From: Catalin Marinas <catalin.marinas@arm.com>
To: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
linux-media@vger.kernel.org, kvm@vger.kernel.org,
linux-kselftest@vger.kernel.org,
Mark Rutland <mark.rutland@arm.com>,
Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
Will Deacon <will.deacon@arm.com>,
Kostya Serebryany <kcc@google.com>,
Khalid Aziz <khalid.aziz@oracle.com>,
Felix Kuehling <Felix.Kuehling@amd.com>,
Jacob Bramley <Jacob.Bramley@arm.com>,
Leon Romanovsky <leon@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
Evgeniy Stepanov <eugenis@google.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Kees Cook <keescook@chromium.org>,
Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>,
Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
Alex Williamson <alex.williamson@redhat.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Yishai Hadas <yishaih@mellanox.com>,
Jens Wiklander <jens.wiklander@linaro.org>,
Lee Smith <Lee.Smith@arm.com>,
Alexander Deucher <Alexander.Deucher@amd.com>,
Andrew Morton <akpm@linux-foundation.org>, enh <enh@google.com>,
Robin Murphy <robin.murphy@arm.com>,
Christian Koenig <Christian.Koenig@amd.com>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: Re: [PATCH v17 03/15] arm64: Introduce prctl() options to control the tagged user addresses ABI
Date: Thu, 13 Jun 2019 16:57:55 +0100 [thread overview]
Message-ID: <20190613155754.GX28951@C02TF0J2HF1T.local> (raw)
In-Reply-To: <99cc257d-5e99-922a-fbe7-3bbaf3621e38@arm.com>
On Thu, Jun 13, 2019 at 04:45:54PM +0100, Vincenzo Frascino wrote:
> On 13/06/2019 16:35, Catalin Marinas wrote:
> > On Thu, Jun 13, 2019 at 12:16:59PM +0100, Dave P Martin wrote:
> >> On Wed, Jun 12, 2019 at 01:43:20PM +0200, Andrey Konovalov wrote:
> >>> +
> >>> +/*
> >>> + * Control the relaxed ABI allowing tagged user addresses into the kernel.
> >>> + */
> >>> +static unsigned int tagged_addr_prctl_allowed = 1;
> >>> +
> >>> +long set_tagged_addr_ctrl(unsigned long arg)
> >>> +{
> >>> + if (!tagged_addr_prctl_allowed)
> >>> + return -EINVAL;
> >>
> >> So, tagging can actually be locked on by having a process enable it and
> >> then some possibly unrelated process clearing tagged_addr_prctl_allowed.
> >> That feels a bit weird.
> >
> > The problem is that if you disable the ABI globally, lots of
> > applications would crash. This sysctl is meant as a way to disable the
> > opt-in to the TBI ABI. Another option would be a kernel command line
> > option (I'm not keen on a Kconfig option).
>
> Why you are not keen on a Kconfig option?
Because I don't want to rebuild the kernel/reboot just to be able to
test how user space handles the ABI opt-in. I'm ok with a Kconfig option
to disable this globally in addition to a run-time option (if actually
needed, I'm not sure).
--
Catalin
next prev parent reply other threads:[~2019-06-13 15:58 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 11:43 [PATCH v17 00/15] arm64: untag user pointers passed to the kernel Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 01/15] arm64: untag user pointers in access_ok and __uaccess_mask_ptr Andrey Konovalov
2019-06-12 14:26 ` Vincenzo Frascino
2019-06-12 11:43 ` [PATCH v17 02/15] lib, arm64: untag user pointers in strn*_user Andrey Konovalov
2019-06-12 14:28 ` Vincenzo Frascino
2019-06-12 11:43 ` [PATCH v17 03/15] arm64: Introduce prctl() options to control the tagged user addresses ABI Andrey Konovalov
2019-06-12 14:30 ` Vincenzo Frascino
2019-06-12 14:55 ` Catalin Marinas
2019-06-13 11:02 ` Dave Martin
2019-06-13 15:26 ` Catalin Marinas
2019-06-14 5:13 ` Kees Cook
2019-06-18 9:18 ` Dave Martin
2019-06-13 11:16 ` Dave Martin
2019-06-13 15:35 ` Catalin Marinas
2019-06-13 15:45 ` Vincenzo Frascino
2019-06-13 15:57 ` Catalin Marinas [this message]
2019-06-13 16:15 ` Vincenzo Frascino
2019-06-17 13:56 ` Catalin Marinas
2019-06-17 16:56 ` Szabolcs Nagy
2019-06-17 16:57 ` Evgenii Stepanov
2019-06-17 17:18 ` Catalin Marinas
2019-06-17 21:59 ` Evgenii Stepanov
2019-06-19 14:45 ` Andrey Konovalov
2019-06-19 15:29 ` Catalin Marinas
2019-06-12 11:43 ` [PATCH v17 04/15] mm, arm64: untag user pointers passed to memory syscalls Andrey Konovalov
2019-06-12 14:31 ` Vincenzo Frascino
2019-06-19 15:55 ` Khalid Aziz
2019-06-19 16:46 ` Khalid Aziz
2019-06-24 14:22 ` Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 05/15] mm, arm64: untag user pointers in mm/gup.c Andrey Konovalov
2019-06-12 14:33 ` Vincenzo Frascino
2019-06-19 16:41 ` Khalid Aziz
2019-06-12 11:43 ` [PATCH v17 06/15] mm, arm64: untag user pointers in get_vaddr_frames Andrey Konovalov
2019-06-12 14:34 ` Vincenzo Frascino
2019-06-19 16:48 ` Khalid Aziz
2019-06-12 11:43 ` [PATCH v17 07/15] fs, arm64: untag user pointers in copy_mount_options Andrey Konovalov
2019-06-12 14:35 ` Vincenzo Frascino
2019-06-19 20:01 ` Khalid Aziz
2019-06-12 11:43 ` [PATCH v17 08/15] userfaultfd, arm64: untag user pointers Andrey Konovalov
2019-06-12 14:40 ` Vincenzo Frascino
2019-06-12 11:43 ` [PATCH v17 09/15] drm/amdgpu, " Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 10/15] drm/radeon, arm64: untag user pointers in radeon_gem_userptr_ioctl Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 11/15] IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 12/15] media/v4l2-core, arm64: untag user pointers in videobuf_dma_contig_user_get Andrey Konovalov
2019-06-19 20:05 ` Khalid Aziz
2019-06-12 11:43 ` [PATCH v17 13/15] tee/shm, arm64: untag user pointers in tee_shm_register Andrey Konovalov
2019-06-12 11:43 ` [PATCH v17 14/15] vfio/type1, arm64: untag user pointers in vaddr_get_pfn Andrey Konovalov
2019-06-12 14:41 ` Vincenzo Frascino
2019-06-12 15:58 ` Auger Eric
2019-06-12 11:43 ` [PATCH v17 15/15] selftests, arm64: add a selftest for passing tagged pointers to kernel Andrey Konovalov
2019-06-12 12:30 ` Szabolcs Nagy
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