Re: kern/53311: boot netbsd -d panics

[christos%zoulas.com@localhost (Christos Zoulas)]

On May 27, 12:10pm, uwe%stderr.spb.ru@localhost (Valery Ushakov) wrote:
-- Subject: Re: kern/53311: boot netbsd -d panics

| The following reply was made to PR kern/53311; it has been noted by GNATS.
| 
| From: Valery Ushakov <uwe%stderr.spb.ru@localhost>
| To: gnats-bugs%NetBSD.org@localhost
| Cc: Andreas Gustafsson <gson%gson.org@localhost>
| Subject: Re: kern/53311: boot netbsd -d panics
| Date: Sun, 27 May 2018 15:07:16 +0300
| 
|  On Sun, May 27, 2018 at 10:40:00 +0000, Andreas Gustafsson wrote:
|  
|  >  By bisection, I found that the problem started with the following
|  >  commit:
|  >  
|  >    2018.03.16.04.48.19 ozaki-r src/sys/arch/x86/x86/db_memrw.c 1.6
|  >  
|  >  I suggest reverting it (and its pullup).
|  
|  This is from March 2018.  The boot -d + bt triple fault that I
|  reported above is on i386 with 8.99.12 from late January 2018.  So
|  that's probably not the whole story.

Indeed, but perhaps a simple way to avoid it right now is:


Index: db_memrw.c
===================================================================
RCS file: /cvsroot/src/sys/arch/x86/x86/db_memrw.c,v
retrieving revision 1.6
diff -u -p -u -r1.6 db_memrw.c
--- db_memrw.c  16 Mar 2018 04:48:19 -0000      1.6
+++ db_memrw.c  27 May 2018 14:20:00 -0000
@@ -70,6 +70,9 @@ db_validate_address(vaddr_t addr)
        struct proc *p = curproc;
        struct pmap *pmap;
 
+       if (cold)
+               return true;
+
        if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap ||
            addr >= VM_MIN_KERNEL_ADDRESS
           )