Re: Panic: Page Fault in Kernel: Yesterday's CURRENT

From: Larry Rosenman <ler_at_lerctr.org>
Date: Fri, 10 Dec 2021 16:43:19 UTC
14-2021_12_07-1217             -      -          1.87G 2021-12-07 12:17
14-2021_12_09-1957             NR     /          121G  2021-12-09 19:57

If that's any help

On 12/10/2021 10:36 am, Alexander Motin wrote:
> Hi Larry,
> 
> This looks like some use-after-free or otherwise corrupted callout
> structure.  Unfortunately the backtrace does not tell what was the
> callout.  When was the previous update to look what could change?
> 
> On 10.12.2021 11:24, Larry Rosenman wrote:
>> FreeBSD borg.lerctr.org 14.0-CURRENT FreeBSD 14.0-CURRENT #15
>> main-n251537-ab639f2398b: Thu Dec  9 19:45:37 CST 2021    
>> root@borg.lerctr.org:/usr/obj/usr/src/amd64.amd64/sys/LER-MINIMAL  
>> amd64
>> 
>> VMCORE *IS* available.
>> 
>> 
>> 
>> 
>> Unread portion of the kernel message buffer:
>> kernel trap 12 with interrupts disabled
>> 
>> 
>> Fatal trap 12: page fault while in kernel mode
>> cpuid = 0; apic id = 20
>> fault virtual address   = 0x0
>> fault code              = supervisor write data, page not present
>> instruction pointer     = 0x20:0xffffffff804e0db4
>> stack pointer           = 0x0:0xfffffe0434de4e10
>> frame pointer           = 0x0:0xfffffe0434de4e70
>> code segment            = base 0x0, limit 0xfffff, type 0x1b
>>                         = DPL 0, pres 1, long 1, def32 0, gran 1
>> processor eflags        = resume, IOPL = 0
>> current process         = 82990 (c++)
>> trap number             = 12
>> panic: page fault
>> cpuid = 0
>> time = 1639111198
>> KDB: stack backtrace:
>> #0 0xffffffff8050fc95 at kdb_backtrace+0x65
>> #1 0xffffffff804c468f at vpanic+0x17f
>> #2 0xffffffff804c4503 at panic+0x43
>> #3 0xffffffff807a2195 at trap_fatal+0x385
>> #4 0xffffffff807a21ef at trap_pfault+0x4f
>> #5 0xffffffff80779c78 at calltrap+0x8
>> #6 0xffffffff8045ddb8 at handleevents+0x188
>> #7 0xffffffff8045ea3e at timercb+0x24e
>> #8 0xffffffff807ca9eb at lapic_handle_timer+0x9b
>> #9 0xffffffff8077b9b1 at Xtimerint+0xb1
>> Uptime: 2h28m57s
>> Dumping 12829 out of 131023
>> MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%
>> 
>> __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:55
>> 55              __asm("movq %%gs:%P1,%0" : "=r" (td) : "n"
>> (offsetof(struct pcpu,
>> (kgdb) #0  __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:55
>> #1  doadump (textdump=<optimized out>)
>>     at /usr/src/sys/kern/kern_shutdown.c:399
>> #2  0xffffffff804c428c in kern_reboot (howto=260)
>>     at /usr/src/sys/kern/kern_shutdown.c:487
>> #3  0xffffffff804c46fe in vpanic (fmt=0xffffffff807e1276 "%s",
>>     ap=<optimized out>) at /usr/src/sys/kern/kern_shutdown.c:920
>> #4  0xffffffff804c4503 in panic (fmt=<unavailable>)
>>     at /usr/src/sys/kern/kern_shutdown.c:844
>> #5  0xffffffff807a2195 in trap_fatal (frame=0xfffffe0434de4d50, eva=0)
>>     at /usr/src/sys/amd64/amd64/trap.c:946
>> #6  0xffffffff807a21ef in trap_pfault (frame=0xfffffe0434de4d50,
>>     usermode=false, signo=<optimized out>, ucode=<optimized out>)
>>     at /usr/src/sys/amd64/amd64/trap.c:765
>> #7  <signal handler called>
>> #8  0xffffffff804e0db4 in callout_process 
>> (now=now@entry=38385536922300)
>>     at /usr/src/sys/kern/kern_timeout.c:488
>> #9  0xffffffff8045ddb8 in handleevents (now=now@entry=38385536922300,
>>     fake=fake@entry=0) at /usr/src/sys/kern/kern_clocksource.c:213
>> #10 0xffffffff8045ea3e in timercb (et=0xffffffff80d475e0 <lapic_et>,
>>     arg=<optimized out>) at /usr/src/sys/kern/kern_clocksource.c:357
>> #11 0xffffffff807ca9eb in lapic_handle_timer 
>> (frame=0xfffffe0434de4f40)
>>     at /usr/src/sys/x86/x86/local_apic.c:1364
>> #12 <signal handler called>
>> #13 0x000000080df42bb6 in ?? ()
>> Backtrace stopped: Cannot access memory at address 0x7ffffdef2c90
>> (kgdb)
>> 
>> ------------------------------------------------------------------------
>> 

-- 
Larry Rosenman                     http://www.lerctr.org/~ler
Phone: +1 214-642-9640                 E-Mail: ler@lerctr.org
US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106