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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.
This commit is contained in:
ozaki-r 2018-03-16 04:48:19 +00:00
parent 5e1f20377c
commit c1510da660
1 changed files with 30 additions and 3 deletions
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33
sys/arch/x86/x86/db_memrw.c
View File

@ -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 1.5 2018/03/15 03:45:05 ozaki-r Exp $")
#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, char *data)
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, char *data)
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++;
}
}
/*