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
