Message ID | 20201127164131.2244124-1-daniel.vetter@ffwll.ch (mailing list archive) |
---|---|
Headers |
Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from <linux-media-owner@vger.kernel.org>) id 1kigoy-00CqgV-1P; Fri, 27 Nov 2020 16:42:08 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731499AbgK0Ql7 (ORCPT <rfc822;mkrufky@linuxtv.org> + 1 other); Fri, 27 Nov 2020 11:41:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728406AbgK0Ql6 (ORCPT <rfc822;linux-media@vger.kernel.org>); Fri, 27 Nov 2020 11:41:58 -0500 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41F13C0613D1 for <linux-media@vger.kernel.org>; Fri, 27 Nov 2020 08:41:58 -0800 (PST) Received: by mail-wm1-x341.google.com with SMTP id c198so5650089wmd.0 for <linux-media@vger.kernel.org>; Fri, 27 Nov 2020 08:41:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ESkSp6C7mvKV6tnu0bv0a5NUd9H7UZA/j9+KxBk62a8=; b=jQ8QYtZGE95X+kQNlT31arGz3fYSGvIwxc8CIQGHUAFqEsxjgCe3vvJrRkP5zcoBFd kyw+1PRtr/v1Vnaw3uyD+fyAim2cfgkJDD5Q3S0vbKD9lObKqNzb5ybH/JvOzGAGkiei EIiVoJbv/O7eYs/rJVz+0K/a9SqrRGH8KrGbM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ESkSp6C7mvKV6tnu0bv0a5NUd9H7UZA/j9+KxBk62a8=; b=gylNgEoeUaTMYGQ3tPBToDSB3Oa124s389ZKRxQg7VGy1u0U0CkaVp4Xwl/ua4y8XL 1BtwIYCJlQTh+6n9QRAR6ElKgHjO2k1AnWU6X6KKg32wWl8RdM4oRWwGNpYy3FrV77ET 0dBv3IGloJCoY4HtMHxjTgwkD6w6a9KwzGLuX5Cn6YOCJpXY3HYwuf/ae6gbjMfVjhNW UDzdaXPtINEN2MgJ1xTE5MHYsD259JOy71jDJkRVkB9DZoZHRehNl7LdJow+Up6AkpBQ MNQYIxf2MQBsohKtmEIxzfQ4cm0gk8vf9dZK3tuQPsuCCqzyV5W+4VLyzwwo6nTrBiiW qqtw== X-Gm-Message-State: AOAM530J00svWFLRwdlEFjMWcV1wuaD0q1/JKS9gU+HNKUdAxzA4pFo9 HIuxqWGBadZY2cGfgWrMOLpUGA== X-Google-Smtp-Source: ABdhPJy6H3y4sUz3l7M4JNsS6NM9YkD0oMXLhvCp0ba6p25GYS5KJlvCz2mFh2Zqh4wJSE93buN0qg== X-Received: by 2002:a1c:6a0d:: with SMTP id f13mr10199588wmc.172.1606495316997; Fri, 27 Nov 2020 08:41:56 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q12sm14859078wrx.86.2020.11.27.08.41.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Nov 2020 08:41:56 -0800 (PST) From: Daniel Vetter <daniel.vetter@ffwll.ch> To: DRI Development <dri-devel@lists.freedesktop.org>, LKML <linux-kernel@vger.kernel.org> Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Daniel Vetter <daniel.vetter@ffwll.ch> Subject: [PATCH v7 00/17] follow_pfn and other iomap races Date: Fri, 27 Nov 2020 17:41:14 +0100 Message-Id: <20201127164131.2244124-1-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: <linux-media.vger.kernel.org> X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.5 (--) X-LSpam-Report: No, score=-2.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no |
Series |
follow_pfn and other iomap races
|
|
Message
Daniel Vetter
Nov. 27, 2020, 4:41 p.m. UTC
Hi all Another update of my patch series to clamp down a bunch of races and gaps around follow_pfn and other access to iomem mmaps. Previous version: v1: https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ v2: https://lore.kernel.org/dri-devel/20201009075934.3509076-1-daniel.vetter@ffwll.ch v3: https://lore.kernel.org/dri-devel/20201021085655.1192025-1-daniel.vetter@ffwll.ch/ v4: https://lore.kernel.org/dri-devel/20201026105818.2585306-1-daniel.vetter@ffwll.ch/ v5: https://lore.kernel.org/dri-devel/20201030100815.2269-1-daniel.vetter@ffwll.ch/ v6: https://lore.kernel.org/dri-devel/20201119144146.1045202-1-daniel.vetter@ffwll.ch/ And the discussion that sparked this journey: https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ I think the first 12 patches are ready for landing. The parts starting with "mm: Add unsafe_follow_pfn" probably need more baking time. Andrew, can you please pick these up, or do you prefer I do a topic branch and send them to Linus directly in the next merge window? Changes in v7: - more acks/reviews - reordered with the ready pieces at the front - simplified the new follow_pfn function as Jason suggested Changes in v6: - Tested v4l userptr as Tomasz suggested. No boom observed - Added RFC for locking down follow_pfn, per discussion with Christoph and Jason. - Explain why pup_fast is safe in relevant patches, there was a bit a confusion when discussing v5. - Fix up the resource patch, with CONFIG_IO_STRICT_DEVMEM it crashed on boot due to an unintended change (reported by John) Changes in v5: - Tomasz found some issues in the media patches - Polish suggested by Christoph for the unsafe_follow_pfn patch Changes in v4: - Drop the s390 patch, that was very stand-alone and now queued up to land through s390 trees. - Comment polish per Dan's review. Changes in v3: - Bunch of polish all over, no functional changes aside from one barrier in the resource code, for consistency. - A few more r-b tags. Changes in v2: - tons of small polish&fixes all over, thanks to all the reviewers who spotted issues - I managed to test at least the generic_access_phys and pci mmap revoke stuff with a few gdb sessions using our i915 debug tools (hence now also the drm/i915 patch to properly request all the pci bar regions) - reworked approach for the pci mmap revoke: Infrastructure moved into kernel/resource.c, address_space mapping is now set up at open time for everyone (which required some sysfs changes). Does indeed look a lot cleaner and a lot less invasive than I feared at first. Coments and review on the remaining bits very much welcome, especially from the kvm and vfio side. Cheers, Daniel Daniel Vetter (17): drm/exynos: Stop using frame_vector helpers drm/exynos: Use FOLL_LONGTERM for g2d cmdlists misc/habana: Stop using frame_vector helpers misc/habana: Use FOLL_LONGTERM for userptr mm/frame-vector: Use FOLL_LONGTERM media: videobuf2: Move frame_vector into media subsystem mm: Close race in generic_access_phys PCI: Obey iomem restrictions for procfs mmap /dev/mem: Only set filp->f_mapping resource: Move devmem revoke code to resource framework sysfs: Support zapping of binary attr mmaps PCI: Revoke mappings like devmem mm: Add unsafe_follow_pfn media/videobuf1|2: Mark follow_pfn usage as unsafe vfio/type1: Mark follow_pfn as unsafe kvm: pass kvm argument to follow_pfn callsites mm: add mmu_notifier argument to follow_pfn arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +- arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +- arch/powerpc/kvm/e500_mmu_host.c | 2 +- arch/x86/kvm/mmu/mmu.c | 8 +- drivers/char/mem.c | 86 +------------- drivers/gpu/drm/exynos/Kconfig | 1 - drivers/gpu/drm/exynos/exynos_drm_g2d.c | 48 ++++---- drivers/media/common/videobuf2/Kconfig | 1 - drivers/media/common/videobuf2/Makefile | 1 + .../media/common/videobuf2}/frame_vector.c | 57 ++++----- .../media/common/videobuf2/videobuf2-memops.c | 3 +- drivers/media/platform/omap/Kconfig | 1 - drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +- drivers/misc/habanalabs/Kconfig | 1 - drivers/misc/habanalabs/common/habanalabs.h | 6 +- drivers/misc/habanalabs/common/memory.c | 52 +++----- drivers/pci/pci-sysfs.c | 4 + drivers/pci/proc.c | 6 + drivers/vfio/vfio_iommu_type1.c | 4 +- fs/sysfs/file.c | 11 ++ include/linux/ioport.h | 6 +- include/linux/kvm_host.h | 9 +- include/linux/mm.h | 50 +------- include/linux/sysfs.h | 2 + include/media/frame_vector.h | 47 ++++++++ include/media/videobuf2-core.h | 1 + kernel/resource.c | 98 ++++++++++++++- mm/Kconfig | 3 - mm/Makefile | 1 - mm/memory.c | 112 +++++++++++++++--- mm/nommu.c | 16 ++- security/Kconfig | 13 ++ virt/kvm/kvm_main.c | 56 +++++---- 33 files changed, 413 insertions(+), 299 deletions(-) rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%) create mode 100644 include/media/frame_vector.h
Comments
On Fri, Nov 27, 2020 at 05:41:14PM +0100, Daniel Vetter wrote: > Hi all > > Another update of my patch series to clamp down a bunch of races and gaps > around follow_pfn and other access to iomem mmaps. Previous version: > > v1: https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ > v2: https://lore.kernel.org/dri-devel/20201009075934.3509076-1-daniel.vetter@ffwll.ch > v3: https://lore.kernel.org/dri-devel/20201021085655.1192025-1-daniel.vetter@ffwll.ch/ > v4: https://lore.kernel.org/dri-devel/20201026105818.2585306-1-daniel.vetter@ffwll.ch/ > v5: https://lore.kernel.org/dri-devel/20201030100815.2269-1-daniel.vetter@ffwll.ch/ > v6: https://lore.kernel.org/dri-devel/20201119144146.1045202-1-daniel.vetter@ffwll.ch/ > > And the discussion that sparked this journey: > > https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ > > I think the first 12 patches are ready for landing. The parts starting > with "mm: Add unsafe_follow_pfn" probably need more baking time. > > Andrew, can you please pick these up, or do you prefer I do a topic branch > and send them to Linus directly in the next merge window? > > Changes in v7: > - more acks/reviews > - reordered with the ready pieces at the front > - simplified the new follow_pfn function as Jason suggested > > Changes in v6: > - Tested v4l userptr as Tomasz suggested. No boom observed > - Added RFC for locking down follow_pfn, per discussion with Christoph and > Jason. > - Explain why pup_fast is safe in relevant patches, there was a bit a > confusion when discussing v5. > - Fix up the resource patch, with CONFIG_IO_STRICT_DEVMEM it crashed on > boot due to an unintended change (reported by John) > > Changes in v5: > - Tomasz found some issues in the media patches > - Polish suggested by Christoph for the unsafe_follow_pfn patch > > Changes in v4: > - Drop the s390 patch, that was very stand-alone and now queued up to land > through s390 trees. > - Comment polish per Dan's review. > > Changes in v3: > - Bunch of polish all over, no functional changes aside from one barrier > in the resource code, for consistency. > - A few more r-b tags. > > Changes in v2: > - tons of small polish&fixes all over, thanks to all the reviewers who > spotted issues > - I managed to test at least the generic_access_phys and pci mmap revoke > stuff with a few gdb sessions using our i915 debug tools (hence now also > the drm/i915 patch to properly request all the pci bar regions) > - reworked approach for the pci mmap revoke: Infrastructure moved into > kernel/resource.c, address_space mapping is now set up at open time for > everyone (which required some sysfs changes). Does indeed look a lot > cleaner and a lot less invasive than I feared at first. > > Coments and review on the remaining bits very much welcome, especially > from the kvm and vfio side. > > Cheers, Daniel > > Daniel Vetter (17): > drm/exynos: Stop using frame_vector helpers > drm/exynos: Use FOLL_LONGTERM for g2d cmdlists > misc/habana: Stop using frame_vector helpers > misc/habana: Use FOLL_LONGTERM for userptr > mm/frame-vector: Use FOLL_LONGTERM > media: videobuf2: Move frame_vector into media subsystem > mm: Close race in generic_access_phys > PCI: Obey iomem restrictions for procfs mmap > /dev/mem: Only set filp->f_mapping > resource: Move devmem revoke code to resource framework > sysfs: Support zapping of binary attr mmaps > PCI: Revoke mappings like devmem As Jason suggested, I've pulled the first 1 patches into a topic branch. Stephen, can you please add the below to linux-next for the 5.12 merge window? git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup Once this part has landed I'll see what to do with the below part. Thanks, Daniel > mm: Add unsafe_follow_pfn > media/videobuf1|2: Mark follow_pfn usage as unsafe > vfio/type1: Mark follow_pfn as unsafe > kvm: pass kvm argument to follow_pfn callsites > mm: add mmu_notifier argument to follow_pfn > > arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +- > arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +- > arch/powerpc/kvm/e500_mmu_host.c | 2 +- > arch/x86/kvm/mmu/mmu.c | 8 +- > drivers/char/mem.c | 86 +------------- > drivers/gpu/drm/exynos/Kconfig | 1 - > drivers/gpu/drm/exynos/exynos_drm_g2d.c | 48 ++++---- > drivers/media/common/videobuf2/Kconfig | 1 - > drivers/media/common/videobuf2/Makefile | 1 + > .../media/common/videobuf2}/frame_vector.c | 57 ++++----- > .../media/common/videobuf2/videobuf2-memops.c | 3 +- > drivers/media/platform/omap/Kconfig | 1 - > drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +- > drivers/misc/habanalabs/Kconfig | 1 - > drivers/misc/habanalabs/common/habanalabs.h | 6 +- > drivers/misc/habanalabs/common/memory.c | 52 +++----- > drivers/pci/pci-sysfs.c | 4 + > drivers/pci/proc.c | 6 + > drivers/vfio/vfio_iommu_type1.c | 4 +- > fs/sysfs/file.c | 11 ++ > include/linux/ioport.h | 6 +- > include/linux/kvm_host.h | 9 +- > include/linux/mm.h | 50 +------- > include/linux/sysfs.h | 2 + > include/media/frame_vector.h | 47 ++++++++ > include/media/videobuf2-core.h | 1 + > kernel/resource.c | 98 ++++++++++++++- > mm/Kconfig | 3 - > mm/Makefile | 1 - > mm/memory.c | 112 +++++++++++++++--- > mm/nommu.c | 16 ++- > security/Kconfig | 13 ++ > virt/kvm/kvm_main.c | 56 +++++---- > 33 files changed, 413 insertions(+), 299 deletions(-) > rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%) > create mode 100644 include/media/frame_vector.h > > -- > 2.29.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Tue, Jan 12, 2021 at 2:24 PM Daniel Vetter <daniel@ffwll.ch> wrote: > > On Fri, Nov 27, 2020 at 05:41:14PM +0100, Daniel Vetter wrote: > > Hi all > > > > Another update of my patch series to clamp down a bunch of races and gaps > > around follow_pfn and other access to iomem mmaps. Previous version: > > > > v1: https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ > > v2: https://lore.kernel.org/dri-devel/20201009075934.3509076-1-daniel.vetter@ffwll.ch > > v3: https://lore.kernel.org/dri-devel/20201021085655.1192025-1-daniel.vetter@ffwll.ch/ > > v4: https://lore.kernel.org/dri-devel/20201026105818.2585306-1-daniel.vetter@ffwll.ch/ > > v5: https://lore.kernel.org/dri-devel/20201030100815.2269-1-daniel.vetter@ffwll.ch/ > > v6: https://lore.kernel.org/dri-devel/20201119144146.1045202-1-daniel.vetter@ffwll.ch/ > > > > And the discussion that sparked this journey: > > > > https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/ > > > > I think the first 12 patches are ready for landing. The parts starting > > with "mm: Add unsafe_follow_pfn" probably need more baking time. > > > > Andrew, can you please pick these up, or do you prefer I do a topic branch > > and send them to Linus directly in the next merge window? > > > > Changes in v7: > > - more acks/reviews > > - reordered with the ready pieces at the front > > - simplified the new follow_pfn function as Jason suggested > > > > Changes in v6: > > - Tested v4l userptr as Tomasz suggested. No boom observed > > - Added RFC for locking down follow_pfn, per discussion with Christoph and > > Jason. > > - Explain why pup_fast is safe in relevant patches, there was a bit a > > confusion when discussing v5. > > - Fix up the resource patch, with CONFIG_IO_STRICT_DEVMEM it crashed on > > boot due to an unintended change (reported by John) > > > > Changes in v5: > > - Tomasz found some issues in the media patches > > - Polish suggested by Christoph for the unsafe_follow_pfn patch > > > > Changes in v4: > > - Drop the s390 patch, that was very stand-alone and now queued up to land > > through s390 trees. > > - Comment polish per Dan's review. > > > > Changes in v3: > > - Bunch of polish all over, no functional changes aside from one barrier > > in the resource code, for consistency. > > - A few more r-b tags. > > > > Changes in v2: > > - tons of small polish&fixes all over, thanks to all the reviewers who > > spotted issues > > - I managed to test at least the generic_access_phys and pci mmap revoke > > stuff with a few gdb sessions using our i915 debug tools (hence now also > > the drm/i915 patch to properly request all the pci bar regions) > > - reworked approach for the pci mmap revoke: Infrastructure moved into > > kernel/resource.c, address_space mapping is now set up at open time for > > everyone (which required some sysfs changes). Does indeed look a lot > > cleaner and a lot less invasive than I feared at first. > > > > Coments and review on the remaining bits very much welcome, especially > > from the kvm and vfio side. > > > > Cheers, Daniel > > > > Daniel Vetter (17): > > drm/exynos: Stop using frame_vector helpers > > drm/exynos: Use FOLL_LONGTERM for g2d cmdlists > > misc/habana: Stop using frame_vector helpers > > misc/habana: Use FOLL_LONGTERM for userptr > > mm/frame-vector: Use FOLL_LONGTERM > > media: videobuf2: Move frame_vector into media subsystem > > mm: Close race in generic_access_phys > > PCI: Obey iomem restrictions for procfs mmap > > /dev/mem: Only set filp->f_mapping > > resource: Move devmem revoke code to resource framework > > sysfs: Support zapping of binary attr mmaps > > PCI: Revoke mappings like devmem > > As Jason suggested, I've pulled the first 1 patches into a topic branch. Uh this was meant to read "first _12_ patches" ofc. -Daniel > > Stephen, can you please add the below to linux-next for the 5.12 merge > window? > > git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup > > Once this part has landed I'll see what to do with the below part. > > Thanks, Daniel > > > mm: Add unsafe_follow_pfn > > media/videobuf1|2: Mark follow_pfn usage as unsafe > > vfio/type1: Mark follow_pfn as unsafe > > kvm: pass kvm argument to follow_pfn callsites > > mm: add mmu_notifier argument to follow_pfn > > > > arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +- > > arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +- > > arch/powerpc/kvm/e500_mmu_host.c | 2 +- > > arch/x86/kvm/mmu/mmu.c | 8 +- > > drivers/char/mem.c | 86 +------------- > > drivers/gpu/drm/exynos/Kconfig | 1 - > > drivers/gpu/drm/exynos/exynos_drm_g2d.c | 48 ++++---- > > drivers/media/common/videobuf2/Kconfig | 1 - > > drivers/media/common/videobuf2/Makefile | 1 + > > .../media/common/videobuf2}/frame_vector.c | 57 ++++----- > > .../media/common/videobuf2/videobuf2-memops.c | 3 +- > > drivers/media/platform/omap/Kconfig | 1 - > > drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +- > > drivers/misc/habanalabs/Kconfig | 1 - > > drivers/misc/habanalabs/common/habanalabs.h | 6 +- > > drivers/misc/habanalabs/common/memory.c | 52 +++----- > > drivers/pci/pci-sysfs.c | 4 + > > drivers/pci/proc.c | 6 + > > drivers/vfio/vfio_iommu_type1.c | 4 +- > > fs/sysfs/file.c | 11 ++ > > include/linux/ioport.h | 6 +- > > include/linux/kvm_host.h | 9 +- > > include/linux/mm.h | 50 +------- > > include/linux/sysfs.h | 2 + > > include/media/frame_vector.h | 47 ++++++++ > > include/media/videobuf2-core.h | 1 + > > kernel/resource.c | 98 ++++++++++++++- > > mm/Kconfig | 3 - > > mm/Makefile | 1 - > > mm/memory.c | 112 +++++++++++++++--- > > mm/nommu.c | 16 ++- > > security/Kconfig | 13 ++ > > virt/kvm/kvm_main.c | 56 +++++---- > > 33 files changed, 413 insertions(+), 299 deletions(-) > > rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%) > > create mode 100644 include/media/frame_vector.h > > > > -- > > 2.29.2 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
Hi Daniel, On Tue, 12 Jan 2021 14:24:27 +0100 Daniel Vetter <daniel@ffwll.ch> wrote: > > As Jason suggested, I've pulled the first 1 patches into a topic branch. > > Stephen, can you please add the below to linux-next for the 5.12 merge > window? > > git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup Added from today. Thanks for adding your subsystem tree as a participant of linux-next. As you may know, this is not a judgement of your code. The purpose of linux-next is for integration testing and to lower the impact of conflicts between subsystems in the next merge window. You will need to ensure that the patches/commits in your tree/series have been: * submitted under GPL v2 (or later) and include the Contributor's Signed-off-by, * posted to the relevant mailing list, * reviewed by you (or another maintainer of your subsystem tree), * successfully unit tested, and * destined for the current or next Linux merge window. Basically, this should be just what you would send to Linus (or ask him to fetch). It is allowed to be rebased if you deem it necessary.