Commit 281327c99bcaa8dbd4fe49cc32178dc59b0e61b8
Committed by
Linus Torvalds
1 parent
9f61589469
lib: make bitmap_parselist_user() a wrapper on bitmap_parselist()
Patch series "lib: rework bitmap_parselist and tests", v5. 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@marvell.com Signed-off-by: Yury Norov <ynorov@marvell.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Mike Travis <travis@sgi.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 11 additions and 8 deletions Side-by-side Diff
lib/bitmap.c
... | ... | @@ -632,19 +632,22 @@ |
632 | 632 | * @nmaskbits: size of bitmap, in bits. |
633 | 633 | * |
634 | 634 | * Wrapper for bitmap_parselist(), providing it with user buffer. |
635 | - * | |
636 | - * We cannot have this as an inline function in bitmap.h because it needs | |
637 | - * linux/uaccess.h to get the access_ok() declaration and this causes | |
638 | - * cyclic dependencies. | |
639 | 635 | */ |
640 | 636 | int bitmap_parselist_user(const char __user *ubuf, |
641 | 637 | unsigned int ulen, unsigned long *maskp, |
642 | 638 | int nmaskbits) |
643 | 639 | { |
644 | - if (!access_ok(ubuf, ulen)) | |
645 | - return -EFAULT; | |
646 | - return __bitmap_parselist((const char __force *)ubuf, | |
647 | - ulen, 1, maskp, nmaskbits); | |
640 | + char *buf; | |
641 | + int ret; | |
642 | + | |
643 | + buf = memdup_user_nul(ubuf, ulen); | |
644 | + if (IS_ERR(buf)) | |
645 | + return PTR_ERR(buf); | |
646 | + | |
647 | + ret = bitmap_parselist(buf, maskp, nmaskbits); | |
648 | + | |
649 | + kfree(buf); | |
650 | + return ret; | |
648 | 651 | } |
649 | 652 | EXPORT_SYMBOL(bitmap_parselist_user); |
650 | 653 |