From ec0cd072e33631cd57cac617087eff4a10a713fa Mon Sep 17 00:00:00 2001
From: Miod Vallat <miod@cvs.openbsd.org>
Date: Mon, 19 Jun 2006 20:25:50 +0000
Subject: Real kvm routines for vax; allows ``target kvm'' to work in gdb for
 kernel crash dumps. ok kettenis@

---
 lib/libkvm/kvm_vax.c | 79 +++++++++++++++++++---------------------------------
 1 file changed, 29 insertions(+), 50 deletions(-)

(limited to 'lib/libkvm')

diff --git a/lib/libkvm/kvm_vax.c b/lib/libkvm/kvm_vax.c
index ad080b0bc76..5a5fb249aca 100644
--- a/lib/libkvm/kvm_vax.c
+++ b/lib/libkvm/kvm_vax.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm_vax.c,v 1.12 2006/03/20 15:11:48 mickey Exp $ */
+/*	$OpenBSD: kvm_vax.c,v 1.13 2006/06/19 20:25:49 miod Exp $ */
 /*	$NetBSD: kvm_vax.c,v 1.3 1996/03/18 22:34:06 thorpej Exp $ */
 
 /*-
@@ -36,15 +36,14 @@
 
 /*
  * VAX machine dependent routines for kvm.  Hopefully, the forthcoming
- * vm code will one day obsolete this module.  Furthermore, I hope it
- * gets here soon, because this basically is an error stub! (sorry)
- * This code may not work anyway.
+ * vm code will one day obsolete this module.
  */
 
 #include <sys/param.h>
 #include <sys/user.h>
 #include <sys/proc.h>
 #include <sys/stat.h>
+#include <sys/kcore.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <nlist.h>
@@ -52,57 +51,26 @@
 
 #include <uvm/uvm_extern.h>
 #include <machine/vmparam.h>
+#include <machine/kcore.h>
 #include <machine/pmap.h>
+#include <machine/pte.h>
 
 #include <limits.h>
 #include <db.h>
 
 #include "kvm_private.h"
 
-struct vmstate {
-	u_long end;
-};
-
 void
 _kvm_freevtop(kvm_t *kd)
 {
-	if (kd->vmst != NULL) {
-		free(kd->vmst);
-		kd->vmst = NULL;
-	}
 }
 
 int
 _kvm_initvtop(kvm_t *kd)
 {
-	struct nlist nlist[2];
-	struct vmstate *vm;
-	struct stat st;
-	int i, off;
-
-	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
-	if (vm == 0)
-		return (-1);
-
-	kd->vmst = vm;
-
-	if (fstat(kd->pmfd, &st) < 0)
-		return (-1);
-
-	/* Get end of kernel address */
-	nlist[0].n_name = "_end";
-	nlist[1].n_name = 0;
-	if (kvm_nlist(kd, nlist) != 0) {
-		_kvm_err(kd, kd->program, "pmap_stod: no such symbol");
-		return (-1);
-	}
-	vm->end = (u_long)nlist[0].n_value;
-
 	return (0);
 }
 
-#define VA_OFF(va) (va & (NBPG - 1))
-
 /*
  * Translate a kernel virtual address to a physical address using the
  * mapping information in kd->vm.  Returns the result in pa, and returns
@@ -112,34 +80,45 @@ _kvm_initvtop(kvm_t *kd)
 int
 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
 {
-	u_long end;
+	paddr_t ofs;
+	u_long pteaddr;
+	pt_entry_t pte;
+	cpu_kcore_hdr_t *cpu_kh;
 
-	if (va < KERNBASE) {
-		_kvm_err(kd, 0, "invalid address (%lx<%lx)", va, KERNBASE);
+	if (ISALIVE(kd)) {
+		_kvm_err(kd, 0, "vatop called in live kernel!");
 		return (0);
 	}
 
-	if (!kd->vmst) {
-		_kvm_err(kd, 0, "vatop called before initvtop");
+	if (va < (u_long)KERNBASE) {
+		_kvm_err(kd, 0, "invalid address (%lx<%lx)", va, KERNBASE);
 		return (0);
 	}
 
-	end = kd->vmst->end;
-	if (va >= end) {
-		_kvm_err(kd, 0, "invalid address (%lx>=%lx)", va, end);
+	/* read pte from Sysmap */
+	cpu_kh = kd->cpu_data;
+	pteaddr = (cpu_kh->sysmap - KERNBASE) +
+	    PG_PFNUM(va) * sizeof(pt_entry_t);
+	if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
+	    (off_t)_kvm_pa2off(kd, pteaddr)) < 0) {
+		_kvm_err(kd, 0, "invalid address (%lx)", va);
+		return (0);
+	}
+	if ((pte & PG_V) == 0) {
+		_kvm_err(kd, 0, "invalid pte %lx (address %lx)", pte, va);
 		return (0);
 	}
 
-	*pa = (va - KERNBASE);
-	return (end - va);
+	ofs = va & PAGE_MASK;
+	*pa = ((pte & PG_FRAME) << VAX_PGSHIFT) | ofs;
+	return (int)(PAGE_SIZE - ofs);
 }
 
 /*
- * Translate a physical address to an offset in the crash dump
- * XXX crashdumps not working yet anyway
+ * Translate a physical address to an offset in the crash dump.
  */
 off_t
 _kvm_pa2off(kvm_t *kd, paddr_t pa)
 {
-	return (kd->dump_off+pa);
+	return (kd->dump_off + pa);
 }
-- 
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