Re: remaining flexible-array conversions

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Kees Cook <keescook@chromium.org>, Jason Gunthorpe <jgg@ziepe.ca>
Cc: Nathan Chancellor <natechancellor@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Greg KH <gregkh@linuxfoundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-rdma@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: Re: remaining flexible-array conversions
Date: Fri, 24 Apr 2020 10:36:02 -0500	[thread overview]
Message-ID: <da06212a-76d7-d68d-164e-9faafded5c09@embeddedor.com> (raw)
In-Reply-To: <202004240824.F042AFFBF@keescook>

On 4/24/20 10:24, Kees Cook wrote:
> On Fri, Apr 24, 2020 at 09:15:53AM -0300, Jason Gunthorpe wrote:
>> On Thu, Apr 23, 2020 at 08:47:04PM -0700, Nathan Chancellor wrote:
>>> Hi Gustavo,
>>>
>>> On Wed, Apr 22, 2020 at 01:26:02PM -0500, Gustavo A. R. Silva wrote:
>>>> Hi Linus,
>>>>
>>>> Just wanted to ask you if you would agree on pulling the remaining
>>>> flexible-array conversions all at once, after they bake for a couple
>>>> of weeks in linux-next[1]
>>>>
>>>> This is not a disruptive change and there are no code generation
>>>> differences. So, I think it would make better use of everyone's time
>>>> if you pull this treewide patch[2] from my tree (after sending you a
>>>> proper pull-request, of course) sometime in the next couple of weeks.
>>>>
>>>> Notice that the treewide patch I mention here has been successfully
>>>> built (on top of v5.7-rc1) for multiple architectures (arm, arm64,
>>>> sparc, powerpc, ia64, s390, i386, nios2, c6x, xtensa, openrisc, mips,
>>>> parisc, x86_64, riscv, sh, sparc64) and 82 different configurations
>>>> with the help of the 0-day CI guys[3].
>>>>
>>>> What do you think?
>>>>
>>>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=d496496793ff69c4a6b1262a0001eb5cd0a56544
>>>> [2] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?h=for-next/kspp&id=d783301058f3d3605f9ad34f0192692ef572d663
>>>> [3] https://github.com/GustavoARSilva/linux-hardening/blob/master/cii/kernel-ci/kspp-fam0-20200420.md
>>>>
>>>> Thanks
>>>
>>> That patch in -next appears to introduce some warnings with clang when
>>> CONFIG_UAPI_HEADER_TEST is enabled (allyesconfig/allmodconfig exposed it
>>> for us with KernelCI [1]):
>>
>> Indeed, I've tried these conversions before and run into problems like
>> this, and more. Particularly in userspace these structs also get
>> embedded in other structs and the warnings explode.
>>
>> Please drop changes to ib_user_verbs.h from your series
> 
> We might need to make the UAPI changes separately (or not at all).
> 

I agree.  In the meantime I've dropped the changes for ib_user_verbs.h
and will do the same for all the UAPI files.

--
Gustavo