Messages in this thread | | | From | Tony Fischetti <> | Date | Mon, 28 Sep 2020 14:14:16 -0400 | Subject | REGRESSION: in intel video driver following introduction of mm_struct.has_pinned |
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After a length git bisection, I determined the commit that introduced a change that ultimately caused a bug/oops null dereference (see below for relevant syslog entries) was 008cfe4418b3dbda2ff.. (mm: Introduce mm_struct.has_pinned)
The RIP (according to syslog) occurs in function `__get_user_pages_remote` and the last function to call it from the i915 code is `gem_userptr_get_pages_worker` More specifically, it appears to be the call to `pin_user_pages_remote` in `gem_userptr_get_pages_worker` in drivers/gpu/drm/i915/gem/i915_gem_userptr.c that directly leads to the oops.
Unfortunately, I don't know enough to try to fix and share the fix myself, but I hope the information I provided is helpful. Please let me know if there is any further information I can provide that might be of use.
BUG: kernel NULL pointer dereference, address: 0000000000000054 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 8 PID: 497 Comm: kworker/u25:0 Not tainted 5.9.0-rc7-alice-investigate-3+ #2 Hardware name: LENOVO 10ST001QUS/312A, BIOS M1UKT4BA 11/11/2019 Workqueue: i915-userptr-acquire __i915_gem_userptr_get_pages_worker [i915] RIP: 0010:__get_user_pages_remote+0xa0/0x2d0 Code: 85 e7 01 00 00 83 3b 01 0f 85 e0 01 00 00 f7 c1 00 00 04 00 0f 84 12 01 00 00 65 48 8b 04 25 00 6d 01 00 48 8b 80 58 03 00 00 <c7> 40 54 01 00 00 00 c6 04 24 00 4d 8d 6f 68 48 c7 44 24 10 00 00 RSP: 0018:ffffa1a58086bde0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffffa1a58086be64 RCX: 0000000000040001 RDX: 00000000000007e9 RSI: 00007f532f800000 RDI: ffff92f22d89c480 RBP: 00007f532f800000 R08: ffff92f23a188000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffa1a58086bcfd R12: ffff92f23a188000 R13: ffff92f22d89c480 R14: 0000000000042003 R15: ffff92f22d89c480 FS: 0000000000000000(0000) GS:ffff92f23e400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000054 CR3: 0000000016c0a002 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __i915_gem_userptr_get_pages_worker+0x1ec/0x392 [i915] process_one_work+0x1c7/0x310 worker_thread+0x28/0x3c0 ? set_worker_desc+0xb0/0xb0 kthread+0x123/0x140 ? kthread_use_mm+0xe0/0xe0 ret_from_fork+0x1f/0x30 Modules linked in: snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio iwlmvm mac80211 libarc4 x86_pkg_temp_thermal intel_powerclamp iwlwifi coretemp i915 crct10dif_pclmul crc32_pclmul crc32c_intel i2c_algo_bit ghash_clmulni_intel drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec mei_hdcp wmi_bmof snd_hda_intel drm tpm_crb snd_intel_dspcfg intel_wmi_thunderbolt snd_hda_codec snd_hwdep aesni_intel crypto_simd glue_helper snd_hda_core cfg80211 i2c_i801 snd_pcm intel_cstate pcspkr snd_timer mei_me i2c_smbus mei i2c_core thermal wmi tpm_tis tpm_tis_core tpm rng_core acpi_pad ppdev lp ip_tables x_tables CR2: 0000000000000054 ---[ end trace 8d080e8b96289c9e ]---
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