Add an extra flags argument to uvm_io(), to specify whether we want to fix

the protection of the memory mapping we're doing I/O on, or if we want to
leave them as they are. This should only be necessary for breakpoint
insertion in code, so we'll only use it for ptrace requests.

Initially from art@ after discussion with kettenis@ millert@ and I,
tested by many.

5 files changed, 23 insertions, 19 deletions

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index bf03966144c..7513ea171f3 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sysctl.c,v 1.131 2005/09/25 20:48:23 miod Exp $	*/
+/*	$OpenBSD: kern_sysctl.c,v 1.132 2005/11/04 21:47:57 miod Exp $	*/
 /*	$NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $	*/
 
 /*-
@@ -1468,7 +1468,7 @@ sysctl_proc_args(int *name, u_int namelen, void *oldp, size_t *oldlenp,
 	uio.uio_rw = UIO_READ;
 	uio.uio_procp = cp;
 
-	if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio)) != 0)
+	if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio, 0)) != 0)
 		goto out;
 
 	if (op == KERN_PROC_NARGV) {
@@ -1525,7 +1525,7 @@ sysctl_proc_args(int *name, u_int namelen, void *oldp, size_t *oldlenp,
 		uio.uio_segflg = UIO_SYSSPACE;
 		uio.uio_rw = UIO_READ;
 		uio.uio_procp = cp;
-		if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio)) != 0)
+		if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio, 0)) != 0)
 			goto out;
 
 		if (varg == NULL)
@@ -1547,7 +1547,7 @@ more:
 		uio.uio_segflg = UIO_SYSSPACE;
 		uio.uio_rw = UIO_READ;
 		uio.uio_procp = cp;
-		if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio)) != 0)
+		if ((error = uvm_io(&vp->p_vmspace->vm_map, &uio, 0)) != 0)
 			goto out;
 
 		for (vstrlen = 0; vstrlen < len; vstrlen++) {
diff --git a/sys/miscfs/procfs/procfs_cmdline.c b/sys/miscfs/procfs/procfs_cmdline.c
index c23a733045e..191130d5e1f 100644
--- a/sys/miscfs/procfs/procfs_cmdline.c
+++ b/sys/miscfs/procfs/procfs_cmdline.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: procfs_cmdline.c,v 1.4 2004/05/05 23:52:09 tedu Exp $	*/
+/*	$OpenBSD: procfs_cmdline.c,v 1.5 2005/11/04 21:48:07 miod Exp $	*/
 /*	$NetBSD: procfs_cmdline.c,v 1.3 1999/03/13 22:26:48 thorpej Exp $	*/
 
 /*
@@ -121,7 +121,7 @@ procfs_docmdline(curp, p, pfs, uio)
 	auio.uio_segflg = UIO_SYSSPACE;
 	auio.uio_rw = UIO_READ;
 	auio.uio_procp = NULL;
-	error = uvm_io(&p->p_vmspace->vm_map, &auio);
+	error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
 	if (error)
 		goto bad;
 
@@ -137,7 +137,7 @@ procfs_docmdline(curp, p, pfs, uio)
 	auio.uio_segflg = UIO_SYSSPACE;
 	auio.uio_rw = UIO_READ; 
 	auio.uio_procp = NULL;
-	error = uvm_io(&p->p_vmspace->vm_map, &auio);
+	error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
 	if (error)
 		goto bad;
 
@@ -160,7 +160,7 @@ procfs_docmdline(curp, p, pfs, uio)
 		auio.uio_segflg = UIO_SYSSPACE;
 		auio.uio_rw = UIO_READ;
 		auio.uio_procp = NULL;
-		error = uvm_io(&p->p_vmspace->vm_map, &auio);
+		error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
 		if (error)
 			goto bad;
 
diff --git a/sys/miscfs/procfs/procfs_mem.c b/sys/miscfs/procfs/procfs_mem.c
index 95d617083ea..56b73a22c04 100644
--- a/sys/miscfs/procfs/procfs_mem.c
+++ b/sys/miscfs/procfs/procfs_mem.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: procfs_mem.c,v 1.22 2004/05/20 09:20:41 kettenis Exp $	*/
+/*	$OpenBSD: procfs_mem.c,v 1.23 2005/11/04 21:48:07 miod Exp $	*/
 /*	$NetBSD: procfs_mem.c,v 1.8 1996/02/09 22:40:50 christos Exp $	*/
 
 /*
@@ -81,7 +81,8 @@ procfs_domem(curp, p, pfs, uio)
 		return(EFAULT);
 	addr = uio->uio_offset;
 	p->p_vmspace->vm_refcnt++;  /* XXX */
-	error = uvm_io(&p->p_vmspace->vm_map, uio);
+	error = uvm_io(&p->p_vmspace->vm_map, uio,
+	    uio->uio_rw == UIO_WRITE ? UVM_IO_FIXPROT : 0);
 	uvmspace_free(p->p_vmspace);
 
 	if (error == 0 && uio->uio_rw == UIO_WRITE)
diff --git a/sys/uvm/uvm_extern.h b/sys/uvm/uvm_extern.h
index f9f52056fee..b45f6380974 100644
--- a/sys/uvm/uvm_extern.h
+++ b/sys/uvm/uvm_extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_extern.h,v 1.58 2005/09/28 00:24:03 pedro Exp $	*/
+/*	$OpenBSD: uvm_extern.h,v 1.59 2005/11/04 21:48:07 miod Exp $	*/
 /*	$NetBSD: uvm_extern.h,v 1.57 2001/03/09 01:02:12 chs Exp $	*/
 
 /*
@@ -491,7 +491,9 @@ void			uvm_init(void);
 				/* init the uvm system */
 
 /* uvm_io.c */
-int			uvm_io(vm_map_t, struct uio *);
+int			uvm_io(vm_map_t, struct uio *, int);
+
+#define	UVM_IO_FIXPROT	0x01
 
 /* uvm_km.c */
 vaddr_t			uvm_km_alloc1(vm_map_t, vsize_t, boolean_t);
diff --git a/sys/uvm/uvm_io.c b/sys/uvm/uvm_io.c
index 25702be8d4b..f9fb928f4bb 100644
--- a/sys/uvm/uvm_io.c
+++ b/sys/uvm/uvm_io.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_io.c,v 1.15 2005/05/24 21:11:47 tedu Exp $	*/
+/*	$OpenBSD: uvm_io.c,v 1.16 2005/11/04 21:48:07 miod Exp $	*/
 /*	$NetBSD: uvm_io.c,v 1.12 2000/06/27 17:29:23 mrg Exp $	*/
 
 /*
@@ -60,14 +60,12 @@
  */
 
 int
-uvm_io(map, uio)
-	vm_map_t map;
-	struct uio *uio;
+uvm_io(vm_map_t map, struct uio *uio, int flags)
 {
 	vaddr_t baseva, endva, pageoffset, kva;
 	vsize_t chunksz, togo, sz;
 	vm_map_entry_t dead_entries;
-	int error;
+	int error, extractflags;
 
 	/*
 	 * step 0: sanity checks and set up for copy loop.  start with a
@@ -95,6 +93,10 @@ uvm_io(map, uio)
 	chunksz = min(round_page(togo + pageoffset), MAXBSIZE);
 	error = 0;
 
+	extractflags = UVM_EXTRACT_QREF | UVM_EXTRACT_CONTIG;
+	if (flags & UVM_IO_FIXPROT)
+		extractflags |= UVM_EXTRACT_FIXPROT;
+
 	/*
 	 * step 1: main loop...  while we've got data to move
 	 */
@@ -106,8 +108,7 @@ uvm_io(map, uio)
 		 */
 
 		error = uvm_map_extract(map, baseva, chunksz, kernel_map, &kva,
-			    UVM_EXTRACT_QREF | UVM_EXTRACT_CONTIG | 
-			    UVM_EXTRACT_FIXPROT);
+		    extractflags);
 		if (error) {
 
 			/* retry with a smaller chunk... */