Re: EFI RT page fault in init pid = 1

From: Dennis Clarke <dclarke_at_blastwave.org>
Date: Sat, 04 Jan 2025 11:52:07 UTC
On 1/4/25 06:45, Konstantin Belousov wrote:
> On Fri, Jan 03, 2025 at 06:43:55PM -0500, Dennis Clarke wrote:
>>
>> I wonder if anyone else has seen such a message at shutdown :
>>
>>
>>
>> Fatal trap 12: page fault while in kernel mode
>> cpuid = 0; apic id = 00
>> fault virtual address   = 0x0
>> fault code              = supervisor read data, page not present
>> instruction pointer     = 0x20:0x7c38f87a
>> stack pointer           = 0x28:0xfffffe035500bba8
>> frame pointer           = 0x28:0x5
>> 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         = 1 (init)
>> rdi: fffffe035500bcd8 rsi: 0000000000000004 rdx: 0000000000000000
>> rcx: 0000000000000000  r8: 0000000000000000  r9: 0000000000000000
>> rax: 00000000800b0040 rbx: 0000000000000002 rbp: 0000000000000005
>> r10: 00000000800b0000 r11: 0000000000000000 r12: fffff80103969000
>> r13: fffff80101c57140 r14: 0000000000004008 r15: fffff801019895a8
>> trap number             = 12
>> EFI RT page fault
>> acpi0: Powering system off
>>
>> I have not seen such a thing while the machine was running.
>>
>> Machine in question is 15.0-CURRENT :
> The reporting of the faults during the calls into EFI RT was added recently.
> Before that, such faults were silently ignored.  Now, the report is printed
> and then the fault is ignored.
> 
> There is no actionable items for users; a developer might be interested.
> 

I see !  Thank you. No need to redo buildworld etc etc and yes this
  seems to be consistent now and even the address data is the same.

All except for r13 :

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x0
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0x7c38f87a
stack pointer           = 0x28:0xfffffe035500bba8
frame pointer           = 0x28:0x5
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         = 1 (init)
rdi: fffffe035500bcd8 rsi: 0000000000000004 rdx: 0000000000000000
rcx: 0000000000000000  r8: 0000000000000000  r9: 0000000000000000
rax: 00000000800b0040 rbx: 0000000000000002 rbp: 0000000000000005
r10: 00000000800b0000 r11: 0000000000000000 r12: fffff80103969000
r13: fffff80101c56140 r14: 0000000000004008 r15: fffff801019895a8
trap number             = 12
EFI RT page fault
acpi0: Powering system off





-- 
--
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken