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

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)
> 
> ------------------------------------------------------------------------
> 

-- 
Alexander Motin