From: Joe Perches <joe@perches•com>
To: Rob Clark <robdclark@gmail•com>
Cc: "Gustavo Padovan" <gustavo@padovan•org>,
"Gustavo Padovan" <gustavo.padovan@collabora•co.uk>,
"Benjamin Herrenschmidt" <benh@kernel•crashing.org>,
"Paul Mackerras" <paulus@samba•org>,
"Michael Ellerman" <mpe@ellerman•id.au>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation•org>,
"Linux Kernel Mailing List" <linux-kernel@vger•kernel.org>,
devel@driverdev•osuosl.org,
"dri-devel@lists•freedesktop.org"
<dri-devel@lists•freedesktop.org>,
"Daniel Stone" <daniels@collabora•com>,
"Arve Hjønnevåg" <arve@android•com>,
"Riley Andrews" <riandrews@android•com>,
"Daniel Vetter" <daniel.vetter@ffwll•ch>,
"Greg Hackmann" <ghackmann@google•com>,
"John Harrison" <John.C.Harrison@intel•com>,
"Maarten Lankhorst" <maarten.lankhorst@linux•intel.com>,
"Andrew Morton" <akpm@linux-foundation•org>,
"David Airlie" <airlied@linux•ie>,
"Daniel Vetter" <daniel.vetter@intel•com>,
linuxppc-dev <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [PATCH v9 2/3] kernel.h: add to_user_ptr()
Date: Thu, 17 Mar 2016 13:40:07 -0700 [thread overview]
Message-ID: <1458247207.9556.28.camel@perches.com> (raw)
In-Reply-To: <CAF6AEGvQa8SOWCtoEfcFAxz6MQ0Nqc-ktqNCdfJU-32-m-mCEQ@mail.gmail.com>
On Thu, 2016-03-17 at 16:33 -0400, Rob Clark wrote:
> On Thu, Mar 17, 2016 at 4:22 PM, Joe Perches <joe@perches•com> wrote:
> > On Thu, 2016-03-17 at 15:43 -0300, Gustavo Padovan wrote:
> > > 2016-03-17 Gustavo Padovan <gustavo.padovan@collabora•co.uk>:
> > > > 2016-03-17 Joe Perches <joe@perches•com>:
> > > > > On Thu, 2016-03-17 at 14:30 -0300, Gustavo Padovan wrote:
> > > > > > This function had copies in 3 different files. Unify them in
> > > > > > kernel.h.
> > > > > This is only used by gpu/drm.
> > > > >
> > > > > I think this is a poor name for a generic function
> > > > > that would be in kernel.h.
> > > > >
> > > > > Isn't there an include file in linux/drm that's
> > > > > appropriate for this. Maybe drmP.h
> > > > >
> > > > > Maybe prefix this function name with drm_ too.
> > > > No, the next patch adds a user to drivers/staging (which will be moved
> > > > to drivers/dma-buf) soon. Maybe move to a different header in
> > > > include/linux/? not sure which one.
> > > >
> > > > >
> > > > >
> > > > > Also, there's this that might conflict:
> > > > >
> > > > > arch/powerpc/kernel/signal_32.c:#define to_user_ptr(p) ptr_to_compat(p)
> > > > > arch/powerpc/kernel/signal_32.c:#define to_user_ptr(p) ((unsigned long)(p))
> > > > Right, I'll figure out how to replace these two too.
> > > The powerpc to_user_ptr has a different meaning from the one I'm adding
> > > in this patch. I propose we just rename powerpc's to_user_ptr to
> > > __to_user_ptr and leave the rest as is.
> > I think that's not a good idea, and you should really check
> > this concept with the powerpc folk (added to to:s and cc:ed)
> >
> > If it were really added, then the function meaning is incorrect.
> >
> > This is taking a u64, casting that to (unsigned long/uint_ptr_t),
> > then converting that to a user pointer.
> >
> > Does that naming and use make sense on x86-32 or arm32?
> >
> fwiw Gustavo's version of to_user_ptr() is in use on arm32 and arm64..
> Not entirely sure what doesn't make sense about it
It's a name that seems like it should be a straightforward
cast of a kernel pointer to a __user pointer like:
static inline void __user *to_user_ptr(void *p)
{
return (void __user *)p;
}
As a static function in a single file, it's not
great, but OK, fine, it's static.
As a global function in kernel.h, it's misleading.
next prev parent reply other threads:[~2016-03-17 20:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1458235817-28375-1-git-send-email-gustavo@padovan.org>
[not found] ` <1458235817-28375-2-git-send-email-gustavo@padovan.org>
[not found] ` <1458236486.9556.11.camel@perches.com>
[not found] ` <20160317180523.GA2619@joana>
[not found] ` <20160317184318.GA2611@joana>
2016-03-17 20:22 ` [PATCH v9 2/3] kernel.h: add to_user_ptr() Joe Perches
2016-03-17 20:33 ` Rob Clark
2016-03-17 20:40 ` Joe Perches [this message]
2016-03-17 20:50 ` Rob Clark
2016-03-17 21:10 ` Joe Perches
2016-03-17 21:19 ` Gustavo Padovan
2016-03-17 21:25 ` Rob Clark
2016-03-17 21:33 ` Joe Perches
2016-03-17 22:16 ` Gustavo Padovan
2016-03-18 8:23 ` Daniel Vetter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1458247207.9556.28.camel@perches.com \
--to=joe@perches$(echo .)com \
--cc=John.C.Harrison@intel$(echo .)com \
--cc=airlied@linux$(echo .)ie \
--cc=akpm@linux-foundation$(echo .)org \
--cc=arve@android$(echo .)com \
--cc=benh@kernel$(echo .)crashing.org \
--cc=daniel.vetter@ffwll$(echo .)ch \
--cc=daniel.vetter@intel$(echo .)com \
--cc=daniels@collabora$(echo .)com \
--cc=devel@driverdev$(echo .)osuosl.org \
--cc=dri-devel@lists$(echo .)freedesktop.org \
--cc=ghackmann@google$(echo .)com \
--cc=gregkh@linuxfoundation$(echo .)org \
--cc=gustavo.padovan@collabora$(echo .)co.uk \
--cc=gustavo@padovan$(echo .)org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=maarten.lankhorst@linux$(echo .)intel.com \
--cc=mpe@ellerman$(echo .)id.au \
--cc=paulus@samba$(echo .)org \
--cc=riandrews@android$(echo .)com \
--cc=robdclark@gmail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox