1. 02 Apr, 2020 6 commits
    • Lyude Paul's avatar
      Revert "drm/dp_mst: Skip validating ports during destruction, just ref" · 013b1465
      Lyude Paul authored
      commit 9765635b upstream.
      
      This reverts commit:
      
      c54c7374 ("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: default avatarLyude Paul <lyude@redhat.com>
      Fixes: c54c7374 ("drm/dp_mst: Skip validating ports during destruction, just ref")
      Cc: Daniel Vetter <daniel@ffwll.ch>
      Cc: Sean Paul <sean@poorly.run>
      Cc: Jerry Zuo <Jerry.Zuo@amd.com>
      Cc: Harry Wentland <Harry.Wentland@amd.com>
      Cc: stable@vger.kernel.org # v4.6+
      Acked-by: default avatarSean Paul <sean@poorly.run>
      Link: https://patchwork.freedesktop.org/patch/msgid/20181128210005.24434-1-lyude@redhat.com
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      013b1465
    • Ulf Hansson's avatar
      mmc: sdhci-tegra: Fix busy detection by enabling MMC_CAP_NEED_RSP_BUSY · ff6471fe
      Ulf Hansson authored
      [ Upstream commit d2f8bfa4 ]
      
      It has turned out that the sdhci-tegra controller requires the R1B response,
      for commands that has this response associated with them. So, converting
      from an R1B to an R1 response for a CMD6 for example, leads to problems
      with the HW busy detection support.
      
      Fix this by informing the mmc core about the requirement, via setting the
      host cap, MMC_CAP_NEED_RSP_BUSY.
      Reported-by: default avatarBitan Biswas <bbiswas@nvidia.com>
      Reported-by: default avatarPeter Geis <pgwipeout@gmail.com>
      Suggested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Cc: <stable@vger.kernel.org>
      Tested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Tested-By: default avatarPeter Geis <pgwipeout@gmail.com>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      ff6471fe
    • Ulf Hansson's avatar
      mmc: sdhci-omap: Fix busy detection by enabling MMC_CAP_NEED_RSP_BUSY · 23161bed
      Ulf Hansson authored
      [ Upstream commit 055e0483 ]
      
      It has turned out that the sdhci-omap controller requires the R1B response,
      for commands that has this response associated with them. So, converting
      from an R1B to an R1 response for a CMD6 for example, leads to problems
      with the HW busy detection support.
      
      Fix this by informing the mmc core about the requirement, via setting the
      host cap, MMC_CAP_NEED_RSP_BUSY.
      Reported-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
      Reported-by: default avatarAnders Roxell <anders.roxell@linaro.org>
      Reported-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
      Cc: <stable@vger.kernel.org>
      Tested-by: default avatarAnders Roxell <anders.roxell@linaro.org>
      Tested-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      23161bed
    • Ulf Hansson's avatar
      mmc: core: Respect MMC_CAP_NEED_RSP_BUSY for eMMC sleep command · d091259b
      Ulf Hansson authored
      [ Upstream commit 18d20046 ]
      
      The busy timeout for the CMD5 to put the eMMC into sleep state, is specific
      to the card. Potentially the timeout may exceed the host->max_busy_timeout.
      If that becomes the case, mmc_sleep() converts from using an R1B response
      to an R1 response, as to prevent the host from doing HW busy detection.
      
      However, it has turned out that some hosts requires an R1B response no
      matter what, so let's respect that via checking MMC_CAP_NEED_RSP_BUSY. Note
      that, if the R1B gets enforced, the host becomes fully responsible of
      managing the needed busy timeout, in one way or the other.
      Suggested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Cc: <stable@vger.kernel.org>
      Link: https://lore.kernel.org/r/20200311092036.16084-1-ulf.hansson@linaro.orgSigned-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      d091259b
    • Ulf Hansson's avatar
      mmc: core: Respect MMC_CAP_NEED_RSP_BUSY for erase/trim/discard · 5fc615c1
      Ulf Hansson authored
      [ Upstream commit 43cc64e5 ]
      
      The busy timeout that is computed for each erase/trim/discard operation,
      can become quite long and may thus exceed the host->max_busy_timeout. If
      that becomes the case, mmc_do_erase() converts from using an R1B response
      to an R1 response, as to prevent the host from doing HW busy detection.
      
      However, it has turned out that some hosts requires an R1B response no
      matter what, so let's respect that via checking MMC_CAP_NEED_RSP_BUSY. Note
      that, if the R1B gets enforced, the host becomes fully responsible of
      managing the needed busy timeout, in one way or the other.
      Suggested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Cc: <stable@vger.kernel.org>
      Tested-by: default avatarAnders Roxell <anders.roxell@linaro.org>
      Tested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Tested-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
      Tested-By: default avatarPeter Geis <pgwipeout@gmail.com>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      5fc615c1
    • Ulf Hansson's avatar
      mmc: core: Allow host controllers to require R1B for CMD6 · 4f32b45c
      Ulf Hansson authored
      [ Upstream commit 1292e3ef ]
      
      It has turned out that some host controllers can't use R1B for CMD6 and
      other commands that have R1B associated with them. Therefore invent a new
      host cap, MMC_CAP_NEED_RSP_BUSY to let them specify this.
      
      In __mmc_switch(), let's check the flag and use it to prevent R1B responses
      from being converted into R1. Note that, this also means that the host are
      on its own, when it comes to manage the busy timeout.
      Suggested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Cc: <stable@vger.kernel.org>
      Tested-by: default avatarAnders Roxell <anders.roxell@linaro.org>
      Tested-by: default avatarSowjanya Komatineni <skomatineni@nvidia.com>
      Tested-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
      Tested-By: default avatarPeter Geis <pgwipeout@gmail.com>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      4f32b45c
  2. 25 Mar, 2020 34 commits