Commit f24659d9 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Linus Torvalds

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: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0deddf43
......@@ -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,
......
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