Re: Failures in x86 pmap

[Andrew Doran <ad%netbsd.org@localhost>]

I think I found the problem, which has existed since ~8PM GMT yesterday.
Hopefully fixed by revision 1.17 of src/sys/arch/x86/x86/x86_tlb.c.

Andrew

On Sun, Feb 23, 2020 at 06:29:38PM +0000, Andrew Doran wrote:
> Having gotten a report of this privately I've now started running into it. 
> Has anyone else seen this, and if so any idea when it started happening? 
> I wonder if there is a memory corruption or TLB coherency issue.
> 
> Andrew
> 
> 
> 
> hanging here:
> 
> db{0}> bt
> pmap_pp_remove() at netbsd:pmap_pp_remove+0x46c
> uvm_anon_dispose() at netbsd:uvm_anon_dispose+0xd0
> uvm_anon_freelst() at netbsd:uvm_anon_freelst+0x3d
> amap_wipeout() at netbsd:amap_wipeout+0x101
> uvm_unmap_detach() at netbsd:uvm_unmap_detach+0x52
> 
> panics:
> 
> [ 107.1489360] panic: kernel diagnostic assertion "pve != NULL" failed: file "../../../../arch/x86/x86/pmap.c", line 1918
> [ 107.1589403] cpu5: Begin traceback...
> [ 107.1589403] vpanic() at netbsd:vpanic+0x178
> [ 107.1689455] kern_assert() at netbsd:kern_assert+0x48
> [ 107.1689455] pmap_enter_pv() at netbsd:pmap_enter_pv+0x295
> [ 107.1789498] pmap_enter_ma() at netbsd:pmap_enter_ma+0x3dd
> [ 107.1889536] pmap_enter_default() at netbsd:pmap_enter_default+0x29
> [ 107.1889536] uvm_fault_upper_enter.isra.6() at netbsd:uvm_fault_upper_enter.isra.6+0xcc
> [ 107.1989589] uvm_fault_internal() at netbsd:uvm_fault_internal+0xb2a
> [ 107.2089635] trap() at netbsd:trap+0x6f4
> [ 107.2089635] --- trap (number 6) ---
> [ 107.2189676] copyout() at netbsd:copyout+0x33
> [ 107.2189676] elf64_copyargs() at netbsd:elf64_copyargs+0x1b
> [ 107.2289730] execve_runproc() at netbsd:execve_runproc+0x4bb
> [ 107.2289730] execve1() at netbsd:execve1+0x4e
> [ 107.2389768] sys_execve() at netbsd:sys_execve+0x2a
> [ 107.2389768] syscall() at netbsd:syscall+0x299
> [ 107.2489822] --- syscall (number 59) ---
> [ 107.2489822] 71c9fa842dfa:
> [ 107.2489822] cpu5: End traceback...
> [ 107.2589851] fatal breakpoint trap in supervisor mode
> [ 107.2589851] trap type 1 code 0 rip 0xffffffff8021f55d cs 0x8 rflags 0x202 cr2 0x7f7fff28a1f0 ilevel 0 rsp 0xffffc3891bdf35b0
> [ 107.2689905] curlwp 0xffffb724ccc90640 pid 6429.1 lowest kstack 0xffffc3891bdf02c0
> Stopped in pid 6429.1 (ls) at   netbsd:breakpoint+0x5:  leave