[PATCH] kprobes: fix race in aggregate kprobe registration

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Ananth N Mavinakayanahalli <[email protected]>

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 changes the order of hlist updation to make sure that there
is always a reference to the kprobe at the location.

Signed-off-by: Ananth N Mavinakayanahalli <[email protected]>
Acked-by: Prasanna S Panchamukhi <[email protected]>
Acked-by: Anil S Keshavamurthy <[email protected]>
---


 kernel/kprobes.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.15-rc5/kernel/kprobes.c
===================================================================
--- linux-2.6.15-rc5.orig/kernel/kprobes.c
+++ linux-2.6.15-rc5/kernel/kprobes.c
@@ -400,9 +400,9 @@ static inline void add_aggr_kprobe(struc
 	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_del_rcu(&p->hlist);
 }
 
 /*
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux