From f24659d96f4e056125f14498285203d1427cb18e Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 6 Jan 2009 14:41:55 -0800 Subject: [PATCH] kprobes: support probing module __init function Allow kprobes to probe module __init routines. When __init functions are freed, kprobes which probe those functions are set to "Gone" flag. These "Gone" probes are disarmed from the code and never be enabled. Signed-off-by: Masami Hiramatsu Acked-by: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kprobes.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ddefb9fae0c8..1b9cbdc0127a 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -677,6 +677,16 @@ int __kprobes register_kprobe(struct kprobe *p) preempt_enable(); return -EINVAL; } + /* + * 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; + } } preempt_enable(); @@ -1073,19 +1083,24 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb, struct hlist_node *node; struct kprobe *p; unsigned int i; + int checkcore = (val == MODULE_STATE_GOING); - if (val != MODULE_STATE_GOING) + if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) return NOTIFY_DONE; /* - * module .text section will be freed. We need to - * disable kprobes which have been inserted in the section. + * 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. */ 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) - if (within_module_core((unsigned long)p->addr, mod)) { + if (within_module_init((unsigned long)p->addr, mod) || + (checkcore && + within_module_core((unsigned long)p->addr, mod))) { /* * The vaddr this probe is installed will soon * be vfreed buy not synced to disk. Hence,