BSD 4.4 Lite Kernel Sources

1 files changed, 302 insertions, 0 deletions

diff --git a/sys/fs/procfs/procfs_mem.c b/sys/fs/procfs/procfs_mem.c
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+++ b/sys/fs/procfs/procfs_mem.c
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+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993 Sean Eric Fagan
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry and Sean Eric Fagan.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)procfs_mem.c	8.4 (Berkeley) 1/21/94
+ *
+ * From:
+ *	$Id: procfs_mem.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+/*
+ * This is a lightly hacked and merged version
+ * of sef's pread/pwrite functions
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>
+#include <vm/vm_kern.h>
+#include <vm/vm_page.h>
+
+static int
+procfs_rwmem(p, uio)
+	struct proc *p;
+	struct uio *uio;
+{
+	int error;
+	int writing;
+
+	writing = uio->uio_rw == UIO_WRITE;
+
+	/*
+	 * Only map in one page at a time.  We don't have to, but it
+	 * makes things easier.  This way is trivial - right?
+	 */
+	do {
+		vm_map_t map, tmap;
+		vm_object_t object;
+		vm_offset_t kva;
+		vm_offset_t uva;
+		int page_offset;		/* offset into page */
+		vm_offset_t pageno;		/* page number */
+		vm_map_entry_t out_entry;
+		vm_prot_t out_prot;
+		vm_page_t m;
+		boolean_t wired, single_use;
+		vm_offset_t off;
+		u_int len;
+		int fix_prot;
+
+		uva = (vm_offset_t) uio->uio_offset;
+		if (uva > VM_MAXUSER_ADDRESS) {
+			error = 0;
+			break;
+		}
+
+		/*
+		 * Get the page number of this segment.
+		 */
+		pageno = trunc_page(uva);
+		page_offset = uva - pageno;
+
+		/*
+		 * How many bytes to copy
+		 */
+		len = min(PAGE_SIZE - page_offset, uio->uio_resid);
+
+		/*
+		 * The map we want...
+		 */
+		map = &p->p_vmspace->vm_map;
+  
+		/*
+		 * Check the permissions for the area we're interested
+		 * in.
+		 */
+		fix_prot = 0;
+		if (writing)
+			fix_prot = !vm_map_check_protection(map, pageno,
+					pageno + PAGE_SIZE, VM_PROT_WRITE);
+
+		if (fix_prot) {
+			/*
+			 * If the page is not writable, we make it so.
+			 * XXX It is possible that a page may *not* be
+			 * read/executable, if a process changes that!
+			 * We will assume, for now, that a page is either
+			 * VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE.
+			 */
+			error = vm_map_protect(map, pageno,
+					pageno + PAGE_SIZE, VM_PROT_ALL, 0);
+			if (error)
+				break;
+		}
+
+		/*
+		 * Now we need to get the page.  out_entry, out_prot, wired,
+		 * and single_use aren't used.  One would think the vm code
+		 * would be a *bit* nicer...  We use tmap because
+		 * vm_map_lookup() can change the map argument.
+		 */
+		tmap = map;
+		error = vm_map_lookup(&tmap, pageno,
+				      writing ? VM_PROT_WRITE : VM_PROT_READ,
+				      &out_entry, &object, &off, &out_prot,
+				      &wired, &single_use);
+		/*
+		 * We're done with tmap now.
+		 */
+		if (!error)
+			vm_map_lookup_done(tmap, out_entry);
+  
+		/*
+		 * Fault the page in...
+		 */
+		if (!error && writing && object->shadow) {
+			m = vm_page_lookup(object, off);
+			if (m == 0 || (m->flags & PG_COPYONWRITE))
+				error = vm_fault(map, pageno,
+							VM_PROT_WRITE, FALSE);
+		}
+
+		/* Find space in kernel_map for the page we're interested in */
+		if (!error)
+			error = vm_map_find(kernel_map, object, off, &kva,
+					PAGE_SIZE, 1);
+
+		if (!error) {
+			/*
+			 * Neither vm_map_lookup() nor vm_map_find() appear
+			 * to add a reference count to the object, so we do
+			 * that here and now.
+			 */
+			vm_object_reference(object);
+
+			/*
+			 * Mark the page we just found as pageable.
+			 */
+			error = vm_map_pageable(kernel_map, kva,
+				kva + PAGE_SIZE, 0);
+
+			/*
+			 * Now do the i/o move.
+			 */
+			if (!error)
+				error = uiomove(kva + page_offset, len, uio);
+
+			vm_map_remove(kernel_map, kva, kva + PAGE_SIZE);
+		}
+		if (fix_prot)
+			vm_map_protect(map, pageno, pageno + PAGE_SIZE,
+					VM_PROT_READ|VM_PROT_EXECUTE, 0);
+	} while (error == 0 && uio->uio_resid > 0);
+
+	return (error);
+}
+
+/*
+ * Copy data in and out of the target process.
+ * We do this by mapping the process's page into
+ * the kernel and then doing a uiomove direct
+ * from the kernel address space.
+ */
+int
+procfs_domem(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	int error;
+
+	if (uio->uio_resid == 0)
+		return (0);
+
+	error = procfs_rwmem(p, uio);
+
+	return (error);
+}
+
+/*
+ * Given process (p), find the vnode from which
+ * it's text segment is being executed.
+ *
+ * It would be nice to grab this information from
+ * the VM system, however, there is no sure-fire
+ * way of doing that.  Instead, fork(), exec() and
+ * wait() all maintain the p_textvp field in the
+ * process proc structure which contains a held
+ * reference to the exec'ed vnode.
+ */
+struct vnode *
+procfs_findtextvp(p)
+	struct proc *p;
+{
+	return (p->p_textvp);
+}
+
+
+#ifdef probably_never
+/*
+ * Given process (p), find the vnode from which
+ * it's text segment is being mapped.
+ *
+ * (This is here, rather than in procfs_subr in order
+ * to keep all the VM related code in one place.)
+ */
+struct vnode *
+procfs_findtextvp(p)
+	struct proc *p;
+{
+	int error;
+	vm_object_t object;
+	vm_offset_t pageno;		/* page number */
+
+	/* find a vnode pager for the user address space */
+
+	for (pageno = VM_MIN_ADDRESS;
+			pageno < VM_MAXUSER_ADDRESS;
+			pageno += PAGE_SIZE) {
+		vm_map_t map;
+		vm_map_entry_t out_entry;
+		vm_prot_t out_prot;
+		boolean_t wired, single_use;
+		vm_offset_t off;
+
+		map = &p->p_vmspace->vm_map;
+		error = vm_map_lookup(&map, pageno,
+			      VM_PROT_READ,
+			      &out_entry, &object, &off, &out_prot,
+			      &wired, &single_use);
+
+		if (!error) {
+			vm_pager_t pager;
+
+			printf("procfs: found vm object\n");
+			vm_map_lookup_done(map, out_entry);
+			printf("procfs: vm object = %x\n", object);
+
+			/*
+			 * At this point, assuming no errors, object
+			 * is the VM object mapping UVA (pageno).
+			 * Ensure it has a vnode pager, then grab
+			 * the vnode from that pager's handle.
+			 */
+
+			pager = object->pager;
+			printf("procfs: pager = %x\n", pager);
+			if (pager)
+				printf("procfs: found pager, type = %d\n", pager->pg_type);
+			if (pager && pager->pg_type == PG_VNODE) {
+				struct vnode *vp;
+
+				vp = (struct vnode *) pager->pg_handle;
+				printf("procfs: vp = 0x%x\n", vp);
+				return (vp);
+			}
+		}
+	}
+
+	printf("procfs: text object not found\n");
+	return (0);
+}
+#endif /* probably_never */