From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: Dennis Zhou <dennis@kernel.org>
Cc: Christopher Lameter <cl@linux.com>,
Ben Dooks <ben.dooks@codethink.co.uk>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Tejun Heo <tj@kernel.org>, Nicholas Piggin <npiggin@gmail.com>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] fix __percpu annotation in asm-generic
Date: Tue, 3 Dec 2019 04:01:08 +0100 [thread overview]
Message-ID: <20191203030108.ch7n6yoqgsco2alj@ltop.local> (raw)
In-Reply-To: <20191202190718.GA18019@dennisz-mbp>
On Mon, Dec 02, 2019 at 02:07:18PM -0500, Dennis Zhou wrote:
> On Sat, Nov 30, 2019 at 01:00:37AM +0100, Luc Van Oostenryck wrote:
> > On Fri, Nov 29, 2019 at 06:11:59PM +0000, Christopher Lameter wrote:
> > > On Wed, 27 Nov 2019, Luc Van Oostenryck wrote:
> > >
> > > > 1) it would strip any address space, not just __percpu, so:
> > > > it would need to be combined with __verify_pcpu_ptr() or,
> > > > * a better name should be used,
> > >
> > > typeof_cast_kernel() to express the fact that it creates a kernel pointer
> > > and ignored the attributes??
> >
> > typeof_strip_address_space() would, I think, express this better.
> > It's not obvious at all to me that 'kernel' in 'typeof_cast_kernel()'
> > relates to the (default) kernel address space.
> > Maybe it's just me. I don't know.
> >
>
> I think typeof_cast_kernel() or typeof_force_kernel() are reasonable
> names. I kind of like the idea of cast/force over strip because we're
> really still moving address spaces even if it is moving it back.
Well, 'typeof_cast_kernel()' somehow conveys the idea but sounds
a bit weird as the macro doesn't contain a cast (expression).
> Thanks for debugging this. I'm still inclined to have a macro for either
> cast/force. I do agree it could be misused, but it's no different doing
> it in a macro than by just adding __force __kernel.
I'm glad to help making the kernel type-clean (with the goal of
catching more bugs earlier) but I admit that I absolutely detest
these layers of ugly macros.
I'm working on a nicer implementation but it's not yet ready.
Best regards,
-- Luc
next prev parent reply other threads:[~2019-12-03 3:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-26 20:06 [PATCH] fix __percpu annotation in asm-generic Luc Van Oostenryck
2019-11-27 15:55 ` Christopher Lameter
2019-11-27 17:53 ` Dennis Zhou
2019-11-27 22:54 ` Luc Van Oostenryck
2019-11-29 18:11 ` Christopher Lameter
2019-11-30 0:00 ` Luc Van Oostenryck
2019-12-02 19:07 ` Dennis Zhou
2019-12-02 19:42 ` Christopher Lameter
2019-12-03 3:01 ` Luc Van Oostenryck [this message]
2020-03-24 4:13 ` Jason A. Donenfeld
2020-03-24 6:44 ` Luc Van Oostenryck
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