kernel/linux.git/drivers/gpu/drm/drm_file.c, branch v6.1.168

drm: Fix use-after-free on framebuffers and property blobs when calling drm_dev_unplug

2026-03-25T10:03:22+00:00

[ Upstream commit 6bee098b91417654703e17eb5c1822c6dfd0c01d ] When trying to do a rather aggressive test of igt's "xe_module_load --r reload" with a full desktop environment and game running I noticed a few OOPSes when dereferencing freed pointers, related to framebuffers and property blobs after the compositor exits. Solve this by guarding the freeing in drm_file with drm_dev_enter/exit, and immediately put the references from struct drm_file objects during drm_dev_unplug(). Related warnings for framebuffers on the subtest: [ 739.713076] ------------[ cut here ]------------ WARN_ON(!list_empty(&dev->mode_config.fb_list)) [ 739.713079] WARNING: drivers/gpu/drm/drm_mode_config.c:584 at drm_mode_config_cleanup+0x30b/0x320 [drm], CPU#12: xe_module_load/13145 .... [ 739.713328] Call Trace: [ 739.713330] [ 739.713335] ? intel_pmdemand_destroy_state+0x11/0x20 [xe] [ 739.713574] ? intel_atomic_global_obj_cleanup+0xe4/0x1a0 [xe] [ 739.713794] intel_display_driver_remove_noirq+0x51/0xb0 [xe] [ 739.714041] xe_display_fini_early+0x33/0x50 [xe] [ 739.714284] devm_action_release+0xf/0x20 [ 739.714294] devres_release_all+0xad/0xf0 [ 739.714301] device_unbind_cleanup+0x12/0xa0 [ 739.714305] device_release_driver_internal+0x1b7/0x210 [ 739.714311] device_driver_detach+0x14/0x20 [ 739.714315] unbind_store+0xa6/0xb0 [ 739.714319] drv_attr_store+0x21/0x30 [ 739.714322] sysfs_kf_write+0x48/0x60 [ 739.714328] kernfs_fop_write_iter+0x16b/0x240 [ 739.714333] vfs_write+0x266/0x520 [ 739.714341] ksys_write+0x72/0xe0 [ 739.714345] __x64_sys_write+0x19/0x20 [ 739.714347] x64_sys_call+0xa15/0xa30 [ 739.714355] do_syscall_64+0xd8/0xab0 [ 739.714361] entry_SYSCALL_64_after_hwframe+0x4b/0x53 and [ 739.714459] ------------[ cut here ]------------ [ 739.714461] xe 0000:67:00.0: [drm] drm_WARN_ON(!list_empty(&fb->filp_head)) [ 739.714464] WARNING: drivers/gpu/drm/drm_framebuffer.c:833 at drm_framebuffer_free+0x6c/0x90 [drm], CPU#12: xe_module_load/13145 [ 739.714715] RIP: 0010:drm_framebuffer_free+0x7a/0x90 [drm] ... [ 739.714869] Call Trace: [ 739.714871] [ 739.714876] drm_mode_config_cleanup+0x26a/0x320 [drm] [ 739.714998] ? __drm_printfn_seq_file+0x20/0x20 [drm] [ 739.715115] ? drm_mode_config_cleanup+0x207/0x320 [drm] [ 739.715235] intel_display_driver_remove_noirq+0x51/0xb0 [xe] [ 739.715576] xe_display_fini_early+0x33/0x50 [xe] [ 739.715821] devm_action_release+0xf/0x20 [ 739.715828] devres_release_all+0xad/0xf0 [ 739.715843] device_unbind_cleanup+0x12/0xa0 [ 739.715850] device_release_driver_internal+0x1b7/0x210 [ 739.715856] device_driver_detach+0x14/0x20 [ 739.715860] unbind_store+0xa6/0xb0 [ 739.715865] drv_attr_store+0x21/0x30 [ 739.715868] sysfs_kf_write+0x48/0x60 [ 739.715873] kernfs_fop_write_iter+0x16b/0x240 [ 739.715878] vfs_write+0x266/0x520 [ 739.715886] ksys_write+0x72/0xe0 [ 739.715890] __x64_sys_write+0x19/0x20 [ 739.715893] x64_sys_call+0xa15/0xa30 [ 739.715900] do_syscall_64+0xd8/0xab0 [ 739.715905] entry_SYSCALL_64_after_hwframe+0x4b/0x53 and then finally file close blows up: [ 743.186530] Oops: general protection fault, probably for non-canonical address 0xdead000000000122: 0000 [#1] SMP [ 743.186535] CPU: 3 UID: 1000 PID: 3453 Comm: kwin_wayland Tainted: G W 7.0.0-rc1-valkyria+ #110 PREEMPT_{RT,(lazy)} [ 743.186537] Tainted: [W]=WARN [ 743.186538] Hardware name: Gigabyte Technology Co., Ltd. X299 AORUS Gaming 3/X299 AORUS Gaming 3-CF, BIOS F8n 12/06/2021 [ 743.186539] RIP: 0010:drm_framebuffer_cleanup+0x55/0xc0 [drm] [ 743.186588] Code: d8 72 73 0f b6 42 05 ff c3 39 c3 72 e8 49 8d bd 50 07 00 00 31 f6 e8 3a 80 d3 e1 49 8b 44 24 10 49 8d 7c 24 08 49 8b 54 24 08 <48> 3b 38 0f 85 95 7f 02 00 48 3b 7a 08 0f 85 8b 7f 02 00 48 89 42 [ 743.186589] RSP: 0018:ffffc900085e3cf8 EFLAGS: 00010202 [ 743.186591] RAX: dead000000000122 RBX: 0000000000000001 RCX: ffffffff8217ed03 [ 743.186592] RDX: dead000000000100 RSI: 0000000000000000 RDI: ffff88814675ba08 [ 743.186593] RBP: ffffc900085e3d10 R08: 0000000000000000 R09: 0000000000000000 [ 743.186593] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88814675ba00 [ 743.186594] R13: ffff88810d778000 R14: ffff888119f6dca0 R15: ffff88810c660bb0 [ 743.186595] FS: 00007ff377d21280(0000) GS:ffff888cec3f8000(0000) knlGS:0000000000000000 [ 743.186596] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 743.186596] CR2: 000055690b55e000 CR3: 0000000113586003 CR4: 00000000003706f0 [ 743.186597] Call Trace: [ 743.186598] [ 743.186603] intel_user_framebuffer_destroy+0x12/0x90 [xe] [ 743.186722] drm_framebuffer_free+0x3a/0x90 [drm] [ 743.186750] ? trace_hardirqs_on+0x5f/0x120 [ 743.186754] drm_mode_object_put+0x51/0x70 [drm] [ 743.186786] drm_fb_release+0x105/0x190 [drm] [ 743.186812] ? rt_mutex_slowunlock+0x3aa/0x410 [ 743.186817] ? rt_spin_lock+0xea/0x1b0 [ 743.186819] drm_file_free+0x1e0/0x2c0 [drm] [ 743.186843] drm_release_noglobal+0x91/0xf0 [drm] [ 743.186865] __fput+0x100/0x2e0 [ 743.186869] fput_close_sync+0x40/0xa0 [ 743.186870] __x64_sys_close+0x3e/0x80 [ 743.186873] x64_sys_call+0xa07/0xa30 [ 743.186879] do_syscall_64+0xd8/0xab0 [ 743.186881] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 743.186882] RIP: 0033:0x7ff37e567732 [ 743.186884] Code: 08 0f 85 a1 38 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 55 bf 01 00 [ 743.186885] RSP: 002b:00007ffc818169a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 743.186886] RAX: ffffffffffffffda RBX: 00007ffc81816a30 RCX: 00007ff37e567732 [ 743.186887] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000012 [ 743.186888] RBP: 00007ffc818169d0 R08: 0000000000000000 R09: 0000000000000000 [ 743.186889] R10: 0000000000000000 R11: 0000000000000246 R12: 000055d60a7996e0 [ 743.186889] R13: 00007ffc81816a90 R14: 00007ffc81816a90 R15: 000055d60a782a30 [ 743.186892] [ 743.186893] Modules linked in: rfcomm snd_hrtimer xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp xt_addrtype nft_compat x_tables nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables overlay cfg80211 bnep mtd_intel_dg snd_hda_codec_intelhdmi mtd snd_hda_codec_hdmi nls_utf8 mxm_wmi intel_wmi_thunderbolt gigabyte_wmi wmi_bmof xe drm_gpuvm drm_gpusvm_helper i2c_algo_bit drm_buddy drm_ttm_helper ttm video drm_suballoc_helper gpu_sched drm_client_lib drm_exec drm_display_helper cec drm_kunit_helpers drm_kms_helper kunit x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_alc882 snd_hda_codec_realtek_lib snd_hda_codec_generic snd_hda_intel snd_soc_avs snd_soc_hda_codec snd_hda_ext_core snd_hda_codec snd_hwdep snd_hda_core snd_intel_dspcfg snd_soc_core snd_compress ac97_bus snd_pcm snd_seq snd_seq_device snd_timer i2c_i801 i2c_mux snd i2c_smbus btusb btrtl btbcm btmtk btintel bluetooth ecdh_generic rfkill ecc mei_me mei ioatdma dca wmi nfsd drm i2c_dev fuse nfnetlink [ 743.186938] ---[ end trace 0000000000000000 ]--- And for property blobs: void drm_mode_config_cleanup(struct drm_device *dev) { ... list_for_each_entry_safe(blob, bt, &dev->mode_config.property_blob_list, head_global) { drm_property_blob_put(blob); } Resulting in: [ 371.072940] BUG: unable to handle page fault for address: 000001ffffffffff [ 371.072944] #PF: supervisor read access in kernel mode [ 371.072945] #PF: error_code(0x0000) - not-present page [ 371.072947] PGD 0 P4D 0 [ 371.072950] Oops: Oops: 0000 [#1] SMP [ 371.072953] CPU: 0 UID: 1000 PID: 3693 Comm: kwin_wayland Not tainted 7.0.0-rc1-valkyria+ #111 PREEMPT_{RT,(lazy)} [ 371.072956] Hardware name: Gigabyte Technology Co., Ltd. X299 AORUS Gaming 3/X299 AORUS Gaming 3-CF, BIOS F8n 12/06/2021 [ 371.072957] RIP: 0010:drm_property_destroy_user_blobs+0x3b/0x90 [drm] [ 371.073019] Code: 00 00 48 83 ec 10 48 8b 86 30 01 00 00 48 39 c3 74 59 48 89 c2 48 8d 48 c8 48 8b 00 4c 8d 60 c8 eb 04 4c 8d 60 c8 48 8b 71 40 <48> 39 16 0f 85 39 32 01 00 48 3b 50 08 0f 85 2f 32 01 00 48 89 70 [ 371.073021] RSP: 0018:ffffc90006a73de8 EFLAGS: 00010293 [ 371.073022] RAX: 000001ffffffffff RBX: ffff888118a1a930 RCX: ffff8881b92355c0 [ 371.073024] RDX: ffff8881b92355f8 RSI: 000001ffffffffff RDI: ffff888118be4000 [ 371.073025] RBP: ffffc90006a73e08 R08: ffff8881009b7300 R09: ffff888cecc5b000 [ 371.073026] R10: ffffc90006a73e90 R11: 0000000000000002 R12: 000001ffffffffc7 [ 371.073027] R13: ffff888118a1a980 R14: ffff88810b366d20 R15: ffff888118a1a970 [ 371.073028] FS: 00007f1faccbb280(0000) GS:ffff888cec2db000(0000) knlGS:0000000000000000 [ 371.073029] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 371.073030] CR2: 000001ffffffffff CR3: 000000010655c001 CR4: 00000000003706f0 [ 371.073031] Call Trace: [ 371.073033] [ 371.073036] drm_file_free+0x1df/0x2a0 [drm] [ 371.073077] drm_release_noglobal+0x7a/0xe0 [drm] [ 371.073113] __fput+0xe2/0x2b0 [ 371.073118] fput_close_sync+0x40/0xa0 [ 371.073119] __x64_sys_close+0x3e/0x80 [ 371.073122] x64_sys_call+0xa07/0xa30 [ 371.073126] do_syscall_64+0xc0/0x840 [ 371.073130] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 371.073132] RIP: 0033:0x7f1fb3501732 [ 371.073133] Code: 08 0f 85 a1 38 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 55 bf 01 00 [ 371.073135] RSP: 002b:00007ffe8e6f0278 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 371.073136] RAX: ffffffffffffffda RBX: 00007ffe8e6f0300 RCX: 00007f1fb3501732 [ 371.073137] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000012 [ 371.073138] RBP: 00007ffe8e6f02a0 R08: 0000000000000000 R09: 0000000000000000 [ 371.073139] R10: 0000000000000000 R11: 0000000000000246 R12: 00005585ba46eea0 [ 371.073140] R13: 00007ffe8e6f0360 R14: 00007ffe8e6f0360 R15: 00005585ba458a30 [ 371.073143] [ 371.073144] Modules linked in: rfcomm snd_hrtimer xt_addrtype xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp nft_compat x_tables nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables overlay cfg80211 bnep snd_hda_codec_intelhdmi snd_hda_codec_hdmi mtd_intel_dg mtd nls_utf8 wmi_bmof mxm_wmi gigabyte_wmi intel_wmi_thunderbolt xe drm_gpuvm drm_gpusvm_helper i2c_algo_bit drm_buddy drm_ttm_helper ttm video drm_suballoc_helper gpu_sched drm_client_lib drm_exec drm_display_helper cec drm_kunit_helpers drm_kms_helper kunit x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_alc882 snd_hda_codec_realtek_lib snd_hda_codec_generic snd_hda_intel snd_soc_avs snd_soc_hda_codec snd_hda_ext_core snd_hda_codec snd_hwdep snd_hda_core snd_intel_dspcfg snd_soc_core snd_compress ac97_bus snd_pcm snd_seq snd_seq_device snd_timer i2c_i801 btusb i2c_mux i2c_smbus btrtl snd btbcm btmtk btintel bluetooth ecdh_generic rfkill ecc mei_me mei ioatdma dca wmi nfsd drm i2c_dev fuse nfnetlink [ 371.073198] CR2: 000001ffffffffff [ 371.073199] ---[ end trace 0000000000000000 ]--- Add a guard around file close, and ensure the warnings from drm_mode_config do not trigger. Fix those by allowing an open reference to the file descriptor and cleaning up the file linked list entry in drm_mode_config_cleanup(). Cc: # v4.18+ Fixes: bee330f3d672 ("drm: Use srcu to protect drm_device.unplugged") Cc: Thomas Hellström Reviewed-by: Thomas Hellström Link: https://patch.msgid.link/20260313151728.14990-4-dev@lankhorst.se Signed-off-by: Maarten Lankhorst [ adapted drm_dbg_printer(dev, DRM_UT_KMS, ...) call to older drm_debug_printer(...) API ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

drm/drm_file: fix use of uninitialized variable

2024-02-05T20:12:55+00:00

[ Upstream commit 1d3062fad9c7313fff9970a88e0538a24480ffb8 ] smatch reports: drivers/gpu/drm/drm_file.c:967 drm_show_memory_stats() error: uninitialized symbol 'supported_status'. 'supported_status' is only set in one code path. I'm not familiar with the code to say if that path will always be ran in real life, but whether that is the case or not, I think it is good to initialize 'supported_status' to 0 to silence the warning (and possibly fix a bug). Reviewed-by: Laurent Pinchart Acked-by: Maxime Ripard Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20231103-uninit-fixes-v2-1-c22b2444f5f5@ideasonboard.com Signed-off-by: Sasha Levin

Merge tag 'drm-misc-next-2022-08-20-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

2022-09-06T08:56:04+00:00

drm-misc-next for v6.1: UAPI Changes: Cross-subsystem Changes: - DMA-buf: documentation updates. - Assorted small fixes to vga16fb - Fix fbdev drivers to use the aperture helpers. - Make removal of conflicting drivers work correctly without fbdev enabled. Core Changes: - bridge, scheduler, dp-mst: Assorted small fixes. - Add more format helpers to fourcc, and use it to replace the cpp usage. - Add DRM_FORMAT_Cxx, DRM_FORMAT_Rxx (single channel), and DRM_FORMAT_Dxx ("darkness", inverted single channel) - Add packed AYUV8888 and XYUV8888 formats. - Assorted documentation updates. - Rename ttm_bo_init to ttm_bo_init_validate. - Allow TTM bo's to exist without backing store. - Convert drm selftests to kunit. - Add managed init functions for (panel) bridge, crtc, encoder and connector. - Fix endianness handling in various format conversion helpers. - Make tests pass on big-endian platforms, and add test for rgb888 -> rgb565 - Move DRM_PLANE_HELPER_NO_SCALING to atomic helpers and rename, so drm_plane_helper is no longer needed in most drivers. - Use idr_init_base instead of idr_init. - Rename FB and GEM CMA helpers to DMA helpers. - Rework XRGB8888 related conversion helpers, and add drm_fb_blit() that takes a iosys_map. Make drm_fb_memcpy take an iosys_map too. - Move edid luminance calculation to core, and use it in i915. Driver Changes: - bridge/{adv7511,ti-sn65dsi86,parade-ps8640}, panel/{simple,nt35510,tc358767}, nouveau, sun4i, mipi-dsi, mgag200, bochs, arm, komeda, vmwgfx, pl111: Assorted small fixes and doc updates. - vc4: Rework hdmi power up, and depend on PM. - panel/simple: Add Samsung LTL101AL01. - ingenic: Add JZ4760(B) support, avoid a modeset when sharpness property is unchanged, and use the new PM ops. - Revert some amdgpu commits that cause garbaged graphics when starting X, and reapply them with the real problem fixed. - Completely rework vc4 init to use managed helpers. - Rename via_drv to via_dri1, and move all stuff there only used by the dri1 implementation in preperation for atomic modeset. - Use regmap bulk write in ssd130x. - Power sequence and clock updates to it6505. - Split panel-sitrox-st7701 init sequence and rework mode programming code. - virtio: Improve error and edge conditions handling, and convert to use managed helpers. - Add Samsung LTL101AL01, B120XAN01.0, R140NWF5 RH, DMT028VGHMCMI-1A T, panels. - Add generic fbdev support to komeda. - Split mgag200 modeset handling to make it more model-specific. - Convert simpledrm to use atomic helpers. - Improve udl suspend/disconnect handling. Signed-off-by: Daniel Vetter From: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/f0c71766-61e8-19b7-763a-5fbcdefc633d@linux.intel.com

drm: Remove the drm_get_unmapped_area() helper

2022-08-04T15:39:27+00:00

This has been only used by the vmwgfx driver and vmwgfx over the last year removed support for transparent hugepages on vram leaving drm_get_unmapped_area completely unused. There's no point in keeping unused code in core drm. Signed-off-by: Zack Rusin Reviewed-by: Thomas Hellström Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Link: https://patchwork.freedesktop.org/patch/msgid/20220425203152.1314211-2-zack@kde.org

drm/gem: rename GEM CMA helpers to GEM DMA helpers

2022-08-03T16:31:49+00:00

Rename "GEM CMA" helpers to "GEM DMA" helpers - considering the hierarchy of APIs (mm/cma -> dma -> gem dma) calling them "GEM DMA" seems to be more applicable. Besides that, commit e57924d4ae80 ("drm/doc: Task to rename CMA helpers") requests to rename the CMA helpers and implies that people seem to be confused about the naming. In order to do this renaming the following script was used: ``` #!/bin/bash DIRS="drivers/gpu include/drm Documentation/gpu" REGEX_SYM_UPPER="[0-9A-Z_\-]" REGEX_SYM_LOWER="[0-9a-z_\-]" REGEX_GREP_UPPER="(${REGEX_SYM_UPPER}*)(GEM)_CMA_(${REGEX_SYM_UPPER}*)" REGEX_GREP_LOWER="(${REGEX_SYM_LOWER}*)(gem)_cma_(${REGEX_SYM_LOWER}*)" REGEX_SED_UPPER="s/${REGEX_GREP_UPPER}/\1\2_DMA_\3/g" REGEX_SED_LOWER="s/${REGEX_GREP_LOWER}/\1\2_dma_\3/g" # Find all upper case 'CMA' symbols and replace them with 'DMA'. for ff in $(grep -REHl "${REGEX_GREP_UPPER}" $DIRS) do sed -i -E "$REGEX_SED_UPPER" $ff done # Find all lower case 'cma' symbols and replace them with 'dma'. for ff in $(grep -REHl "${REGEX_GREP_LOWER}" $DIRS) do sed -i -E "$REGEX_SED_LOWER" $ff done # Replace all occurrences of 'CMA' / 'cma' in comments and # documentation files with 'DMA' / 'dma'. for ff in $(grep -RiHl " cma " $DIRS) do sed -i -E "s/ cma / dma /g" $ff sed -i -E "s/ CMA / DMA /g" $ff done # Rename all 'cma_obj's to 'dma_obj'. for ff in $(grep -RiHl "cma_obj" $DIRS) do sed -i -E "s/cma_obj/dma_obj/g" $ff done ``` Only a few more manual modifications were needed, e.g. reverting the following modifications in some DRM Kconfig files - select CMA if HAVE_DMA_CONTIGUOUS + select DMA if HAVE_DMA_CONTIGUOUS as well as manually picking the occurrences of 'CMA'/'cma' in comments and documentation which relate to "GEM CMA", but not "FB CMA". Also drivers/gpu/drm/Makefile was fixed up manually after renaming drm_gem_cma_helper.c to drm_gem_dma_helper.c. This patch is compile-time tested building a x86_64 kernel with `make allyesconfig && make drivers/gpu/drm`. Acked-by: Sam Ravnborg Acked-by: Thomas Zimmermann Reviewed-by: Laurent Pinchart Signed-off-by: Danilo Krummrich Reviewed-by: Liviu Dudau #drivers/gpu/drm/arm Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220802000405.949236-4-dakr@redhat.com

fs: remove no_llseek

2022-07-16T13:19:47+00:00

Now that all callers of ->llseek are going through vfs_llseek(), we don't gain anything by keeping no_llseek around. Nothing actually calls it and setting ->llseek to no_lseek is completely equivalent to leaving it NULL. Longer term (== by the end of merge window) we want to remove all such intializations. To simplify the merge window this commit does *not* touch initializers - it only defines no_llseek as NULL (and simplifies the tests on file opening). At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Signed-off-by: Jason A. Donenfeld Signed-off-by: Al Viro

drm: Fix typo in comments

2021-08-02T08:19:43+00:00

fix typo for drm v1->v2: respin with the change "iff ==> implies that" Signed-off-by: Cai Huoqing Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210730132729.376-1-caihuoqing@baidu.com

drm: serialize drm_file.master with a new spinlock

2021-07-20T18:17:58+00:00

Currently, drm_file.master pointers should be protected by drm_device.master_mutex when being dereferenced. This is because drm_file.master is not invariant for the lifetime of drm_file. If drm_file is not the creator of master, then drm_file.is_master is false, and a call to drm_setmaster_ioctl will invoke drm_new_set_master, which then allocates a new master for drm_file and puts the old master. Thus, without holding drm_device.master_mutex, the old value of drm_file.master could be freed while it is being used by another concurrent process. However, it is not always possible to lock drm_device.master_mutex to dereference drm_file.master. Through the fbdev emulation code, this might occur in a deep nest of other locks. But drm_device.master_mutex is also the outermost lock in the nesting hierarchy, so this leads to potential deadlocks. To address this, we introduce a new spin lock at the bottom of the lock hierarchy that only serializes drm_file.master. With this change, the value of drm_file.master changes only when both drm_device.master_mutex and drm_file.master_lookup_lock are held. Hence, any process holding either of those locks can ensure that the value of drm_file.master will not change concurrently. Since no lock depends on the new drm_file.master_lookup_lock, when drm_file.master is dereferenced, but drm_device.master_mutex cannot be held, we can safely protect the master pointer with drm_file.master_lookup_lock. Reported-by: Daniel Vetter Signed-off-by: Desmond Cheong Zhi Xi Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-5-desmondcheongzx@gmail.com

drm/drm_file.c: Define drm_send_event_helper() as 'static'

2021-04-27T12:23:12+00:00

drm_send_event_helper() has not prototype, it has internal linkage and therefore it should be defined with storage class 'static'. Signed-off-by: Fabio M. De Francesco Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210427105503.10765-1-fmdefrancesco@gmail.com

drm/drm_vblank: set the dma-fence timestamp during send_vblank_event

2021-01-22T10:52:29+00:00

The explicit out-fences in crtc are signaled as part of vblank event, indicating all framebuffers present on the Atomic Commit request are scanned out on the screen. Though the fence signal and the vblank event notification happens at the same time, triggered by the same hardware vsync event, the timestamp set in both are different. With drivers supporting precise vblank timestamp the difference between the two timestamps would be even higher. This might have an impact on use-mode frameworks using these fence timestamps for purposes other than simple buffer usage. For instance, the Android framework [1] uses the retire-fences as an alternative to vblank when frame-updates are in progress. Set the fence timestamp during send vblank event using a new drm_send_event_timestamp_locked variant to avoid discrepancies. [1] https://android.googlesource.com/platform/frameworks/native/+/master/ services/surfaceflinger/Scheduler/Scheduler.cpp#397 Changes in v2: - Use drm_send_event_timestamp_locked to update fence timestamp - add more information to commit text Changes in v3: - use same backend helper function for variants of drm_send_event to avoid code duplications Changes in v4: - remove WARN_ON from drm_send_event_timestamp_locked Signed-off-by: Veera Sundaram Sankaran Reviewed-by: John Stultz Signed-off-by: Sumit Semwal [sumits: minor parenthesis alignment correction] Link: https://patchwork.freedesktop.org/patch/msgid/1610757107-11892-2-git-send-email-veeras@codeaurora.org