From: Dan Carpenter <dan.carpenter@oracle.com>
To: Chao Yu <yuchao0@huawei.com>
Cc: devel@driverdev.osuosl.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Miao Xie <miaoxie@huawei.com>, Chao Yu <chao@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
stable@vger.kernel.org, weidu.du@huawei.com,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-erofs@lists.ozlabs.org, Fang Wei <fangwei1@huawei.com>
Subject: Re: [PATCH v2] staging: erofs: keep corrupted fs from crashing kernel in erofs_namei()
Date: Fri, 15 Feb 2019 12:35:03 +0300 [thread overview]
Message-ID: <20190215093503.GH2326@kadam> (raw)
In-Reply-To: <fb99bac2-2587-04fa-6ac2-f2e5f83af7c9@huawei.com>
On Fri, Feb 15, 2019 at 05:32:33PM +0800, Chao Yu wrote:
> On 2019/2/15 15:57, Dan Carpenter wrote:
> > On Fri, Feb 15, 2019 at 03:02:25PM +0800, Chao Yu wrote:
> >> On 2019/2/1 20:16, Gao Xiang wrote:
> >>> + /*
> >>> + * on-disk error, let's only BUG_ON in the debugging mode.
> >>> + * otherwise, it will return 1 to just skip the invalid name
> >>> + * and go on (in consideration of the lookup performance).
> >>> + */
> >>> + DBG_BUGON(qd->name > qd->end);
> >>
> >> qd->name == qd->end is not allowed as well?
> >>
> >> So will it be better to return directly here?
> >>
> >> if (unlikely(qd->name >= qd->end)) {
> >> DBG_BUGON(1);
> >> return 1;
> >> }
> >
> > Please don't add likely/unlikely() annotations unless you have
> > benchmarked it and it makes a difference.
>
> Well, it only occur for corrupted image, since the image is readonly, so it
> is really rare.
The likely/unlikely() annotations make the code harder to read. It's
only worth it if it's is a speedup on a fast path.
regards,
dan carpenter
next prev parent reply other threads:[~2019-02-15 9:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-01 12:16 [PATCH v2] staging: erofs: keep corrupted fs from crashing kernel in erofs_namei() Gao Xiang
2019-02-12 5:05 ` Gao Xiang
2019-02-15 7:02 ` Chao Yu
2019-02-15 7:57 ` Dan Carpenter
2019-02-15 9:04 ` Gao Xiang
2019-02-15 9:32 ` Chao Yu
2019-02-15 9:35 ` Dan Carpenter [this message]
2019-02-15 10:33 ` Gao Xiang
2019-02-18 2:41 ` Chao Yu
2019-02-18 6:16 ` Dan Carpenter
2019-02-15 8:58 ` Gao Xiang
2019-02-18 1:39 ` Chao Yu
2019-02-18 2:17 ` Gao Xiang
2019-02-18 2:50 ` Chao Yu
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