diff options
| -rw-r--r-- | include/linux/module.h | 6 | ||||
| -rw-r--r-- | kernel/kprobes.c | 67 | ||||
| -rw-r--r-- | kernel/module.c | 7 | ||||
| -rw-r--r-- | samples/kprobes/kprobe_example.c | 6 | ||||
| -rw-r--r-- | samples/kprobes/kretprobe_example.c | 2 |
5 files changed, 85 insertions, 3 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 1ad393e62bef..1192097c9a69 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -489,6 +489,12 @@ struct module { unsigned int num_ftrace_callsites; unsigned long *ftrace_callsites; #endif +#ifdef CONFIG_KPROBES + void *kprobes_text_start; + unsigned int kprobes_text_size; + unsigned long *kprobe_blacklist; + unsigned int num_kprobe_blacklist; +#endif #ifdef CONFIG_LIVEPATCH bool klp; /* Is this a livepatch module? */ diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 2625c241ac00..9eb5acf0a9f3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2179,6 +2179,24 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) return 0; } +/* Remove all symbols in given area from kprobe blacklist */ +static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) +{ + struct kprobe_blacklist_entry *ent, *n; + + list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { + if (ent->start_addr < start || ent->start_addr >= end) + continue; + list_del(&ent->list); + kfree(ent); + } +} + +static void kprobe_remove_ksym_blacklist(unsigned long entry) +{ + kprobe_remove_area_blacklist(entry, entry + 1); +} + int __init __weak arch_populate_kprobe_blacklist(void) { return 0; @@ -2215,6 +2233,40 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret ? : arch_populate_kprobe_blacklist(); } +static void add_module_kprobe_blacklist(struct module *mod) +{ + unsigned long start, end; + int i; + + if (mod->kprobe_blacklist) { + for (i = 0; i < mod->num_kprobe_blacklist; i++) + kprobe_add_ksym_blacklist(mod->kprobe_blacklist[i]); + } + + start = (unsigned long)mod->kprobes_text_start; + if (start) { + end = start + mod->kprobes_text_size; + kprobe_add_area_blacklist(start, end); + } +} + +static void remove_module_kprobe_blacklist(struct module *mod) +{ + unsigned long start, end; + int i; + + if (mod->kprobe_blacklist) { + for (i = 0; i < mod->num_kprobe_blacklist; i++) + kprobe_remove_ksym_blacklist(mod->kprobe_blacklist[i]); + } + + start = (unsigned long)mod->kprobes_text_start; + if (start) { + end = start + mod->kprobes_text_size; + kprobe_remove_area_blacklist(start, end); + } +} + /* Module notifier call back, checking kprobes on the module */ static int kprobes_module_callback(struct notifier_block *nb, unsigned long val, void *data) @@ -2225,6 +2277,11 @@ static int kprobes_module_callback(struct notifier_block *nb, unsigned int i; int checkcore = (val == MODULE_STATE_GOING); + if (val == MODULE_STATE_COMING) { + mutex_lock(&kprobe_mutex); + add_module_kprobe_blacklist(mod); + mutex_unlock(&kprobe_mutex); + } if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) return NOTIFY_DONE; @@ -2255,6 +2312,8 @@ static int kprobes_module_callback(struct notifier_block *nb, kill_kprobe(p); } } + if (val == MODULE_STATE_GOING) + remove_module_kprobe_blacklist(mod); mutex_unlock(&kprobe_mutex); return NOTIFY_DONE; } @@ -2420,6 +2479,7 @@ static const struct file_operations debugfs_kprobes_operations = { /* kprobes/blacklist -- shows which functions can not be probed */ static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) { + mutex_lock(&kprobe_mutex); return seq_list_start(&kprobe_blacklist, *pos); } @@ -2446,10 +2506,15 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) return 0; } +static void kprobe_blacklist_seq_stop(struct seq_file *f, void *v) +{ + mutex_unlock(&kprobe_mutex); +} + 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 */ + .stop = kprobe_blacklist_seq_stop, .show = kprobe_blacklist_seq_show, }; diff --git a/kernel/module.c b/kernel/module.c index 646f1e2330d2..faf733789560 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3194,6 +3194,13 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->ei_funcs), &mod->num_ei_funcs); #endif +#ifdef CONFIG_KPROBES + mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, + &mod->kprobes_text_size); + mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", + sizeof(unsigned long), + &mod->num_kprobe_blacklist); +#endif mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_example.c index d693c23a85e8..501911d1b327 100644 --- a/samples/kprobes/kprobe_example.c +++ b/samples/kprobes/kprobe_example.c @@ -25,7 +25,7 @@ static struct kprobe kp = { }; /* kprobe pre_handler: called just before the probed instruction is executed */ -static int handler_pre(struct kprobe *p, struct pt_regs *regs) +static int __kprobes handler_pre(struct kprobe *p, struct pt_regs *regs) { #ifdef CONFIG_X86 pr_info("<%s> pre_handler: p->addr = 0x%p, ip = %lx, flags = 0x%lx\n", @@ -54,7 +54,7 @@ static int handler_pre(struct kprobe *p, struct pt_regs *regs) } /* kprobe post_handler: called after the probed instruction is executed */ -static void handler_post(struct kprobe *p, struct pt_regs *regs, +static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs, unsigned long flags) { #ifdef CONFIG_X86 @@ -90,6 +90,8 @@ static int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr) /* Return 0 because we don't handle the fault. */ return 0; } +/* NOKPROBE_SYMBOL() is also available */ +NOKPROBE_SYMBOL(handler_fault); static int __init kprobe_init(void) { diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c index 186315ca88b3..013e8e6ebae9 100644 --- a/samples/kprobes/kretprobe_example.c +++ b/samples/kprobes/kretprobe_example.c @@ -48,6 +48,7 @@ static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs) data->entry_stamp = ktime_get(); return 0; } +NOKPROBE_SYMBOL(entry_handler); /* * Return-probe handler: Log the return value and duration. Duration may turn @@ -67,6 +68,7 @@ static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs) func_name, retval, (long long)delta); return 0; } +NOKPROBE_SYMBOL(ret_handler); static struct kretprobe my_kretprobe = { .handler = ret_handler, |