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 <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ddefb9f..1b9cbdc 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -677,6 +677,16 @@
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 @@
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,
