/* * 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 * * $Id: procfs_mem.c,v 1.13 1995/12/11 04:56:31 dyson Exp $ */ /* * This is a lightly hacked and merged version * of sef's pread/pwrite functions */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int procfs_rwmem __P((struct proc *p, struct uio *uio)); 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 = 0; 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_pindex_t pindex; u_int len; int fix_prot; uva = (vm_offset_t) uio->uio_offset; if (uva >= VM_MAXUSER_ADDRESS) { if (writing || (uva >= (VM_MAXUSER_ADDRESS + UPAGES * PAGE_SIZE))) { 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, &pindex, &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->backing_object) { m = vm_page_lookup(object, pindex); if (m == 0) 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, IDX_TO_OFF(pindex), &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((caddr_t)(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); }