From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Yury Norov <yury.norov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
Matthew Wilcox <willy@infradead.org>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Mike Travis <travis@sgi.com>, Yury Norov <ynorov@marvell.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist()
Date: Wed, 3 Apr 2019 14:17:45 +0300 [thread overview]
Message-ID: <20190403111745.GQ9224@smile.fi.intel.com> (raw)
In-Reply-To: <20190403111522.GP9224@smile.fi.intel.com>
On Wed, Apr 03, 2019 at 02:15:22PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 03, 2019 at 07:45:36AM +0300, Yury Norov wrote:
> > Currently we parse user data byte after byte which leads to
> > overcomplification of parsing algorithm. The only user of
> > bitmap_parselist_user() is not performance-critical, and so we
> > can copy user data to kernel buffer and simply call
> > bitmap_parselist(). This rework lets us unify and simplify
> > bitmap_parselist() and bitmap_parselist_user(), which is done
> > in the following patch.
>
> > + buf = kmalloc(ulen + 1, GFP_KERNEL);
> > + if (!buf)
> > + return -ENOMEM;
> > +
> > + buf[ulen] = 0;
> > +
> > + ret = copy_from_user(buf, ubuf, ulen);
> > + if (ret)
> > + goto out;
>
> Why not memdup_user() ?
Even more precisely (for strings) strndup_user().
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2019-04-03 11:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 4:45 [PATCH v3 0/5] lib: rework bitmap_parselist and tests Yury Norov
2019-04-03 4:45 ` [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist() Yury Norov
2019-04-03 11:15 ` Andy Shevchenko
2019-04-03 11:17 ` Andy Shevchenko [this message]
2019-04-03 12:17 ` Rasmus Villemoes
2019-04-03 12:36 ` Andy Shevchenko
2019-04-03 4:45 ` [PATCH 2/5] lib: rework bitmap_parselist Yury Norov
2019-04-03 11:22 ` Andy Shevchenko
2019-04-03 4:45 ` [PATCH 3/5] lib/test_bitmap: switch test_bitmap_parselist to ktime_get() Yury Norov
2019-04-03 4:54 ` [PATCH v3 0/5] lib: rework bitmap_parselist and tests Yury Norov
2019-04-03 11:23 ` Andy Shevchenko
2019-04-03 11:24 ` Andy Shevchenko
2019-04-05 17:32 [PATCH v4 " Yury Norov
2019-04-05 17:32 ` [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist() Yury Norov
2019-04-08 9:30 ` Andy Shevchenko
2019-04-16 6:37 [PATCH v5 0/5] lib: rework bitmap_parselist and tests Yury Norov
2019-04-16 6:37 ` [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist() Yury Norov
2019-04-16 13:08 ` Andy Shevchenko
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