Commit adad0f33 authored Dec 12, 2005 by Keshavamurthy Anil S Committed by Linus Torvalds Dec 12, 2005

[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>

parent b88cb424

kernel/kprobes.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -399,10 +399,7 @@ static inline void add_aggr_kprobe(struct kprobe ap, struct kprobe p)
		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);
		}

		/*

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