Hi,
From: Mike Larkin <[email protected]>
Subject: Re: amd64: update PTDpaddr with new PA of PML4 for libkvm
Date: Wed, 13 Feb 2019 01:01:28 -0800
> On Wed, Feb 13, 2019 at 05:40:45PM +0900, Naoki Fukaumi wrote:
>> Hi Mike Larkin,
>>
>> since pmap_kernel is randomized, savecore(libkvm) cannot save core
>> dump from dump device. (savecore: magic number mismatch)
>>
>> updating PTDpaddr fixes this issue.
>>
>> by the way, is there any problem to use proc0.p_addr->u_pcb.pcb_cr3
>> instead of PTDpaddr in cpu_dump()?
>>
>
> Thanks for noticing this!
>
> Does using the proc0.p_addr->u_pcb.pcb_cr3 expansion also work?
> If so, we may be able to remove PTPpaddr entirely, if we remove the
> other usage in cpu_dump also.
here is "remove PTDpaddr" patch.
it works, but now I'm not sure which is better... using extra
"PTDpaddr" might be simpler... at least, I don't need to worry about
"is this chain really fine?" ;)
----
for "using PTDpaddr" case, I think it might be better to
- set PTDpaddr later in locore0.S (around setting pcb_cr3)
- use a term "PML4" than "PTD"/"PDP" in comments
to make thing more clear (for me).
Regards,
--
FUKAUMI Naoki
Index: sys/arch/amd64/amd64/locore.S
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/locore.S,v
retrieving revision 1.113
diff -u -p -u -p -r1.113 locore.S
--- sys/arch/amd64/amd64/locore.S 24 Jan 2019 00:00:50 -0000 1.113
+++ sys/arch/amd64/amd64/locore.S 15 Feb 2019 07:07:09 -0000
@@ -172,7 +172,7 @@ _C_LABEL(lapic_isr):
.globl _C_LABEL(ssym),_C_LABEL(esym),_C_LABEL(boothowto)
.globl _C_LABEL(bootdev)
.globl _C_LABEL(bootinfo), _C_LABEL(bootinfo_size), _C_LABEL(atdevbase)
- .globl _C_LABEL(proc0paddr),_C_LABEL(PTDpaddr)
+ .globl _C_LABEL(proc0paddr)
.globl _C_LABEL(biosbasemem)
.globl _C_LABEL(bootapiver)
.globl _C_LABEL(pg_nx)
@@ -198,7 +198,6 @@ _C_LABEL(atdevbase): .quad 0 # location
_C_LABEL(bootapiver): .long 0 # /boot API version
_C_LABEL(bootdev): .long 0 # device we booted from
_C_LABEL(proc0paddr): .quad 0
-_C_LABEL(PTDpaddr): .quad 0 # paddr of PTD, for libkvm
#ifndef REALBASEMEM
_C_LABEL(biosbasemem): .long 0 # base memory reported by BIOS
#else
Index: sys/arch/amd64/amd64/locore0.S
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/locore0.S,v
retrieving revision 1.16
diff -u -p -u -p -r1.16 locore0.S
--- sys/arch/amd64/amd64/locore0.S 24 Jan 2019 00:57:14 -0000 1.16
+++ sys/arch/amd64/amd64/locore0.S 15 Feb 2019 07:07:09 -0000
@@ -548,11 +548,6 @@ store_pte:
movl %ebp, 4(%ebx)
popl %ebp
- /* Save phys. addr of PTD, for libkvm. */
- movl $RELOC(PTDpaddr),%ebp
- movl %esi,(%ebp)
- movl $0,4(%ebp)
-
/*
* Startup checklist:
* 1. Enable PAE (and SSE while here).
Index: sys/arch/amd64/amd64/machdep.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/machdep.c,v
retrieving revision 1.254
diff -u -p -u -p -r1.254 machdep.c
--- sys/arch/amd64/amd64/machdep.c 21 Jan 2019 06:18:37 -0000 1.254
+++ sys/arch/amd64/amd64/machdep.c 15 Feb 2019 07:07:09 -0000
@@ -925,7 +925,7 @@ cpu_dump(void)
/*
* Add the machine-dependent header info.
*/
- cpuhdrp->ptdpaddr = PTDpaddr;
+ cpuhdrp->ptdpaddr = proc0.p_addr->u_pcb.pcb_cr3;
cpuhdrp->nmemsegs = mem_cluster_cnt;
/*
Index: sys/arch/amd64/include/pmap.h
===================================================================
RCS file: /cvs/src/sys/arch/amd64/include/pmap.h,v
retrieving revision 1.73
diff -u -p -u -p -r1.73 pmap.h
--- sys/arch/amd64/include/pmap.h 21 Jan 2019 06:18:37 -0000 1.73
+++ sys/arch/amd64/include/pmap.h 15 Feb 2019 07:07:09 -0000
@@ -344,9 +344,6 @@ struct pv_entry { /* locked by its lis
* global kernel variables
*/
-/* PTDpaddr: is the physical address of the kernel's PDP */
-extern u_long PTDpaddr;
-
extern struct pmap kernel_pmap_store; /* kernel pmap */
extern long nkptp[];
