Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 09 Aug 2023 18:08:58 +0200
Message-ID: <87v8doci5h.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Takashi Iwai <tiwai@suse.de>, Christoph Hellwig <hch@lst.de>,
        linux-kernel@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mark Brown <broonie@kernel.org>, netdev@vger.kernel.org
Subject: Re: [PATCH RFC] Introduce uniptr_t as a generic "universal" pointer
In-Reply-To: <CAHk-=wgGV61xrG=gO0=dXH64o2TDWWrXn1mx-CX885JZ7h84Og@mail.gmail.com>
References: <87edkce118.wl-tiwai@suse.de>
        <20230809143801.GA693@lst.de>
        <87a5v0e0mv.wl-tiwai@suse.de>
        <CAHk-=wgGV61xrG=gO0=dXH64o2TDWWrXn1mx-CX885JZ7h84Og@mail.gmail.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Wed, 09 Aug 2023 17:59:20 +0200,
Linus Torvalds wrote:
> 
> On Wed, 9 Aug 2023 at 07:44, Takashi Iwai <tiwai@suse.de> wrote:
> >
> > The remaining question is whether the use of sockptr_t for other
> > subsystems as a generic pointer is a recommended / acceptable move...
> 
> Very much not recommended. sockptr_t is horrible too, but it was (part
> of) what made it possible to fix an even worse horrible historical
> mistake (ie getting rid of set_fs()).
> 
> So I detest sockptr_t. It's garbage. At the very minimum it should
> have had the length associated with it, not passed separately.
> 
> But it's garbage exactly because it allowed for conversion of some
> much much horrid legacy code with fairly minimal impact.
> 
> New code does *not* have that excuse.
> 
> DO NOT MIX USER AND KERNEL POINTERS. And don't add interfaces that
> think such mixing is ok. Pointers should be statically clearly of one
> type or the other, and never lied about.
> 
> Or you go all the way, and do that whole iterator thing, and make it
> very clear that you're doing something truly generic that can be
> passed fairly widely along across subsystem boundaries.

OK, it looks like we need to scratch the idea...


Takashi