Re: Recent current panic

From: Kyle Evans <kevans_at_FreeBSD.org>
Date: Tue, 07 Jul 2026 20:18:05 UTC
On 7/7/26 15:11, Guido Falsi wrote:
> On 7/7/26 21:54, Kyle Evans wrote:
>> On 7/7/26 14:38, Guido Falsi wrote:
>>> On 7/7/26 20:38, Warner Losh wrote:
>>>>
>>>>
>>>> On Tue, Jul 7, 2026 at 12:17 PM Alan Somers <asomers@freebsd.org <mailto:asomers@freebsd.org>> wrote:
>>>>
>>>>     On Tue, Jul 7, 2026 at 11:24 AM Guido Falsi <mad@madpilot.net
>>>>     <mailto:mad@madpilot.net>> wrote:
>>>>      >
>>>>      > Hi!
>>>>      >
>>>>      > I'm experiencing a fully reproducible panic on recent current.
>>>>     I'm not
>>>>      > sure what is triggering it, looks ZFS related but I could be
>>>>     wrong. It
>>>>      > started when I updated shortly after the latest ZFS import.
>>>>      >
>>>>      > I'm running 2de20c5c77cf8d5b2059054cff0e0c1fc124739d committed
>>>>     on  Fri
>>>>      > Jul 3 10:55:37 2026 -0800 (from the commit message timestamp).
>>>>      >
>>>>      > first just after booting I get this report on the console:
>>>>      >
>>>>      > EFI RT fault page fault
>>>>      >
>>>>      > EFI runtime trap 12: page fault while in kernel mode
>>>>      > cpuid = 5; apic id = 05
>>>>      > fault virtual address   = 0x0
>>>>      > fault code              = supervisor read data, page not present
>>>>      > instruction pointer     = 0x20:0xb8bc1c5f
>>>>      > stack pointer           = 0x28:0xfffffe0121ae6c20
>>>>      > frame pointer           = 0x28:0x1
>>>>      > processor eflags        = interrupt enabled, resume, IOPL = 0
>>>>      > current thread          = 0/100045 (kernel/thread taskq)
>>>>      > rdi: fffffe0121ae6ce0 rsi: fffff80002523cd0 rdx: 0000000000000000
>>>>      > rcx: 00000000b8bc31b8  r8: 00000000b8bc3448  r9: 0000000000000006
>>>>      > rax: 00000000b9254e70 rbx: fffffe0121ae6d98 rbp: 0000000000000001
>>>>      > r10: 0000000000000000 r11: 0000000000000006 r12: fffff800014df658
>>>>      > r13: 0000000000000000 r14: fffffe0121ae6e08 r15: fffffe0121ae6da8
>>>>      >
>>>>      >
>>>>      > The system works fine after this, except if I start building a
>>>>     nanobsd
>>>>      > image with scripts that have worked fine till now. Then when it
>>>>     tries to
>>>>      > install packages in the image jail system panics hard:
>>>>      >
>>>>      > Fatal trap 12: page fault while in kernel mode
>>>>      > cpuid = 1; apic id = 01
>>>>      > fault virtual address   = 0x180
>>>>      > fault code              = supervisor read data, page not present
>>>>      > instruction pointer     = 0x20:0xffffffff807a74e5
>>>>      > stack pointer           = 0x28:0xfffffe016f8ef9e0
>>>>      > frame pointer           = 0x28:0xfffffe016f8efd70
>>>>      > processor eflags        = interrupt enabled, resume, IOPL = 0
>>>>      > current thread          = 15751/101480 (sh/sh)
>>>>      > rdi: fffffe016369e984 rsi: fffff80035ad3000 rdx: 0000000000000000
>>>>      > rcx: 0000000000000000  r8: 0000000000006873  r9: 00000000ffffff01
>>>>      > rax: 0000000000000000 rbx: fffffe016369e984 rbp: fffffe016f8efd70
>>>>      > r10: 0000000000000001 r11: 0000000000000001 r12: fffffe016369e5a0
>>>>      > r13: 0000000000000000 r14: 0000000000000000 r15: 0000000000000000
>>>>      > panic: page fault
>>>>      > cpuid = 1
>>>>      > time = 1783444123
>>>>      > KDB: stack backtrace:
>>>>      > db_trace_self_wrapper() at db_trace_self_wrapper+0x36/frame
>>>>      > 0xfffffe016f8ef720
>>>>      > vpanic() at vpanic+0x149/frame 0xfffffe016f8ef850
>>>>      > panic() at panic+0x43/frame 0xfffffe016f8ef8b0
>>>>      > trap_pfault() at trap_pfault+0x3a8/frame 0xfffffe016f8ef910
>>>>      > calltrap() at calltrap+0x8/frame 0xfffffe016f8ef910
>>>>      > --- trap 0xc, rip = 0xffffffff807a74e5, rsp = 0xfffffe016f8ef9e0,
>>>>     rbp =
>>>>      > 0xfffffe016f8efd70 ---
>>>>      > kern_execve() at kern_execve+0x17f5/frame 0xfffffe016f8efd70
>>>>      > sys_execve() at sys_execve+0xc2/frame 0xfffffe016f8efe00
>>>>      > amd64_syscall() at amd64_syscall+0x133/frame 0xfffffe016f8eff30
>>>>      > fast_syscall_common() at fast_syscall_common+0xf8/frame
>>>>     0xfffffe016f8eff30
>>>>      > --- syscall (59, FreeBSD ELF64, execve), rip = 0x605cefca, rsp =
>>>>      > 0x881310ee8, rbp = 0x881311360 ---
>>>>      > KDB: enter: panic
>>>>      >
>>>>      >
>>>>      > Anyone can help I can trigger this easily. If someone could give
>>>>     me some
>>>>      > steps to perform in the debugger to extract more information I
>>>>     can do that.
>>>>      >
>>>>      >
>>>>      > Thanks in advance.
>>>>      >
>>>>      > --
>>>>      > Guido Falsi <mad@madpilot.net <mailto:mad@madpilot.net>>
>>>>
>>>>     That "EFI RT page fault" message looks very concerning. How confident
>>>>     are you in your system's RAM?  Have you tried something like
>>>>     memtest86+ ?
>>>>
>>>>
>>>> It could also be from the runtime services from EFI that we're calling back into
>>>> as well... Best to check into both.
>>>>
>>>> Warner
>>>
>>> I'll be running a memtest soon, just to be on the safe side, but I've not seen any other instability int he machine.
>>>
>>> How could I investigate the other option?
>>>
>>> This is coming up a few seconds after the login: prompt.
>>>
>>
>> My guess would be that this is from ntpd trying to set the RTC?  What kind of machine/firmware is this?
>>
> 
> Sounds like a reasonable guess.
> 
> This is a Ryzen 5 5600G on a Gigabyte mother board. Nothing fancy though. It's from 3 years ago if I remember correctly. The case itself is much older.
> 

Does `efivar -l` also cause a fault?  Sometimes firmware does stupid things like require regions we wouldn't normally have mapped to operate.  Ahmad (CC'd) had a change to map the first page because of firmware shenanigans in 4add1a7a46b5cb, this might be exactly the case here.  I think they had found other type-based shenanigans as well.

Thanks,

Kyle Evans