The patch titled
Subject: lib: make bitmap_parselist_user() a wrapper on bitmap_parselist()
has been added to the -mm tree. Its filename is
lib-make-bitmap_parselist_user-a-wrapper-on-bitmap_parselist.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-make-bitmap_parselist_user-a-wrapper-on-bitmap_parselist.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-make-bitmap_parselist_user-a-wrapper-on-bitmap_parselist.patch
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------------------------------------------------------
From: Yury Norov <yury.norov@xxxxxxxxx>
Subject: lib: make bitmap_parselist_user() a wrapper on bitmap_parselist()
Patch series "lib: rework bitmap_parselist and tests", v4.
bitmap_parselist has been evolved from a pretty simple idea for long and
now lacks for refactoring. It is not structured, has nested loops and a
set of opaque-named variables.
Things are more complicated because bitmap_parselist() is a part of user
interface, and its behavior should not change.
In this patchset
- bitmap_parselist_user() made a wrapper on bitmap_parselist();
- bitmap_parselist() reworked (patch 2);
- time measurement in test_bitmap_parselist switched to ktime_get
(patch 3);
- new tests introduced (patch 4), and
- bitmap_parselist_user() testing enabled with the same testset as
bitmap_parselist() (patch 5).
This patch (of 5):
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.
Link: http://lkml.kernel.org/r/20190405173211.11373-2-ynorov@xxxxxxxxxxx
Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Mike Travis <travis@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/bitmap.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
--- a/lib/bitmap.c~lib-make-bitmap_parselist_user-a-wrapper-on-bitmap_parselist
+++ a/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);
_
Patches currently in -mm which might be from yury.norov@xxxxxxxxx are
lib-make-bitmap_parselist_user-a-wrapper-on-bitmap_parselist.patch
lib-rework-bitmap_parselist.patch
lib-test_bitmap-switch-test_bitmap_parselist-to-ktime_get.patch
lib-test_bitmap-add-testcases-for-bitmap_parselist.patch
lib-test_bitmap-add-tests-for-bitmap_parselist_user.patch
