Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 30 May 2018 08:13:27 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Baolin Wang <baolin.wang@linaro.org>
Cc:     linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH] mm: dmapool: Check the dma pool name
Message-ID: <20180530151327.GA13951@bombadil.infradead.org>
References: <59623b15001e5a20ac32b1a393db88722be2e718.1527679621.git.baolin.wang@linaro.org>
 <20180530120133.GC17450@bombadil.infradead.org>
 <CAMz4ku+fBt2uY6MbiMX1X-6jtjdpqp=DWNMrefOG4SsUHWN4kQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAMz4ku+fBt2uY6MbiMX1X-6jtjdpqp=DWNMrefOG4SsUHWN4kQ@mail.gmail.com>
User-Agent: Mutt/1.9.2 (2017-12-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, May 30, 2018 at 08:14:09PM +0800, Baolin Wang wrote:
> On 30 May 2018 at 20:01, Matthew Wilcox <willy@infradead.org> wrote:
> > On Wed, May 30, 2018 at 07:28:43PM +0800, Baolin Wang wrote:
> >> It will be crash if we pass one NULL name when creating one dma pool,
> >> so we should check the passing name when copy it to dma pool.
> >
> > NAK.  Crashing is the appropriate thing to do.  Fix the caller to not
> > pass NULL.
> >
> > If you permit NULL to be passed then you're inviting crashes or just
> > bad reporting later when pool->name is printed.
> 
> I think it just prints one NULL pool name. Sometimes the device
> doesn't care the dma pool names, so I think we can make code more
> solid to valid the passing parameters like other code does.
> Or can we add check to return NULL when the passing name is NULL
> instead of crashing the kernel? Thanks.

No.  Fix your driver.