Re: kern/57833: kernel panic on xorg exit

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

The following reply was made to PR kern/57833; it has been noted by GNATS.

From: Ramiro Aceves <ea1abz%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Cc: Taylor R Campbell <riastradh%NetBSD.org@localhost>,
 "David H. Gutteridge" <david%gutteridge.ca@localhost>
Subject: Re: kern/57833: kernel panic on xorg exit
Date: Sat, 13 Jan 2024 22:41:49 +0100

 El 13/1/24 a las 1:40, David H. Gutteridge escribió:
 > The following reply was made to PR kern/57833; it has been noted by GNATS.
 > 
 > From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
 > To: Gnats Bugs <gnats-bugs%netbsd.org@localhost>
 > Cc: Taylor R Campbell <riastradh%netbsd.org@localhost>
 > Subject: Re: kern/57833: kernel panic on xorg exit
 > Date: Fri, 12 Jan 2024 19:37:16 -0500
 > 
 >   On 2024-01-12 17:52, Ramiro Aceves wrote:
 >   > El 12/1/24 a las 0:05, David H. Gutteridge escribió:
 >   >
 >   >> The following reply was made to PR kern/57833; it has been noted by
 >   >> GNATS.
 >   >>
 >   >> From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
 >   >> To: Taylor R Campbell <riastradh%netbsd.org@localhost>
 >   >> Cc: gnats-bugs%netbsd.org@localhost
 >   >> Subject: Re: kern/57833: kernel panic on xorg exit
 >   >> Date: Thu, 11 Jan 2024 18:04:44 -0500
 >   >>
 >   >> --=_79cd473ca3d4e19fbe52c232ee5dd792
 >   >> Content-Transfer-Encoding: 7bit
 >   >> Content-Type: text/plain; charset=US-ASCII;
 >   >> format=flowed
 >   >> On 2024-01-10 23:37, Taylor R Campbell wrote:
 >   >>> Can you also try the attached patch, instead of the other one, to see
 >   >>> what happens?
 >   >>>
 >   >>> (This might break things more spectacularly -- I haven't thought
 >   >>> about
 >   >>> whether it makes a lot of sense -- but it should at least prevent the
 >   >>> particular crash you observed, if we ever get that far with it.)
 >   >> I've supplied a debug log. (It can be found at:
 >   >> https://www.netbsd.org/~gutteridge/pr57833_debug.log .)
 >   >> Applying the first (small) patch did not prevent the panics. But the
 >   >> larger patch did fix the problem for me. There was a slight coding
 >   >> error with the second patch (wrong label for a goto statement), so it
 >   >> didn't compile as-is. I've attached a revised patch that fixes that
 >   >> one
 >   >> line, should anyone else want to test this.
 >   >> Thanks,
 >   >> Dave
 >   >
 >   > Hello Dave, thanks for feedback. Here I had the same problem, I applied
 >   > the patch and could not compile the kernel  because en error in 555
 >   > line when compiling i915_gem_stolen.c file. I changed
 >   >
 >   > goto err;
 >   >
 >   > to
 >   >
 >   > goto out;
 >   >
 >   > (not sure if that is the right fix)
 >   
 >   Yes, it is.
 >   
 >   > File compiled ok. Rebuilt the kernel and I had the same panic the first
 >   > time abandoned Xorg session.
 >   
 >   There must be something different about your hardware than mine here,
 >   then. (Mine is Intel 945GME.) The patch did work for me, but I guess
 >   there's more to it.
 >   
 >   Do you have a build that includes a netbsd.gdb file? If not, you can
 >   generate one (e.g., for your patched kernel) by un-commenting the
 >   line
 >   
 >   makeoptions	DEBUG="-g"
 >   
 >   in your kernel config file (I assume GENERIC?) and re-building. The
 >   extra file should appear.
 >   
 >   Then we would have the means to get the other details Taylor is looking
 >   for here (see the email from Thu, 11 Jan 2024 03:45UTC).
 >   
 >   Dave
 >   
 >   PS Sorry I was not able to send you a patch again earlier. GMail is not
 >   accepting email from my domain, so my email bounced. Evidently my emails
 >   do make it when funnelled through GNATS.
 >   
 
 Hello,
 
 This is the last recorded crash after Taylor's patch and compiling the 
 kernel with debugging symbols ad David suggested:
 
 netbsd-compal# dmesg -M /var/crash/netbsd.7.core -N /var/crash/netbsd.7
 
 ...
 ...
       4.324510] uhid1 at uhidev1 reportid 3: input=2, output=0, feature=0
 [    16.564698] wsdisplay0: screen 1 added (default, vt100 emulation)
 [    16.564698] wsdisplay0: screen 2 added (default, vt100 emulation)
 [    16.564698] wsdisplay0: screen 3 added (default, vt100 emulation)
 [    16.564698] wsdisplay0: screen 4 added (default, vt100 emulation)
 [   234.752732] uvm_fault(0xc151c400, 0xdd4e8000, 1) -> 0xe
 [   234.752732] fatal page fault in supervisor mode
 [   234.752732] trap type 6 code 0 eip 0xc0b02ece cs 0x8 eflags 0x13287 
 cr2 0xdd4e8000 ilevel 0x8 esp 0x4bb1a000
 [   234.752732] curlwp 0xc4341600 pid 0 lid 63 lowest kstack 0xdc7e02c0
 [   234.752732] panic: trap
 [   234.752732] cpu0: Begin traceback...
 [   234.752732] 
 vpanic(c1186d04,dc7e1d7c,dc7e1e38,c012fed8,c1186d04,dc7e1e44,dc7e1e44,3f,dc7e02c0,13287) 
 at netbsd:vpanic+0x196
 [   234.752732] 
 panic(c1186d04,dc7e1e44,dc7e1e44,3f,dc7e02c0,13287,dd4e8000,8,4bb1a000,c157e960) 
 at netbsd:panic+0x18
 [   234.752732] trap() at netbsd:trap+0xd51
 [   234.752732] --- trap (number 6) ---
 [   234.752732] 
 drm_clflush_virt_range(dd4e8000,1000,0,1000,0,0,c147c8c0,dd4e8000,db6ff000,c5c423c0) 
 at netbsd:drm_clflush_virt_range+0x3f
 [   234.752732] 
 i915_gem_object_put_pages_phys(c5c15900,c5c222c4,c5c15900,c5c15900,4,dc7e1f48,c06cd688,c5c15900,54,0) 
 at netbsd:i915_gem_object_put_pages_phys+0x15a
 [   234.752732] 
 __i915_gem_object_put_pages(c5c15900,54,0,c0c5dd4f,0,0,c3dff878,0,c5c159b0,c5c159ac) 
 at netbsd:__i915_gem_object_put_pages+0x70
 [   234.752732] 
 __i915_gem_free_objects(c3dfea1c,c42a2f00,0,0,120,c4341600,c42a2f1c,dc7e1f78,c42a2f04,c42a2f1c) 
 at netbsd:__i915_gem_free_objects+0x104
 [   234.752732] 
 linux_workqueue_thread(c42a2f00,1848000,1853000,0,c01005a8,0,0,0,0,0) at 
 netbsd:linux_workqueue_thread+0xe6
 [   234.752732] cpu0: End traceback...
 
 [   234.752732] dumping to dev 0,1 offset 1023
 [   234.752732] dump
 netbsd-compal#
 
 
 netbsd-compal# gdb /usr/src/sys/arch/i386/compile/MYKERNEL/netbsd.gdb
 GNU gdb (GDB) 11.0.50.20200914-git
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 <https://www.gnu.org/software/gdb/bugs/>.
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 Reading symbols from /usr/src/sys/arch/i386/compile/MYKERNEL/netbsd.gdb...
 (gdb) target kvm /var/crash/netbsd.7.core
 0xc012d6ed in maybe_dump (howto=260) at 
 ../../../../arch/i386/i386/machdep.c:725
 725			dumpsys();
 (gdb) frame 0
 #0  0xc012d6ed in maybe_dump (howto=260) at 
 ../../../../arch/i386/i386/machdep.c:725
 725			dumpsys();
 (gdb) frame 1
 #1  cpu_reboot (howto=howto@entry=260, bootstr=bootstr@entry=0x0) at 
 ../../../../arch/i386/i386/machdep.c:746
 746		maybe_dump(howto);
 (gdb) frame 2
 #2  0xc0c85e17 in kern_reboot (howto=howto@entry=260, 
 bootstr=bootstr@entry=0x0) at ../../../../kern/kern_reboot.c:73
 73		cpu_reboot(howto, bootstr);
 (gdb) frame 3
 #3  0xc0cbc9d8 in vpanic (fmt=fmt@entry=0xc1186d04 "trap", ap=0xdc7e1d7c 
 "D\036~\334D\036~\334?")
      at ../../../../kern/subr_prf.c:291
 291		kern_reboot(bootopt, NULL);
 (gdb) frame 4
 #4  0xc0cbca91 in panic (fmt=fmt@entry=0xc1186d04 "trap") at 
 ../../../../kern/subr_prf.c:208
 208		vpanic(fmt, ap);
 (gdb) frame 5
 #5  0xc012fed8 in trap (frame=0xdc7e1e44) at 
 ../../../../arch/i386/i386/trap.c:358
 358			panic("trap");
 (gdb) frame 6
 #6  0xc012529b in alltraps ()
 (gdb) frame 7
 #7  0xdc7e1e44 in ?? ()
 (gdb) frame 8
 #8  0xc06cf74c in i915_gem_object_put_pages_phys (obj=<optimized out>, 
 pages=<optimized out>)
      at ../../../../external/bsd/drm2/dist/drm/i915/gem/i915_gem_phys.c:206
 206				drm_clflush_virt_range(src, PAGE_SIZE);
 (gdb)
 #8  0xc06cf74c in i915_gem_object_put_pages_phys (obj=<optimized out>, 
 pages=<optimized out>)
      at ../../../../external/bsd/drm2/dist/drm/i915/gem/i915_gem_phys.c:206
 206				drm_clflush_virt_range(src, PAGE_SIZE);
 (gdb) info locals
 page = 0x40
 dst = 0xdb6ff000 "\377\377\377\377\377\377\377\377"
 mapping = <optimized out>
 src = 0xdd4e8000
 i = <optimized out>
 dmat = <optimized out>
 vaddr = <optimized out>
 (gdb) frame 9
 #9  0xc06cf1b2 in __i915_gem_object_put_pages (obj=obj@entry=0xc5c15900)
      at ../../../../external/bsd/drm2/dist/drm/i915/gem/i915_gem_pages.c:246
 246			obj->ops->put_pages(obj, pages);
 (gdb) info locals
 pages = <optimized out>
 err = <optimized out>
 (gdb) frame 10
 #10 0xc06cd688 in __i915_gem_free_objects (i915=0xc3dfd004, 
 freed=<optimized out>)
      at 
 ../../../../external/bsd/drm2/dist/drm/i915/gem/i915_gem_object.c:257
 257			__i915_gem_object_put_pages(obj);
 (gdb) info locals
 mmo = <optimized out>
 mn = <optimized out>
 obj = 0xc5c15900
 on = 0x0
 wakeref = <optimized out>
 (gdb) frame 11
 #11 0xc0aef695 in linux_workqueue_thread (cookie=0xc42a2f00) at 
 ../../../../external/bsd/common/linux/linux_work.c:455
 455					(*func)(work);
 (gdb) info locals
 func = 0xc06cd7f2 <__i915_gem_free_work>
 wq = 0xc42a2f00
 q = {0x0, 0xc42a2f24}
 marker = {work_owner = 3291047360, work_entry = {tqe_next = 0x0, 
 tqe_prev = 0xc42a2f1c}, func = 0xc42a2f00}
 work = 0xc3dfea1c
 i = <optimized out>
 (gdb) frame 12
 #12 0xc0102011 in lwp_trampoline ()
 (gdb) info locals
 No symbol table info available.
 (gdb) frame 13
 No frame at level 13.
 (gdb)
 
 Ramiro.