[Bug 1877394] Autopkgtest regression report (linux-oracle-5.4/5.4.0-1019.19~18.04.1)

All autopkgtests for the newly accepted linux-oracle-5.4 (5.4.0-1019.19~18.04.1) for bionic have finished running.
The following regressions have been reported in tests triggered by the package:

zfs-linux/unknown (armhf)


Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-
migration/bionic/update_excuses.html#linux-oracle-5.4

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

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https://bugs.launchpad.net/bugs/1877394

Title:
Kernel panic due to NULL ringbuffer vaddr dereference in i915

Status in linux package in Ubuntu:
Invalid
Status in linux source package in Focal:
Fix Released

Bug description:
SRU Justification:

[Impact]
A sauce fix for a kernel panic in i915 that I frequently experienced was fixed by upstream.

[Fix]
The sauce patch I made should be dropped in exchange for the proper upstream fix.

[Test]
I tested the upstream fix and can confirm it fixes the crashes I experienced.

[Regression Potential]
Low. The upstream fix for this bug is tiny and we get to remove a nasty sauce patch.
---
This is what the crash looks like:
    BUG: unable to handle page fault for address: 0000000000003448
    RIP: 0010:gen8_emit_flush_render+0x163/0x190
    Call Trace:
     execlists_request_alloc+0x25/0x40
     __i915_request_create+0x1f4/0x2c0
     i915_request_create+0x71/0xc0
     i915_gem_do_execbuffer+0xb98/0x1a80
     ? preempt_count_add+0x68/0xa0
     ? _raw_spin_lock+0x13/0x30
     ? _raw_spin_unlock+0x16/0x30
     i915_gem_execbuffer2_ioctl+0x1de/0x3c0
     ? i915_gem_busy_ioctl+0x7f/0x1d0
     ? i915_gem_execbuffer_ioctl+0x2d0/0x2d0
     drm_ioctl_kernel+0xb2/0x100
     drm_ioctl+0x209/0x360
     ? i915_gem_execbuffer_ioctl+0x2d0/0x2d0
     ksys_ioctl+0x87/0xc0
     __x64_sys_ioctl+0x16/0x20
     do_syscall_64+0x4e/0x150
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

This bug was fixed by "UBUNTU: SAUCE: drm/i915: Synchronize active and
retire callbacks" but there is an upstream fix for it, "drm/i915/gt:
Make intel_ring_unpin() safe for concurrent pint". Let's replace the
sauce patch with the upstream fix.

More info here: https://gitlab.freedesktop.org/drm/intel/issues/1599

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