diff options
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 55 |
1 files changed, 30 insertions, 25 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 9934523..2285700 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -133,7 +133,7 @@ kprobe_opcode_t __kprobes *get_insn_slot(void) struct kprobe_insn_page *kip; struct hlist_node *pos; - retry: + retry: hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { if (kip->nused < INSNS_PER_PAGE) { int i; @@ -155,9 +155,8 @@ kprobe_opcode_t __kprobes *get_insn_slot(void) } /* All out of space. Need to allocate a new page. Use slot 0. */ kip = kmalloc(sizeof(struct kprobe_insn_page), GFP_KERNEL); - if (!kip) { + if (!kip) return NULL; - } /* * Use module_alloc so this page is within +/- 2GB of where the @@ -246,9 +245,9 @@ void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) break; } } - if (dirty && (++kprobe_garbage_slots > INSNS_PER_PAGE)) { + + if (dirty && ++kprobe_garbage_slots > INSNS_PER_PAGE) collect_garbage_slots(); - } } #endif @@ -314,7 +313,6 @@ static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, reset_kprobe_instance(); } } - return; } static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, @@ -533,8 +531,8 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, static int __kprobes in_kprobes_functions(unsigned long addr) { - if (addr >= (unsigned long)__kprobes_text_start - && addr < (unsigned long)__kprobes_text_end) + if (addr >= (unsigned long)__kprobes_text_start && + addr < (unsigned long)__kprobes_text_end) return -EINVAL; return 0; } @@ -561,19 +559,24 @@ static int __kprobes __register_kprobe(struct kprobe *p, return -EINVAL; p->addr = (kprobe_opcode_t *)(((char *)p->addr)+ p->offset); - if ((!kernel_text_address((unsigned long) p->addr)) || - in_kprobes_functions((unsigned long) p->addr)) + if (!kernel_text_address((unsigned long) p->addr) || + in_kprobes_functions((unsigned long) p->addr)) return -EINVAL; p->mod_refcounted = 0; - /* Check are we probing a module */ - if ((probed_mod = module_text_address((unsigned long) p->addr))) { + + /* + * Check if are we probing a module. + */ + probed_mod = module_text_address((unsigned long) p->addr); + if (probed_mod) { struct module *calling_mod = module_text_address(called_from); - /* We must allow modules to probe themself and - * in this case avoid incrementing the module refcount, - * so as to allow unloading of self probing modules. + /* + * We must allow modules to probe themself and in this case + * avoid incrementing the module refcount, so as to allow + * unloading of self probing modules. */ - if (calling_mod && (calling_mod != probed_mod)) { + if (calling_mod && calling_mod != probed_mod) { if (unlikely(!try_module_get(probed_mod))) return -EINVAL; p->mod_refcounted = 1; @@ -591,7 +594,8 @@ static int __kprobes __register_kprobe(struct kprobe *p, goto out; } - if ((ret = arch_prepare_kprobe(p)) != 0) + ret = arch_prepare_kprobe(p); + if (ret) goto out; INIT_HLIST_NODE(&p->hlist); @@ -614,8 +618,7 @@ out: int __kprobes register_kprobe(struct kprobe *p) { - return __register_kprobe(p, - (unsigned long)__builtin_return_address(0)); + return __register_kprobe(p, (unsigned long)__builtin_return_address(0)); } void __kprobes unregister_kprobe(struct kprobe *p) @@ -639,9 +642,9 @@ void __kprobes unregister_kprobe(struct kprobe *p) return; } valid_p: - if ((old_p == p) || ((old_p->pre_handler == aggr_pre_handler) && - (p->list.next == &old_p->list) && - (p->list.prev == &old_p->list))) { + if (old_p == p || + (old_p->pre_handler == aggr_pre_handler && + p->list.next == &old_p->list && p->list.prev == &old_p->list)) { /* Only probe on the hash list */ arch_disarm_kprobe(p); hlist_del_rcu(&old_p->hlist); @@ -654,9 +657,11 @@ valid_p: mutex_unlock(&kprobe_mutex); synchronize_sched(); - if (p->mod_refcounted && - (mod = module_text_address((unsigned long)p->addr))) - module_put(mod); + if (p->mod_refcounted) { + mod = module_text_address((unsigned long)p->addr); + if (mod) + module_put(mod); + } if (cleanup_p) { if (p != old_p) { |