linux-kernel - Re: [PATCH 2/9] fs: fix empty-body warning in posix

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: <722a746a-1438-60e3-04b2-c13eda2ad168@infradead.org>
Date:   Sat, 18 Apr 2020 11:55:38 -0700
From:   Randy Dunlap <rdunlap@...radead.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        linux-input@...r.kernel.org, Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, alsa-devel@...a-project.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org,
        "J. Bruce Fields" <bfields@...ldses.org>,
        Chuck Lever <chuck.lever@...cle.com>,
        "open list:NFS, SUNRPC, AND..." <linux-nfs@...r.kernel.org>,
        Johannes Berg <johannes@...solutions.net>,
        Dan Williams <dan.j.williams@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        Dave Jiang <dave.jiang@...el.com>,
        linux-nvdimm <linux-nvdimm@...ts.01.org>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        linux-scsi <linux-scsi@...r.kernel.org>,
        target-devel <target-devel@...r.kernel.org>,
        Zzy Wysm <zzy@...wysm.com>
Subject: Re: [PATCH 2/9] fs: fix empty-body warning in posix_acl.c

On 4/18/20 11:53 AM, Linus Torvalds wrote:
> On Sat, Apr 18, 2020 at 11:41 AM Randy Dunlap <rdunlap@...radead.org> wrote:
>>
>> Fix gcc empty-body warning when -Wextra is used:
> 
> Please don't do this.
> 
> First off, "do_empty()" adds nothing but confusion. Now it
> syntactically looks like it does something, and it's a new pattern to
> everybody. I've never seen it before.
> 
> Secondly, even if we were to do this, then the patch would be wrong:
> 
>>         if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED)
>> -               /* fall through */ ;
>> +               do_empty(); /* fall through */
> 
> That comment made little sense before, but it makes _no_ sense now.
> 
> What fall-through? I'm guessing it meant to say "nothing", and
> somebody was confused. With "do_empty()", it's even more confusing.
> 
> Thirdly, there's a *reason* why "-Wextra" isn't used.
> 
> The warnings enabled by -Wextra are usually complete garbage, and
> trying to fix them often makes the code worse. Exactly like here.

OK, no problem.  That's why PATCH 0/9 says RFC.

Oops. Crap. It was *supposed* to say RFC. :(

-- 
~Randy