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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 17 Sep 2014 10:23:04 +0200
From:	Rasmus Villemoes <>
To:	Theodore Ts'o <>
Cc:	Andrew Morton <>,
Subject: Re: [PATCH 00/22] treewide: Replace strnicmp with strncasecmp

On Tue, Sep 16 2014, Theodore Ts'o <> wrote:

> On Tue, Sep 16, 2014 at 10:51:14PM +0200, Rasmus Villemoes wrote:
>> The kernel used to contain two functions for length-delimited,
>> case-insensitive string comparison, strnicmp with correct semantics
>> and a slightly buggy strncasecmp. The latter is the POSIX name, so
>> strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper
>> for the new strncasecmp to avoid breaking existing users.
> For the sake of those people who need to review the patches, can you
> say a bit more about the difference in semantics between strnicmp and
> strncasecmp, and why it's safe to do a global search and replace
> without worrying about the semantic differences?

The new strncasecmp is exactly the old strnicmp, making
s/strnicmp/strncasecmp/g a semantic noop. But of course it needs to be
applied after the renaming. Andrew said he'd take these follow-up
patches and make sure they're applied in proper order. Even without the
follow-up patches, strnicmp users shouldn't be affected except for a
very small extra indirection overhead.

The two functions behaved identically whenever the length argument was
non-zero. For len==0, the old strncasecmp however effectively became

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists