Module Name: src
Committed By: ozaki-r
Date: Fri Mar 16 04:48:19 UTC 2018
Modified Files:
src/sys/arch/x86/x86: db_memrw.c
Log Message:
x86: avoid accessing invalid addresses in ddb like arm32
This avoids that a command stops in the middle of an execution if
a fault occurs due to an access to an invalid address.
To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/sys/arch/x86/x86/db_memrw.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/x86/db_memrw.c
diff -u src/sys/arch/x86/x86/db_memrw.c:1.5 src/sys/arch/x86/x86/db_memrw.c:1.6
--- src/sys/arch/x86/x86/db_memrw.c:1.5 Thu Mar 15 03:45:05 2018
+++ src/sys/arch/x86/x86/db_memrw.c Fri Mar 16 04:48:19 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: db_memrw.c,v 1.5 2018/03/15 03:45:05 ozaki-r Exp $ */
+/* $NetBSD: db_memrw.c,v 1.6 2018/03/16 04:48:19 ozaki-r Exp $ */
/*-
* Copyright (c) 1996, 2000 The NetBSD Foundation, Inc.
@@ -53,7 +53,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_memrw.c,v 1.5 2018/03/15 03:45:05 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_memrw.c,v 1.6 2018/03/16 04:48:19 ozaki-r Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@@ -64,6 +64,22 @@ __KERNEL_RCSID(0, "$NetBSD: db_memrw.c,v
#include <ddb/db_access.h>
#include <ddb/db_output.h>
+static int
+db_validate_address(vaddr_t addr)
+{
+ struct proc *p = curproc;
+ struct pmap *pmap;
+
+ if (!p || !p->p_vmspace || !p->p_vmspace->vm_map.pmap ||
+ addr >= VM_MIN_KERNEL_ADDRESS
+ )
+ pmap = pmap_kernel();
+ else
+ pmap = p->p_vmspace->vm_map.pmap;
+
+ return (pmap_extract(pmap, addr, NULL) == false);
+}
+
/*
* Read bytes from kernel address space for debugger.
*/
@@ -74,6 +90,11 @@ db_read_bytes(vaddr_t addr, size_t size,
src = (char *)addr;
+ if (db_validate_address((vaddr_t)src)) {
+ db_printf("address %p is invalid\n", src);
+ return;
+ }
+
if (size == 8) {
*((long *)data) = *((long *)src);
return;
@@ -89,8 +110,14 @@ db_read_bytes(vaddr_t addr, size_t size,
return;
}
- while (size-- > 0)
+ while (size-- > 0) {
+ if (db_validate_address((vaddr_t)src)) {
+ db_printf("address %p is invalid\n", src);
+ return;
+ }
+
*data++ = *src++;
+ }
}
/*
