linux/drivers/dma-buf, branch v5.8

dmabuf: use spinlock to access dmabuf->name

2020-07-10T10:09:29Z

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: [5.3+] Signed-off-by: Charan Teja Kalla Reviewed-by: Michael J. Ruhl Acked-by: Christian König [sumits: added comment to spinlock_t definition to avoid warning] Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/a83e7f0d-4e54-9848-4b58-e1acdbe06735@codeaurora.org

dma-buf: Move dma_buf_release() from fops to dentry_ops

2020-06-25T10:35:40Z

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: [5.3+] Cc: Arnd Bergmann Reported-by: Charan Teja Reddy Reviewed-by: Arnd Bergmann Signed-off-by: Sumit Semwal Tested-by: Charan Teja Reddy Link: https://patchwork.freedesktop.org/patch/msgid/20200611114418.19852-1-sumit.semwal@linaro.org

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21Z

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada

DMA reservations: use the new mmap locking API

2020-06-09T16:39:14Z

This use is converted manually ahead of the next patch in the series, as it requires including a new header which the automated conversion would miss. Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-4-walken@google.com Signed-off-by: Linus Torvalds

Merge tag 'drm-next-2020-06-02' of git://anongit.freedesktop.org/drm/drm

2020-06-02T22:04:15Z

Pull drm updates from Dave Airlie: "Highlights: - Core DRM had a lot of refactoring around managed drm resources to make drivers simpler. - Intel Tigerlake support is on by default - amdgpu now support p2p PCI buffer sharing and encrypted GPU memory Details: core: - uapi: error out EBUSY when existing master - uapi: rework SET/DROP MASTER permission handling - remove drm_pci.h - drm_pci* are now legacy - introduced managed DRM resources - subclassing support for drm_framebuffer - simple encoder helper - edid improvements - vblank + writeback documentation improved - drm/mm - optimise tree searches - port drivers to use devm_drm_dev_alloc dma-buf: - add flag for p2p buffer support mst: - ACT timeout improvements - remove drm_dp_mst_has_audio - don't use 2nd TX slot - spec recommends against it bridge: - dw-hdmi various improvements - chrontel ch7033 support - fix stack issues with old gcc hdmi: - add unpack function for drm infoframe fbdev: - misc fbdev driver fixes i915: - uapi: global sseu pinning - uapi: OA buffer polling - uapi: remove generated perf code - uapi: per-engine default property values in sysfs - Tigerlake GEN12 enabled. - Lots of gem refactoring - Tigerlake enablement patches - move to drm_device logging - Icelake gamma HW readout - push MST link retrain to hotplug work - bandwidth atomic helpers - ICL fixes - RPS/GT refactoring - Cherryview full-ppgtt support - i915 locking guidelines documented - require linear fb stride to be 512 multiple on gen9 - Tigerlake SAGV support amdgpu: - uapi: encrypted GPU memory handling - uapi: add MEM_SYNC IB flag - p2p dma-buf support - export VRAM dma-bufs - FRU chip access support - RAS/SR-IOV updates - Powerplay locking fixes - VCN DPG (powergating) enablement - GFX10 clockgating fixes - DC fixes - GPU reset fixes - navi SDMA fix - expose FP16 for modesetting - DP 1.4 compliance fixes - gfx10 soft recovery - Improved Critical Thermal Faults handling - resizable BAR on gmc10 amdkfd: - uapi: GWS resource management - track GPU memory per process - report PCI domain in topology radeon: - safe reg list generator fixes nouveau: - HD audio fixes on recent systems - vGPU detection (fail probe if we're on one, for now) - Interlaced mode fixes (mostly avoidance on Turing, which doesn't support it) - SVM improvements/fixes - NVIDIA format modifier support - Misc other fixes. adv7511: - HDMI SPDIF support ast: - allocate crtc state size - fix double assignment - fix suspend bochs: - drop connector register cirrus: - move to tiny drivers. exynos: - fix imported dma-buf mapping - enable runtime PM - fixes and cleanups mediatek: - DPI pin mode swap - config mipi_tx current/impedance lima: - devfreq + cooling device support - task handling improvements - runtime PM support pl111: - vexpress init improvements - fix module auto-load rcar-du: - DT bindings conversion to YAML - Planes zpos sanity check and fix - MAINTAINERS entry for LVDS panel driver mcde: - fix return value mgag200: - use managed config init stm: - read endpoints from DT vboxvideo: - use PCI managed functions - drop WC mtrr vkms: - enable cursor by default rockchip: - afbc support virtio: - various cleanups qxl: - fix cursor notify port hisilicon: - 128-byte stride alignment fix sun4i: - improved format handling" * tag 'drm-next-2020-06-02' of git://anongit.freedesktop.org/drm/drm: (1401 commits) drm/amd/display: Fix potential integer wraparound resulting in a hang drm/amd/display: drop cursor position check in atomic test drm/amdgpu: fix device attribute node create failed with multi gpu drm/nouveau: use correct conflicting framebuffer API drm/vblank: Fix -Wformat compile warnings on some arches drm/amdgpu: Sync with VM root BO when switching VM to CPU update mode drm/amd/display: Handle GPU reset for DC block drm/amdgpu: add apu flags (v2) drm/amd/powerpay: Disable gfxoff when setting manual mode on picasso and raven drm/amdgpu: fix pm sysfs node handling (v2) drm/amdgpu: move gpu_info parsing after common early init drm/amdgpu: move discovery gfx config fetching drm/nouveau/dispnv50: fix runtime pm imbalance on error drm/nouveau: fix runtime pm imbalance on error drm/nouveau: fix runtime pm imbalance on error drm/nouveau/debugfs: fix runtime pm imbalance on error drm/nouveau/nouveau/hmm: fix migrate zero page to GPU drm/nouveau/nouveau/hmm: fix nouveau_dmem_chunk allocations drm/nouveau/kms/nv50-: Share DP SST mode_valid() handling with MST drm/nouveau/kms/nv50-: Move 8BPC limit for MST into nv50_mstc_get_modes() ...

dma-buf: Use atomic_fetch_add() for the context id

2020-05-13T12:38:59Z

Now that atomic64_fetch_add() exists we can use it to return the base context id, rather than the atomic64_add_return(N) - N concoction. Suggested-by: Mika Kuoppala Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Maciej Patelczyk Link: https://patchwork.freedesktop.org/patch/msgid/20200513074809.18194-2-chris@chris-wilson.co.uk

dma-buf: fix documentation build warnings

2020-04-30T14:17:39Z

Fix documentation warnings in dma-buf.[hc]: ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_ops' not described in 'dma_buf_dynamic_attach' ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_priv' not described in 'dma_buf_dynamic_attach' ../include/linux/dma-buf.h:339: warning: Incorrect use of kernel-doc format: * @move_notify Signed-off-by: Randy Dunlap Cc: Sumit Semwal Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/7bcbe6fe-0b4b-87da-d003-b68a26eb4cf0@infradead.org

dma-buf: Fix SET_NAME ioctl uapi

2020-04-27T10:59:41Z

The uapi is the same on 32 and 64 bit, but the number isn't. Everyone who botched this please re-read: https://www.kernel.org/doc/html/v5.4-preprc-cpu/ioctl/botching-up-ioctls.html Also, the type argument for the ioctl macros is for the type the void __user *arg pointer points at, which in this case would be the variable-sized char[] of a 0 terminated string. So this was botched in more than just the usual ways. Cc: Sumit Semwal Cc: Chenbo Feng Cc: Greg Hackmann Cc: Daniel Vetter Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: minchan@kernel.org Cc: surenb@google.com Cc: jenhaochen@google.com Cc: Martin Liu Signed-off-by: Daniel Vetter Tested-by: Martin Liu Reviewed-by: Martin Liu Signed-off-by: Sumit Semwal [sumits: updated some checkpatch fixes, corrected author email] Link: https://patchwork.freedesktop.org/patch/msgid/20200407133002.3486387-1-daniel.vetter@ffwll.ch

Merge drm/drm-next into drm-misc-next

2020-04-17T06:12:22Z

Backmerging required to pull topic/phy-compliance. Signed-off-by: Thomas Zimmermann

dma-buf: Exercise dma-fence-chain under selftests

2020-04-09T18:58:55Z

A few very simple testcases to exercise the dma-fence-chain API. Signed-off-by: Chris Wilson Reviewed-by: Venkata Sandeep Dhanalakota Link: https://patchwork.freedesktop.org/patch/msgid/20200409110101.18400-3-chris@chris-wilson.co.uk