linux-kernel - Re: [PATCH/RFC 1/2] lib: string: Remove duplicated function

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20140911152241.22ce7f1ebecef7ce7e01b112@linux-foundation.org>
Date:	Thu, 11 Sep 2014 15:22:41 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Rasmus Villemoes <linux@...musvillemoes.dk>
Cc:	Grant Likely <grant.likely@...aro.org>,
	Andi Kleen <ak@...ux.intel.com>,
	Dan Carpenter <dan.carpenter@...cle.com>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH/RFC 1/2] lib: string: Remove duplicated function

On Wed, 27 Aug 2014 09:36:01 +0200 Rasmus Villemoes <linux@...musvillemoes.dk> wrote:

> lib/string.c contains two functions, strnicmp and strncasecmp, which
> do roughly the same thing, namely compare two strings
> case-insensitively up to a given bound. They have slightly different
> implementations, but the only important difference is that strncasecmp
> doesn't handle len==0 appropriately; it effectively becomes strcasecmp
> in that case. strnicmp correctly says that two strings are always
> equal in their first 0 characters.
> 
> strncasecmp is the POSIX name for this functionality. So rename the
> non-broken function to the standard name. To minimize the impact on
> the rest of the kernel (and since both are exported to modules), make
> strnicmp a wrapper for strncasecmp.

I guess it's safe to assume that nobody was depending on the
strncasecmp() bug.

The existing strnicmp() implementation is rather verbose, but I expect
that avoiding the tolower() cost where possible makes sense.

Yes, please prepare the strnicmp()->strncasecmp() patches and let's get
them merged up.  After a kernel release or two we can zap the
back-compat wrapper.


And it isn't just "out of tree modules" that we should be concerned
about - we'll commonly find that "to be in tree" code is using
interfaces which we're trying to alter or remove, so it takes a cycle
or two to get everything propagated.  Most of this code can be found in
linux-next.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/