Re: kernel panic while copying files

On Mon, Jun 07, 2021 at 11:01:09AM +0200, Gary Jennejohn wrote:
> I've seen this panic three times in the last two days:
> 
> [first panic]
> Unread portion of the kernel message buffer:
> 
> 
> Fatal trap 12: page fault while in kernel mode
> cpuid = 3; apic id = 03
> fault virtual address   = 0x801118000
> fault code              = supervisor write data, page not present
> instruction pointer     = 0x20:0xffffffff808d2212
> stack pointer           = 0x28:0xfffffe00dbc8c760
> frame pointer           = 0x28:0xfffffe00dbc8c7a0
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                         = DPL 0, pres 1, long 1, def32 0, gran 1
> processor eflags        = interrupt enabled, resume, IOPL = 0
> current process         = 28 (dom0)
> trap number             = 12
> panic: page fault
> cpuid = 3
> time = 1622963058
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00dbc8c410
> vpanic() at vpanic+0x181/frame 0xfffffe00dbc8c460
> panic() at panic+0x43/frame 0xfffffe00dbc8c4c0
> trap_fatal() at trap_fatal+0x387/frame 0xfffffe00dbc8c520
> trap_pfault() at trap_pfault+0x4f/frame 0xfffffe00dbc8c580
> trap() at trap+0x253/frame 0xfffffe00dbc8c690
> calltrap() at calltrap+0x8/frame 0xfffffe00dbc8c690
> --- trap 0xc, rip = 0xffffffff808d2212, rsp = 0xfffffe00dbc8c760, rbp = 0xfffffe00dbc8c7a0 ---
> zone_release() at zone_release+0x1f2/frame 0xfffffe00dbc8c7a0
> bucket_drain() at bucket_drain+0xda/frame 0xfffffe00dbc8c7d0
> bucket_cache_reclaim_domain() at bucket_cache_reclaim_domain+0x30a/frame 0xfffffe00dbc8c830
> zone_reclaim() at zone_reclaim+0x162/frame 0xfffffe00dbc8c880
> uma_reclaim_domain() at uma_reclaim_domain+0xa2/frame 0xfffffe00dbc8c8b0
> vm_pageout_worker() at vm_pageout_worker+0x41e/frame 0xfffffe00dbc8cb70
> vm_pageout() at vm_pageout+0x21e/frame 0xfffffe00dbc8cbb0
> fork_exit() at fork_exit+0x7e/frame 0xfffffe00dbc8cbf0
> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00dbc8cbf0
> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
> KDB: enter: panic
> 
> __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:55
> 55       __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" (offsetof(struct pcpu,
> 	   pc_curthread)));
> 
> One difference was that in the second and third panics the fault virtual
> address was 0x0.  But the backtrace was the same.
> 
> Relevant info from the info.x files:
> Architecture: amd64
> Architecture Version: 2
> Version String: FreeBSD 14.0-CURRENT #33 main-n247184-1970d693039: Sat Jun
> 5 09:58:55 CEST 2021
> 
> CPU: AMD Ryzen 5 1600 Six-Core Processor             (3194.09-MHz K8-class CPU)
>   Origin="AuthenticAMD"  Id=0x800f11  Family=0x17  Model=0x1  Stepping=1
>   AMD Features=0x2e500800<SYSCALL,NX,MMX+,FFXSR,Page1GB,RDTSCP,LM>
>   AMD Features2=0x35c233ff<LAHF,CMP,SVM,ExtAPIC,CR8,ABM,SSE4A,MAS,Prefetch,OSVW,SKINIT,WDT,TCE,Topology,PCXC,PNXC,DBE,PL2I,MWAITX>
>   AMD Extended Feature Extensions ID EBX=0x1007<CLZERO,IRPerf,XSaveErPtr,IBPB>
> 
> I have 16GiB of memory in the box.
> 
> The panic occurred while copying files from an internal SATA SSD to a
> SATA 8TB disk in an external USB3 docking station.  The panic seems to
> occur quite quickly, after only a few files have been copied.
> 
> swap is on a different internal disk.
> 
> I can poke around in the crash dumps with kgdb if anyone wants more
> information.

Are you running with invariants configured in the kernel?  If not,
please try to reproduce this in a kernel with

options INVARIANT_SUPPORT
options INVARIANTS

configured.

A stack trace with line numbers would also be helpful.