user/sven/linux.git/drivers/gpu/drm, branch v4.9.220

drm: NULL pointer dereference [null-pointer-deref] (CWE 476) problem

2020-04-24T05:59:07Z

commit 22a07038c0eaf4d1315a493ce66dcd255accba19 upstream. The Parfait (version 2.1.0) static code analysis tool found the following NULL pointer derefernce problem. - drivers/gpu/drm/drm_dp_mst_topology.c The call to drm_dp_calculate_rad() in function drm_dp_port_setup_pdt() could result in a NULL pointer being returned to port->mstb due to a failure to allocate memory for port->mstb. Signed-off-by: Joe Moriarty Reviewed-by: Steven Sistare Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20180212195144.98323-3-joe.moriarty@oracle.com Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

drm: Remove PageReserved manipulation from drm_pci_alloc

2020-04-24T05:59:00Z

[ Upstream commit ea36ec8623f56791c6ff6738d0509b7920f85220 ] drm_pci_alloc/drm_pci_free are very thin wrappers around the core dma facilities, and we have no special reason within the drm layer to behave differently. In particular, since commit de09d31dd38a50fdce106c15abd68432eebbd014 Author: Kirill A. Shutemov Date: Fri Jan 15 16:51:42 2016 -0800 page-flags: define PG_reserved behavior on compound pages As far as I can see there's no users of PG_reserved on compound pages. Let's use PF_NO_COMPOUND here. it has been illegal to combine GFP_COMP with SetPageReserved, so lets stop doing both and leave the dma layer to its own devices. Reported-by: Taketo Kabe Bug: https://gitlab.freedesktop.org/drm/intel/issues/1027 Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages") Signed-off-by: Chris Wilson Cc: # v4.5+ Reviewed-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20200202171635.4039044-1-chris@chris-wilson.co.uk Signed-off-by: Sasha Levin

drm/dp_mst: Fix clearing payload state on topology disable

2020-04-24T05:59:00Z

[ Upstream commit 8732fe46b20c951493bfc4dba0ad08efdf41de81 ] The issues caused by: commit 64e62bdf04ab ("drm/dp_mst: Remove VCPI while disabling topology mgr") Prompted me to take a closer look at how we clear the payload state in general when disabling the topology, and it turns out there's actually two subtle issues here. The first is that we're not grabbing &mgr.payload_lock when clearing the payloads in drm_dp_mst_topology_mgr_set_mst(). Seeing as the canonical lock order is &mgr.payload_lock -> &mgr.lock (because we always want &mgr.lock to be the inner-most lock so topology validation always works), this makes perfect sense. It also means that -technically- there could be racing between someone calling drm_dp_mst_topology_mgr_set_mst() to disable the topology, along with a modeset occurring that's modifying the payload state at the same time. The second is the more obvious issue that Wayne Lin discovered, that we're not clearing proposed_payloads when disabling the topology. I actually can't see any obvious places where the racing caused by the first issue would break something, and it could be that some of our higher-level locks already prevent this by happenstance, but better safe then sorry. So, let's make it so that drm_dp_mst_topology_mgr_set_mst() first grabs &mgr.payload_lock followed by &mgr.lock so that we never race when modifying the payload state. Then, we also clear proposed_payloads to fix the original issue of enabling a new topology with a dirty payload state. This doesn't clear any of the drm_dp_vcpi structures, but those are getting destroyed along with the ports anyway. Changes since v1: * Use sizeof(mgr->payloads[0])/sizeof(mgr->proposed_vcpis[0]) instead - vsyrjala Cc: Sean Paul Cc: Wayne Lin Cc: Ville Syrjälä Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Lyude Paul Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200122194321.14953-1-lyude@redhat.com Signed-off-by: Sasha Levin

drm/msm: Use the correct dma_sync calls in msm_gem

2020-04-13T08:32:59Z

commit 3de433c5b38af49a5fc7602721e2ab5d39f1e69c upstream. [subject was: drm/msm: shake fist angrily at dma-mapping] So, using dma_sync_* for our cache needs works out w/ dma iommu ops, but it falls appart with dma direct ops. The problem is that, depending on display generation, we can have either set of dma ops (mdp4 and dpu have iommu wired to mdss node, which maps to toplevel drm device, but mdp5 has iommu wired up to the mdp sub-node within mdss). Fixes this splat on mdp5 devices: Unable to handle kernel paging request at virtual address ffffffff80000000 Mem abort info: ESR = 0x96000144 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000144 CM = 1, WnR = 1 swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000810e4000 [ffffffff80000000] pgd=0000000000000000 Internal error: Oops: 96000144 [#1] SMP Modules linked in: btqcomsmd btqca bluetooth cfg80211 ecdh_generic ecc rfkill libarc4 panel_simple msm wcnss_ctrl qrtr_smd drm_kms_helper venus_enc venus_dec videobuf2_dma_sg videobuf2_memops drm venus_core ipv6 qrtr qcom_wcnss_pil v4l2_mem2mem qcom_sysmon videobuf2_v4l2 qmi_helpers videobuf2_common crct10dif_ce mdt_loader qcom_common videodev qcom_glink_smem remoteproc bmc150_accel_i2c bmc150_magn_i2c bmc150_accel_core bmc150_magn snd_soc_lpass_apq8016 snd_soc_msm8916_analog mms114 mc nf_defrag_ipv6 snd_soc_lpass_cpu snd_soc_apq8016_sbc industrialio_triggered_buffer kfifo_buf snd_soc_lpass_platform snd_soc_msm8916_digital drm_panel_orientation_quirks CPU: 2 PID: 33 Comm: kworker/2:1 Not tainted 5.3.0-rc2 #1 Hardware name: Samsung Galaxy A5U (EUR) (DT) Workqueue: events deferred_probe_work_func pstate: 80000005 (Nzcv daif -PAN -UAO) pc : __clean_dcache_area_poc+0x20/0x38 lr : arch_sync_dma_for_device+0x28/0x30 sp : ffff0000115736a0 x29: ffff0000115736a0 x28: 0000000000000001 x27: ffff800074830800 x26: ffff000011478000 x25: 0000000000000000 x24: 0000000000000001 x23: ffff000011478a98 x22: ffff800009fd1c10 x21: 0000000000000001 x20: ffff800075ad0a00 x19: 0000000000000000 x18: ffff0000112b2000 x17: 0000000000000000 x16: 0000000000000000 x15: 00000000fffffff0 x14: ffff000011455d70 x13: 0000000000000000 x12: 0000000000000028 x11: 0000000000000001 x10: ffff00001106c000 x9 : ffff7e0001d6b380 x8 : 0000000000001000 x7 : ffff7e0001d6b380 x6 : ffff7e0001d6b382 x5 : 0000000000000000 x4 : 0000000000001000 x3 : 000000000000003f x2 : 0000000000000040 x1 : ffffffff80001000 x0 : ffffffff80000000 Call trace: __clean_dcache_area_poc+0x20/0x38 dma_direct_sync_sg_for_device+0xb8/0xe8 get_pages+0x22c/0x250 [msm] msm_gem_get_and_pin_iova+0xdc/0x168 [msm] ... Fixes the combination of two patches: Fixes: 0036bc73ccbe (drm/msm: stop abusing dma_map/unmap for cache) Fixes: 449fa54d6815 (dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device) Tested-by: Stephan Gerhold Signed-off-by: Rob Clark [seanpaul changed subject to something more desriptive] Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20190730214633.17820-1-robdclark@gmail.com Cc: nobuhiro1.iwamatsu@toshiba.co.jp Signed-off-by: Greg Kroah-Hartman

drm_dp_mst_topology: fix broken drm_dp_sideband_parse_remote_dpcd_read()

2020-04-13T08:32:59Z

commit a4c30a4861c54af78c4eb8b7855524c1a96d9f80 upstream. When parsing the reply of a DP_REMOTE_DPCD_READ DPCD command the result is wrong due to a missing idx increment. This was never noticed since DP_REMOTE_DPCD_READ is currently not used, but if you enable it, then it is all wrong. Signed-off-by: Hans Verkuil Reviewed-by: Lyude Paul Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/e72ddac2-1dc0-100a-d816-9ac98ac009dd@xs4all.nl Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

drm/msm: stop abusing dma_map/unmap for cache

2020-04-13T08:32:58Z

commit 0036bc73ccbe7e600a3468bf8e8879b122252274 upstream. Recently splats like this started showing up: WARNING: CPU: 4 PID: 251 at drivers/iommu/dma-iommu.c:451 __iommu_dma_unmap+0xb8/0xc0 Modules linked in: ath10k_snoc ath10k_core fuse msm ath mac80211 uvcvideo cfg80211 videobuf2_vmalloc videobuf2_memops vide CPU: 4 PID: 251 Comm: kworker/u16:4 Tainted: G W 5.2.0-rc5-next-20190619+ #2317 Hardware name: LENOVO 81JL/LNVNB161216, BIOS 9UCN23WW(V1.06) 10/25/2018 Workqueue: msm msm_gem_free_work [msm] pstate: 80c00005 (Nzcv daif +PAN +UAO) pc : __iommu_dma_unmap+0xb8/0xc0 lr : __iommu_dma_unmap+0x54/0xc0 sp : ffff0000119abce0 x29: ffff0000119abce0 x28: 0000000000000000 x27: ffff8001f9946648 x26: ffff8001ec271068 x25: 0000000000000000 x24: ffff8001ea3580a8 x23: ffff8001f95ba010 x22: ffff80018e83ba88 x21: ffff8001e548f000 x20: fffffffffffff000 x19: 0000000000001000 x18: 00000000c00001fe x17: 0000000000000000 x16: 0000000000000000 x15: ffff000015b70068 x14: 0000000000000005 x13: 0003142cc1be1768 x12: 0000000000000001 x11: ffff8001f6de9100 x10: 0000000000000009 x9 : ffff000015b78000 x8 : 0000000000000000 x7 : 0000000000000001 x6 : fffffffffffff000 x5 : 0000000000000fff x4 : ffff00001065dbc8 x3 : 000000000000000d x2 : 0000000000001000 x1 : fffffffffffff000 x0 : 0000000000000000 Call trace: __iommu_dma_unmap+0xb8/0xc0 iommu_dma_unmap_sg+0x98/0xb8 put_pages+0x5c/0xf0 [msm] msm_gem_free_work+0x10c/0x150 [msm] process_one_work+0x1e0/0x330 worker_thread+0x40/0x438 kthread+0x12c/0x130 ret_from_fork+0x10/0x18 ---[ end trace afc0dc5ab81a06bf ]--- Not quite sure what triggered that, but we really shouldn't be abusing dma_{map,unmap}_sg() for cache maint. Cc: Stephen Boyd Tested-by: Stephen Boyd Reviewed-by: Jordan Crouse Signed-off-by: Rob Clark Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20190630124735.27786-1-robdclark@gmail.com Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

drm/etnaviv: replace MMU flush marker with flush sequence

2020-04-13T08:32:52Z

commit 4900dda90af2cb13bc1d4c12ce94b98acc8fe64e upstream. If a MMU is shared between multiple GPUs, all of them need to flush their TLBs, so a single marker that gets reset on the first flush won't do. Replace the flush marker with a sequence number, so that it's possible to check if the TLB is in sync with the current page table state for each GPU. Signed-off-by: Lucas Stach Reviewed-by: Philipp Zabel Reviewed-by: Guido Günther Signed-off-by: Robert Beckett Signed-off-by: Greg Kroah-Hartman

drm/bochs: downgrade pci_request_region failure from error to warning

2020-04-13T08:32:51Z

[ Upstream commit 8c34cd1a7f089dc03933289c5d4a4d1489549828 ] Shutdown of firmware framebuffer has a bunch of problems. Because of this the framebuffer region might still be reserved even after drm_fb_helper_remove_conflicting_pci_framebuffers() returned. Don't consider pci_request_region() failure for the framebuffer region as fatal error to workaround this issue. Reported-by: Marek Marczykowski-Górecki Signed-off-by: Gerd Hoffmann Acked-by: Sam Ravnborg Link: http://patchwork.freedesktop.org/patch/msgid/20200313084152.2734-1-kraxel@redhat.com Signed-off-by: Sasha Levin

Revert "drm/dp_mst: Skip validating ports during destruction, just ref"

2020-04-02T15:20:29Z

commit 9765635b30756eb74e05e260ac812659c296cd28 upstream. This reverts commit: c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref") ugh. In drm_dp_destroy_connector_work(), we have a pretty good chance of freeing the actual struct drm_dp_mst_port. However, after destroying things we send a hotplug through (*mgr->cbs->hotplug)(mgr) which is where the problems start. For i915, this calls all the way down to the fbcon probing helpers, which start trying to access the port in a modeset. [ 45.062001] ================================================================== [ 45.062112] BUG: KASAN: use-after-free in ex_handler_refcount+0x146/0x180 [ 45.062196] Write of size 4 at addr ffff8882b4b70968 by task kworker/3:1/53 [ 45.062325] CPU: 3 PID: 53 Comm: kworker/3:1 Kdump: loaded Tainted: G O 4.20.0-rc4Lyude-Test+ #3 [ 45.062442] Hardware name: LENOVO 20BWS1KY00/20BWS1KY00, BIOS JBET71WW (1.35 ) 09/14/2018 [ 45.062554] Workqueue: events drm_dp_destroy_connector_work [drm_kms_helper] [ 45.062641] Call Trace: [ 45.062685] dump_stack+0xbd/0x15a [ 45.062735] ? dump_stack_print_info.cold.0+0x1b/0x1b [ 45.062801] ? printk+0x9f/0xc5 [ 45.062847] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 45.062909] ? ex_handler_refcount+0x146/0x180 [ 45.062970] print_address_description+0x71/0x239 [ 45.063036] ? ex_handler_refcount+0x146/0x180 [ 45.063095] kasan_report.cold.5+0x242/0x30b [ 45.063155] __asan_report_store4_noabort+0x1c/0x20 [ 45.063313] ex_handler_refcount+0x146/0x180 [ 45.063371] ? ex_handler_clear_fs+0xb0/0xb0 [ 45.063428] fixup_exception+0x98/0xd7 [ 45.063484] ? raw_notifier_call_chain+0x20/0x20 [ 45.063548] do_trap+0x6d/0x210 [ 45.063605] ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper] [ 45.063732] do_error_trap+0xc0/0x170 [ 45.063802] ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper] [ 45.063929] do_invalid_op+0x3b/0x50 [ 45.063997] ? _GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper] [ 45.064103] invalid_op+0x14/0x20 [ 45.064162] RIP: 0010:_GLOBAL__sub_I_65535_1_drm_dp_aux_unregister_devnode+0x2f/0x1c6 [drm_kms_helper] [ 45.064274] Code: 00 48 c7 c7 80 fe 53 a0 48 89 e5 e8 5b 6f 26 e1 5d c3 48 8d 0e 0f 0b 48 8d 0b 0f 0b 48 8d 0f 0f 0b 48 8d 0f 0f 0b 49 8d 4d 00 <0f> 0b 49 8d 0e 0f 0b 48 8d 08 0f 0b 49 8d 4d 00 0f 0b 48 8d 0b 0f [ 45.064569] RSP: 0018:ffff8882b789ee10 EFLAGS: 00010282 [ 45.064637] RAX: ffff8882af47ae70 RBX: ffff8882af47aa60 RCX: ffff8882b4b70968 [ 45.064723] RDX: ffff8882af47ae70 RSI: 0000000000000008 RDI: ffff8882b788bdb8 [ 45.064808] RBP: ffff8882b789ee28 R08: ffffed1056f13db4 R09: ffffed1056f13db3 [ 45.064894] R10: ffffed1056f13db3 R11: ffff8882b789ed9f R12: ffff8882af47ad28 [ 45.064980] R13: ffff8882b4b70968 R14: ffff8882acd86728 R15: ffff8882b4b75dc8 [ 45.065084] drm_dp_mst_reset_vcpi_slots+0x12/0x80 [drm_kms_helper] [ 45.065225] intel_mst_disable_dp+0xda/0x180 [i915] [ 45.065361] intel_encoders_disable.isra.107+0x197/0x310 [i915] [ 45.065498] haswell_crtc_disable+0xbe/0x400 [i915] [ 45.065622] ? i9xx_disable_plane+0x1c0/0x3e0 [i915] [ 45.065750] intel_atomic_commit_tail+0x74e/0x3e60 [i915] [ 45.065884] ? intel_pre_plane_update+0xbc0/0xbc0 [i915] [ 45.065968] ? drm_atomic_helper_swap_state+0x88b/0x1d90 [drm_kms_helper] [ 45.066054] ? kasan_check_write+0x14/0x20 [ 45.066165] ? i915_gem_track_fb+0x13a/0x330 [i915] [ 45.066277] ? i915_sw_fence_complete+0xe9/0x140 [i915] [ 45.066406] ? __i915_sw_fence_complete+0xc50/0xc50 [i915] [ 45.066540] intel_atomic_commit+0x72e/0xef0 [i915] [ 45.066635] ? drm_dev_dbg+0x200/0x200 [drm] [ 45.066764] ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915] [ 45.066898] ? intel_atomic_commit_tail+0x3e60/0x3e60 [i915] [ 45.067001] drm_atomic_commit+0xc4/0xf0 [drm] [ 45.067074] restore_fbdev_mode_atomic+0x562/0x780 [drm_kms_helper] [ 45.067166] ? drm_fb_helper_debug_leave+0x690/0x690 [drm_kms_helper] [ 45.067249] ? kasan_check_read+0x11/0x20 [ 45.067324] restore_fbdev_mode+0x127/0x4b0 [drm_kms_helper] [ 45.067364] ? kasan_check_read+0x11/0x20 [ 45.067406] drm_fb_helper_restore_fbdev_mode_unlocked+0x164/0x200 [drm_kms_helper] [ 45.067462] ? drm_fb_helper_hotplug_event+0x30/0x30 [drm_kms_helper] [ 45.067508] ? kasan_check_write+0x14/0x20 [ 45.070360] ? mutex_unlock+0x22/0x40 [ 45.073748] drm_fb_helper_set_par+0xb2/0xf0 [drm_kms_helper] [ 45.075846] drm_fb_helper_hotplug_event.part.33+0x1cd/0x290 [drm_kms_helper] [ 45.078088] drm_fb_helper_hotplug_event+0x1c/0x30 [drm_kms_helper] [ 45.082614] intel_fbdev_output_poll_changed+0x9f/0x140 [i915] [ 45.087069] drm_kms_helper_hotplug_event+0x67/0x90 [drm_kms_helper] [ 45.089319] intel_dp_mst_hotplug+0x37/0x50 [i915] [ 45.091496] drm_dp_destroy_connector_work+0x510/0x6f0 [drm_kms_helper] [ 45.093675] ? drm_dp_update_payload_part1+0x1220/0x1220 [drm_kms_helper] [ 45.095851] ? kasan_check_write+0x14/0x20 [ 45.098473] ? kasan_check_read+0x11/0x20 [ 45.101155] ? strscpy+0x17c/0x530 [ 45.103808] ? __switch_to_asm+0x34/0x70 [ 45.106456] ? syscall_return_via_sysret+0xf/0x7f [ 45.109711] ? read_word_at_a_time+0x20/0x20 [ 45.113138] ? __switch_to_asm+0x40/0x70 [ 45.116529] ? __switch_to_asm+0x34/0x70 [ 45.119891] ? __switch_to_asm+0x40/0x70 [ 45.123224] ? __switch_to_asm+0x34/0x70 [ 45.126540] ? __switch_to_asm+0x34/0x70 [ 45.129824] process_one_work+0x88d/0x15d0 [ 45.133172] ? pool_mayday_timeout+0x850/0x850 [ 45.136459] ? pci_mmcfg_check_reserved+0x110/0x128 [ 45.139739] ? wake_q_add+0xb0/0xb0 [ 45.143010] ? check_preempt_wakeup+0x652/0x1050 [ 45.146304] ? worker_enter_idle+0x29e/0x740 [ 45.149589] ? __schedule+0x1ec0/0x1ec0 [ 45.152937] ? kasan_check_read+0x11/0x20 [ 45.156179] ? _raw_spin_lock_irq+0xa3/0x130 [ 45.159382] ? _raw_read_unlock_irqrestore+0x30/0x30 [ 45.162542] ? kasan_check_write+0x14/0x20 [ 45.165657] worker_thread+0x1a5/0x1470 [ 45.168725] ? set_load_weight+0x2e0/0x2e0 [ 45.171755] ? process_one_work+0x15d0/0x15d0 [ 45.174806] ? __switch_to_asm+0x34/0x70 [ 45.177645] ? __switch_to_asm+0x40/0x70 [ 45.180323] ? __switch_to_asm+0x34/0x70 [ 45.182936] ? __switch_to_asm+0x40/0x70 [ 45.185539] ? __switch_to_asm+0x34/0x70 [ 45.188100] ? __switch_to_asm+0x40/0x70 [ 45.190628] ? __schedule+0x7d4/0x1ec0 [ 45.193143] ? save_stack+0xa9/0xd0 [ 45.195632] ? kasan_check_write+0x10/0x20 [ 45.198162] ? kasan_kmalloc+0xc4/0xe0 [ 45.200609] ? kmem_cache_alloc_trace+0xdd/0x190 [ 45.203046] ? kthread+0x9f/0x3b0 [ 45.205470] ? ret_from_fork+0x35/0x40 [ 45.207876] ? unwind_next_frame+0x43/0x50 [ 45.210273] ? __save_stack_trace+0x82/0x100 [ 45.212658] ? deactivate_slab.isra.67+0x3d4/0x580 [ 45.215026] ? default_wake_function+0x35/0x50 [ 45.217399] ? kasan_check_read+0x11/0x20 [ 45.219825] ? _raw_spin_lock_irqsave+0xae/0x140 [ 45.222174] ? __lock_text_start+0x8/0x8 [ 45.224521] ? replenish_dl_entity.cold.62+0x4f/0x4f [ 45.226868] ? __kthread_parkme+0x87/0xf0 [ 45.229200] kthread+0x2f7/0x3b0 [ 45.231557] ? process_one_work+0x15d0/0x15d0 [ 45.233923] ? kthread_park+0x120/0x120 [ 45.236249] ret_from_fork+0x35/0x40 [ 45.240875] Allocated by task 242: [ 45.243136] save_stack+0x43/0xd0 [ 45.245385] kasan_kmalloc+0xc4/0xe0 [ 45.247597] kmem_cache_alloc_trace+0xdd/0x190 [ 45.249793] drm_dp_add_port+0x1e0/0x2170 [drm_kms_helper] [ 45.252000] drm_dp_send_link_address+0x4a7/0x740 [drm_kms_helper] [ 45.254389] drm_dp_check_and_send_link_address+0x1a7/0x210 [drm_kms_helper] [ 45.256803] drm_dp_mst_link_probe_work+0x6f/0xb0 [drm_kms_helper] [ 45.259200] process_one_work+0x88d/0x15d0 [ 45.261597] worker_thread+0x1a5/0x1470 [ 45.264038] kthread+0x2f7/0x3b0 [ 45.266371] ret_from_fork+0x35/0x40 [ 45.270937] Freed by task 53: [ 45.273170] save_stack+0x43/0xd0 [ 45.275382] __kasan_slab_free+0x139/0x190 [ 45.277604] kasan_slab_free+0xe/0x10 [ 45.279826] kfree+0x99/0x1b0 [ 45.282044] drm_dp_free_mst_port+0x4a/0x60 [drm_kms_helper] [ 45.284330] drm_dp_destroy_connector_work+0x43e/0x6f0 [drm_kms_helper] [ 45.286660] process_one_work+0x88d/0x15d0 [ 45.288934] worker_thread+0x1a5/0x1470 [ 45.291231] kthread+0x2f7/0x3b0 [ 45.293547] ret_from_fork+0x35/0x40 [ 45.298206] The buggy address belongs to the object at ffff8882b4b70968 which belongs to the cache kmalloc-2k of size 2048 [ 45.303047] The buggy address is located 0 bytes inside of 2048-byte region [ffff8882b4b70968, ffff8882b4b71168) [ 45.308010] The buggy address belongs to the page: [ 45.310477] page:ffffea000ad2dc00 count:1 mapcount:0 mapping:ffff8882c080cf40 index:0x0 compound_mapcount: 0 [ 45.313051] flags: 0x8000000000010200(slab|head) [ 45.315635] raw: 8000000000010200 ffffea000aac2808 ffffea000abe8608 ffff8882c080cf40 [ 45.318300] raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000 [ 45.320966] page dumped because: kasan: bad access detected [ 45.326312] Memory state around the buggy address: [ 45.329085] ffff8882b4b70800: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 45.331845] ffff8882b4b70880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 45.334584] >ffff8882b4b70900: fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb [ 45.337302] ^ [ 45.340061] ffff8882b4b70980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.342910] ffff8882b4b70a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.345748] ================================================================== So, this definitely isn't a fix that we want. This being said; there's no real easy fix for this problem because of some of the catch-22's of the MST helpers current design. For starters; we always need to validate a port with drm_dp_get_validated_port_ref(), but validation relies on the lifetime of the port in the actual topology. So once the port is gone, it can't be validated again. If we were to try to make the payload helpers not use port validation, then we'd cause another problem: if the port isn't validated, it could be freed and we'd just start causing more KASAN issues. There are already hacks that attempt to workaround this in drm_dp_mst_destroy_connector_work() by re-initializing the kref so that it can be used again and it's memory can be freed once the VCPI helpers finish removing the port's respective payloads. But none of these really do anything helpful since the port still can't be validated since it's gone from the topology. Also, that workaround is immensely confusing to read through. What really needs to be done in order to fix this is to teach DRM how to track the lifetime of the structs for MST ports and branch devices separately from their lifetime in the actual topology. Simply put; this means having two different krefs-one that removes the port/branch device from the topology, and one that finally calls kfree(). This would let us simplify things, since we'd now be able to keep ports around without having to keep them in the topology at the same time, which is exactly what we need in order to teach our VCPI helpers to only validate ports when it's actually necessary without running the risk of trying to use unallocated memory. Such a fix is on it's way, but for now let's play it safe and just revert this. If this bug has been around for well over a year, we can wait a little while to get an actual proper fix here. Signed-off-by: Lyude Paul Fixes: c54c7374ff44 ("drm/dp_mst: Skip validating ports during destruction, just ref") Cc: Daniel Vetter Cc: Sean Paul Cc: Jerry Zuo Cc: Harry Wentland Cc: stable@vger.kernel.org # v4.6+ Acked-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20181128210005.24434-1-lyude@redhat.com Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

drm/exynos: dsi: fix workaround for the legacy clock name

2020-04-02T15:20:22Z

[ Upstream commit c0fd99d659ba5582e09625c7a985d63fc2ca74b5 ] Writing to the built-in strings arrays doesn't work if driver is loaded as kernel module. This is also considered as a bad pattern. Fix this by adding a call to clk_get() with legacy clock name. This fixes following kernel oops if driver is loaded as module: Unable to handle kernel paging request at virtual address bf047978 pgd = (ptrval) [bf047978] *pgd=59344811, *pte=5903c6df, *ppte=5903c65f Internal error: Oops: 80f [#1] SMP ARM Modules linked in: mc exynosdrm(+) analogix_dp rtc_s3c exynos_ppmu i2c_gpio CPU: 1 PID: 212 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200219 #326 videodev: Linux video capture interface: v2.00 Hardware name: Samsung Exynos (Flattened Device Tree) PC is at exynos_dsi_probe+0x1f0/0x384 [exynosdrm] LR is at exynos_dsi_probe+0x1dc/0x384 [exynosdrm] ... Process systemd-udevd (pid: 212, stack limit = 0x(ptrval)) ... [] (exynos_dsi_probe [exynosdrm]) from [] (platform_drv_probe+0x6c/0xa4) [] (platform_drv_probe) from [] (really_probe+0x210/0x350) [] (really_probe) from [] (driver_probe_device+0x60/0x1a0) [] (driver_probe_device) from [] (device_driver_attach+0x58/0x60) [] (device_driver_attach) from [] (__driver_attach+0x80/0xbc) [] (__driver_attach) from [] (bus_for_each_dev+0x68/0xb4) [] (bus_for_each_dev) from [] (bus_add_driver+0x130/0x1e8) [] (bus_add_driver) from [] (driver_register+0x78/0x110) [] (driver_register) from [] (exynos_drm_init+0xe8/0x11c [exynosdrm]) [] (exynos_drm_init [exynosdrm]) from [] (do_one_initcall+0x50/0x220) [] (do_one_initcall) from [] (do_init_module+0x60/0x210) [] (do_init_module) from [] (load_module+0x1c0c/0x2310) [] (load_module) from [] (sys_finit_module+0xac/0xbc) [] (sys_finit_module) from [] (ret_fast_syscall+0x0/0x54) Exception stack(0xd979bfa8 to 0xd979bff0) ... ---[ end trace db16efe05faab470 ]--- Signed-off-by: Marek Szyprowski Reviewed-by: Andrzej Hajda Signed-off-by: Inki Dae Signed-off-by: Sasha Levin