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Only allow access to physical RAM.

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This commit is contained in:
scottr 1998-11-10 07:29:59 +00:00
parent 5b5d141230
commit 610fe40379
1 changed files with 21 additions and 7 deletions
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28
sys/arch/mac68k/mac68k/mem.c
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@ -1,4 +1,4 @@
/* $NetBSD: mem.c,v 1.15 1998/05/07 21:01:42 kleink Exp $ */
/* $NetBSD: mem.c,v 1.16 1998/11/10 07:29:59 scottr Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@ -61,6 +61,7 @@
#include <uvm/uvm_extern.h>
#endif
extern u_long maxaddr;
static caddr_t devzeropage;
#define mmread mmrw
@ -127,6 +128,15 @@ mmrw(dev, uio, flags)
/* minor device 0 is physical memory */
case 0:
v = uio->uio_offset;
/*
* Only allow reads in physical RAM.
*/
if (v >= maxaddr || v < 0) {
error = EFAULT;
goto unlock;
}
pmap_enter(pmap_kernel(), (vm_offset_t)vmmap,
trunc_page(v), uio->uio_rw == UIO_READ ?
VM_PROT_READ : VM_PROT_WRITE, TRUE);
@ -165,6 +175,10 @@ mmrw(dev, uio, flags)
c = iov->iov_len;
break;
}
/*
* On the first call, allocate and zero a page
* of memory for use with /dev/zero.
*/
if (devzeropage == NULL) {
devzeropage = (caddr_t)
malloc(CLBYTES, M_TEMP, M_WAITOK);
@ -185,6 +199,7 @@ mmrw(dev, uio, flags)
uio->uio_resid -= c;
}
if (minor(dev) == 0) {
unlock:
if (physlock > 1)
wakeup((caddr_t)&physlock);
physlock = 0;
@ -207,13 +222,12 @@ mmmmap(dev, off, prot)
*/
if (minor(dev) != 0)
return (-1);
/*
* Allow access only in RAM.
*
* XXX could be extended to allow access to IO space but must
* be very careful.
if ((unsigned)off < lowram || (unsigned)off >= 0xFFFFFFFC)
return (-1);
* Only allow access to physical RAM.
*/
if ((unsigned)off >= maxaddr)
return (-1);
return (m68k_btop(off));
}