Re: [PATCH] lockdep: fix invalid list_del_rcu in zap_class

[Ingo Molnar]

* Zhu Yi <yi.zhu@xxxxxxxxx> wrote:

> BUG: unable to handle kernel NULL pointer dereference at
> 0000000000000008
> IP: [<ffffffff810531e1>] zap_class+0x24/0x82

> The root cause for this oops is in add_lock_to_list() when 
> save_trace() fails due to MAX_STACK_TRACE_ENTRIES is reached, 
> entry->class is assigned but entry is never added into any lock list. 
> This makes the list_del_rcu() in zap_class() oops later when the 
> module is unloaded. This patch fixes the problem by assigning 
> entry->class after save_trace() returns success.

good spotting! Applied to tip/core/urgent, thanks.

	Ingo
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