<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu/drm/vgem, branch linux-5.10.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/vgem-fence: Fix potential deadlock on release</title>
<updated>2026-01-19T12:11:27+00:00</updated>
<author>
<name>Janusz Krzysztofik</name>
<email>janusz.krzysztofik@linux.intel.com</email>
</author>
<published>2025-09-26T15:26:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37289a18099fc7ce916933bd542926a7334791a3'/>
<id>37289a18099fc7ce916933bd542926a7334791a3</id>
<content type='text'>
[ Upstream commit 78b4d6463e9e69e5103f98b367f8984ad12cdc6f ]

A timer that expires a vgem fence automatically in 10 seconds is now
released with timer_delete_sync() from fence-&gt;ops.release() called on last
dma_fence_put().  In some scenarios, it can run in IRQ context, which is
not safe unless TIMER_IRQSAFE is used.  One potentially risky scenario was
demonstrated in Intel DRM CI trybot, BAT run on machine bat-adlp-6, while
working on new IGT subtests syncobj_timeline@stress-* as user space
replacements of some problematic test cases of a dma-fence-chain selftest
[1].

[117.004338] ================================
[117.004340] WARNING: inconsistent lock state
[117.004342] 6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 Tainted: G S   U
[117.004346] --------------------------------
[117.004347] inconsistent {HARDIRQ-ON-W} -&gt; {IN-HARDIRQ-W} usage.
[117.004349] swapper/0/0 [HC1[1]:SC1[1]:HE0:SE0] takes:
[117.004352] ffff888138f86aa8 ((&amp;fence-&gt;timer)){?.-.}-{0:0}, at: __timer_delete_sync+0x4b/0x190
[117.004361] {HARDIRQ-ON-W} state was registered at:
[117.004363]   lock_acquire+0xc4/0x2e0
[117.004366]   call_timer_fn+0x80/0x2a0
[117.004368]   __run_timers+0x231/0x310
[117.004370]   run_timer_softirq+0x76/0xe0
[117.004372]   handle_softirqs+0xd4/0x4d0
[117.004375]   __irq_exit_rcu+0x13f/0x160
[117.004377]   irq_exit_rcu+0xe/0x20
[117.004379]   sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004382]   asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004385]   cpuidle_enter_state+0x12b/0x8a0
[117.004388]   cpuidle_enter+0x2e/0x50
[117.004393]   call_cpuidle+0x22/0x60
[117.004395]   do_idle+0x1fd/0x260
[117.004398]   cpu_startup_entry+0x29/0x30
[117.004401]   start_secondary+0x12d/0x160
[117.004404]   common_startup_64+0x13e/0x141
[117.004407] irq event stamp: 2282669
[117.004409] hardirqs last  enabled at (2282668): [&lt;ffffffff8289db71&gt;] _raw_spin_unlock_irqrestore+0x51/0x80
[117.004414] hardirqs last disabled at (2282669): [&lt;ffffffff82882021&gt;] sysvec_irq_work+0x11/0xc0
[117.004419] softirqs last  enabled at (2254702): [&lt;ffffffff8289fd00&gt;] __do_softirq+0x10/0x18
[117.004423] softirqs last disabled at (2254725): [&lt;ffffffff813d4ddf&gt;] __irq_exit_rcu+0x13f/0x160
[117.004426]
other info that might help us debug this:
[117.004429]  Possible unsafe locking scenario:
[117.004432]        CPU0
[117.004433]        ----
[117.004434]   lock((&amp;fence-&gt;timer));
[117.004436]   &lt;Interrupt&gt;
[117.004438]     lock((&amp;fence-&gt;timer));
[117.004440]
 *** DEADLOCK ***
[117.004443] 1 lock held by swapper/0/0:
[117.004445]  #0: ffffc90000003d50 ((&amp;fence-&gt;timer)){?.-.}-{0:0}, at: call_timer_fn+0x7a/0x2a0
[117.004450]
stack backtrace:
[117.004453] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G S   U              6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 PREEMPT(voluntary)
[117.004455] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[117.004455] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[117.004456] Call Trace:
[117.004456]  &lt;IRQ&gt;
[117.004457]  dump_stack_lvl+0x91/0xf0
[117.004460]  dump_stack+0x10/0x20
[117.004461]  print_usage_bug.part.0+0x260/0x360
[117.004463]  mark_lock+0x76e/0x9c0
[117.004465]  ? register_lock_class+0x48/0x4a0
[117.004467]  __lock_acquire+0xbc3/0x2860
[117.004469]  lock_acquire+0xc4/0x2e0
[117.004470]  ? __timer_delete_sync+0x4b/0x190
[117.004472]  ? __timer_delete_sync+0x4b/0x190
[117.004473]  __timer_delete_sync+0x68/0x190
[117.004474]  ? __timer_delete_sync+0x4b/0x190
[117.004475]  timer_delete_sync+0x10/0x20
[117.004476]  vgem_fence_release+0x19/0x30 [vgem]
[117.004478]  dma_fence_release+0xc1/0x3b0
[117.004480]  ? dma_fence_release+0xa1/0x3b0
[117.004481]  dma_fence_chain_release+0xe7/0x130
[117.004483]  dma_fence_release+0xc1/0x3b0
[117.004484]  ? _raw_spin_unlock_irqrestore+0x27/0x80
[117.004485]  dma_fence_chain_irq_work+0x59/0x80
[117.004487]  irq_work_single+0x75/0xa0
[117.004490]  irq_work_run_list+0x33/0x60
[117.004491]  irq_work_run+0x18/0x40
[117.004493]  __sysvec_irq_work+0x35/0x170
[117.004494]  sysvec_irq_work+0x47/0xc0
[117.004496]  asm_sysvec_irq_work+0x1b/0x20
[117.004497] RIP: 0010:_raw_spin_unlock_irqrestore+0x57/0x80
[117.004499] Code: 00 75 1c 65 ff 0d d9 34 68 01 74 20 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc e8 7f 9d d3 fe fb 0f 1f 44 00 00 &lt;eb&gt; d7 0f 1f 44 00 00 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3
[117.004499] RSP: 0018:ffffc90000003cf0 EFLAGS: 00000246
[117.004500] RAX: 0000000000000000 RBX: ffff888155e94c40 RCX: 0000000000000000
[117.004501] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004502] RBP: ffffc90000003d00 R08: 0000000000000000 R09: 0000000000000000
[117.004502] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000246
[117.004502] R13: 0000000000000001 R14: 0000000000000246 R15: ffff888155e94c80
[117.004506]  dma_fence_signal+0x49/0xb0
[117.004507]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004508]  vgem_fence_timeout+0x12/0x20 [vgem]
[117.004509]  call_timer_fn+0xa1/0x2a0
[117.004512]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004513]  __run_timers+0x231/0x310
[117.004514]  ? tmigr_handle_remote+0x2ac/0x560
[117.004517]  timer_expire_remote+0x46/0x70
[117.004518]  tmigr_handle_remote+0x433/0x560
[117.004520]  ? __run_timers+0x239/0x310
[117.004521]  ? run_timer_softirq+0x21/0xe0
[117.004522]  ? lock_release+0xce/0x2a0
[117.004524]  run_timer_softirq+0xcf/0xe0
[117.004525]  handle_softirqs+0xd4/0x4d0
[117.004526]  __irq_exit_rcu+0x13f/0x160
[117.004527]  irq_exit_rcu+0xe/0x20
[117.004528]  sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004529]  &lt;/IRQ&gt;
[117.004529]  &lt;TASK&gt;
[117.004529]  asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004530] RIP: 0010:cpuidle_enter_state+0x12b/0x8a0
[117.004532] Code: 48 0f a3 05 97 ce 0e 01 0f 82 2e 03 00 00 31 ff e8 8a 41 bd fe 80 7d d0 00 0f 85 11 03 00 00 e8 8b 06 d5 fe fb 0f 1f 44 00 00 &lt;45&gt; 85 f6 0f 88 67 02 00 00 4d 63 ee 49 83 fd 0a 0f 83 34 06 00 00
[117.004532] RSP: 0018:ffffffff83403d88 EFLAGS: 00000246
[117.004533] RAX: 0000000000000000 RBX: ffff88888f046440 RCX: 0000000000000000
[117.004533] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004534] RBP: ffffffff83403dd8 R08: 0000000000000000 R09: 0000000000000000
[117.004534] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff837cbe80
[117.004534] R13: 0000000000000004 R14: 0000000000000004 R15: 0000001ad1df466b
[117.004537]  ? cpuidle_enter_state+0x125/0x8a0
[117.004538]  ? sched_clock_noinstr+0x9/0x10
[117.004540]  cpuidle_enter+0x2e/0x50
[117.004542]  call_cpuidle+0x22/0x60
[117.004542]  do_idle+0x1fd/0x260
[117.004544]  cpu_startup_entry+0x29/0x30
[117.004546]  rest_init+0x104/0x200
[117.004548]  start_kernel+0x93d/0xbd0
[117.004550]  ? load_ucode_intel_bsp+0x2a/0x90
[117.004551]  ? sme_unmap_bootdata+0x14/0x80
[117.004554]  x86_64_start_reservations+0x18/0x30
[117.004555]  x86_64_start_kernel+0xfd/0x150
[117.004556]  ? soft_restart_cpu+0x14/0x14
[117.004558]  common_startup_64+0x13e/0x141
[117.004560]  &lt;/TASK&gt;
[117.004565] ------------[ cut here ]------------
[117.004692] WARNING: CPU: 0 PID: 0 at kernel/time/timer.c:1610 __timer_delete_sync+0x126/0x190
[117.004697] Modules linked in: vgem snd_hda_codec_intelhdmi snd_hda_codec_hdmi i915 prime_numbers ttm drm_buddy drm_display_helper cec rc_core i2c_algo_bit hid_sensor_custom hid_sensor_hub hid_generic intel_ishtp_hid hid intel_uncore_frequency intel_uncore_frequency_common x86_pkg_temp_thermal intel_powerclamp cmdlinepart ee1004 r8153_ecm spi_nor coretemp cdc_ether mei_pxp mei_hdcp usbnet mtd intel_rapl_msr wmi_bmof kvm_intel snd_hda_intel snd_intel_dspcfg processor_thermal_device_pci kvm snd_hda_codec processor_thermal_device irqbypass processor_thermal_wt_hint polyval_clmulni platform_temperature_control snd_hda_core ghash_clmulni_intel processor_thermal_rfim spi_pxa2xx_platform snd_hwdep aesni_intel processor_thermal_rapl dw_dmac snd_pcm dw_dmac_core intel_rapl_common r8152 rapl mii intel_cstate spi_pxa2xx_core i2c_i801 processor_thermal_wt_req snd_timer i2c_mux mei_me intel_ish_ipc processor_thermal_power_floor e1000e snd i2c_smbus spi_intel_pci processor_thermal_mbox mei soundcore intel_ishtp thunderbolt idma64
[117.004733]  spi_intel int340x_thermal_zone igen6_edac binfmt_misc intel_skl_int3472_tps68470 intel_pmc_core tps68470_regulator video clk_tps68470 pmt_telemetry pmt_discovery nls_iso8859_1 pmt_class intel_pmc_ssram_telemetry intel_skl_int3472_discrete int3400_thermal intel_hid intel_skl_int3472_common acpi_thermal_rel intel_vsec wmi pinctrl_tigerlake acpi_tad sparse_keymap acpi_pad dm_multipath msr nvme_fabrics fuse efi_pstore nfnetlink autofs4
[117.004782] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G S   U              6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 PREEMPT(voluntary)
[117.004787] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[117.004789] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[117.004793] RIP: 0010:__timer_delete_sync+0x126/0x190
[117.004795] Code: 31 c0 45 31 c9 c3 cc cc cc cc 48 8b 75 d0 45 84 f6 74 63 49 c7 45 18 00 00 00 00 48 89 c7 e8 51 46 39 01 f3 90 e9 66 ff ff ff &lt;0f&gt; 0b e9 5f ff ff ff e8 ee e4 0c 00 49 8d 5d 28 45 31 c9 31 c9 4c
[117.004801] RSP: 0018:ffffc90000003a40 EFLAGS: 00010046
[117.004804] RAX: ffffffff815093fb RBX: ffff888138f86aa8 RCX: 0000000000000000
[117.004807] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004809] RBP: ffffc90000003a70 R08: 0000000000000000 R09: 0000000000000000
[117.004812] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff815093fb
[117.004814] R13: ffff888138f86a80 R14: 0000000000000000 R15: 0000000000000000
[117.004817] FS:  0000000000000000(0000) GS:ffff88890b0f7000(0000) knlGS:0000000000000000
[117.004820] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[117.004823] CR2: 00005db8131eb7f0 CR3: 0000000003448000 CR4: 0000000000f52ef0
[117.004826] PKRU: 55555554
[117.004827] Call Trace:
[117.004829]  &lt;IRQ&gt;
[117.004831]  timer_delete_sync+0x10/0x20
[117.004833]  vgem_fence_release+0x19/0x30 [vgem]
[117.004836]  dma_fence_release+0xc1/0x3b0
[117.004838]  ? dma_fence_release+0xa1/0x3b0
[117.004841]  dma_fence_chain_release+0xe7/0x130
[117.004844]  dma_fence_release+0xc1/0x3b0
[117.004847]  ? _raw_spin_unlock_irqrestore+0x27/0x80
[117.004850]  dma_fence_chain_irq_work+0x59/0x80
[117.004853]  irq_work_single+0x75/0xa0
[117.004857]  irq_work_run_list+0x33/0x60
[117.004860]  irq_work_run+0x18/0x40
[117.004863]  __sysvec_irq_work+0x35/0x170
[117.004865]  sysvec_irq_work+0x47/0xc0
[117.004868]  asm_sysvec_irq_work+0x1b/0x20
[117.004871] RIP: 0010:_raw_spin_unlock_irqrestore+0x57/0x80
[117.004874] Code: 00 75 1c 65 ff 0d d9 34 68 01 74 20 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc e8 7f 9d d3 fe fb 0f 1f 44 00 00 &lt;eb&gt; d7 0f 1f 44 00 00 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3
[117.004879] RSP: 0018:ffffc90000003cf0 EFLAGS: 00000246
[117.004882] RAX: 0000000000000000 RBX: ffff888155e94c40 RCX: 0000000000000000
[117.004884] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004887] RBP: ffffc90000003d00 R08: 0000000000000000 R09: 0000000000000000
[117.004890] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000246
[117.004892] R13: 0000000000000001 R14: 0000000000000246 R15: ffff888155e94c80
[117.004897]  dma_fence_signal+0x49/0xb0
[117.004899]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004902]  vgem_fence_timeout+0x12/0x20 [vgem]
[117.004904]  call_timer_fn+0xa1/0x2a0
[117.004908]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004910]  __run_timers+0x231/0x310
[117.004913]  ? tmigr_handle_remote+0x2ac/0x560
[117.004917]  timer_expire_remote+0x46/0x70
[117.004919]  tmigr_handle_remote+0x433/0x560
[117.004923]  ? __run_timers+0x239/0x310
[117.004925]  ? run_timer_softirq+0x21/0xe0
[117.004928]  ? lock_release+0xce/0x2a0
[117.004931]  run_timer_softirq+0xcf/0xe0
[117.004933]  handle_softirqs+0xd4/0x4d0
[117.004936]  __irq_exit_rcu+0x13f/0x160
[117.004938]  irq_exit_rcu+0xe/0x20
[117.004940]  sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004943]  &lt;/IRQ&gt;
[117.004944]  &lt;TASK&gt;
[117.004946]  asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004949] RIP: 0010:cpuidle_enter_state+0x12b/0x8a0
[117.004953] Code: 48 0f a3 05 97 ce 0e 01 0f 82 2e 03 00 00 31 ff e8 8a 41 bd fe 80 7d d0 00 0f 85 11 03 00 00 e8 8b 06 d5 fe fb 0f 1f 44 00 00 &lt;45&gt; 85 f6 0f 88 67 02 00 00 4d 63 ee 49 83 fd 0a 0f 83 34 06 00 00
[117.004961] RSP: 0018:ffffffff83403d88 EFLAGS: 00000246
[117.004963] RAX: 0000000000000000 RBX: ffff88888f046440 RCX: 0000000000000000
[117.004966] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004968] RBP: ffffffff83403dd8 R08: 0000000000000000 R09: 0000000000000000
[117.004971] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff837cbe80
[117.004974] R13: 0000000000000004 R14: 0000000000000004 R15: 0000001ad1df466b
[117.004978]  ? cpuidle_enter_state+0x125/0x8a0
[117.004981]  ? sched_clock_noinstr+0x9/0x10
[117.004985]  cpuidle_enter+0x2e/0x50
[117.004989]  call_cpuidle+0x22/0x60
[117.004991]  do_idle+0x1fd/0x260
[117.005001]  cpu_startup_entry+0x29/0x30
[117.005004]  rest_init+0x104/0x200
[117.005008]  start_kernel+0x93d/0xbd0
[117.005011]  ? load_ucode_intel_bsp+0x2a/0x90
[117.005014]  ? sme_unmap_bootdata+0x14/0x80
[117.005017]  x86_64_start_reservations+0x18/0x30
[117.005020]  x86_64_start_kernel+0xfd/0x150
[117.005023]  ? soft_restart_cpu+0x14/0x14
[117.005026]  common_startup_64+0x13e/0x141
[117.005030]  &lt;/TASK&gt;
[117.005032] irq event stamp: 2282669
[117.005034] hardirqs last  enabled at (2282668): [&lt;ffffffff8289db71&gt;] _raw_spin_unlock_irqrestore+0x51/0x80
[117.005038] hardirqs last disabled at (2282669): [&lt;ffffffff82882021&gt;] sysvec_irq_work+0x11/0xc0
[117.005043] softirqs last  enabled at (2254702): [&lt;ffffffff8289fd00&gt;] __do_softirq+0x10/0x18
[117.005047] softirqs last disabled at (2254725): [&lt;ffffffff813d4ddf&gt;] __irq_exit_rcu+0x13f/0x160
[117.005051] ---[ end trace 0000000000000000 ]---

Make the timer IRQ safe.

[1] https://patchwork.freedesktop.org/series/154987/#rev2

Fixes: 4077798484459 ("drm/vgem: Attach sw fences to exported vGEM dma-buf (ioctl)")
Signed-off-by: Janusz Krzysztofik &lt;janusz.krzysztofik@linux.intel.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250926152628.2165080-2-janusz.krzysztofik@linux.intel.com
Signed-off-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 78b4d6463e9e69e5103f98b367f8984ad12cdc6f ]

A timer that expires a vgem fence automatically in 10 seconds is now
released with timer_delete_sync() from fence-&gt;ops.release() called on last
dma_fence_put().  In some scenarios, it can run in IRQ context, which is
not safe unless TIMER_IRQSAFE is used.  One potentially risky scenario was
demonstrated in Intel DRM CI trybot, BAT run on machine bat-adlp-6, while
working on new IGT subtests syncobj_timeline@stress-* as user space
replacements of some problematic test cases of a dma-fence-chain selftest
[1].

[117.004338] ================================
[117.004340] WARNING: inconsistent lock state
[117.004342] 6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 Tainted: G S   U
[117.004346] --------------------------------
[117.004347] inconsistent {HARDIRQ-ON-W} -&gt; {IN-HARDIRQ-W} usage.
[117.004349] swapper/0/0 [HC1[1]:SC1[1]:HE0:SE0] takes:
[117.004352] ffff888138f86aa8 ((&amp;fence-&gt;timer)){?.-.}-{0:0}, at: __timer_delete_sync+0x4b/0x190
[117.004361] {HARDIRQ-ON-W} state was registered at:
[117.004363]   lock_acquire+0xc4/0x2e0
[117.004366]   call_timer_fn+0x80/0x2a0
[117.004368]   __run_timers+0x231/0x310
[117.004370]   run_timer_softirq+0x76/0xe0
[117.004372]   handle_softirqs+0xd4/0x4d0
[117.004375]   __irq_exit_rcu+0x13f/0x160
[117.004377]   irq_exit_rcu+0xe/0x20
[117.004379]   sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004382]   asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004385]   cpuidle_enter_state+0x12b/0x8a0
[117.004388]   cpuidle_enter+0x2e/0x50
[117.004393]   call_cpuidle+0x22/0x60
[117.004395]   do_idle+0x1fd/0x260
[117.004398]   cpu_startup_entry+0x29/0x30
[117.004401]   start_secondary+0x12d/0x160
[117.004404]   common_startup_64+0x13e/0x141
[117.004407] irq event stamp: 2282669
[117.004409] hardirqs last  enabled at (2282668): [&lt;ffffffff8289db71&gt;] _raw_spin_unlock_irqrestore+0x51/0x80
[117.004414] hardirqs last disabled at (2282669): [&lt;ffffffff82882021&gt;] sysvec_irq_work+0x11/0xc0
[117.004419] softirqs last  enabled at (2254702): [&lt;ffffffff8289fd00&gt;] __do_softirq+0x10/0x18
[117.004423] softirqs last disabled at (2254725): [&lt;ffffffff813d4ddf&gt;] __irq_exit_rcu+0x13f/0x160
[117.004426]
other info that might help us debug this:
[117.004429]  Possible unsafe locking scenario:
[117.004432]        CPU0
[117.004433]        ----
[117.004434]   lock((&amp;fence-&gt;timer));
[117.004436]   &lt;Interrupt&gt;
[117.004438]     lock((&amp;fence-&gt;timer));
[117.004440]
 *** DEADLOCK ***
[117.004443] 1 lock held by swapper/0/0:
[117.004445]  #0: ffffc90000003d50 ((&amp;fence-&gt;timer)){?.-.}-{0:0}, at: call_timer_fn+0x7a/0x2a0
[117.004450]
stack backtrace:
[117.004453] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G S   U              6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 PREEMPT(voluntary)
[117.004455] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[117.004455] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[117.004456] Call Trace:
[117.004456]  &lt;IRQ&gt;
[117.004457]  dump_stack_lvl+0x91/0xf0
[117.004460]  dump_stack+0x10/0x20
[117.004461]  print_usage_bug.part.0+0x260/0x360
[117.004463]  mark_lock+0x76e/0x9c0
[117.004465]  ? register_lock_class+0x48/0x4a0
[117.004467]  __lock_acquire+0xbc3/0x2860
[117.004469]  lock_acquire+0xc4/0x2e0
[117.004470]  ? __timer_delete_sync+0x4b/0x190
[117.004472]  ? __timer_delete_sync+0x4b/0x190
[117.004473]  __timer_delete_sync+0x68/0x190
[117.004474]  ? __timer_delete_sync+0x4b/0x190
[117.004475]  timer_delete_sync+0x10/0x20
[117.004476]  vgem_fence_release+0x19/0x30 [vgem]
[117.004478]  dma_fence_release+0xc1/0x3b0
[117.004480]  ? dma_fence_release+0xa1/0x3b0
[117.004481]  dma_fence_chain_release+0xe7/0x130
[117.004483]  dma_fence_release+0xc1/0x3b0
[117.004484]  ? _raw_spin_unlock_irqrestore+0x27/0x80
[117.004485]  dma_fence_chain_irq_work+0x59/0x80
[117.004487]  irq_work_single+0x75/0xa0
[117.004490]  irq_work_run_list+0x33/0x60
[117.004491]  irq_work_run+0x18/0x40
[117.004493]  __sysvec_irq_work+0x35/0x170
[117.004494]  sysvec_irq_work+0x47/0xc0
[117.004496]  asm_sysvec_irq_work+0x1b/0x20
[117.004497] RIP: 0010:_raw_spin_unlock_irqrestore+0x57/0x80
[117.004499] Code: 00 75 1c 65 ff 0d d9 34 68 01 74 20 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc e8 7f 9d d3 fe fb 0f 1f 44 00 00 &lt;eb&gt; d7 0f 1f 44 00 00 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3
[117.004499] RSP: 0018:ffffc90000003cf0 EFLAGS: 00000246
[117.004500] RAX: 0000000000000000 RBX: ffff888155e94c40 RCX: 0000000000000000
[117.004501] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004502] RBP: ffffc90000003d00 R08: 0000000000000000 R09: 0000000000000000
[117.004502] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000246
[117.004502] R13: 0000000000000001 R14: 0000000000000246 R15: ffff888155e94c80
[117.004506]  dma_fence_signal+0x49/0xb0
[117.004507]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004508]  vgem_fence_timeout+0x12/0x20 [vgem]
[117.004509]  call_timer_fn+0xa1/0x2a0
[117.004512]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004513]  __run_timers+0x231/0x310
[117.004514]  ? tmigr_handle_remote+0x2ac/0x560
[117.004517]  timer_expire_remote+0x46/0x70
[117.004518]  tmigr_handle_remote+0x433/0x560
[117.004520]  ? __run_timers+0x239/0x310
[117.004521]  ? run_timer_softirq+0x21/0xe0
[117.004522]  ? lock_release+0xce/0x2a0
[117.004524]  run_timer_softirq+0xcf/0xe0
[117.004525]  handle_softirqs+0xd4/0x4d0
[117.004526]  __irq_exit_rcu+0x13f/0x160
[117.004527]  irq_exit_rcu+0xe/0x20
[117.004528]  sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004529]  &lt;/IRQ&gt;
[117.004529]  &lt;TASK&gt;
[117.004529]  asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004530] RIP: 0010:cpuidle_enter_state+0x12b/0x8a0
[117.004532] Code: 48 0f a3 05 97 ce 0e 01 0f 82 2e 03 00 00 31 ff e8 8a 41 bd fe 80 7d d0 00 0f 85 11 03 00 00 e8 8b 06 d5 fe fb 0f 1f 44 00 00 &lt;45&gt; 85 f6 0f 88 67 02 00 00 4d 63 ee 49 83 fd 0a 0f 83 34 06 00 00
[117.004532] RSP: 0018:ffffffff83403d88 EFLAGS: 00000246
[117.004533] RAX: 0000000000000000 RBX: ffff88888f046440 RCX: 0000000000000000
[117.004533] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004534] RBP: ffffffff83403dd8 R08: 0000000000000000 R09: 0000000000000000
[117.004534] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff837cbe80
[117.004534] R13: 0000000000000004 R14: 0000000000000004 R15: 0000001ad1df466b
[117.004537]  ? cpuidle_enter_state+0x125/0x8a0
[117.004538]  ? sched_clock_noinstr+0x9/0x10
[117.004540]  cpuidle_enter+0x2e/0x50
[117.004542]  call_cpuidle+0x22/0x60
[117.004542]  do_idle+0x1fd/0x260
[117.004544]  cpu_startup_entry+0x29/0x30
[117.004546]  rest_init+0x104/0x200
[117.004548]  start_kernel+0x93d/0xbd0
[117.004550]  ? load_ucode_intel_bsp+0x2a/0x90
[117.004551]  ? sme_unmap_bootdata+0x14/0x80
[117.004554]  x86_64_start_reservations+0x18/0x30
[117.004555]  x86_64_start_kernel+0xfd/0x150
[117.004556]  ? soft_restart_cpu+0x14/0x14
[117.004558]  common_startup_64+0x13e/0x141
[117.004560]  &lt;/TASK&gt;
[117.004565] ------------[ cut here ]------------
[117.004692] WARNING: CPU: 0 PID: 0 at kernel/time/timer.c:1610 __timer_delete_sync+0x126/0x190
[117.004697] Modules linked in: vgem snd_hda_codec_intelhdmi snd_hda_codec_hdmi i915 prime_numbers ttm drm_buddy drm_display_helper cec rc_core i2c_algo_bit hid_sensor_custom hid_sensor_hub hid_generic intel_ishtp_hid hid intel_uncore_frequency intel_uncore_frequency_common x86_pkg_temp_thermal intel_powerclamp cmdlinepart ee1004 r8153_ecm spi_nor coretemp cdc_ether mei_pxp mei_hdcp usbnet mtd intel_rapl_msr wmi_bmof kvm_intel snd_hda_intel snd_intel_dspcfg processor_thermal_device_pci kvm snd_hda_codec processor_thermal_device irqbypass processor_thermal_wt_hint polyval_clmulni platform_temperature_control snd_hda_core ghash_clmulni_intel processor_thermal_rfim spi_pxa2xx_platform snd_hwdep aesni_intel processor_thermal_rapl dw_dmac snd_pcm dw_dmac_core intel_rapl_common r8152 rapl mii intel_cstate spi_pxa2xx_core i2c_i801 processor_thermal_wt_req snd_timer i2c_mux mei_me intel_ish_ipc processor_thermal_power_floor e1000e snd i2c_smbus spi_intel_pci processor_thermal_mbox mei soundcore intel_ishtp thunderbolt idma64
[117.004733]  spi_intel int340x_thermal_zone igen6_edac binfmt_misc intel_skl_int3472_tps68470 intel_pmc_core tps68470_regulator video clk_tps68470 pmt_telemetry pmt_discovery nls_iso8859_1 pmt_class intel_pmc_ssram_telemetry intel_skl_int3472_discrete int3400_thermal intel_hid intel_skl_int3472_common acpi_thermal_rel intel_vsec wmi pinctrl_tigerlake acpi_tad sparse_keymap acpi_pad dm_multipath msr nvme_fabrics fuse efi_pstore nfnetlink autofs4
[117.004782] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G S   U              6.17.0-rc7-CI_DRM_17270-g7644974e648c+ #1 PREEMPT(voluntary)
[117.004787] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[117.004789] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
[117.004793] RIP: 0010:__timer_delete_sync+0x126/0x190
[117.004795] Code: 31 c0 45 31 c9 c3 cc cc cc cc 48 8b 75 d0 45 84 f6 74 63 49 c7 45 18 00 00 00 00 48 89 c7 e8 51 46 39 01 f3 90 e9 66 ff ff ff &lt;0f&gt; 0b e9 5f ff ff ff e8 ee e4 0c 00 49 8d 5d 28 45 31 c9 31 c9 4c
[117.004801] RSP: 0018:ffffc90000003a40 EFLAGS: 00010046
[117.004804] RAX: ffffffff815093fb RBX: ffff888138f86aa8 RCX: 0000000000000000
[117.004807] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004809] RBP: ffffc90000003a70 R08: 0000000000000000 R09: 0000000000000000
[117.004812] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff815093fb
[117.004814] R13: ffff888138f86a80 R14: 0000000000000000 R15: 0000000000000000
[117.004817] FS:  0000000000000000(0000) GS:ffff88890b0f7000(0000) knlGS:0000000000000000
[117.004820] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[117.004823] CR2: 00005db8131eb7f0 CR3: 0000000003448000 CR4: 0000000000f52ef0
[117.004826] PKRU: 55555554
[117.004827] Call Trace:
[117.004829]  &lt;IRQ&gt;
[117.004831]  timer_delete_sync+0x10/0x20
[117.004833]  vgem_fence_release+0x19/0x30 [vgem]
[117.004836]  dma_fence_release+0xc1/0x3b0
[117.004838]  ? dma_fence_release+0xa1/0x3b0
[117.004841]  dma_fence_chain_release+0xe7/0x130
[117.004844]  dma_fence_release+0xc1/0x3b0
[117.004847]  ? _raw_spin_unlock_irqrestore+0x27/0x80
[117.004850]  dma_fence_chain_irq_work+0x59/0x80
[117.004853]  irq_work_single+0x75/0xa0
[117.004857]  irq_work_run_list+0x33/0x60
[117.004860]  irq_work_run+0x18/0x40
[117.004863]  __sysvec_irq_work+0x35/0x170
[117.004865]  sysvec_irq_work+0x47/0xc0
[117.004868]  asm_sysvec_irq_work+0x1b/0x20
[117.004871] RIP: 0010:_raw_spin_unlock_irqrestore+0x57/0x80
[117.004874] Code: 00 75 1c 65 ff 0d d9 34 68 01 74 20 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc e8 7f 9d d3 fe fb 0f 1f 44 00 00 &lt;eb&gt; d7 0f 1f 44 00 00 5b 41 5c 5d 31 c0 31 d2 31 c9 31 f6 31 ff c3
[117.004879] RSP: 0018:ffffc90000003cf0 EFLAGS: 00000246
[117.004882] RAX: 0000000000000000 RBX: ffff888155e94c40 RCX: 0000000000000000
[117.004884] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004887] RBP: ffffc90000003d00 R08: 0000000000000000 R09: 0000000000000000
[117.004890] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000246
[117.004892] R13: 0000000000000001 R14: 0000000000000246 R15: ffff888155e94c80
[117.004897]  dma_fence_signal+0x49/0xb0
[117.004899]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004902]  vgem_fence_timeout+0x12/0x20 [vgem]
[117.004904]  call_timer_fn+0xa1/0x2a0
[117.004908]  ? __pfx_vgem_fence_timeout+0x10/0x10 [vgem]
[117.004910]  __run_timers+0x231/0x310
[117.004913]  ? tmigr_handle_remote+0x2ac/0x560
[117.004917]  timer_expire_remote+0x46/0x70
[117.004919]  tmigr_handle_remote+0x433/0x560
[117.004923]  ? __run_timers+0x239/0x310
[117.004925]  ? run_timer_softirq+0x21/0xe0
[117.004928]  ? lock_release+0xce/0x2a0
[117.004931]  run_timer_softirq+0xcf/0xe0
[117.004933]  handle_softirqs+0xd4/0x4d0
[117.004936]  __irq_exit_rcu+0x13f/0x160
[117.004938]  irq_exit_rcu+0xe/0x20
[117.004940]  sysvec_apic_timer_interrupt+0xa0/0xc0
[117.004943]  &lt;/IRQ&gt;
[117.004944]  &lt;TASK&gt;
[117.004946]  asm_sysvec_apic_timer_interrupt+0x1b/0x20
[117.004949] RIP: 0010:cpuidle_enter_state+0x12b/0x8a0
[117.004953] Code: 48 0f a3 05 97 ce 0e 01 0f 82 2e 03 00 00 31 ff e8 8a 41 bd fe 80 7d d0 00 0f 85 11 03 00 00 e8 8b 06 d5 fe fb 0f 1f 44 00 00 &lt;45&gt; 85 f6 0f 88 67 02 00 00 4d 63 ee 49 83 fd 0a 0f 83 34 06 00 00
[117.004961] RSP: 0018:ffffffff83403d88 EFLAGS: 00000246
[117.004963] RAX: 0000000000000000 RBX: ffff88888f046440 RCX: 0000000000000000
[117.004966] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[117.004968] RBP: ffffffff83403dd8 R08: 0000000000000000 R09: 0000000000000000
[117.004971] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff837cbe80
[117.004974] R13: 0000000000000004 R14: 0000000000000004 R15: 0000001ad1df466b
[117.004978]  ? cpuidle_enter_state+0x125/0x8a0
[117.004981]  ? sched_clock_noinstr+0x9/0x10
[117.004985]  cpuidle_enter+0x2e/0x50
[117.004989]  call_cpuidle+0x22/0x60
[117.004991]  do_idle+0x1fd/0x260
[117.005001]  cpu_startup_entry+0x29/0x30
[117.005004]  rest_init+0x104/0x200
[117.005008]  start_kernel+0x93d/0xbd0
[117.005011]  ? load_ucode_intel_bsp+0x2a/0x90
[117.005014]  ? sme_unmap_bootdata+0x14/0x80
[117.005017]  x86_64_start_reservations+0x18/0x30
[117.005020]  x86_64_start_kernel+0xfd/0x150
[117.005023]  ? soft_restart_cpu+0x14/0x14
[117.005026]  common_startup_64+0x13e/0x141
[117.005030]  &lt;/TASK&gt;
[117.005032] irq event stamp: 2282669
[117.005034] hardirqs last  enabled at (2282668): [&lt;ffffffff8289db71&gt;] _raw_spin_unlock_irqrestore+0x51/0x80
[117.005038] hardirqs last disabled at (2282669): [&lt;ffffffff82882021&gt;] sysvec_irq_work+0x11/0xc0
[117.005043] softirqs last  enabled at (2254702): [&lt;ffffffff8289fd00&gt;] __do_softirq+0x10/0x18
[117.005047] softirqs last disabled at (2254725): [&lt;ffffffff813d4ddf&gt;] __irq_exit_rcu+0x13f/0x160
[117.005051] ---[ end trace 0000000000000000 ]---

Make the timer IRQ safe.

[1] https://patchwork.freedesktop.org/series/154987/#rev2

Fixes: 4077798484459 ("drm/vgem: Attach sw fences to exported vGEM dma-buf (ioctl)")
Signed-off-by: Janusz Krzysztofik &lt;janusz.krzysztofik@linux.intel.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250926152628.2165080-2-janusz.krzysztofik@linux.intel.com
Signed-off-by: Maarten Lankhorst &lt;dev@lankhorst.se&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: add missing mutex_destroy</title>
<updated>2023-05-17T09:47:38+00:00</updated>
<author>
<name>Maíra Canal</name>
<email>mcanal@igalia.com</email>
</author>
<published>2023-02-02T12:55:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=67f07215eb8b19cab11dc0929c06c71e069afbcf'/>
<id>67f07215eb8b19cab11dc0929c06c71e069afbcf</id>
<content type='text'>
[ Upstream commit 7c18189b14b33c1fbf76480b1bd217877c086e67 ]

vgem_fence_open() instantiates a mutex for a particular fence
instance, but never destroys it by calling mutex_destroy() in
vgem_fence_close().

So, add the missing mutex_destroy() to guarantee proper resource
destruction.

Fixes: 407779848445 ("drm/vgem: Attach sw fences to exported vGEM dma-buf (ioctl)")
Signed-off-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Reviewed-by: Stanislaw Gruszka &lt;stanislaw.gruszka@linux.intel.com&gt;
Signed-off-by: Maíra Canal &lt;mairacanal@riseup.net&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230202125517.427976-1-mcanal@igalia.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7c18189b14b33c1fbf76480b1bd217877c086e67 ]

vgem_fence_open() instantiates a mutex for a particular fence
instance, but never destroys it by calling mutex_destroy() in
vgem_fence_close().

So, add the missing mutex_destroy() to guarantee proper resource
destruction.

Fixes: 407779848445 ("drm/vgem: Attach sw fences to exported vGEM dma-buf (ioctl)")
Signed-off-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Reviewed-by: Stanislaw Gruszka &lt;stanislaw.gruszka@linux.intel.com&gt;
Signed-off-by: Maíra Canal &lt;mairacanal@riseup.net&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230202125517.427976-1-mcanal@igalia.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: Use devm_drm_dev_alloc</title>
<updated>2020-09-11T08:47:19+00:00</updated>
<author>
<name>Daniel Vetter</name>
<email>daniel.vetter@ffwll.ch</email>
</author>
<published>2020-09-09T12:07:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bcc0ef7f57e51e5a5607eafb2a8ab63c6c1f21ff'/>
<id>bcc0ef7f57e51e5a5607eafb2a8ab63c6c1f21ff</id>
<content type='text'>
This means we also need to slightly restructure the exit code, so that
final cleanup of the drm_device is triggered by unregistering the
platform device. Note that devres is both clean up when the driver is
unbound (not the case for vgem, we don't bind), and also when unregistering
the device (very much the case for vgem). Therefore we can rely on devres
even though vgem isn't a proper platform device driver.

This also somewhat untangles the load code, since the drm and platform device
setup are no longer interleaved, but two distinct steps.

v2: use devres_open/release_group so we can use devm without real
hacks in the driver core or having to create an entire fake bus for
testing drivers. Might want to extract this into helpers eventually,
maybe as a mock_drm_dev_alloc or test_drm_dev_alloc.

v3: Fix error code handling (Melissa)

Cc: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Reviewed-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200909120745.716178-1-daniel.vetter@ffwll.ch
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This means we also need to slightly restructure the exit code, so that
final cleanup of the drm_device is triggered by unregistering the
platform device. Note that devres is both clean up when the driver is
unbound (not the case for vgem, we don't bind), and also when unregistering
the device (very much the case for vgem). Therefore we can rely on devres
even though vgem isn't a proper platform device driver.

This also somewhat untangles the load code, since the drm and platform device
setup are no longer interleaved, but two distinct steps.

v2: use devres_open/release_group so we can use devm without real
hacks in the driver core or having to create an entire fake bus for
testing drivers. Might want to extract this into helpers eventually,
maybe as a mock_drm_dev_alloc or test_drm_dev_alloc.

v3: Fix error code handling (Melissa)

Cc: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Reviewed-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200909120745.716178-1-daniel.vetter@ffwll.ch
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: allow limiting the scatter list size.</title>
<updated>2020-09-09T05:58:56+00:00</updated>
<author>
<name>Gerd Hoffmann</name>
<email>kraxel@redhat.com</email>
</author>
<published>2020-09-07T11:24:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=707d561f77b5e2a6f90c9786bee44ee7a8dedc7e'/>
<id>707d561f77b5e2a6f90c9786bee44ee7a8dedc7e</id>
<content type='text'>
Add drm_device argument to drm_prime_pages_to_sg(), so we can
call dma_max_mapping_size() to figure the segment size limit
and call into __sg_alloc_table_from_pages() with the correct
limit.

This fixes virtio-gpu with sev.  Possibly it'll fix other bugs
too given that drm seems to totaly ignore segment size limits
so far ...

v2: place max_segment in drm driver not gem object.
v3: move max_segment next to the other gem fields.
v4: just use dma_max_mapping_size().

Signed-off-by: Gerd Hoffmann &lt;kraxel@redhat.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: http://patchwork.freedesktop.org/patch/msgid/20200907112425.15610-2-kraxel@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add drm_device argument to drm_prime_pages_to_sg(), so we can
call dma_max_mapping_size() to figure the segment size limit
and call into __sg_alloc_table_from_pages() with the correct
limit.

This fixes virtio-gpu with sev.  Possibly it'll fix other bugs
too given that drm seems to totaly ignore segment size limits
so far ...

v2: place max_segment in drm driver not gem object.
v3: move max_segment next to the other gem fields.
v4: just use dma_max_mapping_size().

Signed-off-by: Gerd Hoffmann &lt;kraxel@redhat.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: http://patchwork.freedesktop.org/patch/msgid/20200907112425.15610-2-kraxel@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: add missing platform_device_unregister() in vgem_init()</title>
<updated>2020-08-10T13:31:02+00:00</updated>
<author>
<name>Qinglang Miao</name>
<email>miaoqinglang@huawei.com</email>
</author>
<published>2020-08-10T12:59:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=57fb54082d5d14512dfd21bc39d91945d3ad1ee9'/>
<id>57fb54082d5d14512dfd21bc39d91945d3ad1ee9</id>
<content type='text'>
When vgem_init() get into out_put, the unregister call of
vgem_device-&gt;platform is missing. So add it before return.

Fixes: 363de9e7d4f6 ("drm/vgem: Use drmm_add_final_kfree")
Signed-off-by: Qinglang Miao &lt;miaoqinglang@huawei.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200810125942.186637-1-miaoqinglang@huawei.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When vgem_init() get into out_put, the unregister call of
vgem_device-&gt;platform is missing. So add it before return.

Fixes: 363de9e7d4f6 ("drm/vgem: Use drmm_add_final_kfree")
Signed-off-by: Qinglang Miao &lt;miaoqinglang@huawei.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200810125942.186637-1-miaoqinglang@huawei.com
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: Replace opencoded version of drm_gem_dumb_map_offset()</title>
<updated>2020-07-08T21:00:21+00:00</updated>
<author>
<name>Chris Wilson</name>
<email>chris@chris-wilson.co.uk</email>
</author>
<published>2020-07-08T15:49:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=119c53d2d4044c59c450c4f5a568d80b9d861856'/>
<id>119c53d2d4044c59c450c4f5a568d80b9d861856</id>
<content type='text'>
drm_gem_dumb_map_offset() now exists and does everything
vgem_gem_dump_map does and *ought* to do.

In particular, vgem_gem_dumb_map() was trying to reject mmapping an
imported dmabuf by checking the existence of obj-&gt;filp. Unfortunately,
we always allocated an obj-&gt;filp, even if unused for an imported dmabuf.
Instead, the drm_gem_dumb_map_offset(), since commit 90378e589192
("drm/gem: drm_gem_dumb_map_offset(): reject dma-buf"), uses the
obj-&gt;import_attach to reject such invalid mmaps.

This prevents vgem from allowing userspace mmapping the dumb handle and
attempting to incorrectly fault in remote pages belonging to another
device, where there may not even be a struct page.

v2: Use the default drm_gem_dumb_map_offset() callback

Fixes: af33a9190d02 ("drm/vgem: Enable dmabuf import interfaces")
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v4.13+
Link: https://patchwork.freedesktop.org/patch/msgid/20200708154911.21236-1-chris@chris-wilson.co.uk
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
drm_gem_dumb_map_offset() now exists and does everything
vgem_gem_dump_map does and *ought* to do.

In particular, vgem_gem_dumb_map() was trying to reject mmapping an
imported dmabuf by checking the existence of obj-&gt;filp. Unfortunately,
we always allocated an obj-&gt;filp, even if unused for an imported dmabuf.
Instead, the drm_gem_dumb_map_offset(), since commit 90378e589192
("drm/gem: drm_gem_dumb_map_offset(): reject dma-buf"), uses the
obj-&gt;import_attach to reject such invalid mmaps.

This prevents vgem from allowing userspace mmapping the dumb handle and
attempting to incorrectly fault in remote pages belonging to another
device, where there may not even be a struct page.

v2: Use the default drm_gem_dumb_map_offset() callback

Fixes: af33a9190d02 ("drm/vgem: Enable dmabuf import interfaces")
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v4.13+
Link: https://patchwork.freedesktop.org/patch/msgid/20200708154911.21236-1-chris@chris-wilson.co.uk
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: remove _unlocked suffix in drm_gem_object_put_unlocked</title>
<updated>2020-05-19T21:31:36+00:00</updated>
<author>
<name>Emil Velikov</name>
<email>emil.velikov@collabora.com</email>
</author>
<published>2020-05-15T09:51:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a71a215a04e5dd82c302563ba3a8102d0b4683f5'/>
<id>a71a215a04e5dd82c302563ba3a8102d0b4683f5</id>
<content type='text'>
Spelling out _unlocked for each and every driver is a annoying.
Especially if we consider how many drivers, do not know (or need to)
about the horror stories involving struct_mutex.

Just drop the suffix. It makes the API cleaner.

Done via the following script:

__from=drm_gem_object_put_unlocked
__to=drm_gem_object_put
for __file in $(git grep --name-only $__from); do
  sed -i  "s/$__from/$__to/g" $__file;
done

Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Signed-off-by: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Acked-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200515095118.2743122-35-emil.l.velikov@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Spelling out _unlocked for each and every driver is a annoying.
Especially if we consider how many drivers, do not know (or need to)
about the horror stories involving struct_mutex.

Just drop the suffix. It makes the API cleaner.

Done via the following script:

__from=drm_gem_object_put_unlocked
__to=drm_gem_object_put
for __file in $(git grep --name-only $__from); do
  sed -i  "s/$__from/$__to/g" $__file;
done

Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Signed-off-by: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Acked-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200515095118.2743122-35-emil.l.velikov@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: Garbage collect drm_dev_fini</title>
<updated>2020-03-26T14:45:36+00:00</updated>
<author>
<name>Daniel Vetter</name>
<email>daniel.vetter@ffwll.ch</email>
</author>
<published>2020-03-23T14:49:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d33b58d0115e7eee011fddee2d8e25c6a09fb279'/>
<id>d33b58d0115e7eee011fddee2d8e25c6a09fb279</id>
<content type='text'>
It has become empty. Given the few users I figured not much point
splitting this up.

v2: Rebase over i915 changes.

v3: Rebase over patch split fix.

Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-26-daniel.vetter@ffwll.ch
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It has become empty. Given the few users I figured not much point
splitting this up.

v2: Rebase over i915 changes.

v3: Rebase over patch split fix.

Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-26-daniel.vetter@ffwll.ch
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: Use drmm_add_final_kfree</title>
<updated>2020-03-26T14:26:51+00:00</updated>
<author>
<name>Daniel Vetter</name>
<email>daniel.vetter@ffwll.ch</email>
</author>
<published>2020-03-23T14:49:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=363de9e7d4f6b1dd7993f316a064df1f9abc3341'/>
<id>363de9e7d4f6b1dd7993f316a064df1f9abc3341</id>
<content type='text'>
With this we can drop the final kfree from the release function.

v2: After drm_dev_init/drmm_add_final_kfree we need to clean up
everything through a drm_dev_put. Rework the unwind code to match
that.

Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Eric Anholt &lt;eric@anholt.net&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-14-daniel.vetter@ffwll.ch
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With this we can drop the final kfree from the release function.

v2: After drm_dev_init/drmm_add_final_kfree we need to clean up
everything through a drm_dev_put. Rework the unwind code to match
that.

Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Eric Anholt &lt;eric@anholt.net&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-14-daniel.vetter@ffwll.ch
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vgem: Close use-after-free race in vgem_gem_create</title>
<updated>2020-02-06T18:04:41+00:00</updated>
<author>
<name>Daniel Vetter</name>
<email>daniel.vetter@ffwll.ch</email>
</author>
<published>2020-02-02T13:21:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4b848f20eda5974020f043ca14bacf7a7e634fc8'/>
<id>4b848f20eda5974020f043ca14bacf7a7e634fc8</id>
<content type='text'>
There's two references floating around here (for the object reference,
not the handle_count reference, that's a different thing):

- The temporary reference held by vgem_gem_create, acquired by
  creating the object and released by calling
  drm_gem_object_put_unlocked.

- The reference held by the object handle, created by
  drm_gem_handle_create. This one generally outlives the function,
  except if a 2nd thread races with a GEM_CLOSE ioctl call.

So usually everything is correct, except in that race case, where the
access to gem_object-&gt;size could be looking at freed data already.
Which again isn't a real problem (userspace shot its feet off already
with the race, we could return garbage), but maybe someone can exploit
this as an information leak.

Cc: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Hillf Danton &lt;hdanton@sina.com&gt;
Reported-by: syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Eric Anholt &lt;eric@anholt.net&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Reviewed-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200202132133.1891846-1-daniel.vetter@ffwll.ch
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's two references floating around here (for the object reference,
not the handle_count reference, that's a different thing):

- The temporary reference held by vgem_gem_create, acquired by
  creating the object and released by calling
  drm_gem_object_put_unlocked.

- The reference held by the object handle, created by
  drm_gem_handle_create. This one generally outlives the function,
  except if a 2nd thread races with a GEM_CLOSE ioctl call.

So usually everything is correct, except in that race case, where the
access to gem_object-&gt;size could be looking at freed data already.
Which again isn't a real problem (userspace shot its feet off already
with the race, we could return garbage), but maybe someone can exploit
this as an information leak.

Cc: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Hillf Danton &lt;hdanton@sina.com&gt;
Reported-by: syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Cc: Emil Velikov &lt;emil.velikov@collabora.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Eric Anholt &lt;eric@anholt.net&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: Rob Clark &lt;robdclark@chromium.org&gt;
Reviewed-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20200202132133.1891846-1-daniel.vetter@ffwll.ch
</pre>
</div>
</content>
</entry>
</feed>
