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* Merge drm/drm-next into drm-misc-nextMaxime Ripard2022-04-051-11/+11
|\ | | | | | | | | | | Let's start the 5.19 development cycle. Signed-off-by: Maxime Ripard <maxime@cerno.tech>
| * dma-buf-map: Rename to iosys-mapLucas De Marchi2022-02-081-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include <linux/dma-buf-map.h> + #include <linux/iosys-map.h> Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
* | drivers/dma-buf: dma-buf.c: fix a typoSui Jingfeng2022-04-031-1/+1
|/ | | | | | | Signed-off-by: Sui Jingfeng <15330273260@189.cn> Link: https://patchwork.freedesktop.org/patch/msgid/20220402134413.1705246-1-15330273260@189.cn Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com>
* Merge drm/drm-next into drm-misc-nextThomas Zimmermann2021-11-181-23/+32
|\ | | | | | | | | | | Backmerging from drm/drm-next for v5.16-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
| * Merge tag 'drm-next-2021-11-12' of git://anongit.freedesktop.org/drm/drmLinus Torvalds2021-11-121-54/+27
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more drm updates from Dave Airlie: "I missed a drm-misc-next pull for the main pull last week. It wasn't that major and isn't the bulk of this at all. This has a bunch of fixes all over, a lot for amdgpu and i915. bridge: - HPD improvments for lt9611uxc - eDP aux-bus support for ps8640 - LVDS data-mapping selection support ttm: - remove huge page functionality (needs reworking) - fix a race condition during BO eviction panels: - add some new panels fbdev: - fix double-free - remove unused scrolling acceleration - CONFIG_FB dep improvements locking: - improve contended locking logging - naming collision fix dma-buf: - add dma_resv_for_each_fence iterator - fix fence refcounting bug - name locking fixesA prime: - fix object references during mmap nouveau: - various code style changes - refcount fix - device removal fixes - protect client list with a mutex - fix CE0 address calculation i915: - DP rates related fixes - Revert disabling dual eDP that was causing state readout problems - put the cdclk vtables in const data - Fix DVO port type for older platforms - Fix blankscreen by turning DP++ TMDS output buffers on encoder->shutdown - CCS FBs related fixes - Fix recursive lock in GuC submission - Revert guc_id from i915_request tracepoint - Build fix around dmabuf amdgpu: - GPU reset fix - Aldebaran fix - Yellow Carp fixes - DCN2.1 DMCUB fix - IOMMU regression fix for Picasso - DSC display fixes - BPC display calculation fixes - Other misc display fixes - Don't allow partial copy from user for DC debugfs - SRIOV fixes - GFX9 CSB pin count fix - Various IP version check fixes - DP 2.0 fixes - Limit DCN1 MPO fix to DCN1 amdkfd: - SVM fixes - Fix gfx version for renoir - Reset fixes udl: - timeout fix imx: - circular locking fix virtio: - NULL ptr deref fix" * tag 'drm-next-2021-11-12' of git://anongit.freedesktop.org/drm/drm: (126 commits) drm/ttm: Double check mem_type of BO while eviction drm/amdgpu: add missed support for UVD IP_VERSION(3, 0, 64) drm/amdgpu: drop jpeg IP initialization in SRIOV case drm/amd/display: reject both non-zero src_x and src_y only for DCN1x drm/amd/display: Add callbacks for DMUB HPD IRQ notifications drm/amd/display: Don't lock connection_mutex for DMUB HPD drm/amd/display: Add comment where CONFIG_DRM_AMD_DC_DCN macro ends drm/amdkfd: Fix retry fault drain race conditions drm/amdkfd: lower the VAs base offset to 8KB drm/amd/display: fix exit from amdgpu_dm_atomic_check() abruptly drm/amd/amdgpu: fix the kfd pre_reset sequence in sriov drm/amdgpu: fix uvd crash on Polaris12 during driver unloading drm/i915/adlp/fb: Prevent the mapping of redundant trailing padding NULL pages drm/i915/fb: Fix rounding error in subsampled plane size calculation drm/i915/hdmi: Turn DP++ TMDS output buffers back on in encoder->shutdown() drm/locking: fix __stack_depot_* name conflict drm/virtio: Fix NULL dereference error in virtio_gpu_poll drm/amdgpu: fix SI handling in amdgpu_device_asic_has_dc_support() drm/amdgpu: Fix dangling kfd_bo pointer for shared BOs drm/amd/amdkfd: Don't sent command to HWS on kfd reset ...
| | * Merge tag 'drm-misc-fixes-2021-11-11' of ↵Dave Airlie2021-11-121-0/+3
| | |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://anongit.freedesktop.org/drm/drm-misc into drm-next * dma-buf: name_lock fixes * prime: Keep object ref during mmap * nouveau: Fix a refcount issue; Fix device removal; Protect client list with dedicated mutex; Fix address CE0 address calculation * ttm: Fix race condition during BO eviction Signed-off-by: Dave Airlie <airlied@redhat.com> From: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/YYzY6jeox9EeI15i@linux-uq9g.fritz.box
| | | * dma-buf: acquire name lock before read/write dma_buf.nameGuangming Cao2021-10-291-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because dma-buf.name can be freed in func: "dma_buf_set_name", so, we need to acquire lock first before we read/write dma_buf.name to prevent Use After Free(UAF) issue. Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211008075420.42874-1-guangming.cao@mediatek.com
| | * | dma-buf/poll: Get a file reference for outstanding fence callbacksMichel Dänzer2021-11-041-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes sure we don't hit the BUG_ON(dmabuf->cb_in.active || dmabuf->cb_out.active); in dma_buf_release, which could be triggered by user space closing the dma-buf file description while there are outstanding fence callbacks from dma_buf_poll. Cc: stable@vger.kernel.org Signed-off-by: Michel Dänzer <mdaenzer@redhat.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210723075857.4065-1-michel@daenzer.net Signed-off-by: Christian König <christian.koenig@amd.com>
| * | | Merge tag 'char-misc-5.16-rc1' of ↵Linus Torvalds2021-11-041-17/+17
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of char and misc and other tiny driver subsystem updates for 5.16-rc1. Loads of things in here, all of which have been in linux-next for a while with no reported problems (except for one called out below.) Included are: - habanana labs driver updates, including dma_buf usage, reviewed and acked by the dma_buf maintainers - iio driver update (going through this tree not staging as they really do not belong going through that tree anymore) - counter driver updates - hwmon driver updates that the counter drivers needed, acked by the hwmon maintainer - xillybus driver updates - binder driver updates - extcon driver updates - dma_buf module namespaces added (will cause a build error in arm64 for allmodconfig, but that change is on its way through the drm tree) - lkdtm driver updates - pvpanic driver updates - phy driver updates - virt acrn and nitr_enclaves driver updates - smaller char and misc driver updates" * tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (386 commits) comedi: dt9812: fix DMA buffers on stack comedi: ni_usb6501: fix NULL-deref in command paths arm64: errata: Enable TRBE workaround for write to out-of-range address arm64: errata: Enable workaround for TRBE overwrite in FILL mode coresight: trbe: Work around write to out of range coresight: trbe: Make sure we have enough space coresight: trbe: Add a helper to determine the minimum buffer size coresight: trbe: Workaround TRBE errata overwrite in FILL mode coresight: trbe: Add infrastructure for Errata handling coresight: trbe: Allow driver to choose a different alignment coresight: trbe: Decouple buffer base from the hardware base coresight: trbe: Add a helper to pad a given buffer area coresight: trbe: Add a helper to calculate the trace generated coresight: trbe: Defer the probe on offline CPUs coresight: trbe: Fix incorrect access of the sink specific data coresight: etm4x: Add ETM PID for Kryo-5XX coresight: trbe: Prohibit trace before disabling TRBE coresight: trbe: End the AUX handle on truncation coresight: trbe: Do not truncate buffer on IRQ coresight: trbe: Fix handling of spurious interrupts ...
| | * | | dma-buf: move dma-buf symbols into the DMA_BUF module namespaceGreg Kroah-Hartman2021-10-251-17/+17
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to better track where in the kernel the dma-buf code is used, put the symbols in the namespace DMA_BUF and modify all users of the symbols to properly import the namespace to not break the build at the same time. Now the output of modinfo shows the use of these symbols, making it easier to watch for users over time: $ modinfo drivers/misc/fastrpc.ko | grep import import_ns: DMA_BUF Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: dri-devel@lists.freedesktop.org Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Alex Deucher <alexander.deucher@amd.com> Link: https://lore.kernel.org/r/20211010124628.17691-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | dma-buf: add dma_fence_describe and dma_resv_describe v2Christian König2021-11-111-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functions to dump dma_fence and dma_resv objects into a seq_file and use them for printing the debugfs information. v2: fix missing include reported by test robot. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Rob Clark <robdclark@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211103081231.18578-2-christian.koenig@amd.com
* | | | dma-buf: remove restriction of IOCTL:DMA_BUF_SET_NAMEGuangming Cao2021-10-281-14/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this patch(https://patchwork.freedesktop.org/patch/310349), it add a new IOCTL to support dma-buf user to set debug name. But it also added a limitation of this IOCTL, it needs the attachments of dmabuf should be empty, otherwise it will fail. For the original series, the idea was that allowing name change mid-use could confuse the users about the dma-buf. However, the rest of the series also makes sure each dma-buf have a unique inode(https://patchwork.freedesktop.org/patch/310387/), and any accounting should probably use that, without relying on the name as much. So, removing this restriction will let dma-buf userspace users to use it more comfortably and without any side effect. Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211014102551.54983-1-guangming.cao@mediatek.com Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com>
* | | | dma-buf: Update obsoluted comments on dma_buf_vmap/vunmap()Shunsuke Mie2021-10-181-2/+2
| |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | A comment for the dma_buf_vmap/vunmap() is not catching up a corresponding implementation. Signed-off-by: Shunsuke Mie <mie@igel.co.jp> Link: https://patchwork.freedesktop.org/patch/msgid/20211008112009.118996-1-mie@igel.co.jp Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com>
* | | dma-buf: use the new iterator in dma_resv_pollChristian König2021-10-071-30/+6
| | | | | | | | | | | | | | | | | | | | | | | | Simplify the code a bit. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211005113742.1101-10-christian.koenig@amd.com
* | | dma-buf: use the new iterator in dma_buf_debug_showChristian König2021-10-071-18/+6
|/ / | | | | | | | | | | | | | | Simplifying the code a bit. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211005113742.1101-9-christian.koenig@amd.com
* | dma-buf: fix and rework dma_buf_poll v7Christian König2021-10-011-82/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel pointed me towards this function and there are multiple obvious problems in the implementation. First of all the retry loop is not working as intended. In general the retry makes only sense if you grab the reference first and then check the sequence values. Then we should always also wait for the exclusive fence. It's also good practice to keep the reference around when installing callbacks to fences you don't own. And last the whole implementation was unnecessary complex and rather hard to understand which could lead to probably unexpected behavior of the IOCTL. Fix all this by reworking the implementation from scratch. Dropping the whole RCU approach and taking the lock instead. Only mildly tested and needs a thoughtful review of the code. Pushing through drm-misc-next to avoid merge conflicts and give the code another round of testing. v2: fix the reference counting as well v3: keep the excl fence handling as is for stable v4: back to testing all fences, drop RCU v5: handle in and out separately v6: add missing clear of events v7: change coding style as suggested by Michel, drop unused variables Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Michel Dänzer <mdaenzer@redhat.com> CC: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20210720131110.88512-1-christian.koenig@amd.com
* | dma-buf: WARN on dmabuf release with pending attachmentsCharan Teja Reddy2021-08-161-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | It is expected from the clients to follow the below steps on an imported dmabuf fd: a) dmabuf = dma_buf_get(fd) // Get the dmabuf from fd b) dma_buf_attach(dmabuf); // Clients attach to the dmabuf o Here the kernel does some slab allocations, say for dma_buf_attachment and may be some other slab allocation in the dmabuf->ops->attach(). c) Client may need to do dma_buf_map_attachment(). d) Accordingly dma_buf_unmap_attachment() should be called. e) dma_buf_detach () // Clients detach to the dmabuf. o Here the slab allocations made in b) are freed. f) dma_buf_put(dmabuf) // Can free the dmabuf if it is the last reference. Now say an erroneous client failed at step c) above thus it directly called dma_buf_put(), step f) above. Considering that it may be the last reference to the dmabuf, buffer will be freed with pending attachments left to the dmabuf which can show up as the 'memory leak'. This should at least be reported as the WARN(). Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/1627043468-16381-1-git-send-email-charante@codeaurora.org Signed-off-by: Christian König <christian.koenig@amd.com>
* dma_buf: remove dmabuf sysfs teardown before releaseGuangming Cao2021-07-201-1/+1
| | | | | | | | | | | Dmabuf sysfs stat is used for dmabuf info track. But these file maybe still in use after buffer released, should clear it before buffer release. Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210720103158.83439-1-guangming.cao@mediatek.com Signed-off-by: Christian König <christian.koenig@amd.com>
* dma-buf: Delete the DMA-BUF attachment sysfs statisticsHridya Valsaraju2021-07-201-16/+0
| | | | | | | | | | | | | | | | | | The DMA-BUF attachment statistics form a subset of the DMA-BUF sysfs statistics that recently merged to the drm-misc tree. They are not UABI yet since they have not merged to the upstream Linux kernel. Since there has been a reported a performance regression due to the overhead of sysfs directory creation/teardown during dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF attachment statistics from sysfs. Fixes: bdb8d06dfefd ("dmabuf: Add the capability to expose DMA-BUF stats in sysfs") Signed-off-by: Hridya Valsaraju <hridya@google.com> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patchwork.freedesktop.org/patch/msgid/20210713040742.2680135-1-hridya@google.com Signed-off-by: Christian König <christian.koenig@amd.com>
* dma-buf: Document non-dynamic exporter expectations betterDaniel Vetter2021-06-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | Christian and me realized we have a pretty massive disconnect about different interpretations of what dma_resv is used for by different drivers. The discussion is much, much bigger than this change here, but this is an important one: Non-dynamic exporters must guarantee that the memory they return is ready for use. They cannot expect importers to wait for the exclusive fence. Only dynamic importers are required to obey the dma_resv fences strictly (and more patches are needed to define exactly what this means). Christian has patches to update nouvea, radeon and amdgpu. The only other driver using both ttm and supporting dma-buf export is qxl, which only uses synchronous ttm_bo_move. v2: To hammer this in document that dynamic importers _must_ wait for the exclusive fence after having called dma_buf_map_attachment. Reviewed-by: Christian König <christian.koenig@amd.com> Cc: Christian König <ckoenig.leichtzumerken@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210621151758.2347474-1-daniel.vetter@ffwll.ch
* dmabuf: Add the capability to expose DMA-BUF stats in sysfsHridya Valsaraju2021-06-151-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Overview ======== The patch adds DMA-BUF statistics to /sys/kernel/dmabuf/buffers. It allows statistics to be enabled for each DMA-BUF in sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS. The following stats will be exposed by the interface: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name /sys/kernel/dmabuf/buffers/<inode_number>/size /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter The inode_number is unique for each DMA-BUF and was added earlier [1] in order to allow userspace to track DMA-BUF usage across different processes. Use Cases ========= The interface provides a way to gather DMA-BUF per-buffer statistics from production devices. These statistics will be used to derive DMA-BUF per-exporter stats and per-device usage stats for Android Bug reports. The corresponding userspace changes can be found at [2]. Telemetry tools will also capture this information(along with other memory metrics) periodically as well as on important events like a foreground app kill (which might have been triggered by Low Memory Killer). It will also contribute to provide a snapshot of the system memory usage on other events such as OOM kills and Application Not Responding events. Background ========== Currently, there are two existing interfaces that provide information about DMA-BUFs. 1) /sys/kernel/debug/dma_buf/bufinfo debugfs is however unsuitable to be mounted in production systems and cannot be considered as an alternative to the sysfs interface being proposed. 2) proc/<pid>/fdinfo/<fd> The proc/<pid>/fdinfo/<fd> files expose information about DMA-BUF fds. However, the existing procfs interfaces can only provide information about the buffers for which processes hold fds or have the buffers mmapped into their address space. Since the procfs interfaces alone cannot provide a full picture of all DMA-BUFs in the system, there is the need for an alternate interface to provide this information on production systems. The patch contains the following major improvements over v1: 1) Each attachment is represented by its own directory to allow creating a symlink to the importing device and to also provide room for future expansion. 2) The number of distinct mappings of each attachment is exposed in a separate file. 3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers inorder to make the interface expandable in future. All of the improvements above are based on suggestions/feedback from Daniel Vetter and Christian König. A shell script that can be run on a classic Linux environment to read out the DMA-BUF statistics can be found at [3](suggested by John Stultz). [1]: https://lore.kernel.org/patchwork/patch/1088791/ [2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:open%20OR%20status:merged) [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Hridya Valsaraju <hridya@google.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210603214758.2955251-1-hridya@google.com
* dma-buf: drop the _rcu postfix on function names v3Christian König2021-06-061-2/+1
| | | | | | | | | | | | | The functions can be called both in _rcu context as well as while holding the lock. v2: add some kerneldoc as suggested by Daniel v3: fix indentation Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210602111714.212426-7-christian.koenig@amd.com
* dma-buf: rename and cleanup dma_resv_get_excl v3Christian König2021-06-061-3/+2
| | | | | | | | | | | | | | | | | | When the comment needs to state explicitly that this doesn't get a reference to the object then the function is named rather badly. Rename the function and use rcu_dereference_check(), this way it can be used from both rcu as well as lock protected critical sections. v2: improve kerneldoc as suggested by Daniel v3: use dma_resv_excl_fence as function name Signed-off-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> Link: https://patchwork.freedesktop.org/patch/msgid/20210602111714.212426-4-christian.koenig@amd.com
* dma-buf: fix inconsistent debug print v2Christian König2021-06-041-18/+9
| | | | | | | | | | Drop the whole rcu handling since we are holding the resv lock anyway. v2: drop all rcu handling instead. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210602140359.272601-1-christian.koenig@amd.com
* dma-buf: fix unintended pin/unpin warningsChristian König2021-05-201-5/+5
| | | | | | | | | | | | | DMA-buf internal users call the pin/unpin functions without having a dynamic attachment. Avoid the warning and backtrace in the logs. Signed-off-by: Christian König <christian.koenig@amd.com> Bugs: https://gitlab.freedesktop.org/drm/intel/-/issues/3481 Fixes: c545781e1c55 ("dma-buf: doc polish for pin/unpin") Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> CC: stable@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20210517115705.2141-1-christian.koenig@amd.com
* Merge tag 'v5.11-rc5' of ↵Dave Airlie2021-01-251-4/+17
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next Backmerge v5.11-rc5 into drm-next to clean up a bunch of conflicts we are dragging around. Signed-off-by: Dave Airlie <airlied@redhat.com>
| * dmabuf: fix use-after-free of dmabuf's file->f_inodeCharan Teja Reddy2021-01-071-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is observed 'use-after-free' on the dmabuf's file->f_inode with the race between closing the dmabuf file and reading the dmabuf's debug info. Consider the below scenario where P1 is closing the dma_buf file and P2 is reading the dma_buf's debug info in the system: P1 P2 dma_buf_debug_show() dma_buf_put() __fput() file->f_op->release() dput() .... dentry_unlink_inode() iput(dentry->d_inode) (where the inode is freed) mutex_lock(&db_list.lock) read 'dma_buf->file->f_inode' (the same inode is freed by P1) mutex_unlock(&db_list.lock) dentry->d_op->d_release()--> dma_buf_release() ..... mutex_lock(&db_list.lock) removes the dmabuf from the list mutex_unlock(&db_list.lock) In the above scenario, when dma_buf_put() is called on a dma_buf, it first frees the dma_buf's file->f_inode(=dentry->d_inode) and then removes this dma_buf from the system db_list. In between P2 traversing the db_list tries to access this dma_buf's file->f_inode that was freed by P1 which is a use-after-free case. Since, __fput() calls f_op->release first and then later calls the d_op->d_release, move the dma_buf's db_list removal from d_release() to f_op->release(). This ensures that dma_buf's file->f_inode is not accessed after it is released. Cc: <stable@vger.kernel.org> # 5.4.x- Fixes: 4ab59c3c638c ("dma-buf: Move dma_buf_release() from fops to dentry_ops") Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/1609857399-31549-1-git-send-email-charante@codeaurora.org
* | dma-buf: Add debug optionDaniel Vetter2021-01-181-4/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have too many people abusing the struct page they can get at but really shouldn't in importers. Aside from that the backing page might simply not exist (for dynamic p2p mappings) looking at it and using it e.g. for mmap can also wreak the page handling of the exporter completely. Importers really must go through the proper interface like dma_buf_mmap for everything. I'm semi-tempted to enforce this for dynamic importers since those really have no excuse at all to break the rules. Unfortuantely we can't store the right pointers somewhere safe to make sure we oops on something recognizable, so best is to just wrangle them a bit by flipping all the bits. At least on x86 kernel addresses have all their high bits sets and the struct page array is fairly low in the kernel mapping, so flipping all the bits gives us a very high pointer in userspace and hence excellent chances for an invalid dereference. v2: Add a note to the @map_dma_buf hook that exporters shouldn't do fancy caching tricks, which would blow up with this address scrambling trick here (Chris) Enable by default when CONFIG_DMA_API_DEBUG is enabled. v3: Only one copy of the mangle/unmangle code (Christian) v4: #ifdef, not #if (0day) v5: sg_table can also be an ERR_PTR (Chris, Christian) Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: David Stevens <stevensd@chromium.org> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210115164739.3958206-1-daniel.vetter@ffwll.ch
* | dma-buf: doc polish for pin/unpinDaniel Vetter2020-12-161-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Motivated by a discussion with Christian and Thomas: Try to untangle a bit what's relevant for importers and what's relevant for exporters. Also add an assert that really only dynamic importers use the api function, anything else doesn't make sense. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-4-daniel.vetter@ffwll.ch
* | dma-buf: begin/end_cpu might lock the dma_resv lockDaniel Vetter2020-12-161-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At least amdgpu and i915 do, so lets just document this as the rule. v2: Works better with less typos (intel-gfx-ci) Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201214171622.3868883-1-daniel.vetter@ffwll.ch
* | dma-buf: some kerneldoc formatting fixesDaniel Vetter2020-12-161-13/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Noticed while reviewing the output. Adds a bunch more links and fixes the function interface quoting. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-2-daniel.vetter@ffwll.ch
* | dma-buf: Remove kmap kerneldoc vestigesDaniel Vetter2020-12-161-6/+14
|/ | | | | | | | | | | | | | Also try to clarify a bit when dma_buf_begin/end_cpu_access should be called. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-1-daniel.vetter@ffwll.ch
* mm: introduce vma_set_file function v5Christian König2020-11-191-2/+1
| | | | | | | | | | | | | | | | | Add the new vma_set_file() function to allow changing vma->vm_file with the necessary refcount dance. v2: add more users of this. v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup, add comments why we drop the reference on two occasions. v4: make it clear that changing an anonymous vma is illegal. v5: move vma_set_file to mm/util.c Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Link: https://patchwork.freedesktop.org/patch/399360/
* mm: mmap: fix fput in error path v2Christian König2020-11-191-17/+3
| | | | | | | | | | | | | | | | | Patch "495c10cc1c0c CHROMIUM: dma-buf: restore args..." adds a workaround for a bug in mmap_region. As the comment states ->mmap() callback can change vma->vm_file and so we might call fput() on the wrong file. Revert the workaround and proper fix this in mmap_region. v2: drop the extra if in dma_buf_mmap as well Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Link: https://patchwork.freedesktop.org/patch/399359/
* Revert "mm: mmap: fix fput in error path v2"Christian König2020-11-051-3/+17
| | | | | | | | | | The kernel test robot is not happy with that. This reverts commit 0227da01f2559626396af5f6c7453360db86c1f6. Signed-off-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/394772/
* Revert "mm: introduce vma_set_file function v4"Christian König2020-11-051-1/+2
| | | | | | | | | | The kernel test robot is not happy with that. This reverts commit 2b5b95b1ff3d70a95013a45e3b5b90f1daf42348. Signed-off-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/394773/
* dma-buf: Fix static checker warningJianxin Xiong2020-11-051-1/+1
| | | | | | | | | | | | | | | | Here is the warning message: drivers/dma-buf/dma-buf.c:917 dma_buf_map_attachment() error: 'sg_table' dereferencing possible ERR_PTR() Fix by adding error checking before dereferencing the pointer. Fixes: ac80cd17a615 ("dma-buf: Clarify that dma-buf sg lists are page aligned") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/398485/
* mm: introduce vma_set_file function v4Christian König2020-11-051-2/+1
| | | | | | | | | | | | | | | Add the new vma_set_file() function to allow changing vma->vm_file with the necessary refcount dance. v2: add more users of this. v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup, add comments why we drop the reference on two occasions. v4: make it clear that changing an anonymous vma is illegal. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://patchwork.freedesktop.org/patch/394773/
* mm: mmap: fix fput in error path v2Christian König2020-11-051-17/+3
| | | | | | | | | | | | | | | | Patch "495c10cc1c0c CHROMIUM: dma-buf: restore args..." adds a workaround for a bug in mmap_region. As the comment states ->mmap() callback can change vma->vm_file and so we might call fput() on the wrong file. Revert the workaround and proper fix this in mmap_region. v2: drop the extra if in dma_buf_mmap as well Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://patchwork.freedesktop.org/patch/394772/
* Merge drm/drm-next into drm-misc-nextMaxime Ripard2020-11-021-0/+2
|\ | | | | | | | | | | Daniel needs -rc2 in drm-misc-next to merge some patches Signed-off-by: Maxime Ripard <maxime@cerno.tech>
| * dmabuf: fix NULL pointer dereference in dma_buf_release()Charan Teja Reddy2020-09-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | NULL pointer dereference is observed while exporting the dmabuf but failed to allocate the 'struct file' which results into the dropping of the allocated dentry corresponding to this file in the dmabuf fs, which is ending up in dma_buf_release() and accessing the uninitialzed dentry->d_fsdata. Call stack on 5.4 is below: dma_buf_release+0x2c/0x254 drivers/dma-buf/dma-buf.c:88 __dentry_kill+0x294/0x31c fs/dcache.c:584 dentry_kill fs/dcache.c:673 [inline] dput+0x250/0x380 fs/dcache.c:859 path_put+0x24/0x40 fs/namei.c:485 alloc_file_pseudo+0x1a4/0x200 fs/file_table.c:235 dma_buf_getfile drivers/dma-buf/dma-buf.c:473 [inline] dma_buf_export+0x25c/0x3ec drivers/dma-buf/dma-buf.c:585 Fix this by checking for the valid pointer in the dentry->d_fsdata. Fixes: 4ab59c3c638c ("dma-buf: Move dma_buf_release() from fops to dentry_ops") Cc: <stable@vger.kernel.org> [5.7+] Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/391319/ Signed-off-by: Christian König <christian.koenig@amd.com>
* | dma-buf: Clarify that dma-buf sg lists are page alignedJianxin Xiong2020-10-151-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | The dma-buf API have been used under the assumption that the sg lists returned from dma_buf_map_attachment() are fully page aligned. Lots of stuff can break otherwise all over the place. Clarify this in the documentation and add a check when DMA API debug is enabled. Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/1602692161-107096-1-git-send-email-jianxin.xiong@intel.com
* | dma-buf: Use struct dma_buf_map in dma_buf_vunmap() interfacesThomas Zimmermann2020-09-291-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates dma_buf_vunmap() and dma-buf's vunmap callback to use struct dma_buf_map. The interfaces used to receive a buffer address. This address is now given in an instance of the structure. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v2: * include dma-buf-heaps and i915 selftests (kernel test robot) * initialize cma_obj before using it in drm_gem_cma_free_object() (kernel test robot) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-4-tzimmermann@suse.de
* | dma-buf: Use struct dma_buf_map in dma_buf_vmap() interfacesThomas Zimmermann2020-09-291-12/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates dma_buf_vmap() and dma-buf's vmap callback to use struct dma_buf_map. The interfaces used to return a buffer address. This address now gets stored in an instance of the structure that is given as an additional argument. The functions return an errno code on errors. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v3: * update fastrpc driver (kernel test robot) v2: * always clear map parameter in dma_buf_vmap() (Daniel) * include dma-buf-heaps and i915 selftests (kernel test robot) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-3-tzimmermann@suse.de
* | dma-buf: Add struct dma-buf-map for storing struct dma_buf.vaddr_ptrThomas Zimmermann2020-09-291-7/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new type struct dma_buf_map represents a mapping of dma-buf memory into kernel space. It contains a flag, is_iomem, that signals users to access the mapped memory with I/O operations instead of regular loads and stores. It was assumed that DMA buffer memory can be accessed with regular load and store operations. Some architectures, such as sparc64, require the use of I/O operations to access dma-map buffers that are located in I/O memory. Providing struct dma_buf_map allows drivers to implement this. This was specifically a problem when refreshing the graphics framebuffer on such systems. [1] As the first step, struct dma_buf stores an instance of struct dma_buf_map internally. Afterwards, dma-buf's vmap and vunmap interfaces are be converted. Finally, affected drivers can be fixed. v3: * moved documentation into separate patch * test for NULL pointers with !<ptr> [1] https://lore.kernel.org/dri-devel/20200725191012.GA434957@ravnborg.org/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-2-tzimmermann@suse.de
* dma-buf: Fix kerneldoc of dma_buf_set_name()Krzysztof Kozlowski2020-09-031-3/+3
| | | | | | | | | | Fix W=1 compile warnings (invalid kerneldoc): drivers/dma-buf/dma-buf.c:328: warning: Function parameter or member 'dmabuf' not described in 'dma_buf_set_name' Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200819175134.19261-1-krzk@kernel.org
* Merge v5.8-rc6 into drm-nextDave Airlie2020-07-241-33/+32
|\ | | | | | | | | | | | | | | I've got a silent conflict + two trees based on fixes to merge. Fixes a silent merge with amdgpu Signed-off-by: Dave Airlie <airlied@redhat.com>
| * dmabuf: use spinlock to access dmabuf->nameCharan Teja Kalla2020-07-101-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There exists a sleep-while-atomic bug while accessing the dmabuf->name under mutex in the dmabuffs_dname(). This is caused from the SELinux permissions checks on a process where it tries to validate the inherited files from fork() by traversing them through iterate_fd() (which traverse files under spin_lock) and call match_file(security/selinux/hooks.c) where the permission checks happen. This audit information is logged using dump_common_audit_data() where it calls d_path() to get the file path name. If the file check happen on the dmabuf's fd, then it ends up in ->dmabuffs_dname() and use mutex to access dmabuf->name. The flow will be like below: flush_unauthorized_files() iterate_fd() spin_lock() --> Start of the atomic section. match_file() file_has_perm() avc_has_perm() avc_audit() slow_avc_audit() common_lsm_audit() dump_common_audit_data() audit_log_d_path() d_path() dmabuffs_dname() mutex_lock()--> Sleep while atomic. Call trace captured (on 4.19 kernels) is below: ___might_sleep+0x204/0x208 __might_sleep+0x50/0x88 __mutex_lock_common+0x5c/0x1068 __mutex_lock_common+0x5c/0x1068 mutex_lock_nested+0x40/0x50 dmabuffs_dname+0xa0/0x170 d_path+0x84/0x290 audit_log_d_path+0x74/0x130 common_lsm_audit+0x334/0x6e8 slow_avc_audit+0xb8/0xf8 avc_has_perm+0x154/0x218 file_has_perm+0x70/0x180 match_file+0x60/0x78 iterate_fd+0x128/0x168 selinux_bprm_committing_creds+0x178/0x248 security_bprm_committing_creds+0x30/0x48 install_exec_creds+0x1c/0x68 load_elf_binary+0x3a4/0x14e0 search_binary_handler+0xb0/0x1e0 So, use spinlock to access dmabuf->name to avoid sleep-while-atomic. Cc: <stable@vger.kernel.org> [5.3+] Signed-off-by: Charan Teja Kalla <charante@codeaurora.org> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Acked-by: Christian König <christian.koenig@amd.com> [sumits: added comment to spinlock_t definition to avoid warning] Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/a83e7f0d-4e54-9848-4b58-e1acdbe06735@codeaurora.org
| * dma-buf: Move dma_buf_release() from fops to dentry_opsSumit Semwal2020-06-251-29/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Charan Teja reported a 'use-after-free' in dmabuffs_dname [1], which happens if the dma_buf_release() is called while the userspace is accessing the dma_buf pseudo fs's dmabuffs_dname() in another process, and dma_buf_release() releases the dmabuf object when the last reference to the struct file goes away. I discussed with Arnd Bergmann, and he suggested that rather than tying the dma_buf_release() to the file_operations' release(), we can tie it to the dentry_operations' d_release(), which will be called when the last ref to the dentry is removed. The path exercised by __fput() calls f_op->release() first, and then calls dput, which eventually calls d_op->d_release(). In the 'normal' case, when no userspace access is happening via dma_buf pseudo fs, there should be exactly one fd, file, dentry and inode, so closing the fd will kill of everything right away. In the presented case, the dentry's d_release() will be called only when the dentry's last ref is released. Therefore, lets move dma_buf_release() from fops->release() to d_ops->d_release() Many thanks to Arnd for his FS insights :) [1]: https://lore.kernel.org/patchwork/patch/1238278/ Fixes: bb2bb9030425 ("dma-buf: add DMA_BUF_SET_NAME ioctls") Reported-by: syzbot+3643a18836bce555bff6@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> [5.3+] Cc: Arnd Bergmann <arnd@arndb.de> Reported-by: Charan Teja Reddy <charante@codeaurora.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Tested-by: Charan Teja Reddy <charante@codeaurora.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200611114418.19852-1-sumit.semwal@linaro.org
* | Merge tag 'drm-misc-next-2020-06-26' of ↵Dave Airlie2020-06-301-3/+3
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://anongit.freedesktop.org/drm/drm-misc into drm-next drm-misc-next for v5.9: Cross-subsystem Changes: - Improve dma-buf docs. Core Changes: - Add NV15, Q410, Q401 yuv formats. - Add uncompressed AFBC modifier. - Add DP helepr for reading Ignore MSA from DPCD. - Add missing panel type for some panels - Optimize drm/mm hole handling. - Constify connector to infoframe functions. - Add debugfs for VRR monitor range. Driver Changes: - Assorted small bugfixes in panfrost, malidp, panel/otm8009a. - Convert tfp410 dt bindings to yaml, and rework time calculations. - Add support for a few more simple panels. - Cleanups and optimizations for ast. - Allow adv7511 and simple-bridge to be used without connector creation. - Cleanups to dw-hdmi function prototypes. - Remove enabled bool from tiny/repaper and mipi-dbi, atomic handles it. - Remove unused header file from dw-mipi-dsi - Begin removing ttm_bo->offset. Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/b1e53620-7937-895c-bfcf-ed208be59c7c@linux.intel.com