized_kprobe(ap); |
e8386a0cb
|
1289 |
/* |
de5bd88d5
|
1290 1291 |
* Clear gone flag to prevent allocating new slot again, and * set disabled flag because it is not armed yet. |
e8386a0cb
|
1292 |
*/ |
de5bd88d5
|
1293 1294 |
ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) | KPROBE_FLAG_DISABLED; |
e8386a0cb
|
1295 |
} |
b918e5e60
|
1296 |
|
afd66255b
|
1297 |
/* Copy ap's insn slot to p */ |
b918e5e60
|
1298 |
copy_kprobe(ap, p); |
25764288d
|
1299 1300 1301 1302 |
ret = add_new_kprobe(ap, p); out: mutex_unlock(&text_mutex); |
25764288d
|
1303 |
jump_label_unlock(); |
2d1e38f56
|
1304 |
cpus_read_unlock(); |
25764288d
|
1305 1306 1307 1308 1309 1310 1311 1312 |
if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) { ap->flags &= ~KPROBE_FLAG_DISABLED; if (!kprobes_all_disarmed) /* Arm the breakpoint again. */ arm_kprobe(ap); } return ret; |
64f562c6d
|
1313 |
} |
be8f27432
|
1314 1315 1316 1317 1318 1319 |
bool __weak arch_within_kprobe_blacklist(unsigned long addr) { /* The __kprobes marked functions and entry code must not be probed */ return addr >= (unsigned long)__kprobes_text_start && addr < (unsigned long)__kprobes_text_end; } |
e5779e8e1
|
1320 |
bool within_kprobe_blacklist(unsigned long addr) |
d0aaff979
|
1321 |
{ |
376e24242
|
1322 |
struct kprobe_blacklist_entry *ent; |
3d8d996e0
|
1323 |
|
be8f27432
|
1324 |
if (arch_within_kprobe_blacklist(addr)) |
376e24242
|
1325 |
return true; |
3d8d996e0
|
1326 1327 1328 1329 |
/* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area */ |
376e24242
|
1330 1331 1332 |
list_for_each_entry(ent, &kprobe_blacklist, list) { if (addr >= ent->start_addr && addr < ent->end_addr) return true; |
3d8d996e0
|
1333 |
} |
376e24242
|
1334 1335 |
return false; |
d0aaff979
|
1336 |
} |
b2a5cd693
|
1337 1338 1339 |
/* * If we have a symbol_name argument, look it up and add the offset field * to it. This way, we can specify a relative address to a symbol. |
bc81d48d1
|
1340 1341 |
* This returns encoded errors if it fails to look up symbol or invalid * combination of parameters. |
b2a5cd693
|
1342 |
*/ |
1d585e709
|
1343 1344 |
static kprobe_opcode_t *_kprobe_addr(kprobe_opcode_t *addr, const char *symbol_name, unsigned int offset) |
b2a5cd693
|
1345 |
{ |
1d585e709
|
1346 |
if ((symbol_name && addr) || (!symbol_name && !addr)) |
bc81d48d1
|
1347 |
goto invalid; |
1d585e709
|
1348 |
if (symbol_name) { |
7246f6006
|
1349 |
addr = kprobe_lookup_name(symbol_name, offset); |
bc81d48d1
|
1350 1351 |
if (!addr) return ERR_PTR(-ENOENT); |
b2a5cd693
|
1352 |
} |
1d585e709
|
1353 |
addr = (kprobe_opcode_t *)(((char *)addr) + offset); |
bc81d48d1
|
1354 1355 1356 1357 1358 |
if (addr) return addr; invalid: return ERR_PTR(-EINVAL); |
b2a5cd693
|
1359 |
} |
1d585e709
|
1360 1361 1362 1363 |
static kprobe_opcode_t *kprobe_addr(struct kprobe *p) { return _kprobe_addr(p->addr, p->symbol_name, p->offset); } |
1f0ab4097
|
1364 |
/* Check passed kprobe is valid and return kprobe in kprobe_table. */ |
55479f647
|
1365 |
static struct kprobe *__get_valid_kprobe(struct kprobe *p) |
1f0ab4097
|
1366 |
{ |
6d8e40a85
|
1367 |
struct kprobe *ap, *list_p; |
1f0ab4097
|
1368 |
|
6d8e40a85
|
1369 1370 |
ap = get_kprobe(p->addr); if (unlikely(!ap)) |
1f0ab4097
|
1371 |
return NULL; |
6d8e40a85
|
1372 1373 |
if (p != ap) { list_for_each_entry_rcu(list_p, &ap->list, list) |
1f0ab4097
|
1374 1375 1376 1377 1378 1379 |
if (list_p == p) /* kprobe p is a valid probe */ goto valid; return NULL; } valid: |
6d8e40a85
|
1380 |
return ap; |
1f0ab4097
|
1381 1382 1383 1384 1385 1386 |
} /* Return error if the kprobe is being re-registered */ static inline int check_kprobe_rereg(struct kprobe *p) { int ret = 0; |
1f0ab4097
|
1387 1388 |
mutex_lock(&kprobe_mutex); |
6d8e40a85
|
1389 |
if (__get_valid_kprobe(p)) |
1f0ab4097
|
1390 1391 |
ret = -EINVAL; mutex_unlock(&kprobe_mutex); |
6d8e40a85
|
1392 |
|
1f0ab4097
|
1393 1394 |
return ret; } |
f7f242ff0
|
1395 |
int __weak arch_check_ftrace_location(struct kprobe *p) |
1da177e4c
|
1396 |
{ |
ae6aa16fd
|
1397 |
unsigned long ftrace_addr; |
ae6aa16fd
|
1398 1399 |
ftrace_addr = ftrace_location((unsigned long)p->addr); if (ftrace_addr) { |
e7dbfe349
|
1400 |
#ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16fd
|
1401 1402 1403 |
/* Given address is not on the instruction boundary */ if ((unsigned long)p->addr != ftrace_addr) return -EILSEQ; |
ae6aa16fd
|
1404 |
p->flags |= KPROBE_FLAG_FTRACE; |
e7dbfe349
|
1405 |
#else /* !CONFIG_KPROBES_ON_FTRACE */ |
ae6aa16fd
|
1406 1407 1408 |
return -EINVAL; #endif } |
f7f242ff0
|
1409 1410 1411 1412 1413 1414 1415 |
return 0; } static int check_kprobe_address_safe(struct kprobe *p, struct module **probed_mod) { int ret; |
1f0ab4097
|
1416 |
|
f7f242ff0
|
1417 1418 1419 |
ret = arch_check_ftrace_location(p); if (ret) return ret; |
91bad2f8d
|
1420 |
jump_label_lock(); |
de31c3ca8
|
1421 |
preempt_disable(); |
f7fa6ef0d
|
1422 1423 |
/* Ensure it is not in reserved area nor out of text */ |
ec30c5f3a
|
1424 |
if (!kernel_text_address((unsigned long) p->addr) || |
376e24242
|
1425 |
within_kprobe_blacklist((unsigned long) p->addr) || |
f986a499e
|
1426 1427 |
jump_label_text_reserved(p->addr, p->addr)) { ret = -EINVAL; |
f7fa6ef0d
|
1428 |
goto out; |
f986a499e
|
1429 |
} |
b3e55c727
|
1430 |
|
f7fa6ef0d
|
1431 1432 1433 |
/* Check if are we probing a module */ *probed_mod = __module_text_address((unsigned long) p->addr); if (*probed_mod) { |
6f716acd5
|
1434 |
/* |
e8386a0cb
|
1435 1436 |
* We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. |
df019b1d8
|
1437 |
*/ |
f7fa6ef0d
|
1438 1439 1440 1441 |
if (unlikely(!try_module_get(*probed_mod))) { ret = -ENOENT; goto out; } |
de31c3ca8
|
1442 |
|
f24659d96
|
1443 1444 1445 1446 |
/* * If the module freed .init.text, we couldn't insert * kprobes in there. */ |
f7fa6ef0d
|
1447 1448 1449 1450 1451 |
if (within_module_init((unsigned long)p->addr, *probed_mod) && (*probed_mod)->state != MODULE_STATE_COMING) { module_put(*probed_mod); *probed_mod = NULL; ret = -ENOENT; |
f24659d96
|
1452 |
} |
df019b1d8
|
1453 |
} |
f7fa6ef0d
|
1454 |
out: |
a189d0350
|
1455 |
preempt_enable(); |
de31c3ca8
|
1456 |
jump_label_unlock(); |
1da177e4c
|
1457 |
|
f7fa6ef0d
|
1458 1459 |
return ret; } |
55479f647
|
1460 |
int register_kprobe(struct kprobe *p) |
f7fa6ef0d
|
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 |
{ int ret; struct kprobe *old_p; struct module *probed_mod; kprobe_opcode_t *addr; /* Adjust probe address from symbol */ addr = kprobe_addr(p); if (IS_ERR(addr)) return PTR_ERR(addr); p->addr = addr; ret = check_kprobe_rereg(p); if (ret) return ret; /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ p->flags &= KPROBE_FLAG_DISABLED; |
3516a4604
|
1479 |
p->nmissed = 0; |
9861668f7
|
1480 |
INIT_LIST_HEAD(&p->list); |
afd66255b
|
1481 |
|
f7fa6ef0d
|
1482 1483 1484 1485 1486 |
ret = check_kprobe_address_safe(p, &probed_mod); if (ret) return ret; mutex_lock(&kprobe_mutex); |
afd66255b
|
1487 |
|
64f562c6d
|
1488 1489 |
old_p = get_kprobe(p->addr); if (old_p) { |
afd66255b
|
1490 |
/* Since this may unoptimize old_p, locking text_mutex. */ |
64f562c6d
|
1491 |
ret = register_aggr_kprobe(old_p, p); |
1da177e4c
|
1492 1493 |
goto out; } |
1da177e4c
|
1494 |
|
2d1e38f56
|
1495 1496 1497 |
cpus_read_lock(); /* Prevent text modification */ mutex_lock(&text_mutex); |
ae6aa16fd
|
1498 |
ret = prepare_kprobe(p); |
25764288d
|
1499 |
mutex_unlock(&text_mutex); |
2d1e38f56
|
1500 |
cpus_read_unlock(); |
6f716acd5
|
1501 |
if (ret) |
afd66255b
|
1502 |
goto out; |
49a2a1b83
|
1503 |
|
64f562c6d
|
1504 |
INIT_HLIST_NODE(&p->hlist); |
3516a4604
|
1505 |
hlist_add_head_rcu(&p->hlist, |
1da177e4c
|
1506 |
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
de5bd88d5
|
1507 |
if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
25764288d
|
1508 |
arm_kprobe(p); |
afd66255b
|
1509 1510 1511 |
/* Try to optimize kprobe */ try_to_optimize_kprobe(p); |
1da177e4c
|
1512 |
out: |
7a7d1cf95
|
1513 |
mutex_unlock(&kprobe_mutex); |
49a2a1b83
|
1514 |
|
e8386a0cb
|
1515 |
if (probed_mod) |
df019b1d8
|
1516 |
module_put(probed_mod); |
e8386a0cb
|
1517 |
|
1da177e4c
|
1518 1519 |
return ret; } |
99081ab55
|
1520 |
EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4c
|
1521 |
|
6f0f1dd71
|
1522 |
/* Check if all probes on the aggrprobe are disabled */ |
55479f647
|
1523 |
static int aggr_kprobe_disabled(struct kprobe *ap) |
6f0f1dd71
|
1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 |
{ struct kprobe *kp; list_for_each_entry_rcu(kp, &ap->list, list) if (!kprobe_disabled(kp)) /* * There is an active probe on the list. * We can't disable this ap. */ return 0; return 1; } /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ |
55479f647
|
1539 |
static struct kprobe *__disable_kprobe(struct kprobe *p) |
6f0f1dd71
|
1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 |
{ struct kprobe *orig_p; /* Get an original kprobe for return */ orig_p = __get_valid_kprobe(p); if (unlikely(orig_p == NULL)) return NULL; if (!kprobe_disabled(p)) { /* Disable probe if it is a child probe */ if (p != orig_p) p->flags |= KPROBE_FLAG_DISABLED; /* Try to disarm and disable this/parent probe */ if (p == orig_p || aggr_kprobe_disabled(orig_p)) { |
69d54b916
|
1555 1556 1557 1558 1559 1560 1561 |
/* * If kprobes_all_disarmed is set, orig_p * should have already been disarmed, so * skip unneed disarming process. */ if (!kprobes_all_disarmed) disarm_kprobe(orig_p, true); |
6f0f1dd71
|
1562 1563 1564 1565 1566 1567 |
orig_p->flags |= KPROBE_FLAG_DISABLED; } } return orig_p; } |
de5bd88d5
|
1568 1569 1570 |
/* * Unregister a kprobe without a scheduler synchronization. */ |
55479f647
|
1571 |
static int __unregister_kprobe_top(struct kprobe *p) |
de5bd88d5
|
1572 |
{ |
6d8e40a85
|
1573 |
struct kprobe *ap, *list_p; |
de5bd88d5
|
1574 |
|
6f0f1dd71
|
1575 1576 |
/* Disable kprobe. This will disarm it if needed. */ ap = __disable_kprobe(p); |
6d8e40a85
|
1577 |
if (ap == NULL) |
de5bd88d5
|
1578 |
return -EINVAL; |
6f0f1dd71
|
1579 |
if (ap == p) |
bf8f6e5b3
|
1580 |
/* |
6f0f1dd71
|
1581 1582 |
* This probe is an independent(and non-optimized) kprobe * (not an aggrprobe). Remove from the hash list. |
bf8f6e5b3
|
1583 |
*/ |
6f0f1dd71
|
1584 1585 1586 1587 |
goto disarmed; /* Following process expects this probe is an aggrprobe */ WARN_ON(!kprobe_aggrprobe(ap)); |
6274de498
|
1588 1589 1590 1591 1592 |
if (list_is_singular(&ap->list) && kprobe_disarmed(ap)) /* * !disarmed could be happen if the probe is under delayed * unoptimizing. */ |
6f0f1dd71
|
1593 1594 1595 |
goto disarmed; else { /* If disabling probe has special handlers, update aggrprobe */ |
e8386a0cb
|
1596 |
if (p->break_handler && !kprobe_gone(p)) |
6d8e40a85
|
1597 |
ap->break_handler = NULL; |
e8386a0cb
|
1598 |
if (p->post_handler && !kprobe_gone(p)) { |
6d8e40a85
|
1599 |
list_for_each_entry_rcu(list_p, &ap->list, list) { |
9861668f7
|
1600 1601 1602 |
if ((list_p != p) && (list_p->post_handler)) goto noclean; } |
6d8e40a85
|
1603 |
ap->post_handler = NULL; |
9861668f7
|
1604 1605 |
} noclean: |
6f0f1dd71
|
1606 1607 1608 1609 |
/* * Remove from the aggrprobe: this path will do nothing in * __unregister_kprobe_bottom(). */ |
49a2a1b83
|
1610 |
list_del_rcu(&p->list); |
6f0f1dd71
|
1611 1612 1613 1614 1615 1616 |
if (!kprobe_disabled(ap) && !kprobes_all_disarmed) /* * Try to optimize this probe again, because post * handler may have been changed. */ optimize_kprobe(ap); |
49a2a1b83
|
1617 |
} |
9861668f7
|
1618 |
return 0; |
6f0f1dd71
|
1619 1620 |
disarmed: |
6274de498
|
1621 |
BUG_ON(!kprobe_disarmed(ap)); |
6f0f1dd71
|
1622 1623 |
hlist_del_rcu(&ap->hlist); return 0; |
9861668f7
|
1624 |
} |
3516a4604
|
1625 |
|
55479f647
|
1626 |
static void __unregister_kprobe_bottom(struct kprobe *p) |
9861668f7
|
1627 |
{ |
6d8e40a85
|
1628 |
struct kprobe *ap; |
b3e55c727
|
1629 |
|
e8386a0cb
|
1630 |
if (list_empty(&p->list)) |
6274de498
|
1631 |
/* This is an independent kprobe */ |
0498b6350
|
1632 |
arch_remove_kprobe(p); |
e8386a0cb
|
1633 |
else if (list_is_singular(&p->list)) { |
6274de498
|
1634 |
/* This is the last child of an aggrprobe */ |
6d8e40a85
|
1635 |
ap = list_entry(p->list.next, struct kprobe, list); |
e8386a0cb
|
1636 |
list_del(&p->list); |
6d8e40a85
|
1637 |
free_aggr_kprobe(ap); |
9861668f7
|
1638 |
} |
6274de498
|
1639 |
/* Otherwise, do nothing. */ |
9861668f7
|
1640 |
} |
55479f647
|
1641 |
int register_kprobes(struct kprobe **kps, int num) |
9861668f7
|
1642 1643 1644 1645 1646 1647 |
{ int i, ret = 0; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { |
49ad2fd76
|
1648 |
ret = register_kprobe(kps[i]); |
67dddaad5
|
1649 1650 1651 |
if (ret < 0) { if (i > 0) unregister_kprobes(kps, i); |
9861668f7
|
1652 |
break; |
367216567
|
1653 |
} |
49a2a1b83
|
1654 |
} |
9861668f7
|
1655 1656 |
return ret; } |
99081ab55
|
1657 |
EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f7
|
1658 |
|
55479f647
|
1659 |
void unregister_kprobe(struct kprobe *p) |
9861668f7
|
1660 1661 1662 |
{ unregister_kprobes(&p, 1); } |
99081ab55
|
1663 |
EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f7
|
1664 |
|
55479f647
|
1665 |
void unregister_kprobes(struct kprobe **kps, int num) |
9861668f7
|
1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 |
{ int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(kps[i]) < 0) kps[i]->addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) if (kps[i]->addr) __unregister_kprobe_bottom(kps[i]); |
1da177e4c
|
1681 |
} |
99081ab55
|
1682 |
EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4c
|
1683 |
|
5f6bee347
|
1684 1685 |
int __weak kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) |
fc62d0207
|
1686 1687 1688 |
{ return NOTIFY_DONE; } |
5f6bee347
|
1689 |
NOKPROBE_SYMBOL(kprobe_exceptions_notify); |
fc62d0207
|
1690 |
|
1da177e4c
|
1691 1692 |
static struct notifier_block kprobe_exceptions_nb = { .notifier_call = kprobe_exceptions_notify, |
3d5631e06
|
1693 1694 |
.priority = 0x7fffffff /* we need to be notified first */ }; |
3d7e33825
|
1695 1696 1697 1698 |
unsigned long __weak arch_deref_entry_point(void *entry) { return (unsigned long)entry; } |
1da177e4c
|
1699 |
|
55479f647
|
1700 |
int register_jprobes(struct jprobe **jps, int num) |
1da177e4c
|
1701 |
{ |
26b31c190
|
1702 |
int ret = 0, i; |
3d7e33825
|
1703 |
|
26b31c190
|
1704 |
if (num <= 0) |
3d7e33825
|
1705 |
return -EINVAL; |
0f73ff80b
|
1706 |
|
26b31c190
|
1707 |
for (i = 0; i < num; i++) { |
0f73ff80b
|
1708 |
ret = register_jprobe(jps[i]); |
edbaadbe4
|
1709 |
|
67dddaad5
|
1710 1711 1712 |
if (ret < 0) { if (i > 0) unregister_jprobes(jps, i); |
26b31c190
|
1713 1714 1715 |
break; } } |
0f73ff80b
|
1716 |
|
26b31c190
|
1717 1718 |
return ret; } |
99081ab55
|
1719 |
EXPORT_SYMBOL_GPL(register_jprobes); |
3d7e33825
|
1720 |
|
55479f647
|
1721 |
int register_jprobe(struct jprobe *jp) |
26b31c190
|
1722 |
{ |
0f73ff80b
|
1723 1724 |
unsigned long addr, offset; struct kprobe *kp = &jp->kp; |
dbf580623
|
1725 1726 1727 1728 |
/* * Verify probepoint as well as the jprobe handler are * valid function entry points. */ |
0f73ff80b
|
1729 |
addr = arch_deref_entry_point(jp->entry); |
dbf580623
|
1730 1731 |
if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0 && kprobe_on_func_entry(kp->addr, kp->symbol_name, kp->offset)) { |
0f73ff80b
|
1732 1733 1734 1735 1736 1737 |
kp->pre_handler = setjmp_pre_handler; kp->break_handler = longjmp_break_handler; return register_kprobe(kp); } return -EINVAL; |
1da177e4c
|
1738 |
} |
99081ab55
|
1739 |
EXPORT_SYMBOL_GPL(register_jprobe); |
1da177e4c
|
1740 |
|
55479f647
|
1741 |
void unregister_jprobe(struct jprobe *jp) |
1da177e4c
|
1742 |
{ |
26b31c190
|
1743 1744 |
unregister_jprobes(&jp, 1); } |
99081ab55
|
1745 |
EXPORT_SYMBOL_GPL(unregister_jprobe); |
26b31c190
|
1746 |
|
55479f647
|
1747 |
void unregister_jprobes(struct jprobe **jps, int num) |
26b31c190
|
1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 |
{ int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(&jps[i]->kp) < 0) jps[i]->kp.addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) { if (jps[i]->kp.addr) __unregister_kprobe_bottom(&jps[i]->kp); } |
1da177e4c
|
1764 |
} |
99081ab55
|
1765 |
EXPORT_SYMBOL_GPL(unregister_jprobes); |
1da177e4c
|
1766 |
|
9edddaa20
|
1767 |
#ifdef CONFIG_KRETPROBES |
e65cefe87
|
1768 1769 1770 1771 |
/* * This kprobe pre_handler is registered with every kretprobe. When probe * hits it will set up the return probe. */ |
820aede02
|
1772 |
static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
e65cefe87
|
1773 1774 |
{ struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
ef53d9c5e
|
1775 1776 |
unsigned long hash, flags = 0; struct kretprobe_instance *ri; |
e65cefe87
|
1777 |
|
f96f56780
|
1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 |
/* * To avoid deadlocks, prohibit return probing in NMI contexts, * just skip the probe and increase the (inexact) 'nmissed' * statistical counter, so that the user is informed that * something happened: */ if (unlikely(in_nmi())) { rp->nmissed++; return 0; } /* TODO: consider to only swap the RA after the last pre_handler fired */ |
ef53d9c5e
|
1790 |
hash = hash_ptr(current, KPROBE_HASH_BITS); |
ec484608c
|
1791 |
raw_spin_lock_irqsave(&rp->lock, flags); |
4c4308cb9
|
1792 |
if (!hlist_empty(&rp->free_instances)) { |
4c4308cb9
|
1793 |
ri = hlist_entry(rp->free_instances.first, |
ef53d9c5e
|
1794 1795 |
struct kretprobe_instance, hlist); hlist_del(&ri->hlist); |
ec484608c
|
1796 |
raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5e
|
1797 |
|
4c4308cb9
|
1798 1799 |
ri->rp = rp; ri->task = current; |
f47cd9b55
|
1800 |
|
55ca6140e
|
1801 1802 1803 1804 |
if (rp->entry_handler && rp->entry_handler(ri, regs)) { raw_spin_lock_irqsave(&rp->lock, flags); hlist_add_head(&ri->hlist, &rp->free_instances); raw_spin_unlock_irqrestore(&rp->lock, flags); |
f47cd9b55
|
1805 |
return 0; |
55ca6140e
|
1806 |
} |
f47cd9b55
|
1807 |
|
4c4308cb9
|
1808 1809 1810 |
arch_prepare_kretprobe(ri, regs); /* XXX(hch): why is there no hlist_move_head? */ |
ef53d9c5e
|
1811 1812 1813 1814 1815 |
INIT_HLIST_NODE(&ri->hlist); kretprobe_table_lock(hash, &flags); hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); kretprobe_table_unlock(hash, &flags); } else { |
4c4308cb9
|
1816 |
rp->nmissed++; |
ec484608c
|
1817 |
raw_spin_unlock_irqrestore(&rp->lock, flags); |
ef53d9c5e
|
1818 |
} |
e65cefe87
|
1819 1820 |
return 0; } |
820aede02
|
1821 |
NOKPROBE_SYMBOL(pre_handler_kretprobe); |
e65cefe87
|
1822 |
|
659b957f2
|
1823 |
bool __weak arch_kprobe_on_func_entry(unsigned long offset) |
90ec5e89e
|
1824 1825 1826 |
{ return !offset; } |
659b957f2
|
1827 |
bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset) |
1d585e709
|
1828 1829 1830 1831 1832 1833 1834 |
{ kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset); if (IS_ERR(kp_addr)) return false; if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) || |
659b957f2
|
1835 |
!arch_kprobe_on_func_entry(offset)) |
1d585e709
|
1836 1837 1838 1839 |
return false; return true; } |
55479f647
|
1840 |
int register_kretprobe(struct kretprobe *rp) |
b94cce926
|
1841 1842 1843 1844 |
{ int ret = 0; struct kretprobe_instance *inst; int i; |
b2a5cd693
|
1845 |
void *addr; |
90ec5e89e
|
1846 |
|
659b957f2
|
1847 |
if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset)) |
90ec5e89e
|
1848 |
return -EINVAL; |
f438d914b
|
1849 1850 |
if (kretprobe_blacklist_size) { |
b2a5cd693
|
1851 |
addr = kprobe_addr(&rp->kp); |
bc81d48d1
|
1852 1853 |
if (IS_ERR(addr)) return PTR_ERR(addr); |
f438d914b
|
1854 1855 1856 1857 1858 1859 |
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { if (kretprobe_blacklist[i].addr == addr) return -EINVAL; } } |
b94cce926
|
1860 1861 |
rp->kp.pre_handler = pre_handler_kretprobe; |
7522a8423
|
1862 1863 1864 |
rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; rp->kp.break_handler = NULL; |
b94cce926
|
1865 1866 1867 1868 |
/* Pre-allocate memory for max kretprobe instances */ if (rp->maxactive <= 0) { #ifdef CONFIG_PREEMPT |
c2ef6661c
|
1869 |
rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
b94cce926
|
1870 |
#else |
4dae560f9
|
1871 |
rp->maxactive = num_possible_cpus(); |
b94cce926
|
1872 1873 |
#endif } |
ec484608c
|
1874 |
raw_spin_lock_init(&rp->lock); |
b94cce926
|
1875 1876 |
INIT_HLIST_HEAD(&rp->free_instances); for (i = 0; i < rp->maxactive; i++) { |
f47cd9b55
|
1877 1878 |
inst = kmalloc(sizeof(struct kretprobe_instance) + rp->data_size, GFP_KERNEL); |
b94cce926
|
1879 1880 1881 1882 |
if (inst == NULL) { free_rp_inst(rp); return -ENOMEM; } |
ef53d9c5e
|
1883 1884 |
INIT_HLIST_NODE(&inst->hlist); hlist_add_head(&inst->hlist, &rp->free_instances); |
b94cce926
|
1885 1886 1887 1888 |
} rp->nmissed = 0; /* Establish function entry probe point */ |
49ad2fd76
|
1889 |
ret = register_kprobe(&rp->kp); |
4a296e07c
|
1890 |
if (ret != 0) |
b94cce926
|
1891 1892 1893 |
free_rp_inst(rp); return ret; } |
99081ab55
|
1894 |
EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce926
|
1895 |
|
55479f647
|
1896 |
int register_kretprobes(struct kretprobe **rps, int num) |
4a296e07c
|
1897 1898 1899 1900 1901 1902 |
{ int ret = 0, i; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { |
49ad2fd76
|
1903 |
ret = register_kretprobe(rps[i]); |
67dddaad5
|
1904 1905 1906 |
if (ret < 0) { if (i > 0) unregister_kretprobes(rps, i); |
4a296e07c
|
1907 1908 1909 1910 1911 |
break; } } return ret; } |
99081ab55
|
1912 |
EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07c
|
1913 |
|
55479f647
|
1914 |
void unregister_kretprobe(struct kretprobe *rp) |
4a296e07c
|
1915 1916 1917 |
{ unregister_kretprobes(&rp, 1); } |
99081ab55
|
1918 |
EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07c
|
1919 |
|
55479f647
|
1920 |
void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07c
|
1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 |
{ int i; if (num <= 0) return; mutex_lock(&kprobe_mutex); for (i = 0; i < num; i++) if (__unregister_kprobe_top(&rps[i]->kp) < 0) rps[i]->kp.addr = NULL; mutex_unlock(&kprobe_mutex); synchronize_sched(); for (i = 0; i < num; i++) { if (rps[i]->kp.addr) { __unregister_kprobe_bottom(&rps[i]->kp); cleanup_rp_inst(rps[i]); } } } |
99081ab55
|
1940 |
EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07c
|
1941 |
|
9edddaa20
|
1942 |
#else /* CONFIG_KRETPROBES */ |
55479f647
|
1943 |
int register_kretprobe(struct kretprobe *rp) |
b94cce926
|
1944 1945 1946 |
{ return -ENOSYS; } |
99081ab55
|
1947 |
EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce926
|
1948 |
|
55479f647
|
1949 |
int register_kretprobes(struct kretprobe **rps, int num) |
346fd59ba
|
1950 |
{ |
4a296e07c
|
1951 |
return -ENOSYS; |
346fd59ba
|
1952 |
} |
99081ab55
|
1953 |
EXPORT_SYMBOL_GPL(register_kretprobes); |
55479f647
|
1954 |
void unregister_kretprobe(struct kretprobe *rp) |
b94cce926
|
1955 |
{ |
4a296e07c
|
1956 |
} |
99081ab55
|
1957 |
EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce926
|
1958 |
|
55479f647
|
1959 |
void unregister_kretprobes(struct kretprobe **rps, int num) |
4a296e07c
|
1960 1961 |
{ } |
99081ab55
|
1962 |
EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb9
|
1963 |
|
820aede02
|
1964 |
static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) |
4a296e07c
|
1965 1966 |
{ return 0; |
b94cce926
|
1967 |
} |
820aede02
|
1968 |
NOKPROBE_SYMBOL(pre_handler_kretprobe); |
b94cce926
|
1969 |
|
4a296e07c
|
1970 |
#endif /* CONFIG_KRETPROBES */ |
e8386a0cb
|
1971 |
/* Set the kprobe gone and remove its instruction buffer. */ |
55479f647
|
1972 |
static void kill_kprobe(struct kprobe *p) |
e8386a0cb
|
1973 1974 |
{ struct kprobe *kp; |
de5bd88d5
|
1975 |
|
e8386a0cb
|
1976 |
p->flags |= KPROBE_FLAG_GONE; |
afd66255b
|
1977 |
if (kprobe_aggrprobe(p)) { |
e8386a0cb
|
1978 1979 1980 1981 1982 1983 1984 1985 |
/* * If this is an aggr_kprobe, we have to list all the * chained probes and mark them GONE. */ list_for_each_entry_rcu(kp, &p->list, list) kp->flags |= KPROBE_FLAG_GONE; p->post_handler = NULL; p->break_handler = NULL; |
afd66255b
|
1986 |
kill_optimized_kprobe(p); |
e8386a0cb
|
1987 1988 1989 1990 1991 1992 1993 |
} /* * Here, we can remove insn_slot safely, because no thread calls * the original probed function (which will be freed soon) any more. */ arch_remove_kprobe(p); } |
c0614829c
|
1994 |
/* Disable one kprobe */ |
55479f647
|
1995 |
int disable_kprobe(struct kprobe *kp) |
c0614829c
|
1996 1997 |
{ int ret = 0; |
c0614829c
|
1998 1999 |
mutex_lock(&kprobe_mutex); |
6f0f1dd71
|
2000 2001 |
/* Disable this kprobe */ if (__disable_kprobe(kp) == NULL) |
c0614829c
|
2002 |
ret = -EINVAL; |
c0614829c
|
2003 |
|
c0614829c
|
2004 2005 2006 2007 2008 2009 |
mutex_unlock(&kprobe_mutex); return ret; } EXPORT_SYMBOL_GPL(disable_kprobe); /* Enable one kprobe */ |
55479f647
|
2010 |
int enable_kprobe(struct kprobe *kp) |
c0614829c
|
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 |
{ int ret = 0; struct kprobe *p; mutex_lock(&kprobe_mutex); /* Check whether specified probe is valid. */ p = __get_valid_kprobe(kp); if (unlikely(p == NULL)) { ret = -EINVAL; goto out; } if (kprobe_gone(kp)) { /* This kprobe has gone, we couldn't enable it. */ ret = -EINVAL; goto out; } if (p != kp) kp->flags &= ~KPROBE_FLAG_DISABLED; if (!kprobes_all_disarmed && kprobe_disabled(p)) { p->flags &= ~KPROBE_FLAG_DISABLED; arm_kprobe(p); } out: mutex_unlock(&kprobe_mutex); return ret; } EXPORT_SYMBOL_GPL(enable_kprobe); |
820aede02
|
2042 |
void dump_kprobe(struct kprobe *kp) |
24851d244
|
2043 2044 2045 2046 2047 2048 2049 2050 2051 |
{ printk(KERN_WARNING "Dumping kprobe: "); printk(KERN_WARNING "Name: %s Address: %p Offset: %x ", kp->symbol_name, kp->addr, kp->offset); } |
820aede02
|
2052 |
NOKPROBE_SYMBOL(dump_kprobe); |
24851d244
|
2053 |
|
376e24242
|
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 |
/* * Lookup and populate the kprobe_blacklist. * * Unlike the kretprobe blacklist, we'll need to determine * the range of addresses that belong to the said functions, * since a kprobe need not necessarily be at the beginning * of a function. */ static int __init populate_kprobe_blacklist(unsigned long *start, unsigned long *end) { unsigned long *iter; struct kprobe_blacklist_entry *ent; |
d81b4253b
|
2067 |
unsigned long entry, offset = 0, size = 0; |
376e24242
|
2068 2069 |
for (iter = start; iter < end; iter++) { |
d81b4253b
|
2070 2071 2072 2073 2074 2075 2076 |
entry = arch_deref_entry_point((void *)*iter); if (!kernel_text_address(entry) || !kallsyms_lookup_size_offset(entry, &size, &offset)) { pr_err("Failed to find blacklist at %p ", (void *)entry); |
376e24242
|
2077 2078 2079 2080 2081 2082 |
continue; } ent = kmalloc(sizeof(*ent), GFP_KERNEL); if (!ent) return -ENOMEM; |
d81b4253b
|
2083 2084 |
ent->start_addr = entry; ent->end_addr = entry + size; |
376e24242
|
2085 2086 2087 2088 2089 |
INIT_LIST_HEAD(&ent->list); list_add_tail(&ent->list, &kprobe_blacklist); } return 0; } |
e8386a0cb
|
2090 |
/* Module notifier call back, checking kprobes on the module */ |
55479f647
|
2091 2092 |
static int kprobes_module_callback(struct notifier_block *nb, unsigned long val, void *data) |
e8386a0cb
|
2093 2094 2095 |
{ struct module *mod = data; struct hlist_head *head; |
e8386a0cb
|
2096 2097 |
struct kprobe *p; unsigned int i; |
f24659d96
|
2098 |
int checkcore = (val == MODULE_STATE_GOING); |
e8386a0cb
|
2099 |
|
f24659d96
|
2100 |
if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0cb
|
2101 2102 2103 |
return NOTIFY_DONE; /* |
f24659d96
|
2104 2105 2106 2107 |
* When MODULE_STATE_GOING was notified, both of module .text and * .init.text sections would be freed. When MODULE_STATE_LIVE was * notified, only .init.text section would be freed. We need to * disable kprobes which have been inserted in the sections. |
e8386a0cb
|
2108 2109 2110 2111 |
*/ mutex_lock(&kprobe_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; |
b67bfe0d4
|
2112 |
hlist_for_each_entry_rcu(p, head, hlist) |
f24659d96
|
2113 2114 2115 |
if (within_module_init((unsigned long)p->addr, mod) || (checkcore && within_module_core((unsigned long)p->addr, mod))) { |
e8386a0cb
|
2116 2117 2118 2119 |
/* * The vaddr this probe is installed will soon * be vfreed buy not synced to disk. Hence, * disarming the breakpoint isn't needed. |
545a02819
|
2120 2121 2122 2123 2124 2125 |
* * Note, this will also move any optimized probes * that are pending to be removed from their * corresponding lists to the freeing_list and * will not be touched by the delayed * kprobe_optimizer work handler. |
e8386a0cb
|
2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 |
*/ kill_kprobe(p); } } mutex_unlock(&kprobe_mutex); return NOTIFY_DONE; } static struct notifier_block kprobe_module_nb = { .notifier_call = kprobes_module_callback, .priority = 0 }; |
376e24242
|
2138 2139 2140 |
/* Markers of _kprobe_blacklist section */ extern unsigned long __start_kprobe_blacklist[]; extern unsigned long __stop_kprobe_blacklist[]; |
1da177e4c
|
2141 2142 2143 2144 2145 2146 |
static int __init init_kprobes(void) { int i, err = 0; /* FIXME allocate the probe table, currently defined statically */ /* initialize all list heads */ |
b94cce926
|
2147 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4c
|
2148 |
INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce926
|
2149 |
INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ec484608c
|
2150 |
raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce926
|
2151 |
} |
1da177e4c
|
2152 |
|
376e24242
|
2153 2154 2155 2156 2157 2158 2159 |
err = populate_kprobe_blacklist(__start_kprobe_blacklist, __stop_kprobe_blacklist); if (err) { pr_err("kprobes: failed to populate blacklist: %d ", err); pr_err("Please take care of using kprobes. "); |
3d8d996e0
|
2160 |
} |
f438d914b
|
2161 2162 2163 |
if (kretprobe_blacklist_size) { /* lookup the function address from its name */ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { |
49e0b4658
|
2164 |
kretprobe_blacklist[i].addr = |
290e30707
|
2165 |
kprobe_lookup_name(kretprobe_blacklist[i].name, 0); |
f438d914b
|
2166 2167 2168 2169 2170 2171 |
if (!kretprobe_blacklist[i].addr) printk("kretprobe: lookup failed: %s ", kretprobe_blacklist[i].name); } } |
b2be84df9
|
2172 2173 |
#if defined(CONFIG_OPTPROBES) #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) |
afd66255b
|
2174 2175 2176 |
/* Init kprobe_optinsn_slots */ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; #endif |
b2be84df9
|
2177 2178 2179 |
/* By default, kprobes can be optimized */ kprobes_allow_optimization = true; #endif |
afd66255b
|
2180 |
|
e579abeb5
|
2181 2182 |
/* By default, kprobes are armed */ kprobes_all_disarmed = false; |
bf8f6e5b3
|
2183 |
|
6772926be
|
2184 |
err = arch_init_kprobes(); |
802eae7c8
|
2185 2186 |
if (!err) err = register_die_notifier(&kprobe_exceptions_nb); |
e8386a0cb
|
2187 2188 |
if (!err) err = register_module_notifier(&kprobe_module_nb); |
ef53d9c5e
|
2189 |
kprobes_initialized = (err == 0); |
802eae7c8
|
2190 |
|
8c1c93564
|
2191 2192 |
if (!err) init_test_probes(); |
1da177e4c
|
2193 2194 |
return err; } |
346fd59ba
|
2195 |
#ifdef CONFIG_DEBUG_FS |
55479f647
|
2196 |
static void report_probe(struct seq_file *pi, struct kprobe *p, |
afd66255b
|
2197 |
const char *sym, int offset, char *modname, struct kprobe *pp) |
346fd59ba
|
2198 2199 2200 2201 2202 2203 2204 2205 2206 |
{ char *kprobe_type; if (p->pre_handler == pre_handler_kretprobe) kprobe_type = "r"; else if (p->pre_handler == setjmp_pre_handler) kprobe_type = "j"; else kprobe_type = "k"; |
afd66255b
|
2207 |
|
346fd59ba
|
2208 |
if (sym) |
afd66255b
|
2209 |
seq_printf(pi, "%p %s %s+0x%x %s ", |
de5bd88d5
|
2210 |
p->addr, kprobe_type, sym, offset, |
afd66255b
|
2211 |
(modname ? modname : " ")); |
346fd59ba
|
2212 |
else |
afd66255b
|
2213 2214 2215 2216 2217 |
seq_printf(pi, "%p %s %p ", p->addr, kprobe_type, p->addr); if (!pp) pp = p; |
ae6aa16fd
|
2218 2219 |
seq_printf(pi, "%s%s%s%s ", |
afd66255b
|
2220 2221 |
(kprobe_gone(p) ? "[GONE]" : ""), ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), |
ae6aa16fd
|
2222 2223 |
(kprobe_optimized(pp) ? "[OPTIMIZED]" : ""), (kprobe_ftrace(pp) ? "[FTRACE]" : "")); |
346fd59ba
|
2224 |
} |
55479f647
|
2225 |
static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
346fd59ba
|
2226 2227 2228 |
{ return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; } |
55479f647
|
2229 |
static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) |
346fd59ba
|
2230 2231 2232 2233 2234 2235 |
{ (*pos)++; if (*pos >= KPROBE_TABLE_SIZE) return NULL; return pos; } |
55479f647
|
2236 |
static void kprobe_seq_stop(struct seq_file *f, void *v) |
346fd59ba
|
2237 2238 2239 |
{ /* Nothing to do */ } |
55479f647
|
2240 |
static int show_kprobe_addr(struct seq_file *pi, void *v) |
346fd59ba
|
2241 2242 |
{ struct hlist_head *head; |
346fd59ba
|
2243 2244 2245 |
struct kprobe *p, *kp; const char *sym = NULL; unsigned int i = *(loff_t *) v; |
ffb451227
|
2246 |
unsigned long offset = 0; |
ab7678656
|
2247 |
char *modname, namebuf[KSYM_NAME_LEN]; |
346fd59ba
|
2248 2249 2250 |
head = &kprobe_table[i]; preempt_disable(); |
b67bfe0d4
|
2251 |
hlist_for_each_entry_rcu(p, head, hlist) { |
ffb451227
|
2252 |
sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59ba
|
2253 |
&offset, &modname, namebuf); |
afd66255b
|
2254 |
if (kprobe_aggrprobe(p)) { |
346fd59ba
|
2255 |
list_for_each_entry_rcu(kp, &p->list, list) |
afd66255b
|
2256 |
report_probe(pi, kp, sym, offset, modname, p); |
346fd59ba
|
2257 |
} else |
afd66255b
|
2258 |
report_probe(pi, p, sym, offset, modname, NULL); |
346fd59ba
|
2259 2260 2261 2262 |
} preempt_enable(); return 0; } |
88e9d34c7
|
2263 |
static const struct seq_operations kprobes_seq_ops = { |
346fd59ba
|
2264 2265 2266 2267 2268 |
.start = kprobe_seq_start, .next = kprobe_seq_next, .stop = kprobe_seq_stop, .show = show_kprobe_addr }; |
55479f647
|
2269 |
static int kprobes_open(struct inode *inode, struct file *filp) |
346fd59ba
|
2270 2271 2272 |
{ return seq_open(filp, &kprobes_seq_ops); } |
828c09509
|
2273 |
static const struct file_operations debugfs_kprobes_operations = { |
346fd59ba
|
2274 2275 2276 2277 2278 |
.open = kprobes_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; |
637247403
|
2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 |
/* kprobes/blacklist -- shows which functions can not be probed */ static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) { return seq_list_start(&kprobe_blacklist, *pos); } static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) { return seq_list_next(v, &kprobe_blacklist, pos); } static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) { struct kprobe_blacklist_entry *ent = list_entry(v, struct kprobe_blacklist_entry, list); seq_printf(m, "0x%p-0x%p\t%ps ", (void *)ent->start_addr, (void *)ent->end_addr, (void *)ent->start_addr); return 0; } static const struct seq_operations kprobe_blacklist_seq_ops = { .start = kprobe_blacklist_seq_start, .next = kprobe_blacklist_seq_next, .stop = kprobe_seq_stop, /* Reuse void function */ .show = kprobe_blacklist_seq_show, }; static int kprobe_blacklist_open(struct inode *inode, struct file *filp) { return seq_open(filp, &kprobe_blacklist_seq_ops); } static const struct file_operations debugfs_kprobe_blacklist_ops = { .open = kprobe_blacklist_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; |
55479f647
|
2319 |
static void arm_all_kprobes(void) |
bf8f6e5b3
|
2320 2321 |
{ struct hlist_head *head; |
bf8f6e5b3
|
2322 2323 2324 2325 |
struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); |
e579abeb5
|
2326 2327 |
/* If kprobes are armed, just return */ if (!kprobes_all_disarmed) |
bf8f6e5b3
|
2328 |
goto already_enabled; |
977ad481b
|
2329 2330 2331 2332 2333 2334 |
/* * optimize_kprobe() called by arm_kprobe() checks * kprobes_all_disarmed, so set kprobes_all_disarmed before * arm_kprobe. */ kprobes_all_disarmed = false; |
afd66255b
|
2335 |
/* Arming kprobes doesn't optimize kprobe itself */ |
bf8f6e5b3
|
2336 2337 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; |
b67bfe0d4
|
2338 |
hlist_for_each_entry_rcu(p, head, hlist) |
de5bd88d5
|
2339 |
if (!kprobe_disabled(p)) |
ae6aa16fd
|
2340 |
arm_kprobe(p); |
bf8f6e5b3
|
2341 |
} |
bf8f6e5b3
|
2342 2343 2344 2345 2346 2347 2348 |
printk(KERN_INFO "Kprobes globally enabled "); already_enabled: mutex_unlock(&kprobe_mutex); return; } |
55479f647
|
2349 |
static void disarm_all_kprobes(void) |
bf8f6e5b3
|
2350 2351 |
{ struct hlist_head *head; |
bf8f6e5b3
|
2352 2353 2354 2355 |
struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); |
e579abeb5
|
2356 |
/* If kprobes are already disarmed, just return */ |
6274de498
|
2357 2358 2359 2360 |
if (kprobes_all_disarmed) { mutex_unlock(&kprobe_mutex); return; } |
bf8f6e5b3
|
2361 |
|
e579abeb5
|
2362 |
kprobes_all_disarmed = true; |
bf8f6e5b3
|
2363 2364 |
printk(KERN_INFO "Kprobes globally disabled "); |
afd66255b
|
2365 |
|
bf8f6e5b3
|
2366 2367 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; |
b67bfe0d4
|
2368 |
hlist_for_each_entry_rcu(p, head, hlist) { |
de5bd88d5
|
2369 |
if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
ae6aa16fd
|
2370 |
disarm_kprobe(p, false); |
bf8f6e5b3
|
2371 2372 |
} } |
bf8f6e5b3
|
2373 |
mutex_unlock(&kprobe_mutex); |
bf8f6e5b3
|
2374 |
|
6274de498
|
2375 2376 |
/* Wait for disarming all kprobes by optimizer */ wait_for_kprobe_optimizer(); |
bf8f6e5b3
|
2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 |
} /* * XXX: The debugfs bool file interface doesn't allow for callbacks * when the bool state is switched. We can reuse that facility when * available */ static ssize_t read_enabled_file_bool(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { char buf[3]; |
e579abeb5
|
2388 |
if (!kprobes_all_disarmed) |
bf8f6e5b3
|
2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 |
buf[0] = '1'; else buf[0] = '0'; buf[1] = ' '; buf[2] = 0x00; return simple_read_from_buffer(user_buf, count, ppos, buf, 2); } static ssize_t write_enabled_file_bool(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { char buf[32]; |
efeb156e7
|
2402 |
size_t buf_size; |
bf8f6e5b3
|
2403 2404 2405 2406 |
buf_size = min(count, (sizeof(buf)-1)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; |
10fb46d5f
|
2407 |
buf[buf_size] = '\0'; |
bf8f6e5b3
|
2408 2409 2410 2411 |
switch (buf[0]) { case 'y': case 'Y': case '1': |
e579abeb5
|
2412 |
arm_all_kprobes(); |
bf8f6e5b3
|
2413 2414 2415 2416 |
break; case 'n': case 'N': case '0': |
e579abeb5
|
2417 |
disarm_all_kprobes(); |
bf8f6e5b3
|
2418 |
break; |
10fb46d5f
|
2419 2420 |
default: return -EINVAL; |
bf8f6e5b3
|
2421 2422 2423 2424 |
} return count; } |
828c09509
|
2425 |
static const struct file_operations fops_kp = { |
bf8f6e5b3
|
2426 2427 |
.read = read_enabled_file_bool, .write = write_enabled_file_bool, |
6038f373a
|
2428 |
.llseek = default_llseek, |
bf8f6e5b3
|
2429 |
}; |
55479f647
|
2430 |
static int __init debugfs_kprobe_init(void) |
346fd59ba
|
2431 2432 |
{ struct dentry *dir, *file; |
bf8f6e5b3
|
2433 |
unsigned int value = 1; |
346fd59ba
|
2434 2435 2436 2437 |
dir = debugfs_create_dir("kprobes", NULL); if (!dir) return -ENOMEM; |
e38697929
|
2438 |
file = debugfs_create_file("list", 0444, dir, NULL, |
346fd59ba
|
2439 |
&debugfs_kprobes_operations); |
637247403
|
2440 2441 |
if (!file) goto error; |
346fd59ba
|
2442 |
|
bf8f6e5b3
|
2443 2444 |
file = debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); |
637247403
|
2445 2446 2447 2448 2449 2450 2451 |
if (!file) goto error; file = debugfs_create_file("blacklist", 0444, dir, NULL, &debugfs_kprobe_blacklist_ops); if (!file) goto error; |
bf8f6e5b3
|
2452 |
|
346fd59ba
|
2453 |
return 0; |
637247403
|
2454 2455 2456 2457 |
error: debugfs_remove(dir); return -ENOMEM; |
346fd59ba
|
2458 2459 2460 2461 2462 2463 |
} late_initcall(debugfs_kprobe_init); #endif /* CONFIG_DEBUG_FS */ module_init(init_kprobes); |
1da177e4c
|
2464 |
|
99081ab55
|
2465 |
/* defined in arch/.../kernel/kprobes.c */ |
1da177e4c
|
2466 |
EXPORT_SYMBOL_GPL(jprobe_return); |