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.
Signed-off-by: Yury Norov <yno...@marvell.com>
---
lib/bitmap.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/lib/bitmap.c b/lib/bitmap.c
index f235434df87b..300732031fad 100644
--- a/lib/bitmap.c
+++ b/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);
--
2.17.1
