Messages in this thread | | | Date | Sun, 18 Jul 2021 00:32:31 +0800 (GMT+08:00) | From | "Xiyu Yang" <> | Subject | Re: Re: [PATCH] SUNRPC: Convert from atomic_t to refcount_t on rpc_clnt->cl_count |
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Sorry, I'm not sure why you need to bump a zero refcount in a normal situation. But maybe we can use refcount_inc_not_zero() API in rpc_free_auth() instead?
> -----Original Messages----- > From: "Trond Myklebust" <trondmy@hammerspace.com> > Sent Time: 2021-07-17 22:43:26 (Saturday) > To: "tanxin.ctf@gmail.com" <tanxin.ctf@gmail.com>, "xiyuyang19@fudan.edu.cn" <xiyuyang19@fudan.edu.cn>, "davem@davemloft.net" <davem@davemloft.net>, "chuck.lever@oracle.com" <chuck.lever@oracle.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "kolga@netapp.com" <kolga@netapp.com>, "kuba@kernel.org" <kuba@kernel.org>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "bfields@fieldses.org" <bfields@fieldses.org>, "anna.schumaker@netapp.com" <anna.schumaker@netapp.com>, "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org> > Cc: "yuanxzhang@fudan.edu.cn" <yuanxzhang@fudan.edu.cn> > Subject: Re: [PATCH] SUNRPC: Convert from atomic_t to refcount_t on rpc_clnt->cl_count > > On Sat, 2021-07-17 at 18:18 +0800, Xiyu Yang wrote: > > refcount_t type and corresponding API can protect refcounters from > > accidental underflow and overflow and further use-after-free > > situations. > > > > Have you tested this patch? As far as I remember, the reason why we > never converted is that refcount_inc() gets upset and WARNs when you > bump a zero refcount, like we do very much on purpose in > rpc_free_auth(). Is that no longer the case? > > > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@hammerspace.com > >
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