From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Geliang Tang" <geliangtang@gmail.com>,
"Felipe Balbi" <balbi@kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Michal Nazarewicz" <mina86@mina86.com>,
"Vincent Pelletier" <plr.vincent@gmail.com>,
"Felix Hädicke" <felixhaedicke@web.de>,
"Jim Lin" <jilin@nvidia.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: gadget: f_fs: use memdup_user
Date: Sun, 21 May 2017 04:25:10 +0100 [thread overview]
Message-ID: <20170521032453.GW390@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20170513080530.2rsqs3apd6w3psve@mwanda>
On Sat, May 13, 2017 at 11:05:30AM +0300, Dan Carpenter wrote:
> > + data = memdup_user(buf, len);
> > + if (unlikely(IS_ERR(data)))
>
> Don't use likely/unlikely() here. It's not a fast path.
More to the point,
#define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO)
static inline bool __must_check IS_ERR(__force const void *ptr)
{
return IS_ERR_VALUE((unsigned long)ptr);
}
IOW, IS_ERR() already produces unlikely(....), fast path or not.
next prev parent reply other threads:[~2017-05-21 3:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-13 3:15 [PATCH] KEYS: use memdup_user Geliang Tang
2017-05-13 3:15 ` Geliang Tang
2017-05-13 3:15 ` [PATCH] mmc: block: " Geliang Tang
2017-05-19 7:43 ` Ulf Hansson
2017-05-13 3:15 ` [PATCH] usb: gadget: f_fs: " Geliang Tang
2017-05-13 8:05 ` Dan Carpenter
2017-05-21 3:25 ` Al Viro [this message]
2017-05-14 11:33 ` Michal Nazarewicz
2017-05-13 3:16 ` [PATCH] USB: iowarrior: " Geliang Tang
2017-05-15 10:14 ` Johan Hovold
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