From: Mauro Carvalho Chehab <mchehab@kernel.org>
To: Joe Perches <joe@perches.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Arnd Bergmann <arnd@arndb.de>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Randy Dunlap <rdunlap@infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] media: do not use C++ style comments in uapi headers
Date: Wed, 5 Jun 2019 07:14:13 -0300 [thread overview]
Message-ID: <20190605071413.779bd821@coco.lan> (raw)
In-Reply-To: <b70cf8c1f901ea09abbdb22dd28244b18fd1a39d.camel@perches.com>
Em Tue, 04 Jun 2019 22:22:05 -0700
Joe Perches <joe@perches.com> escreveu:
> On Wed, 2019-06-05 at 07:10 +0200, Greg KH wrote:
> > On Wed, Jun 05, 2019 at 01:10:41PM +0900, Masahiro Yamada wrote:
> > > On Wed, Jun 5, 2019 at 3:21 AM Arnd Bergmann <arnd@arndb.de> wrote:
> []
> > > This means we cannot reliably use uint{8,16,32,64}_t in UAPI headers.
> >
> > We should not be doing that as they are in the userspace "namespace" of
> > variables, not in the kernel namespace. We've been over this many times
> > in the past :(
>
> Just not very successfully...
>
> $ git grep -w -P 'u?_?int(?:8|16|32|64)_t' include/uapi | wc -l
> 342
> $ git grep -w -P --name-only 'u?_?int(?:8|16|32|64)_t' include/uapi | wc -l
> 13
Out of curiosity, I decided to check those occurrences...
About half of those 13 files are false-positives:
- bpf.h, pps.h and amdgpu_drm.h use those int types only inside comments;
- drm.h and coda.h have their own typedefs for those int types;
- vmwgfx_drm.h includes drm.h (which has the typedefs).
So, only 6 headers actually use posix types in a way that it seems that
it would require including stdint.h:
- include/uapi/linux/fuse.h
This one explicitly includes stdint.h if !__KERNEL__
- include/uapi/linux/netfilter_bridge/ebtables.h,
include/uapi/linux/sctp.h,
include/uapi/scsi/scsi_netlink.h and
include/uapi/scsi/scsi_netlink_fc.h
They include linux/types.h unconditionally, relying on
scripts/headers_install.sh to remove it;
- include/uapi/scsi/scsi_bsg_fc.h
It doesn't include anything. In other words, it assumes that the c file
would include either linux/types.h or stdint.h.
---
Not saying that this is a good idea, but, as we have already a script that
it is meant to sanitize uAPI header files when installing them
(scripts/headers_install.sh), one could modify it (or convert to perl/python)
in a way that it would be doing something like[1]:
sed -E
...
-e 's,//(.*),/* \1 */,'
[1] the actual rule should be more complex than that, in order to avoid
replacing // inside /**/ comments.
Thanks,
Mauro
next prev parent reply other threads:[~2019-06-05 10:14 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-04 11:13 [PATCH] media: do not use C++ style comments in uapi headers Masahiro Yamada
2019-06-04 11:23 ` Joe Perches
2019-06-04 11:48 ` Masahiro Yamada
2019-06-04 12:04 ` Joe Perches
2019-06-04 11:54 ` Arnd Bergmann
2019-06-04 12:48 ` Masahiro Yamada
2019-06-04 13:32 ` Masahiro Yamada
2019-06-04 13:42 ` Greg KH
2019-06-04 15:27 ` Masahiro Yamada
2019-06-04 18:20 ` Arnd Bergmann
2019-06-05 4:10 ` Masahiro Yamada
2019-06-05 5:10 ` Greg KH
2019-06-05 5:22 ` Joe Perches
2019-06-05 6:02 ` Greg KH
2019-06-05 10:08 ` Masahiro Yamada
2019-06-05 10:14 ` Mauro Carvalho Chehab [this message]
2019-06-05 17:03 ` Joe Perches
2019-06-09 7:14 ` Masahiro Yamada
2019-06-09 11:55 ` Joe Perches
2019-06-09 13:08 ` Masahiro Yamada
2019-06-09 13:35 ` Joe Perches
2019-06-09 17:19 ` Masahiro Yamada
2019-06-09 17:42 ` Pavel Machek
2019-06-16 15:48 ` Pavel Machek
2019-06-04 14:42 ` Mauro Carvalho Chehab
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