From: Yury Norov <yury.norov@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
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>, Guenter Roeck <linux@roeck-us.net>
Cc: Yury Norov <ynorov@marvell.com>,
Yury Norov <yury.norov@gmail.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist()
Date: Mon, 15 Apr 2019 23:37:57 -0700 [thread overview]
Message-ID: <20190416063801.20134-2-ynorov@marvell.com> (raw)
In-Reply-To: <20190416063801.20134-1-ynorov@marvell.com>
From: Yury Norov <ynorov@marvell.com>
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 duplicate 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.
Signed-off-by: Yury Norov <ynorov@marvell.com>
---
lib/bitmap.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 3f3b8051f342..c63ddd06a5da 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -632,19 +632,22 @@ EXPORT_SYMBOL(bitmap_parselist);
* @nmaskbits: size of bitmap, in bits.
*
* Wrapper for bitmap_parselist(), providing it with user buffer.
- *
- * We cannot have this as an inline function in bitmap.h because it needs
- * linux/uaccess.h to get the access_ok() declaration and this causes
- * cyclic dependencies.
*/
int bitmap_parselist_user(const char __user *ubuf,
unsigned int ulen, unsigned long *maskp,
int nmaskbits)
{
- if (!access_ok(ubuf, ulen))
- return -EFAULT;
- return __bitmap_parselist((const char __force *)ubuf,
- ulen, 1, maskp, nmaskbits);
+ char *buf;
+ int ret;
+
+ buf = memdup_user_nul(ubuf, ulen);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ ret = bitmap_parselist(buf, maskp, nmaskbits);
+
+ kfree(buf);
+ return ret;
}
EXPORT_SYMBOL(bitmap_parselist_user);
--
2.17.1
next prev parent reply other threads:[~2019-04-16 6:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-16 6:37 [PATCH v5 0/5] lib: rework bitmap_parselist and tests Yury Norov
2019-04-16 6:37 ` Yury Norov [this message]
2019-04-16 13:08 ` [PATCH 1/5] lib: make bitmap_parselist_user() a wrapper on bitmap_parselist() Andy Shevchenko
2019-04-16 6:37 ` [PATCH 2/5] lib: rework bitmap_parselist Yury Norov
2019-04-16 13:18 ` Andy Shevchenko
2019-04-16 6:37 ` [PATCH 3/5] lib/test_bitmap: switch test_bitmap_parselist to ktime_get() Yury Norov
2019-04-16 6:38 ` [PATCH 4/5] lib/test_bitmap: add testcases for bitmap_parselist Yury Norov
2019-04-16 6:38 ` [PATCH 5/5] lib/test_bitmap: add tests for bitmap_parselist_user Yury Norov
-- strict thread matches above, loose matches on Subject: below --
2019-04-05 17:32 [PATCH v4 0/5] lib: rework bitmap_parselist and tests 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
2019-04-03 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
2019-04-03 12:17 ` Rasmus Villemoes
2019-04-03 12:36 ` Andy Shevchenko
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