diff options
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 14 | ||||
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 6 | ||||
| -rw-r--r-- | arch/x86_64/kernel/kprobes.c | 7 | ||||
| -rw-r--r-- | include/asm-ia64/kprobes.h | 5 | ||||
| -rw-r--r-- | include/linux/kprobes.h | 1 | ||||
| -rw-r--r-- | kernel/kprobes.c | 91 |
7 files changed, 53 insertions, 77 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 19edcd526ba4..68fe10250486 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -58,13 +58,9 @@ static inline int is_IF_modifier(kprobe_opcode_t opcode) int __kprobes arch_prepare_kprobe(struct kprobe *p) { - return 0; -} - -void __kprobes arch_copy_kprobe(struct kprobe *p) -{ memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); p->opcode = *p->addr; + return 0; } void __kprobes arch_arm_kprobe(struct kprobe *p) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 5368f9c2e6bf..331e169e8629 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -60,13 +60,13 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) if (!p->ainsn.insn) ret = -ENOMEM; } - return ret; -} -void __kprobes arch_copy_kprobe(struct kprobe *p) -{ - memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); - p->opcode = *p->addr; + if (!ret) { + memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + p->opcode = *p->addr; + } + + return ret; } void __kprobes arch_arm_kprobe(struct kprobe *p) @@ -85,9 +85,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p) void __kprobes arch_remove_kprobe(struct kprobe *p) { - down(&kprobe_mutex); free_insn_slot(p->ainsn.insn); - up(&kprobe_mutex); } static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index a97b0f0727ab..bbd5aa6818ea 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -43,14 +43,10 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); int __kprobes arch_prepare_kprobe(struct kprobe *p) { - return 0; -} - -void __kprobes arch_copy_kprobe(struct kprobe *p) -{ p->ainsn.insn[0] = *p->addr; p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2; p->opcode = *p->addr; + return 0; } void __kprobes arch_arm_kprobe(struct kprobe *p) diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c index afe11f4fbd1d..8b8943bfb89e 100644 --- a/arch/x86_64/kernel/kprobes.c +++ b/arch/x86_64/kernel/kprobes.c @@ -42,8 +42,8 @@ #include <asm/pgtable.h> #include <asm/kdebug.h> -static DECLARE_MUTEX(kprobe_mutex); void jprobe_return_end(void); +void __kprobes arch_copy_kprobe(struct kprobe *p); DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); @@ -69,12 +69,11 @@ static inline int is_IF_modifier(kprobe_opcode_t *insn) int __kprobes arch_prepare_kprobe(struct kprobe *p) { /* insn: must be on special executable page on x86_64. */ - down(&kprobe_mutex); p->ainsn.insn = get_insn_slot(); - up(&kprobe_mutex); if (!p->ainsn.insn) { return -ENOMEM; } + arch_copy_kprobe(p); return 0; } @@ -223,9 +222,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p) void __kprobes arch_remove_kprobe(struct kprobe *p) { - down(&kprobe_mutex); free_insn_slot(p->ainsn.insn); - up(&kprobe_mutex); } static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h index 5b26462674a7..12a0b93020da 100644 --- a/include/asm-ia64/kprobes.h +++ b/include/asm-ia64/kprobes.h @@ -110,11 +110,6 @@ struct arch_specific_insn { unsigned short target_br_reg; }; -/* ia64 does not need this */ -static inline void arch_copy_kprobe(struct kprobe *p) -{ -} - extern int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index c03f2dc933de..ad6e4fe970fd 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -150,7 +150,6 @@ struct kretprobe_instance { extern spinlock_t kretprobe_lock; extern int arch_prepare_kprobe(struct kprobe *p); -extern void arch_copy_kprobe(struct kprobe *p); extern void arch_arm_kprobe(struct kprobe *p); extern void arch_disarm_kprobe(struct kprobe *p); extern void arch_remove_kprobe(struct kprobe *p); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 3897630d2335..f14ccd35e9b6 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -48,7 +48,7 @@ static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; -static DEFINE_SPINLOCK(kprobe_lock); /* Protects kprobe_table */ +static DECLARE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */ static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; @@ -167,7 +167,7 @@ static inline void reset_kprobe_instance(void) /* * This routine is called either: - * - under the kprobe_lock spinlock - during kprobe_[un]register() + * - under the kprobe_mutex - during kprobe_[un]register() * OR * - with preemption disabled - from arch/xxx/kernel/kprobes.c */ @@ -420,7 +420,6 @@ static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) /* * This is the second or subsequent kprobe at the address - handle * the intricacies - * TODO: Move kcalloc outside the spin_lock */ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, struct kprobe *p) @@ -442,25 +441,6 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, return ret; } -/* kprobe removal house-keeping routines */ -static inline void cleanup_kprobe(struct kprobe *p, unsigned long flags) -{ - arch_disarm_kprobe(p); - hlist_del_rcu(&p->hlist); - spin_unlock_irqrestore(&kprobe_lock, flags); - arch_remove_kprobe(p); -} - -static inline void cleanup_aggr_kprobe(struct kprobe *old_p, - struct kprobe *p, unsigned long flags) -{ - list_del_rcu(&p->list); - if (list_empty(&old_p->list)) - cleanup_kprobe(old_p, flags); - else - spin_unlock_irqrestore(&kprobe_lock, flags); -} - static int __kprobes in_kprobes_functions(unsigned long addr) { if (addr >= (unsigned long)__kprobes_text_start @@ -472,7 +452,6 @@ static int __kprobes in_kprobes_functions(unsigned long addr) int __kprobes register_kprobe(struct kprobe *p) { int ret = 0; - unsigned long flags = 0; struct kprobe *old_p; struct module *mod; @@ -484,18 +463,17 @@ int __kprobes register_kprobe(struct kprobe *p) (unlikely(!try_module_get(mod)))) return -EINVAL; - if ((ret = arch_prepare_kprobe(p)) != 0) - goto rm_kprobe; - p->nmissed = 0; - spin_lock_irqsave(&kprobe_lock, flags); + down(&kprobe_mutex); old_p = get_kprobe(p->addr); if (old_p) { ret = register_aggr_kprobe(old_p, p); goto out; } - arch_copy_kprobe(p); + if ((ret = arch_prepare_kprobe(p)) != 0) + goto out; + INIT_HLIST_NODE(&p->hlist); hlist_add_head_rcu(&p->hlist, &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); @@ -503,10 +481,8 @@ int __kprobes register_kprobe(struct kprobe *p) arch_arm_kprobe(p); out: - spin_unlock_irqrestore(&kprobe_lock, flags); -rm_kprobe: - if (ret == -EEXIST) - arch_remove_kprobe(p); + up(&kprobe_mutex); + if (ret && mod) module_put(mod); return ret; @@ -514,29 +490,48 @@ rm_kprobe: void __kprobes unregister_kprobe(struct kprobe *p) { - unsigned long flags; - struct kprobe *old_p; struct module *mod; + struct kprobe *old_p, *cleanup_p; - spin_lock_irqsave(&kprobe_lock, flags); + down(&kprobe_mutex); old_p = get_kprobe(p->addr); - if (old_p) { - /* cleanup_*_kprobe() does the spin_unlock_irqrestore */ - if (old_p->pre_handler == aggr_pre_handler) - cleanup_aggr_kprobe(old_p, p, flags); - else - cleanup_kprobe(p, flags); + if (unlikely(!old_p)) { + up(&kprobe_mutex); + return; + } - synchronize_sched(); + if ((old_p->pre_handler == aggr_pre_handler) && + (p->list.next == &old_p->list) && + (p->list.prev == &old_p->list)) { + /* Only one element in the aggregate list */ + arch_disarm_kprobe(p); + hlist_del_rcu(&old_p->hlist); + cleanup_p = old_p; + } else if (old_p == p) { + /* Only one kprobe element in the hash list */ + arch_disarm_kprobe(p); + hlist_del_rcu(&p->hlist); + cleanup_p = p; + } else { + list_del_rcu(&p->list); + cleanup_p = NULL; + } - if ((mod = module_text_address((unsigned long)p->addr))) - module_put(mod); + up(&kprobe_mutex); - if (old_p->pre_handler == aggr_pre_handler && - list_empty(&old_p->list)) + synchronize_sched(); + if ((mod = module_text_address((unsigned long)p->addr))) + module_put(mod); + + if (cleanup_p) { + if (cleanup_p->pre_handler == aggr_pre_handler) { + list_del_rcu(&p->list); kfree(old_p); - } else - spin_unlock_irqrestore(&kprobe_lock, flags); + } + down(&kprobe_mutex); + arch_remove_kprobe(p); + up(&kprobe_mutex); + } } static struct notifier_block kprobe_exceptions_nb = { |