maintainer-feedback requested: [Bug 267204] graphics/drm-510-kmod 5.10.113_7 i915kms kernel page fault

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-x11 (Nobody)
<x11@FreeBSD.org> for maintainer-feedback:
Bug 267204: graphics/drm-510-kmod 5.10.113_7 i915kms kernel page fault
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=267204



--- Description ---
FreeBSD 13.1-STABLE amd64 (a8925e0e578f355a201f81bf52161d6312826911)

i915kms from drm-510-kmod-5.10.113_7 causes a kernel page fault when I start
the X11 server.

I updated base on stable/13, from two weeks ago to today (a8925e0e578f355a).
I rebuilt and reinstalled graphics/drm-510-kmod.
I load the i915kms module on startup (kld_list="i915kms" in /etc/rc.conf).

The console works fine with i915kms, but once I start the Xorg server, the
machine dies with a kernel page fault.	Also see the attached dmesg.

#0 0xffffffff80c505f5 at kdb_backtrace+0x65
#1 0xffffffff80c033d1 at vpanic+0x151
#2 0xffffffff80c03273 at panic+0x43
#3 0xffffffff810a4d87 at trap_fatal+0x387
#4 0xffffffff810a4ddf at trap_pfault+0x4f
#5 0xffffffff8107cac8 at calltrap+0x8
#6 0xffffffff80e44aec at linux_root_RB_REMOVE+0xbc
#7 0xffffffff82dc84fb at drm_mm_reserve_node+0x17b
#8 0xffffffff82c1a48b at i915_gem_gtt_reserve+0x2b
#9 0xffffffff82c2fcae at i915_vma_insert+0x16e
#10 0xffffffff82c2f8dc at i915_vma_pin_ww+0x59c
#11 0xffffffff82d36c63 at eb_validate_vmas+0x173
#12 0xffffffff82d35d0a at eb_relocate_parse+0xaa
#13 0xffffffff82d349c8 at i915_gem_do_execbuffer+0x6b8
#14 0xffffffff82d34e62 at i915_gem_execbuffer2_ioctl+0x1a2
#15 0xffffffff82dc6e3a at drm_ioctl_kernel+0xca
#16 0xffffffff82dc71e0 at drm_ioctl+0x2a0
#17 0xffffffff80e46e73 at linux_file_ioctl+0x313

This may not be a bug in drm-510-kmod.	It must have been triggered by a change
in LinuKPI or rb_tree.