[PATCH] kprobes: fix race in aggregate kprobe registration
When registering multiple kprobes at the same address, we leave a small
window where the kprobe hlist will not contain a reference to the
registered kprobe, leading to potentially, a system crash if the breakpoint
is hit on another processor.
Patch below now automically relpace the old kprobe with the new
kprobe from the hash list.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index fde5a16..e4f0fc62 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -399,10 +399,7 @@
INIT_LIST_HEAD(&ap->list);
list_add_rcu(&p->list, &ap->list);
- INIT_HLIST_NODE(&ap->hlist);
- hlist_del_rcu(&p->hlist);
- hlist_add_head_rcu(&ap->hlist,
- &kprobe_table[hash_ptr(ap->addr, KPROBE_HASH_BITS)]);
+ hlist_replace_rcu(&p->hlist, &ap->hlist);
}
/*