linux-kernel - Re: [PATCH v2] kbuild: check uniqueness of module names

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <CAJ1xhMVaeQPoW1v91bcNOkw1FJOr7ddhDc-ir=3AiKRCSzCj=g@mail.gmail.com>
Date:   Fri, 17 May 2019 12:25:10 +0300
From:   Alexander Kapshuk <alexander.kapshuk@...il.com>
To:     Bernd Petrovitsch <bernd@...rovitsch.priv.at>
Cc:     Masahiro Yamada <yamada.masahiro@...ionext.com>,
        linux-kbuild@...r.kernel.org, Sam Ravnborg <sam@...nborg.org>,
        Arnd Bergmann <arnd@...db.de>,
        Greg KH <gregkh@...uxfoundation.org>,
        Jessica Yu <jeyu@...nel.org>,
        Lucas De Marchi <lucas.de.marchi@...il.com>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        Michael Schmitz <schmitzmic@...il.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Rusty Russell <rusty@...tcorp.com.au>,
        Kees Cook <keescook@...omium.org>,
        Michal Marek <michal.lkml@...kovi.net>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] kbuild: check uniqueness of module names

On Fri, May 17, 2019 at 11:58 AM Bernd Petrovitsch
<bernd@...rovitsch.priv.at> wrote:
>
> On 17/05/2019 10:16, Alexander Kapshuk wrote:
> [...]
> > The 'xargs' '-r' flag is a GNU extension.
> > If POSIX compliance is important here, the use of 'cat', 'xargs' and
> > 'basename' may be substituted with that of 'sed' to initialise
> > same_name_modules:
> > sed 's!.*/!!' modules.order modules.builtin | sort | uniq -d
>
> 's!' is TTBOMK also a GNU-extension:
> sed 's/.*\///' modules.order modules.builtin | sort | uniq -d

It isn't.
Here's an excerpt from the POSIX manpage for 'sed',
http://pubs.opengroup.org/onlinepubs/009695399/utilities/sed.html:
[2addr]s/BRE/replacement/flags
...  Any character other than backslash or <newline> can be used
instead of a slash to delimit the BRE and the replacement....

>
> > 'Sed' may also be used on its own in the 'for' loop instead of as part
> > of a pipeline along with 'grep' to generate the desired output:
> > sed '/\/'$m'/!d;s:^kernel/:  :' modules.order modules.builtin
>
> sed "/\/${m}/!d;s/^kernel\//  /" modules.order modules.builtin

The parameter expansion syntax is redundant here.
See https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_02:
The parameter name or symbol can be enclosed in braces, which are
optional except for positional parameters with more than one digit or
when parameter is a name and is followed by a character that could be
interpreted as part of the name.

Here's an alternative version using double quotes.
sed "/\/$m/!d;s:^kernel/:  :" modules.order modules.builtin

>
> MfG,
>         Bernd
> --
> Bernd Petrovitsch                  Email : bernd@...rovitsch.priv.at
>                      LUGA : http://www.luga.at