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kernel/kprobes.c
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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/module.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 <asm-generic/sections.h> |
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#include <asm/cacheflush.h> #include <asm/errno.h> |
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#include <asm/uaccess.h> |
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#define KPROBE_HASH_BITS 6 #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) |
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/* * Some oddball architectures like 64bit powerpc have function descriptors * so this must be overridable. */ #ifndef kprobe_lookup_name #define kprobe_lookup_name(name, addr) \ addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) #endif |
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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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static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ |
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static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; |
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static struct { |
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spinlock_t lock ____cacheline_aligned_in_smp; |
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} kretprobe_table_locks[KPROBE_TABLE_SIZE]; static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) { return &(kretprobe_table_locks[hash].lock); } |
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/* * Normally, functions that we'd want to prohibit kprobes in, are marked * __kprobes. But, there are cases where such functions already belong to * a different section (__sched for preempt_schedule) * * For such cases, we now have a blacklist */ |
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static struct kprobe_blackpoint kprobe_blacklist[] = { |
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{"preempt_schedule",}, |
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{"native_get_debugreg",}, |
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{"irq_entries_start",}, {"common_interrupt",}, |
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{"mcount",}, /* mcount can be called from everywhere */ |
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{NULL} /* Terminator */ }; |
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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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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))) struct kprobe_insn_cache { struct list_head pages; /* list of kprobe_insn_page */ size_t insn_size; /* size of instruction slot */ int nr_garbage; }; 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 DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */ static struct kprobe_insn_cache kprobe_insn_slots = { .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages), .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, }; static int __kprobes 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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static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) |
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{ struct kprobe_insn_page *kip; |
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retry: |
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list_for_each_entry(kip, &c->pages, list) { 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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return kip->insns + (i * c->insn_size); |
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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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/* 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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return NULL; |
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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. */ kip->insns = module_alloc(PAGE_SIZE); if (!kip->insns) { kfree(kip); return NULL; } |
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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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list_add(&kip->list, &c->pages); |
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return kip->insns; } |
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kprobe_opcode_t __kprobes *get_insn_slot(void) { |
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kprobe_opcode_t *ret = NULL; |
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mutex_lock(&kprobe_insn_mutex); |
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ret = __get_insn_slot(&kprobe_insn_slots); |
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mutex_unlock(&kprobe_insn_mutex); |
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return ret; } |
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/* Return 1 if all garbages are collected, otherwise 0. */ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) { |
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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(&kip->list); |
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module_free(NULL, kip->insns); kfree(kip); } return 1; } return 0; } |
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static int __kprobes 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 && |
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collect_one_slot(kip, i)) break; } } |
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c->nr_garbage = 0; |
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return 0; } |
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static void __kprobes __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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list_for_each_entry(kip, &c->pages, list) { |
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long idx = ((long)slot - (long)kip->insns) / (c->insn_size * sizeof(kprobe_opcode_t)); |
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if (idx >= 0 && idx < slots_per_page(c)) { WARN_ON(kip->slot_used[idx] != SLOT_USED); |
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if (dirty) { |
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kip->slot_used[idx] = SLOT_DIRTY; |
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kip->ngarbage++; |
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if (++c->nr_garbage > slots_per_page(c)) collect_garbage_slots(c); |
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} else |
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collect_one_slot(kip, idx); return; |
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} } |
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/* Could not free this slot. */ WARN_ON(1); } |
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void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) { mutex_lock(&kprobe_insn_mutex); __free_insn_slot(&kprobe_insn_slots, slot, dirty); |
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mutex_unlock(&kprobe_insn_mutex); |
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} |
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#ifdef CONFIG_OPTPROBES /* For optimized_kprobe buffer */ static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */ static struct kprobe_insn_cache kprobe_optinsn_slots = { .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), /* .insn_size is initialized later */ .nr_garbage = 0, }; /* Get a slot for optimized_kprobe buffer */ kprobe_opcode_t __kprobes *get_optinsn_slot(void) { kprobe_opcode_t *ret = NULL; mutex_lock(&kprobe_optinsn_mutex); ret = __get_insn_slot(&kprobe_optinsn_slots); mutex_unlock(&kprobe_optinsn_mutex); return ret; } void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty) { mutex_lock(&kprobe_optinsn_mutex); __free_insn_slot(&kprobe_optinsn_slots, slot, dirty); mutex_unlock(&kprobe_optinsn_mutex); } #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) { __get_cpu_var(kprobe_instance) = kp; } static inline void reset_kprobe_instance(void) { __get_cpu_var(kprobe_instance) = NULL; } |
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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 __kprobes *get_kprobe(void *addr) |
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{ struct hlist_head *head; struct hlist_node *node; |
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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, node, head, hlist) { |
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if (p->addr == addr) return p; } |
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return NULL; } |
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static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); /* Return true if the kprobe is an aggregator */ static inline int kprobe_aggrprobe(struct kprobe *p) { return p->pre_handler == aggr_pre_handler; } /* * Keep all fields in the kprobe consistent */ static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) { memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); } #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. */ void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs) { 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(); } } /* 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; } /* * Return an optimized kprobe whose optimizing code replaces * instructions including addr (exclude breakpoint). */ struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr) { 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); static void kprobe_optimizer(struct work_struct *work); static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); #define OPTIMIZE_DELAY 5 /* Kprobe jump optimizer */ static __kprobes void kprobe_optimizer(struct work_struct *work) { struct optimized_kprobe *op, *tmp; /* Lock modules while optimizing kprobes */ mutex_lock(&module_mutex); mutex_lock(&kprobe_mutex); |
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if (kprobes_all_disarmed || !kprobes_allow_optimization) |
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goto end; /* * Wait for quiesence period to ensure all running interrupts * 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(); /* * 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) * To avoid this deadlock, we need to call get_online_cpus() * for preventing cpu-hotplug outside of text_mutex locking. */ get_online_cpus(); mutex_lock(&text_mutex); list_for_each_entry_safe(op, tmp, &optimizing_list, list) { WARN_ON(kprobe_disabled(&op->kp)); if (arch_optimize_kprobe(op) < 0) op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; list_del_init(&op->list); } mutex_unlock(&text_mutex); put_online_cpus(); end: mutex_unlock(&kprobe_mutex); mutex_unlock(&module_mutex); } /* Optimize kprobe if p is ready to be optimized */ static __kprobes void optimize_kprobe(struct kprobe *p) { struct optimized_kprobe *op; /* Check if the kprobe is disabled or not ready for optimization. */ |
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if (!kprobe_optready(p) || !kprobes_allow_optimization || |
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(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; op->kp.flags |= KPROBE_FLAG_OPTIMIZED; list_add(&op->list, &optimizing_list); if (!delayed_work_pending(&optimizing_work)) schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); } /* Unoptimize a kprobe if p is optimized */ static __kprobes void unoptimize_kprobe(struct kprobe *p) { struct optimized_kprobe *op; if ((p->flags & KPROBE_FLAG_OPTIMIZED) && kprobe_aggrprobe(p)) { op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) /* Dequeue from the optimization queue */ list_del_init(&op->list); else /* Replace jump with break */ arch_unoptimize_kprobe(op); op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; } } /* Remove optimized instructions */ static void __kprobes kill_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); if (!list_empty(&op->list)) { /* Dequeue from the optimization queue */ list_del_init(&op->list); op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; } /* Don't unoptimize, because the target code will be freed. */ arch_remove_optimized_kprobe(op); } /* Try to prepare optimized instructions */ static __kprobes void prepare_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); arch_prepare_optimized_kprobe(op); } /* Free optimized instructions and optimized_kprobe */ static __kprobes void free_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; op = container_of(p, struct optimized_kprobe, kp); arch_remove_optimized_kprobe(op); kfree(op); } /* Allocate new optimized_kprobe and try to prepare optimized instructions */ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { 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; arch_prepare_optimized_kprobe(op); return &op->kp; } static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); /* * Prepare an optimized_kprobe and optimize it * NOTE: p must be a normal registered kprobe */ static __kprobes void try_to_optimize_kprobe(struct kprobe *p) { struct kprobe *ap; struct optimized_kprobe *op; ap = alloc_aggr_kprobe(p); if (!ap) return; op = container_of(ap, struct optimized_kprobe, kp); if (!arch_prepared_optinsn(&op->optinsn)) { /* If failed to setup optimizing, fallback to kprobe */ free_aggr_kprobe(ap); return; } init_aggr_kprobe(ap, p); optimize_kprobe(ap); } |
b2be84df9
|
580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 |
#ifdef CONFIG_SYSCTL static void __kprobes optimize_all_kprobes(void) { struct hlist_head *head; struct hlist_node *node; struct kprobe *p; unsigned int i; /* If optimization is already allowed, just return */ if (kprobes_allow_optimization) return; kprobes_allow_optimization = true; mutex_lock(&text_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) if (!kprobe_disabled(p)) optimize_kprobe(p); } mutex_unlock(&text_mutex); printk(KERN_INFO "Kprobes globally optimized "); } static void __kprobes unoptimize_all_kprobes(void) { struct hlist_head *head; struct hlist_node *node; struct kprobe *p; unsigned int i; /* If optimization is already prohibited, just return */ if (!kprobes_allow_optimization) return; kprobes_allow_optimization = false; printk(KERN_INFO "Kprobes globally unoptimized "); get_online_cpus(); /* For avoiding text_mutex deadlock */ mutex_lock(&text_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) { if (!kprobe_disabled(p)) unoptimize_kprobe(p); } } mutex_unlock(&text_mutex); put_online_cpus(); /* Allow all currently running kprobes to complete */ synchronize_sched(); } 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; mutex_lock(&kprobe_mutex); 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(); mutex_unlock(&kprobe_mutex); return ret; } #endif /* CONFIG_SYSCTL */ |
afd66255b
|
655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 |
static void __kprobes __arm_kprobe(struct kprobe *p) { struct kprobe *old_p; /* Check collision with other optimized kprobes */ old_p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(old_p)) unoptimize_kprobe(old_p); /* Fallback to unoptimized kprobe */ arch_arm_kprobe(p); optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ } static void __kprobes __disarm_kprobe(struct kprobe *p) { struct kprobe *old_p; unoptimize_kprobe(p); /* Try to unoptimize */ arch_disarm_kprobe(p); /* If another kprobe was blocked, optimize it. */ old_p = get_optimized_kprobe((unsigned long)p->addr); if (unlikely(old_p)) optimize_kprobe(old_p); } #else /* !CONFIG_OPTPROBES */ #define optimize_kprobe(p) do {} while (0) #define unoptimize_kprobe(p) do {} while (0) #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) #define __disarm_kprobe(p) arch_disarm_kprobe(p) static __kprobes void free_aggr_kprobe(struct kprobe *p) { kfree(p); } static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { return kzalloc(sizeof(struct kprobe), GFP_KERNEL); } #endif /* CONFIG_OPTPROBES */ |
201517a7f
|
701 702 703 |
/* Arm a kprobe with text_mutex */ static void __kprobes arm_kprobe(struct kprobe *kp) { |
afd66255b
|
704 705 706 707 708 |
/* * Here, since __arm_kprobe() doesn't use stop_machine(), * this doesn't cause deadlock on text_mutex. So, we don't * need get_online_cpus(). */ |
201517a7f
|
709 |
mutex_lock(&text_mutex); |
afd66255b
|
710 |
__arm_kprobe(kp); |
201517a7f
|
711 712 713 714 715 716 |
mutex_unlock(&text_mutex); } /* Disarm a kprobe with text_mutex */ static void __kprobes disarm_kprobe(struct kprobe *kp) { |
afd66255b
|
717 |
get_online_cpus(); /* For avoiding text_mutex deadlock */ |
201517a7f
|
718 |
mutex_lock(&text_mutex); |
afd66255b
|
719 |
__disarm_kprobe(kp); |
201517a7f
|
720 |
mutex_unlock(&text_mutex); |
afd66255b
|
721 |
put_online_cpus(); |
201517a7f
|
722 |
} |
64f562c6d
|
723 724 725 726 |
/* * Aggregate handlers for multiple kprobes support - these handlers * take care of invoking the individual kprobe handlers on p->list */ |
d0aaff979
|
727 |
static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) |
64f562c6d
|
728 729 |
{ struct kprobe *kp; |
3516a4604
|
730 |
list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d5
|
731 |
if (kp->pre_handler && likely(!kprobe_disabled(kp))) { |
e65845235
|
732 |
set_kprobe_instance(kp); |
8b0914ea7
|
733 734 |
if (kp->pre_handler(kp, regs)) return 1; |
64f562c6d
|
735 |
} |
e65845235
|
736 |
reset_kprobe_instance(); |
64f562c6d
|
737 738 739 |
} return 0; } |
d0aaff979
|
740 741 |
static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, unsigned long flags) |
64f562c6d
|
742 743 |
{ struct kprobe *kp; |
3516a4604
|
744 |
list_for_each_entry_rcu(kp, &p->list, list) { |
de5bd88d5
|
745 |
if (kp->post_handler && likely(!kprobe_disabled(kp))) { |
e65845235
|
746 |
set_kprobe_instance(kp); |
64f562c6d
|
747 |
kp->post_handler(kp, regs, flags); |
e65845235
|
748 |
reset_kprobe_instance(); |
64f562c6d
|
749 750 |
} } |
64f562c6d
|
751 |
} |
d0aaff979
|
752 753 |
static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, int trapnr) |
64f562c6d
|
754 |
{ |
e65845235
|
755 |
struct kprobe *cur = __get_cpu_var(kprobe_instance); |
64f562c6d
|
756 757 758 759 |
/* * if we faulted "during" the execution of a user specified * probe handler, invoke just that probe's fault handler */ |
e65845235
|
760 761 |
if (cur && cur->fault_handler) { if (cur->fault_handler(cur, regs, trapnr)) |
64f562c6d
|
762 763 764 765 |
return 1; } return 0; } |
d0aaff979
|
766 |
static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) |
8b0914ea7
|
767 |
{ |
e65845235
|
768 769 770 771 772 773 |
struct kprobe *cur = __get_cpu_var(kprobe_instance); int ret = 0; if (cur && cur->break_handler) { if (cur->break_handler(cur, regs)) ret = 1; |
8b0914ea7
|
774 |
} |
e65845235
|
775 776 |
reset_kprobe_instance(); return ret; |
8b0914ea7
|
777 |
} |
bf8d5c52c
|
778 779 780 781 |
/* Walks the list and increments nmissed count for multiprobe case */ void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) { struct kprobe *kp; |
afd66255b
|
782 |
if (!kprobe_aggrprobe(p)) { |
bf8d5c52c
|
783 784 785 786 787 788 789 |
p->nmissed++; } else { list_for_each_entry_rcu(kp, &p->list, list) kp->nmissed++; } return; } |
99219a3fb
|
790 791 |
void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head) |
b94cce926
|
792 |
{ |
ef53d9c5e
|
793 |
struct kretprobe *rp = ri->rp; |
b94cce926
|
794 795 |
/* remove rp inst off the rprobe_inst_table */ hlist_del(&ri->hlist); |
ef53d9c5e
|
796 797 798 799 800 |
INIT_HLIST_NODE(&ri->hlist); if (likely(rp)) { spin_lock(&rp->lock); hlist_add_head(&ri->hlist, &rp->free_instances); spin_unlock(&rp->lock); |
b94cce926
|
801 802 |
} else /* Unregistering */ |
99219a3fb
|
803 |
hlist_add_head(&ri->hlist, head); |
b94cce926
|
804 |
} |
017c39bdb
|
805 |
void __kprobes kretprobe_hash_lock(struct task_struct *tsk, |
ef53d9c5e
|
806 807 808 809 810 811 812 813 814 |
struct hlist_head **head, unsigned long *flags) { unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); spinlock_t *hlist_lock; *head = &kretprobe_inst_table[hash]; hlist_lock = kretprobe_table_lock_ptr(hash); spin_lock_irqsave(hlist_lock, *flags); } |
017c39bdb
|
815 816 |
static void __kprobes kretprobe_table_lock(unsigned long hash, unsigned long *flags) |
b94cce926
|
817 |
{ |
ef53d9c5e
|
818 819 820 |
spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); spin_lock_irqsave(hlist_lock, *flags); } |
017c39bdb
|
821 822 |
void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags) |
ef53d9c5e
|
823 824 825 826 827 828 829 |
{ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); spinlock_t *hlist_lock; hlist_lock = kretprobe_table_lock_ptr(hash); spin_unlock_irqrestore(hlist_lock, *flags); } |
017c39bdb
|
830 |
void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags) |
ef53d9c5e
|
831 832 833 |
{ spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); spin_unlock_irqrestore(hlist_lock, *flags); |
b94cce926
|
834 |
} |
b94cce926
|
835 |
/* |
c6fd91f0b
|
836 837 838 839 |
* 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
|
840 |
*/ |
d0aaff979
|
841 |
void __kprobes kprobe_flush_task(struct task_struct *tk) |
b94cce926
|
842 |
{ |
62c27be0d
|
843 |
struct kretprobe_instance *ri; |
99219a3fb
|
844 |
struct hlist_head *head, empty_rp; |
802eae7c8
|
845 |
struct hlist_node *node, *tmp; |
ef53d9c5e
|
846 |
unsigned long hash, flags = 0; |
802eae7c8
|
847 |
|
ef53d9c5e
|
848 849 850 851 852 853 854 |
if (unlikely(!kprobes_initialized)) /* Early boot. kretprobe_table_locks not yet initialized. */ return; hash = hash_ptr(tk, KPROBE_HASH_BITS); head = &kretprobe_inst_table[hash]; kretprobe_table_lock(hash, &flags); |
62c27be0d
|
855 856 |
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task == tk) |
99219a3fb
|
857 |
recycle_rp_inst(ri, &empty_rp); |
62c27be0d
|
858 |
} |
ef53d9c5e
|
859 860 |
kretprobe_table_unlock(hash, &flags); INIT_HLIST_HEAD(&empty_rp); |
99219a3fb
|
861 862 863 864 |
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); } |
b94cce926
|
865 |
} |
b94cce926
|
866 867 868 |
static inline void free_rp_inst(struct kretprobe *rp) { struct kretprobe_instance *ri; |
4c4308cb9
|
869 |
struct hlist_node *pos, *next; |
ef53d9c5e
|
870 871 |
hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { hlist_del(&ri->hlist); |
b94cce926
|
872 873 874 |
kfree(ri); } } |
4a296e07c
|
875 876 |
static void __kprobes cleanup_rp_inst(struct kretprobe *rp) { |
ef53d9c5e
|
877 |
unsigned long flags, hash; |
4a296e07c
|
878 879 |
struct kretprobe_instance *ri; struct hlist_node *pos, *next; |
ef53d9c5e
|
880 |
struct hlist_head *head; |
4a296e07c
|
881 |
/* No race here */ |
ef53d9c5e
|
882 883 884 885 886 887 888 889 |
for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { kretprobe_table_lock(hash, &flags); head = &kretprobe_inst_table[hash]; hlist_for_each_entry_safe(ri, pos, next, head, hlist) { if (ri->rp == rp) ri->rp = NULL; } kretprobe_table_unlock(hash, &flags); |
4a296e07c
|
890 |
} |
4a296e07c
|
891 892 |
free_rp_inst(rp); } |
64f562c6d
|
893 |
/* |
b918e5e60
|
894 |
* Add the new probe to ap->list. Fail if this is the |
8b0914ea7
|
895 896 |
* second jprobe at the address - two jprobes can't coexist */ |
b918e5e60
|
897 |
static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
8b0914ea7
|
898 |
{ |
de5bd88d5
|
899 |
BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
afd66255b
|
900 901 902 |
if (p->break_handler || p->post_handler) unoptimize_kprobe(ap); /* Fall back to normal kprobe */ |
8b0914ea7
|
903 |
if (p->break_handler) { |
b918e5e60
|
904 |
if (ap->break_handler) |
367216567
|
905 |
return -EEXIST; |
b918e5e60
|
906 907 |
list_add_tail_rcu(&p->list, &ap->list); ap->break_handler = aggr_break_handler; |
8b0914ea7
|
908 |
} else |
b918e5e60
|
909 910 911 |
list_add_rcu(&p->list, &ap->list); if (p->post_handler && !ap->post_handler) ap->post_handler = aggr_post_handler; |
de5bd88d5
|
912 913 914 915 916 |
if (kprobe_disabled(ap) && !kprobe_disabled(p)) { ap->flags &= ~KPROBE_FLAG_DISABLED; if (!kprobes_all_disarmed) /* Arm the breakpoint again. */ |
afd66255b
|
917 |
__arm_kprobe(ap); |
de5bd88d5
|
918 |
} |
8b0914ea7
|
919 920 921 922 |
return 0; } /* |
64f562c6d
|
923 924 925 |
* Fill in the required fields of the "manager kprobe". Replace the * earlier kprobe in the hlist with the manager kprobe */ |
afd66255b
|
926 |
static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
64f562c6d
|
927 |
{ |
afd66255b
|
928 |
/* Copy p's insn slot to ap */ |
8b0914ea7
|
929 |
copy_kprobe(p, ap); |
a9ad965ea
|
930 |
flush_insn_slot(ap); |
64f562c6d
|
931 |
ap->addr = p->addr; |
afd66255b
|
932 |
ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
64f562c6d
|
933 |
ap->pre_handler = aggr_pre_handler; |
64f562c6d
|
934 |
ap->fault_handler = aggr_fault_handler; |
e8386a0cb
|
935 936 |
/* We don't care the kprobe which has gone. */ if (p->post_handler && !kprobe_gone(p)) |
367216567
|
937 |
ap->post_handler = aggr_post_handler; |
e8386a0cb
|
938 |
if (p->break_handler && !kprobe_gone(p)) |
367216567
|
939 |
ap->break_handler = aggr_break_handler; |
64f562c6d
|
940 941 |
INIT_LIST_HEAD(&ap->list); |
afd66255b
|
942 |
INIT_HLIST_NODE(&ap->hlist); |
64f562c6d
|
943 |
|
afd66255b
|
944 |
list_add_rcu(&p->list, &ap->list); |
adad0f331
|
945 |
hlist_replace_rcu(&p->hlist, &ap->hlist); |
64f562c6d
|
946 947 948 949 950 |
} /* * This is the second or subsequent kprobe at the address - handle * the intricacies |
64f562c6d
|
951 |
*/ |
d0aaff979
|
952 953 |
static int __kprobes register_aggr_kprobe(struct kprobe *old_p, struct kprobe *p) |
64f562c6d
|
954 955 |
{ int ret = 0; |
b918e5e60
|
956 |
struct kprobe *ap = old_p; |
64f562c6d
|
957 |
|
afd66255b
|
958 959 960 |
if (!kprobe_aggrprobe(old_p)) { /* If old_p is not an aggr_kprobe, create new aggr_kprobe. */ ap = alloc_aggr_kprobe(old_p); |
b918e5e60
|
961 962 |
if (!ap) return -ENOMEM; |
afd66255b
|
963 |
init_aggr_kprobe(ap, old_p); |
b918e5e60
|
964 965 966 |
} if (kprobe_gone(ap)) { |
e8386a0cb
|
967 968 969 970 971 972 |
/* * 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
|
973 |
ret = arch_prepare_kprobe(ap); |
e8386a0cb
|
974 |
if (ret) |
b918e5e60
|
975 976 977 978 979 |
/* * 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. */ |
e8386a0cb
|
980 |
return ret; |
de5bd88d5
|
981 |
|
afd66255b
|
982 983 |
/* Prepare optimized instructions if possible. */ prepare_optimized_kprobe(ap); |
e8386a0cb
|
984 |
/* |
de5bd88d5
|
985 986 |
* Clear gone flag to prevent allocating new slot again, and * set disabled flag because it is not armed yet. |
e8386a0cb
|
987 |
*/ |
de5bd88d5
|
988 989 |
ap->flags = (ap->flags & ~KPROBE_FLAG_GONE) | KPROBE_FLAG_DISABLED; |
e8386a0cb
|
990 |
} |
b918e5e60
|
991 |
|
afd66255b
|
992 |
/* Copy ap's insn slot to p */ |
b918e5e60
|
993 994 |
copy_kprobe(ap, p); return add_new_kprobe(ap, p); |
64f562c6d
|
995 |
} |
de5bd88d5
|
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 |
/* Try to disable aggr_kprobe, and return 1 if succeeded.*/ static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) { struct kprobe *kp; list_for_each_entry_rcu(kp, &p->list, list) { if (!kprobe_disabled(kp)) /* * There is an active probe on the list. * We can't disable aggr_kprobe. */ return 0; } p->flags |= KPROBE_FLAG_DISABLED; return 1; } |
d0aaff979
|
1012 1013 |
static int __kprobes in_kprobes_functions(unsigned long addr) { |
3d8d996e0
|
1014 |
struct kprobe_blackpoint *kb; |
6f716acd5
|
1015 1016 |
if (addr >= (unsigned long)__kprobes_text_start && addr < (unsigned long)__kprobes_text_end) |
d0aaff979
|
1017 |
return -EINVAL; |
3d8d996e0
|
1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 |
/* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area */ for (kb = kprobe_blacklist; kb->name != NULL; kb++) { if (kb->start_addr) { if (addr >= kb->start_addr && addr < (kb->start_addr + kb->range)) return -EINVAL; } } |
d0aaff979
|
1029 1030 |
return 0; } |
b2a5cd693
|
1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 |
/* * 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. */ static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) { kprobe_opcode_t *addr = p->addr; if (p->symbol_name) { if (addr) return NULL; kprobe_lookup_name(p->symbol_name, addr); } if (!addr) return NULL; return (kprobe_opcode_t *)(((char *)addr) + p->offset); } |
1f0ab4097
|
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 |
/* Check passed kprobe is valid and return kprobe in kprobe_table. */ static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) { struct kprobe *old_p, *list_p; old_p = get_kprobe(p->addr); if (unlikely(!old_p)) return NULL; if (p != old_p) { list_for_each_entry_rcu(list_p, &old_p->list, list) if (list_p == p) /* kprobe p is a valid probe */ goto valid; return NULL; } valid: return old_p; } /* Return error if the kprobe is being re-registered */ static inline int check_kprobe_rereg(struct kprobe *p) { int ret = 0; struct kprobe *old_p; mutex_lock(&kprobe_mutex); old_p = __get_valid_kprobe(p); if (old_p) ret = -EINVAL; mutex_unlock(&kprobe_mutex); return ret; } |
49ad2fd76
|
1081 |
int __kprobes register_kprobe(struct kprobe *p) |
1da177e4c
|
1082 1083 |
{ int ret = 0; |
64f562c6d
|
1084 |
struct kprobe *old_p; |
df019b1d8
|
1085 |
struct module *probed_mod; |
b2a5cd693
|
1086 |
kprobe_opcode_t *addr; |
b3e55c727
|
1087 |
|
b2a5cd693
|
1088 1089 |
addr = kprobe_addr(p); if (!addr) |
3a872d89b
|
1090 |
return -EINVAL; |
b2a5cd693
|
1091 |
p->addr = addr; |
3a872d89b
|
1092 |
|
1f0ab4097
|
1093 1094 1095 |
ret = check_kprobe_rereg(p); if (ret) return ret; |
a189d0350
|
1096 |
preempt_disable(); |
ec30c5f3a
|
1097 |
if (!kernel_text_address((unsigned long) p->addr) || |
4554dbcb8
|
1098 1099 |
in_kprobes_functions((unsigned long) p->addr) || ftrace_text_reserved(p->addr, p->addr)) { |
a189d0350
|
1100 |
preempt_enable(); |
b3e55c727
|
1101 |
return -EINVAL; |
a189d0350
|
1102 |
} |
b3e55c727
|
1103 |
|
de5bd88d5
|
1104 1105 |
/* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ p->flags &= KPROBE_FLAG_DISABLED; |
6f716acd5
|
1106 1107 1108 |
/* * Check if are we probing a module. */ |
a189d0350
|
1109 |
probed_mod = __module_text_address((unsigned long) p->addr); |
6f716acd5
|
1110 |
if (probed_mod) { |
6f716acd5
|
1111 |
/* |
e8386a0cb
|
1112 1113 |
* We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. |
df019b1d8
|
1114 |
*/ |
49ad2fd76
|
1115 1116 1117 1118 |
if (unlikely(!try_module_get(probed_mod))) { preempt_enable(); return -EINVAL; } |
f24659d96
|
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 |
/* * If the module freed .init.text, we couldn't insert * kprobes in there. */ if (within_module_init((unsigned long)p->addr, probed_mod) && probed_mod->state != MODULE_STATE_COMING) { module_put(probed_mod); preempt_enable(); return -EINVAL; } |
df019b1d8
|
1129 |
} |
a189d0350
|
1130 |
preempt_enable(); |
1da177e4c
|
1131 |
|
3516a4604
|
1132 |
p->nmissed = 0; |
9861668f7
|
1133 |
INIT_LIST_HEAD(&p->list); |
7a7d1cf95
|
1134 |
mutex_lock(&kprobe_mutex); |
afd66255b
|
1135 1136 1137 |
get_online_cpus(); /* For avoiding text_mutex deadlock. */ mutex_lock(&text_mutex); |
64f562c6d
|
1138 1139 |
old_p = get_kprobe(p->addr); if (old_p) { |
afd66255b
|
1140 |
/* Since this may unoptimize old_p, locking text_mutex. */ |
64f562c6d
|
1141 |
ret = register_aggr_kprobe(old_p, p); |
1da177e4c
|
1142 1143 |
goto out; } |
1da177e4c
|
1144 |
|
6f716acd5
|
1145 1146 |
ret = arch_prepare_kprobe(p); if (ret) |
afd66255b
|
1147 |
goto out; |
49a2a1b83
|
1148 |
|
64f562c6d
|
1149 |
INIT_HLIST_NODE(&p->hlist); |
3516a4604
|
1150 |
hlist_add_head_rcu(&p->hlist, |
1da177e4c
|
1151 |
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
de5bd88d5
|
1152 |
if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
afd66255b
|
1153 1154 1155 1156 |
__arm_kprobe(p); /* Try to optimize kprobe */ try_to_optimize_kprobe(p); |
74a0b5762
|
1157 |
|
1da177e4c
|
1158 |
out: |
afd66255b
|
1159 1160 |
mutex_unlock(&text_mutex); put_online_cpus(); |
7a7d1cf95
|
1161 |
mutex_unlock(&kprobe_mutex); |
49a2a1b83
|
1162 |
|
e8386a0cb
|
1163 |
if (probed_mod) |
df019b1d8
|
1164 |
module_put(probed_mod); |
e8386a0cb
|
1165 |
|
1da177e4c
|
1166 1167 |
return ret; } |
99081ab55
|
1168 |
EXPORT_SYMBOL_GPL(register_kprobe); |
1da177e4c
|
1169 |
|
de5bd88d5
|
1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 |
/* * Unregister a kprobe without a scheduler synchronization. */ static int __kprobes __unregister_kprobe_top(struct kprobe *p) { struct kprobe *old_p, *list_p; old_p = __get_valid_kprobe(p); if (old_p == NULL) return -EINVAL; |
6f716acd5
|
1180 |
if (old_p == p || |
afd66255b
|
1181 |
(kprobe_aggrprobe(old_p) && |
9861668f7
|
1182 |
list_is_singular(&old_p->list))) { |
bf8f6e5b3
|
1183 1184 |
/* * Only probe on the hash list. Disarm only if kprobes are |
e8386a0cb
|
1185 1186 |
* enabled and not gone - otherwise, the breakpoint would * already have been removed. We save on flushing icache. |
bf8f6e5b3
|
1187 |
*/ |
201517a7f
|
1188 |
if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
afd66255b
|
1189 |
disarm_kprobe(old_p); |
49a2a1b83
|
1190 |
hlist_del_rcu(&old_p->hlist); |
49a2a1b83
|
1191 |
} else { |
e8386a0cb
|
1192 |
if (p->break_handler && !kprobe_gone(p)) |
9861668f7
|
1193 |
old_p->break_handler = NULL; |
e8386a0cb
|
1194 |
if (p->post_handler && !kprobe_gone(p)) { |
9861668f7
|
1195 1196 1197 1198 1199 1200 1201 |
list_for_each_entry_rcu(list_p, &old_p->list, list) { if ((list_p != p) && (list_p->post_handler)) goto noclean; } old_p->post_handler = NULL; } noclean: |
49a2a1b83
|
1202 |
list_del_rcu(&p->list); |
de5bd88d5
|
1203 1204 |
if (!kprobe_disabled(old_p)) { try_to_disable_aggr_kprobe(old_p); |
afd66255b
|
1205 1206 1207 1208 1209 1210 1211 |
if (!kprobes_all_disarmed) { if (kprobe_disabled(old_p)) disarm_kprobe(old_p); else /* Try to optimize this probe again */ optimize_kprobe(old_p); } |
de5bd88d5
|
1212 |
} |
49a2a1b83
|
1213 |
} |
9861668f7
|
1214 1215 |
return 0; } |
3516a4604
|
1216 |
|
9861668f7
|
1217 1218 |
static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) { |
9861668f7
|
1219 |
struct kprobe *old_p; |
b3e55c727
|
1220 |
|
e8386a0cb
|
1221 |
if (list_empty(&p->list)) |
0498b6350
|
1222 |
arch_remove_kprobe(p); |
e8386a0cb
|
1223 1224 1225 1226 1227 |
else if (list_is_singular(&p->list)) { /* "p" is the last child of an aggr_kprobe */ old_p = list_entry(p->list.next, struct kprobe, list); list_del(&p->list); arch_remove_kprobe(old_p); |
afd66255b
|
1228 |
free_aggr_kprobe(old_p); |
9861668f7
|
1229 1230 |
} } |
49ad2fd76
|
1231 |
int __kprobes register_kprobes(struct kprobe **kps, int num) |
9861668f7
|
1232 1233 1234 1235 1236 1237 |
{ int i, ret = 0; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { |
49ad2fd76
|
1238 |
ret = register_kprobe(kps[i]); |
67dddaad5
|
1239 1240 1241 |
if (ret < 0) { if (i > 0) unregister_kprobes(kps, i); |
9861668f7
|
1242 |
break; |
367216567
|
1243 |
} |
49a2a1b83
|
1244 |
} |
9861668f7
|
1245 1246 |
return ret; } |
99081ab55
|
1247 |
EXPORT_SYMBOL_GPL(register_kprobes); |
9861668f7
|
1248 |
|
9861668f7
|
1249 1250 1251 1252 |
void __kprobes unregister_kprobe(struct kprobe *p) { unregister_kprobes(&p, 1); } |
99081ab55
|
1253 |
EXPORT_SYMBOL_GPL(unregister_kprobe); |
9861668f7
|
1254 |
|
9861668f7
|
1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 |
void __kprobes unregister_kprobes(struct kprobe **kps, int num) { 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
|
1271 |
} |
99081ab55
|
1272 |
EXPORT_SYMBOL_GPL(unregister_kprobes); |
1da177e4c
|
1273 1274 1275 |
static struct notifier_block kprobe_exceptions_nb = { .notifier_call = kprobe_exceptions_notify, |
3d5631e06
|
1276 1277 |
.priority = 0x7fffffff /* we need to be notified first */ }; |
3d7e33825
|
1278 1279 1280 1281 |
unsigned long __weak arch_deref_entry_point(void *entry) { return (unsigned long)entry; } |
1da177e4c
|
1282 |
|
49ad2fd76
|
1283 |
int __kprobes register_jprobes(struct jprobe **jps, int num) |
1da177e4c
|
1284 |
{ |
26b31c190
|
1285 1286 |
struct jprobe *jp; int ret = 0, i; |
3d7e33825
|
1287 |
|
26b31c190
|
1288 |
if (num <= 0) |
3d7e33825
|
1289 |
return -EINVAL; |
26b31c190
|
1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 |
for (i = 0; i < num; i++) { unsigned long addr; jp = jps[i]; addr = arch_deref_entry_point(jp->entry); if (!kernel_text_address(addr)) ret = -EINVAL; else { /* Todo: Verify probepoint is a function entry point */ jp->kp.pre_handler = setjmp_pre_handler; jp->kp.break_handler = longjmp_break_handler; |
49ad2fd76
|
1301 |
ret = register_kprobe(&jp->kp); |
26b31c190
|
1302 |
} |
67dddaad5
|
1303 1304 1305 |
if (ret < 0) { if (i > 0) unregister_jprobes(jps, i); |
26b31c190
|
1306 1307 1308 1309 1310 |
break; } } return ret; } |
99081ab55
|
1311 |
EXPORT_SYMBOL_GPL(register_jprobes); |
3d7e33825
|
1312 |
|
26b31c190
|
1313 1314 |
int __kprobes register_jprobe(struct jprobe *jp) { |
49ad2fd76
|
1315 |
return register_jprobes(&jp, 1); |
1da177e4c
|
1316 |
} |
99081ab55
|
1317 |
EXPORT_SYMBOL_GPL(register_jprobe); |
1da177e4c
|
1318 |
|
d0aaff979
|
1319 |
void __kprobes unregister_jprobe(struct jprobe *jp) |
1da177e4c
|
1320 |
{ |
26b31c190
|
1321 1322 |
unregister_jprobes(&jp, 1); } |
99081ab55
|
1323 |
EXPORT_SYMBOL_GPL(unregister_jprobe); |
26b31c190
|
1324 |
|
26b31c190
|
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 |
void __kprobes unregister_jprobes(struct jprobe **jps, int num) { 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
|
1342 |
} |
99081ab55
|
1343 |
EXPORT_SYMBOL_GPL(unregister_jprobes); |
1da177e4c
|
1344 |
|
9edddaa20
|
1345 |
#ifdef CONFIG_KRETPROBES |
e65cefe87
|
1346 1347 1348 1349 1350 1351 1352 1353 |
/* * This kprobe pre_handler is registered with every kretprobe. When probe * hits it will set up the return probe. */ static int __kprobes pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { struct kretprobe *rp = container_of(p, struct kretprobe, kp); |
ef53d9c5e
|
1354 1355 |
unsigned long hash, flags = 0; struct kretprobe_instance *ri; |
e65cefe87
|
1356 1357 |
/*TODO: consider to only swap the RA after the last pre_handler fired */ |
ef53d9c5e
|
1358 1359 |
hash = hash_ptr(current, KPROBE_HASH_BITS); spin_lock_irqsave(&rp->lock, flags); |
4c4308cb9
|
1360 |
if (!hlist_empty(&rp->free_instances)) { |
4c4308cb9
|
1361 |
ri = hlist_entry(rp->free_instances.first, |
ef53d9c5e
|
1362 1363 1364 |
struct kretprobe_instance, hlist); hlist_del(&ri->hlist); spin_unlock_irqrestore(&rp->lock, flags); |
4c4308cb9
|
1365 1366 |
ri->rp = rp; ri->task = current; |
f47cd9b55
|
1367 |
|
f02b8624f
|
1368 |
if (rp->entry_handler && rp->entry_handler(ri, regs)) |
f47cd9b55
|
1369 |
return 0; |
f47cd9b55
|
1370 |
|
4c4308cb9
|
1371 1372 1373 |
arch_prepare_kretprobe(ri, regs); /* XXX(hch): why is there no hlist_move_head? */ |
ef53d9c5e
|
1374 1375 1376 1377 1378 |
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
|
1379 |
rp->nmissed++; |
ef53d9c5e
|
1380 1381 |
spin_unlock_irqrestore(&rp->lock, flags); } |
e65cefe87
|
1382 1383 |
return 0; } |
49ad2fd76
|
1384 |
int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce926
|
1385 1386 1387 1388 |
{ int ret = 0; struct kretprobe_instance *inst; int i; |
b2a5cd693
|
1389 |
void *addr; |
f438d914b
|
1390 1391 |
if (kretprobe_blacklist_size) { |
b2a5cd693
|
1392 1393 1394 |
addr = kprobe_addr(&rp->kp); if (!addr) return -EINVAL; |
f438d914b
|
1395 1396 1397 1398 1399 1400 |
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { if (kretprobe_blacklist[i].addr == addr) return -EINVAL; } } |
b94cce926
|
1401 1402 |
rp->kp.pre_handler = pre_handler_kretprobe; |
7522a8423
|
1403 1404 1405 |
rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; rp->kp.break_handler = NULL; |
b94cce926
|
1406 1407 1408 1409 |
/* Pre-allocate memory for max kretprobe instances */ if (rp->maxactive <= 0) { #ifdef CONFIG_PREEMPT |
c2ef6661c
|
1410 |
rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus()); |
b94cce926
|
1411 |
#else |
4dae560f9
|
1412 |
rp->maxactive = num_possible_cpus(); |
b94cce926
|
1413 1414 |
#endif } |
ef53d9c5e
|
1415 |
spin_lock_init(&rp->lock); |
b94cce926
|
1416 1417 |
INIT_HLIST_HEAD(&rp->free_instances); for (i = 0; i < rp->maxactive; i++) { |
f47cd9b55
|
1418 1419 |
inst = kmalloc(sizeof(struct kretprobe_instance) + rp->data_size, GFP_KERNEL); |
b94cce926
|
1420 1421 1422 1423 |
if (inst == NULL) { free_rp_inst(rp); return -ENOMEM; } |
ef53d9c5e
|
1424 1425 |
INIT_HLIST_NODE(&inst->hlist); hlist_add_head(&inst->hlist, &rp->free_instances); |
b94cce926
|
1426 1427 1428 1429 |
} rp->nmissed = 0; /* Establish function entry probe point */ |
49ad2fd76
|
1430 |
ret = register_kprobe(&rp->kp); |
4a296e07c
|
1431 |
if (ret != 0) |
b94cce926
|
1432 1433 1434 |
free_rp_inst(rp); return ret; } |
99081ab55
|
1435 |
EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce926
|
1436 |
|
49ad2fd76
|
1437 |
int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
4a296e07c
|
1438 1439 1440 1441 1442 1443 |
{ int ret = 0, i; if (num <= 0) return -EINVAL; for (i = 0; i < num; i++) { |
49ad2fd76
|
1444 |
ret = register_kretprobe(rps[i]); |
67dddaad5
|
1445 1446 1447 |
if (ret < 0) { if (i > 0) unregister_kretprobes(rps, i); |
4a296e07c
|
1448 1449 1450 1451 1452 |
break; } } return ret; } |
99081ab55
|
1453 |
EXPORT_SYMBOL_GPL(register_kretprobes); |
4a296e07c
|
1454 |
|
4a296e07c
|
1455 1456 1457 1458 |
void __kprobes unregister_kretprobe(struct kretprobe *rp) { unregister_kretprobes(&rp, 1); } |
99081ab55
|
1459 |
EXPORT_SYMBOL_GPL(unregister_kretprobe); |
4a296e07c
|
1460 |
|
4a296e07c
|
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 |
void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) { 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
|
1481 |
EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4a296e07c
|
1482 |
|
9edddaa20
|
1483 |
#else /* CONFIG_KRETPROBES */ |
d0aaff979
|
1484 |
int __kprobes register_kretprobe(struct kretprobe *rp) |
b94cce926
|
1485 1486 1487 |
{ return -ENOSYS; } |
99081ab55
|
1488 |
EXPORT_SYMBOL_GPL(register_kretprobe); |
b94cce926
|
1489 |
|
4a296e07c
|
1490 |
int __kprobes register_kretprobes(struct kretprobe **rps, int num) |
346fd59ba
|
1491 |
{ |
4a296e07c
|
1492 |
return -ENOSYS; |
346fd59ba
|
1493 |
} |
99081ab55
|
1494 |
EXPORT_SYMBOL_GPL(register_kretprobes); |
d0aaff979
|
1495 |
void __kprobes unregister_kretprobe(struct kretprobe *rp) |
b94cce926
|
1496 |
{ |
4a296e07c
|
1497 |
} |
99081ab55
|
1498 |
EXPORT_SYMBOL_GPL(unregister_kretprobe); |
b94cce926
|
1499 |
|
4a296e07c
|
1500 1501 1502 |
void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) { } |
99081ab55
|
1503 |
EXPORT_SYMBOL_GPL(unregister_kretprobes); |
4c4308cb9
|
1504 |
|
4a296e07c
|
1505 1506 1507 1508 |
static int __kprobes pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { return 0; |
b94cce926
|
1509 |
} |
4a296e07c
|
1510 |
#endif /* CONFIG_KRETPROBES */ |
e8386a0cb
|
1511 1512 1513 1514 |
/* Set the kprobe gone and remove its instruction buffer. */ static void __kprobes kill_kprobe(struct kprobe *p) { struct kprobe *kp; |
de5bd88d5
|
1515 |
|
e8386a0cb
|
1516 |
p->flags |= KPROBE_FLAG_GONE; |
afd66255b
|
1517 |
if (kprobe_aggrprobe(p)) { |
e8386a0cb
|
1518 1519 1520 1521 1522 1523 1524 1525 |
/* * 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
|
1526 |
kill_optimized_kprobe(p); |
e8386a0cb
|
1527 1528 1529 1530 1531 1532 1533 |
} /* * 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); } |
24851d244
|
1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 |
void __kprobes dump_kprobe(struct kprobe *kp) { printk(KERN_WARNING "Dumping kprobe: "); printk(KERN_WARNING "Name: %s Address: %p Offset: %x ", kp->symbol_name, kp->addr, kp->offset); } |
e8386a0cb
|
1544 1545 1546 1547 1548 1549 1550 1551 1552 |
/* Module notifier call back, checking kprobes on the module */ static int __kprobes kprobes_module_callback(struct notifier_block *nb, unsigned long val, void *data) { struct module *mod = data; struct hlist_head *head; struct hlist_node *node; struct kprobe *p; unsigned int i; |
f24659d96
|
1553 |
int checkcore = (val == MODULE_STATE_GOING); |
e8386a0cb
|
1554 |
|
f24659d96
|
1555 |
if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) |
e8386a0cb
|
1556 1557 1558 |
return NOTIFY_DONE; /* |
f24659d96
|
1559 1560 1561 1562 |
* 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
|
1563 1564 1565 1566 1567 |
*/ mutex_lock(&kprobe_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) |
f24659d96
|
1568 1569 1570 |
if (within_module_init((unsigned long)p->addr, mod) || (checkcore && within_module_core((unsigned long)p->addr, mod))) { |
e8386a0cb
|
1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 |
/* * The vaddr this probe is installed will soon * be vfreed buy not synced to disk. Hence, * disarming the breakpoint isn't needed. */ kill_kprobe(p); } } mutex_unlock(&kprobe_mutex); return NOTIFY_DONE; } static struct notifier_block kprobe_module_nb = { .notifier_call = kprobes_module_callback, .priority = 0 }; |
1da177e4c
|
1587 1588 1589 |
static int __init init_kprobes(void) { int i, err = 0; |
3d8d996e0
|
1590 1591 1592 1593 1594 |
unsigned long offset = 0, size = 0; char *modname, namebuf[128]; const char *symbol_name; void *addr; struct kprobe_blackpoint *kb; |
1da177e4c
|
1595 1596 1597 |
/* FIXME allocate the probe table, currently defined statically */ /* initialize all list heads */ |
b94cce926
|
1598 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1da177e4c
|
1599 |
INIT_HLIST_HEAD(&kprobe_table[i]); |
b94cce926
|
1600 |
INIT_HLIST_HEAD(&kretprobe_inst_table[i]); |
ef53d9c5e
|
1601 |
spin_lock_init(&(kretprobe_table_locks[i].lock)); |
b94cce926
|
1602 |
} |
1da177e4c
|
1603 |
|
3d8d996e0
|
1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 |
/* * 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. */ for (kb = kprobe_blacklist; kb->name != NULL; kb++) { kprobe_lookup_name(kb->name, addr); if (!addr) continue; kb->start_addr = (unsigned long)addr; symbol_name = kallsyms_lookup(kb->start_addr, &size, &offset, &modname, namebuf); if (!symbol_name) kb->range = 0; else kb->range = size; } |
f438d914b
|
1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 |
if (kretprobe_blacklist_size) { /* lookup the function address from its name */ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { kprobe_lookup_name(kretprobe_blacklist[i].name, kretprobe_blacklist[i].addr); if (!kretprobe_blacklist[i].addr) printk("kretprobe: lookup failed: %s ", kretprobe_blacklist[i].name); } } |
b2be84df9
|
1636 1637 |
#if defined(CONFIG_OPTPROBES) #if defined(__ARCH_WANT_KPROBES_INSN_SLOT) |
afd66255b
|
1638 1639 1640 |
/* Init kprobe_optinsn_slots */ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; #endif |
b2be84df9
|
1641 1642 1643 |
/* By default, kprobes can be optimized */ kprobes_allow_optimization = true; #endif |
afd66255b
|
1644 |
|
e579abeb5
|
1645 1646 |
/* By default, kprobes are armed */ kprobes_all_disarmed = false; |
bf8f6e5b3
|
1647 |
|
6772926be
|
1648 |
err = arch_init_kprobes(); |
802eae7c8
|
1649 1650 |
if (!err) err = register_die_notifier(&kprobe_exceptions_nb); |
e8386a0cb
|
1651 1652 |
if (!err) err = register_module_notifier(&kprobe_module_nb); |
ef53d9c5e
|
1653 |
kprobes_initialized = (err == 0); |
802eae7c8
|
1654 |
|
8c1c93564
|
1655 1656 |
if (!err) init_test_probes(); |
1da177e4c
|
1657 1658 |
return err; } |
346fd59ba
|
1659 1660 |
#ifdef CONFIG_DEBUG_FS static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, |
afd66255b
|
1661 |
const char *sym, int offset, char *modname, struct kprobe *pp) |
346fd59ba
|
1662 1663 1664 1665 1666 1667 1668 1669 1670 |
{ 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
|
1671 |
|
346fd59ba
|
1672 |
if (sym) |
afd66255b
|
1673 |
seq_printf(pi, "%p %s %s+0x%x %s ", |
de5bd88d5
|
1674 |
p->addr, kprobe_type, sym, offset, |
afd66255b
|
1675 |
(modname ? modname : " ")); |
346fd59ba
|
1676 |
else |
afd66255b
|
1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 |
seq_printf(pi, "%p %s %p ", p->addr, kprobe_type, p->addr); if (!pp) pp = p; seq_printf(pi, "%s%s%s ", (kprobe_gone(p) ? "[GONE]" : ""), ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), (kprobe_optimized(pp) ? "[OPTIMIZED]" : "")); |
346fd59ba
|
1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 |
} static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) { return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; } static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) { (*pos)++; if (*pos >= KPROBE_TABLE_SIZE) return NULL; return pos; } static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) { /* Nothing to do */ } static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) { struct hlist_head *head; struct hlist_node *node; struct kprobe *p, *kp; const char *sym = NULL; unsigned int i = *(loff_t *) v; |
ffb451227
|
1714 |
unsigned long offset = 0; |
346fd59ba
|
1715 1716 1717 1718 1719 |
char *modname, namebuf[128]; head = &kprobe_table[i]; preempt_disable(); hlist_for_each_entry_rcu(p, node, head, hlist) { |
ffb451227
|
1720 |
sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
346fd59ba
|
1721 |
&offset, &modname, namebuf); |
afd66255b
|
1722 |
if (kprobe_aggrprobe(p)) { |
346fd59ba
|
1723 |
list_for_each_entry_rcu(kp, &p->list, list) |
afd66255b
|
1724 |
report_probe(pi, kp, sym, offset, modname, p); |
346fd59ba
|
1725 |
} else |
afd66255b
|
1726 |
report_probe(pi, p, sym, offset, modname, NULL); |
346fd59ba
|
1727 1728 1729 1730 |
} preempt_enable(); return 0; } |
88e9d34c7
|
1731 |
static const struct seq_operations kprobes_seq_ops = { |
346fd59ba
|
1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 |
.start = kprobe_seq_start, .next = kprobe_seq_next, .stop = kprobe_seq_stop, .show = show_kprobe_addr }; static int __kprobes kprobes_open(struct inode *inode, struct file *filp) { return seq_open(filp, &kprobes_seq_ops); } |
828c09509
|
1742 |
static const struct file_operations debugfs_kprobes_operations = { |
346fd59ba
|
1743 1744 1745 1746 1747 |
.open = kprobes_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; |
de5bd88d5
|
1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 |
/* Disable one kprobe */ int __kprobes disable_kprobe(struct kprobe *kp) { 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 the probe is already disabled (or gone), just return */ if (kprobe_disabled(kp)) goto out; kp->flags |= KPROBE_FLAG_DISABLED; if (p != kp) /* When kp != p, p is always enabled. */ try_to_disable_aggr_kprobe(p); if (!kprobes_all_disarmed && kprobe_disabled(p)) |
201517a7f
|
1773 |
disarm_kprobe(p); |
de5bd88d5
|
1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 |
out: mutex_unlock(&kprobe_mutex); return ret; } EXPORT_SYMBOL_GPL(disable_kprobe); /* Enable one kprobe */ int __kprobes enable_kprobe(struct kprobe *kp) { 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; } |
de5bd88d5
|
1800 1801 |
if (p != kp) kp->flags &= ~KPROBE_FLAG_DISABLED; |
afd66255b
|
1802 1803 1804 1805 1806 |
if (!kprobes_all_disarmed && kprobe_disabled(p)) { p->flags &= ~KPROBE_FLAG_DISABLED; arm_kprobe(p); } |
de5bd88d5
|
1807 1808 1809 1810 1811 |
out: mutex_unlock(&kprobe_mutex); return ret; } EXPORT_SYMBOL_GPL(enable_kprobe); |
e579abeb5
|
1812 |
static void __kprobes arm_all_kprobes(void) |
bf8f6e5b3
|
1813 1814 1815 1816 1817 1818 1819 |
{ struct hlist_head *head; struct hlist_node *node; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); |
e579abeb5
|
1820 1821 |
/* If kprobes are armed, just return */ if (!kprobes_all_disarmed) |
bf8f6e5b3
|
1822 |
goto already_enabled; |
afd66255b
|
1823 |
/* Arming kprobes doesn't optimize kprobe itself */ |
4460fdad8
|
1824 |
mutex_lock(&text_mutex); |
bf8f6e5b3
|
1825 1826 1827 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) |
de5bd88d5
|
1828 |
if (!kprobe_disabled(p)) |
afd66255b
|
1829 |
__arm_kprobe(p); |
bf8f6e5b3
|
1830 |
} |
4460fdad8
|
1831 |
mutex_unlock(&text_mutex); |
bf8f6e5b3
|
1832 |
|
e579abeb5
|
1833 |
kprobes_all_disarmed = false; |
bf8f6e5b3
|
1834 1835 1836 1837 1838 1839 1840 |
printk(KERN_INFO "Kprobes globally enabled "); already_enabled: mutex_unlock(&kprobe_mutex); return; } |
e579abeb5
|
1841 |
static void __kprobes disarm_all_kprobes(void) |
bf8f6e5b3
|
1842 1843 1844 1845 1846 1847 1848 |
{ struct hlist_head *head; struct hlist_node *node; struct kprobe *p; unsigned int i; mutex_lock(&kprobe_mutex); |
e579abeb5
|
1849 1850 |
/* If kprobes are already disarmed, just return */ if (kprobes_all_disarmed) |
bf8f6e5b3
|
1851 |
goto already_disabled; |
e579abeb5
|
1852 |
kprobes_all_disarmed = true; |
bf8f6e5b3
|
1853 1854 |
printk(KERN_INFO "Kprobes globally disabled "); |
afd66255b
|
1855 1856 1857 1858 1859 1860 |
/* * Here we call get_online_cpus() for avoiding text_mutex deadlock, * because disarming may also unoptimize kprobes. */ get_online_cpus(); |
4460fdad8
|
1861 |
mutex_lock(&text_mutex); |
bf8f6e5b3
|
1862 1863 1864 |
for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) { |
de5bd88d5
|
1865 |
if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
afd66255b
|
1866 |
__disarm_kprobe(p); |
bf8f6e5b3
|
1867 1868 |
} } |
4460fdad8
|
1869 |
mutex_unlock(&text_mutex); |
afd66255b
|
1870 |
put_online_cpus(); |
bf8f6e5b3
|
1871 1872 1873 |
mutex_unlock(&kprobe_mutex); /* Allow all currently running kprobes to complete */ synchronize_sched(); |
74a0b5762
|
1874 |
return; |
bf8f6e5b3
|
1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 |
already_disabled: mutex_unlock(&kprobe_mutex); return; } /* * 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
|
1890 |
if (!kprobes_all_disarmed) |
bf8f6e5b3
|
1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 |
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]; int buf_size; buf_size = min(count, (sizeof(buf)-1)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; switch (buf[0]) { case 'y': case 'Y': case '1': |
e579abeb5
|
1914 |
arm_all_kprobes(); |
bf8f6e5b3
|
1915 1916 1917 1918 |
break; case 'n': case 'N': case '0': |
e579abeb5
|
1919 |
disarm_all_kprobes(); |
bf8f6e5b3
|
1920 1921 1922 1923 1924 |
break; } return count; } |
828c09509
|
1925 |
static const struct file_operations fops_kp = { |
bf8f6e5b3
|
1926 1927 1928 |
.read = read_enabled_file_bool, .write = write_enabled_file_bool, }; |
346fd59ba
|
1929 1930 1931 |
static int __kprobes debugfs_kprobe_init(void) { struct dentry *dir, *file; |
bf8f6e5b3
|
1932 |
unsigned int value = 1; |
346fd59ba
|
1933 1934 1935 1936 |
dir = debugfs_create_dir("kprobes", NULL); if (!dir) return -ENOMEM; |
e38697929
|
1937 |
file = debugfs_create_file("list", 0444, dir, NULL, |
346fd59ba
|
1938 1939 1940 1941 1942 |
&debugfs_kprobes_operations); if (!file) { debugfs_remove(dir); return -ENOMEM; } |
bf8f6e5b3
|
1943 1944 1945 1946 1947 1948 |
file = debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); if (!file) { debugfs_remove(dir); return -ENOMEM; } |
346fd59ba
|
1949 1950 1951 1952 1953 1954 1955 |
return 0; } late_initcall(debugfs_kprobe_init); #endif /* CONFIG_DEBUG_FS */ module_init(init_kprobes); |
1da177e4c
|
1956 |
|
99081ab55
|
1957 |
/* defined in arch/.../kernel/kprobes.c */ |
1da177e4c
|
1958 |
EXPORT_SYMBOL_GPL(jprobe_return); |