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author | Yury Norov <yury.norov@gmail.com> | 2020-02-03 17:37:31 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-04 03:05:26 +0000 |
commit | e66eda0615c8767694150b3c595f3e9cf9ac4294 (patch) | |
tree | 60b674b6ae9d3cecbc006314167702237f662bc2 | |
parent | 7eb2e94e969435519cfd8e07dc654508b3a42d81 (diff) | |
download | linux-stable-e66eda0615c8767694150b3c595f3e9cf9ac4294.tar.gz linux-stable-e66eda0615c8767694150b3c595f3e9cf9ac4294.tar.bz2 linux-stable-e66eda0615c8767694150b3c595f3e9cf9ac4294.zip |
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/20200102043031.30357-5-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: "Tobin C . Harding" <tobin@kernel.org>
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | lib/bitmap.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index 6e175fbd69a9..0a24ce484e91 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -530,22 +530,22 @@ 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); |