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Diffstat (limited to 'sys/fs/procfs/procfs_mem.c')
-rw-r--r-- | sys/fs/procfs/procfs_mem.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/sys/fs/procfs/procfs_mem.c b/sys/fs/procfs/procfs_mem.c new file mode 100644 index 0000000..039983d --- /dev/null +++ b/sys/fs/procfs/procfs_mem.c @@ -0,0 +1,302 @@ +/* + * 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 */ |