The patch titled
Subject: lib: make bitmap_parse_user a wrapper on bitmap_parse
has been added to the -mm tree. Its filename is
lib-make-bitmap_parse_user-a-wrapper-on-bitmap_parse.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-make-bitmap_parse_user-a-wrapper-on-bitmap_parse.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-make-bitmap_parse_user-a-wrapper-on-bitmap_parse.patch
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------------------------------------------------------
From: Yury Norov <yury.norov@xxxxxxxxx>
Subject: lib: make bitmap_parse_user a wrapper on bitmap_parse
Currently we parse user data byte after byte which leads to
overcomplicating of parsing algorithm. There are no performance critical
users of bitmap_parse_user(), and so we can duplicate user data to kernel
buffer and simply call bitmap_parselist(). This rework lets us unify and
simplify bitmap_parse() and bitmap_parse_user(), which is done in the
following patch.
Link: http://lkml.kernel.org/r/20190501010636.30595-5-ynorov@xxxxxxxxxxx
Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Amritha Nambiar <amritha.nambiar@xxxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Tobin C . Harding" <tobin@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/bitmap.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
--- a/lib/bitmap.c~lib-make-bitmap_parse_user-a-wrapper-on-bitmap_parse
+++ a/lib/bitmap.c
@@ -434,22 +434,22 @@ EXPORT_SYMBOL(__bitmap_parse);
* then it must be terminated with a \0.
* @maskp: pointer to bitmap array that will contain result.
* @nmaskbits: size of bitmap, in bits.
- *
- * Wrapper for __bitmap_parse(), 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_parse_user(const char __user *ubuf,
unsigned int ulen, unsigned long *maskp,
int nmaskbits)
{
- if (!access_ok(ubuf, ulen))
- return -EFAULT;
- return __bitmap_parse((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_parse(buf, ulen, maskp, nmaskbits);
+
+ kfree(buf);
+ return ret;
}
EXPORT_SYMBOL(bitmap_parse_user);
_
Patches currently in -mm which might be from yury.norov@xxxxxxxxx are
mm-slub-avoid-double-string-traverse-in-kmem_cache_flags.patch
lib-string-add-strnchrnul.patch
bitops-more-bits_to_-macros.patch
lib-add-test-for-bitmap_parse.patch
lib-make-bitmap_parse_user-a-wrapper-on-bitmap_parse.patch
lib-rework-bitmap_parse.patch
lib-new-testcases-for-bitmap_parse_user.patch
cpumask-dont-calculate-length-of-the-input-string.patch
