diff options
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 124 |
1 files changed, 104 insertions, 20 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 185badc780b7..dbe57df2e199 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1237,6 +1237,27 @@ void kprobes_inc_nmissed_count(struct kprobe *p) } NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); +static struct kprobe kprobe_busy = { + .addr = (void *) get_kprobe, +}; + +void kprobe_busy_begin(void) +{ + struct kprobe_ctlblk *kcb; + + preempt_disable(); + __this_cpu_write(current_kprobe, &kprobe_busy); + kcb = get_kprobe_ctlblk(); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; +} + +void kprobe_busy_end(void) +{ + __this_cpu_write(current_kprobe, NULL); + preempt_enable(); +} + +#if !defined(CONFIG_KRETPROBE_ON_RETHOOK) static void free_rp_inst_rcu(struct rcu_head *head) { struct kretprobe_instance *ri = container_of(head, struct kretprobe_instance, rcu); @@ -1258,26 +1279,6 @@ static void recycle_rp_inst(struct kretprobe_instance *ri) } NOKPROBE_SYMBOL(recycle_rp_inst); -static struct kprobe kprobe_busy = { - .addr = (void *) get_kprobe, -}; - -void kprobe_busy_begin(void) -{ - struct kprobe_ctlblk *kcb; - - preempt_disable(); - __this_cpu_write(current_kprobe, &kprobe_busy); - kcb = get_kprobe_ctlblk(); - kcb->kprobe_status = KPROBE_HIT_ACTIVE; -} - -void kprobe_busy_end(void) -{ - __this_cpu_write(current_kprobe, NULL); - preempt_enable(); -} - /* * This function is called from delayed_put_task_struct() when a task is * dead and cleaned up to recycle any kretprobe instances associated with @@ -1327,6 +1328,7 @@ static inline void free_rp_inst(struct kretprobe *rp) rp->rph = NULL; } } +#endif /* !CONFIG_KRETPROBE_ON_RETHOOK */ /* Add the new probe to 'ap->list'. */ static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) @@ -1925,6 +1927,7 @@ static struct notifier_block kprobe_exceptions_nb = { #ifdef CONFIG_KRETPROBES +#if !defined(CONFIG_KRETPROBE_ON_RETHOOK) /* This assumes the 'tsk' is the current task or the is not running. */ static kprobe_opcode_t *__kretprobe_find_ret_addr(struct task_struct *tsk, struct llist_node **cur) @@ -2087,6 +2090,57 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) return 0; } NOKPROBE_SYMBOL(pre_handler_kretprobe); +#else /* CONFIG_KRETPROBE_ON_RETHOOK */ +/* + * This kprobe pre_handler is registered with every kretprobe. When probe + * hits it will set up the return probe. + */ +static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) +{ + struct kretprobe *rp = container_of(p, struct kretprobe, kp); + struct kretprobe_instance *ri; + struct rethook_node *rhn; + + rhn = rethook_try_get(rp->rh); + if (!rhn) { + rp->nmissed++; + return 0; + } + + ri = container_of(rhn, struct kretprobe_instance, node); + + if (rp->entry_handler && rp->entry_handler(ri, regs)) + rethook_recycle(rhn); + else + rethook_hook(rhn, regs, kprobe_ftrace(p)); + + return 0; +} +NOKPROBE_SYMBOL(pre_handler_kretprobe); + +static void kretprobe_rethook_handler(struct rethook_node *rh, void *data, + struct pt_regs *regs) +{ + struct kretprobe *rp = (struct kretprobe *)data; + struct kretprobe_instance *ri; + struct kprobe_ctlblk *kcb; + + /* The data must NOT be null. This means rethook data structure is broken. */ + if (WARN_ON_ONCE(!data)) + return; + + __this_cpu_write(current_kprobe, &rp->kp); + kcb = get_kprobe_ctlblk(); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; + + ri = container_of(rh, struct kretprobe_instance, node); + rp->handler(ri, regs); + + __this_cpu_write(current_kprobe, NULL); +} +NOKPROBE_SYMBOL(kretprobe_rethook_handler); + +#endif /* !CONFIG_KRETPROBE_ON_RETHOOK */ /** * kprobe_on_func_entry() -- check whether given address is function entry @@ -2155,6 +2209,29 @@ int register_kretprobe(struct kretprobe *rp) rp->maxactive = num_possible_cpus(); #endif } +#ifdef CONFIG_KRETPROBE_ON_RETHOOK + rp->rh = rethook_alloc((void *)rp, kretprobe_rethook_handler); + if (!rp->rh) + return -ENOMEM; + + for (i = 0; i < rp->maxactive; i++) { + inst = kzalloc(sizeof(struct kretprobe_instance) + + rp->data_size, GFP_KERNEL); + if (inst == NULL) { + rethook_free(rp->rh); + rp->rh = NULL; + return -ENOMEM; + } + rethook_add_node(rp->rh, &inst->node); + } + rp->nmissed = 0; + /* Establish function entry probe point */ + ret = register_kprobe(&rp->kp); + if (ret != 0) { + rethook_free(rp->rh); + rp->rh = NULL; + } +#else /* !CONFIG_KRETPROBE_ON_RETHOOK */ rp->freelist.head = NULL; rp->rph = kzalloc(sizeof(struct kretprobe_holder), GFP_KERNEL); if (!rp->rph) @@ -2179,6 +2256,7 @@ int register_kretprobe(struct kretprobe *rp) ret = register_kprobe(&rp->kp); if (ret != 0) free_rp_inst(rp); +#endif return ret; } EXPORT_SYMBOL_GPL(register_kretprobe); @@ -2217,7 +2295,11 @@ void unregister_kretprobes(struct kretprobe **rps, int num) for (i = 0; i < num; i++) { if (__unregister_kprobe_top(&rps[i]->kp) < 0) rps[i]->kp.addr = NULL; +#ifdef CONFIG_KRETPROBE_ON_RETHOOK + rethook_free(rps[i]->rh); +#else rps[i]->rph->rp = NULL; +#endif } mutex_unlock(&kprobe_mutex); @@ -2225,7 +2307,9 @@ void unregister_kretprobes(struct kretprobe **rps, int num) for (i = 0; i < num; i++) { if (rps[i]->kp.addr) { __unregister_kprobe_bottom(&rps[i]->kp); +#ifndef CONFIG_KRETPROBE_ON_RETHOOK free_rp_inst(rps[i]); +#endif } } } |