lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <8322099f-4ef3-6a5d-4a66-27c4b3329884@amd.com>
Date:   Thu, 1 Sep 2022 09:49:01 +0200
From:   Christian König <christian.koenig@....com>
To:     Dmitry Osipenko <dmitry.osipenko@...labora.com>,
        David Airlie <airlied@...ux.ie>,
        Gerd Hoffmann <kraxel@...hat.com>,
        Gurchetan Singh <gurchetansingh@...omium.org>,
        Chia-I Wu <olvaffe@...il.com>, Daniel Vetter <daniel@...ll.ch>,
        Daniel Almeida <daniel.almeida@...labora.com>,
        Gert Wollny <gert.wollny@...labora.com>,
        Gustavo Padovan <gustavo.padovan@...labora.com>,
        Daniel Stone <daniel@...ishbar.org>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Rob Clark <robdclark@...il.com>,
        Sumit Semwal <sumit.semwal@...aro.org>,
        "Pan, Xinhui" <Xinhui.Pan@....com>,
        Thierry Reding <thierry.reding@...il.com>,
        Tomasz Figa <tfiga@...omium.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Alex Deucher <alexander.deucher@....com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        Thomas Hellström <thomas_os@...pmail.org>,
        Qiang Yu <yuq825@...il.com>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Amol Maheshwari <amahesh@....qualcomm.com>,
        Jason Gunthorpe <jgg@...pe.ca>,
        Leon Romanovsky <leon@...nel.org>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
        Tomi Valkeinen <tomba@...nel.org>,
        Russell King <linux@...linux.org.uk>,
        Lucas Stach <l.stach@...gutronix.de>,
        Christian Gmeiner <christian.gmeiner@...il.com>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Dmitry Osipenko <digetx@...il.com>,
        linux-media@...r.kernel.org, linaro-mm-sig@...ts.linaro.org,
        amd-gfx@...ts.freedesktop.org, intel-gfx@...ts.freedesktop.org,
        kernel@...labora.com, virtualization@...ts.linux-foundation.org,
        linux-rdma@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v4 00/21] Move all drivers to a common dma-buf locking
 convention

Hi Dmitry,

I've gone over this multiple times now and while it is still possible 
that we missed something I think that this should land now.

The whole topic is just to complicated that we can 100% sure guarantee 
that there isn't anything wrong with the locking, but lockdep and driver 
testing should allow us to quickly find remaining issues.

Do you have commit rights to drm-misc-next or should I push it?

Thanks,
Christian.

Am 31.08.22 um 17:37 schrieb Dmitry Osipenko:
> Hello,
>
> This series moves all drivers to a dynamic dma-buf locking specification.
>  From now on all dma-buf importers are made responsible for holding
> dma-buf's reservation lock around all operations performed over dma-bufs
> in accordance to the locking specification. This allows us to utilize
> reservation lock more broadly around kernel without fearing of a potential
> deadlocks.
>
> This patchset passes all i915 selftests. It was also tested using VirtIO,
> Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
> of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
> which covers majority of kernel drivers since rest of the drivers share
> same or similar code paths.
>
> Changelog:
>
> v4: - Added dma_buf_mmap() to the "locking convention" documentation,
>        which was missed by accident in v3.
>
>      - Added acks from Christian König, Tomasz Figa and Hans Verkuil that
>        they gave to couple v3 patches.
>
>      - Dropped the "_unlocked" postfix from function names that don't have
>        the locked variant, as was requested by Christian König.
>
>      - Factored out the per-driver preparations into separate patches
>        to ease reviewing of the changes, which is now doable without the
>        global dma-buf functions renaming.
>
>      - Factored out the dynamic locking convention enforcements into separate
>        patches which add the final dma_resv_assert_held(dmabuf->resv) to the
>        dma-buf API functions.
>
> v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
>        into aseparate patches, like was suggested by Christian König.
>
>      - Corrected and factored out dma-buf locking documentation into
>        a separate patch, like was suggested by Christian König.
>
>      - Intel driver dropped the reservation locking fews days ago from
>        its BO-release code path, but we need that locking for the imported
>        GEMs because in the end that code path unmaps the imported GEM.
>        So I added back the locking needed by the imported GEMs, updating
>        the "dma-buf attachment locking specification" patch appropriately.
>
>      - Tested Nouveau+Intel dma-buf import/export combo.
>
>      - Tested udmabuf import to i915/Nouveau/AMDGPU.
>
>      - Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
>        to switch to locked dma-buf vmapping in the drm/gem: Take reservation
>        lock for vmap/vunmap operations" patch. In a result invalidated the
>        Christian's r-b that he gave to v2.
>
>      - Added locked dma-buf vmap/vunmap functions that are needed for fixing
>        vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
>        I actually had this change stashed for the drm-shmem shrinker patchset,
>        but then realized that it's already needed by the dma-buf patches.
>        Also improved my tests to better cover these code paths.
>
> v2: - Changed locking specification to avoid problems with a cross-driver
>        ww locking, like was suggested by Christian König. Now the attach/detach
>        callbacks are invoked without the held lock and exporter should take the
>        lock.
>
>      - Added "locking convention" documentation that explains which dma-buf
>        functions and callbacks are locked/unlocked for importers and exporters,
>        which was requested by Christian König.
>
>      - Added ack from Tomasz Figa to the V4L patches that he gave to v1.
>
> Dmitry Osipenko (21):
>    dma-buf: Add unlocked variant of vmapping functions
>    dma-buf: Add unlocked variant of attachment-mapping functions
>    drm/gem: Take reservation lock for vmap/vunmap operations
>    drm/prime: Prepare to dynamic dma-buf locking specification
>    drm/armada: Prepare to dynamic dma-buf locking specification
>    drm/i915: Prepare to dynamic dma-buf locking specification
>    drm/omapdrm: Prepare to dynamic dma-buf locking specification
>    drm/tegra: Prepare to dynamic dma-buf locking specification
>    drm/etnaviv: Prepare to dynamic dma-buf locking specification
>    RDMA/umem: Prepare to dynamic dma-buf locking specification
>    misc: fastrpc: Prepare to dynamic dma-buf locking specification
>    xen/gntdev: Prepare to dynamic dma-buf locking specification
>    media: videobuf2: Prepare to dynamic dma-buf locking specification
>    media: tegra-vde: Prepare to dynamic dma-buf locking specification
>    dma-buf: Move dma_buf_vmap() to dynamic locking specification
>    dma-buf: Move dma_buf_attach() to dynamic locking specification
>    dma-buf: Move dma_buf_map_attachment() to dynamic locking
>      specification
>    dma-buf: Move dma_buf_mmap() to dynamic locking specification
>    dma-buf: Document dynamic locking convention
>    media: videobuf2: Stop using internal dma-buf lock
>    dma-buf: Remove obsoleted internal lock
>
>   Documentation/driver-api/dma-buf.rst          |   6 +
>   drivers/dma-buf/dma-buf.c                     | 211 +++++++++++++++---
>   drivers/gpu/drm/armada/armada_gem.c           |   8 +-
>   drivers/gpu/drm/drm_client.c                  |   4 +-
>   drivers/gpu/drm/drm_gem.c                     |  24 ++
>   drivers/gpu/drm/drm_gem_dma_helper.c          |   6 +-
>   drivers/gpu/drm/drm_gem_framebuffer_helper.c  |   6 +-
>   drivers/gpu/drm/drm_gem_ttm_helper.c          |   9 +-
>   drivers/gpu/drm/drm_prime.c                   |   6 +-
>   drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c   |   2 +-
>   drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    |   2 +-
>   drivers/gpu/drm/i915/gem/i915_gem_object.c    |  12 +
>   .../drm/i915/gem/selftests/i915_gem_dmabuf.c  |  16 +-
>   drivers/gpu/drm/lima/lima_sched.c             |   4 +-
>   drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c     |   4 +-
>   drivers/gpu/drm/panfrost/panfrost_dump.c      |   4 +-
>   drivers/gpu/drm/panfrost/panfrost_perfcnt.c   |   6 +-
>   drivers/gpu/drm/qxl/qxl_object.c              |  17 +-
>   drivers/gpu/drm/qxl/qxl_prime.c               |   4 +-
>   drivers/gpu/drm/tegra/gem.c                   |  17 +-
>   drivers/infiniband/core/umem_dmabuf.c         |   7 +-
>   .../common/videobuf2/videobuf2-dma-contig.c   |  22 +-
>   .../media/common/videobuf2/videobuf2-dma-sg.c |  19 +-
>   .../common/videobuf2/videobuf2-vmalloc.c      |  17 +-
>   .../platform/nvidia/tegra-vde/dmabuf-cache.c  |   6 +-
>   drivers/misc/fastrpc.c                        |   6 +-
>   drivers/xen/gntdev-dmabuf.c                   |   8 +-
>   include/drm/drm_gem.h                         |   3 +
>   include/linux/dma-buf.h                       |  17 +-
>   29 files changed, 318 insertions(+), 155 deletions(-)
>

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ