1 /* $NetBSD: procfs_mem.c,v 1.29 2001/11/10 13:33:43 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1993 Jan-Simon Pendry 5 * Copyright (c) 1993 Sean Eric Fagan 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Jan-Simon Pendry and Sean Eric Fagan. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)procfs_mem.c 8.5 (Berkeley) 6/15/94 41 */ 42 43 /* 44 * This is a lightly hacked and merged version 45 * of sef's pread/pwrite functions 46 */ 47 48 #include <sys/cdefs.h> 49 __KERNEL_RCSID(0, "$NetBSD: procfs_mem.c,v 1.29 2001/11/10 13:33:43 lukem Exp $"); 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/time.h> 54 #include <sys/kernel.h> 55 #include <sys/proc.h> 56 #include <sys/vnode.h> 57 58 #include <miscfs/procfs/procfs.h> 59 60 #include <uvm/uvm_extern.h> 61 62 #define ISSET(t, f) ((t) & (f)) 63 64 /* 65 * Copy data in and out of the target process. 66 * We do this by mapping the process's page into 67 * the kernel and then doing a uiomove direct 68 * from the kernel address space. 69 */ 70 int 71 procfs_domem(curp, p, pfs, uio) 72 struct proc *curp; /* tracer */ 73 struct proc *p; /* traced */ 74 struct pfsnode *pfs; 75 struct uio *uio; 76 { 77 int error; 78 79 size_t len; 80 #ifdef PMAP_NEED_PROCWR 81 vaddr_t addr; 82 #endif 83 84 len = uio->uio_resid; 85 86 if (len == 0) 87 return (0); 88 89 #ifdef PMAP_NEED_PROCWR 90 addr = uio->uio_offset; 91 #endif 92 93 if ((error = procfs_checkioperm(curp, p)) != 0) 94 return (error); 95 96 /* XXXCDC: how should locking work here? */ 97 if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1)) 98 return(EFAULT); 99 p->p_vmspace->vm_refcnt++; /* XXX */ 100 error = uvm_io(&p->p_vmspace->vm_map, uio); 101 uvmspace_free(p->p_vmspace); 102 103 #ifdef PMAP_NEED_PROCWR 104 if (uio->uio_rw == UIO_WRITE) 105 pmap_procwr(p, addr, len); 106 #endif 107 return (error); 108 } 109 110 /* 111 * Ensure that a process has permission to perform I/O on another. 112 * Arguments: 113 * p The process wishing to do the I/O (the tracer). 114 * t The process who's memory/registers will be read/written. 115 */ 116 int 117 procfs_checkioperm(p, t) 118 struct proc *p, *t; 119 { 120 int error; 121 122 /* 123 * You cannot attach to a processes mem/regs if: 124 * 125 * (1) it's not owned by you, or is set-id on exec 126 * (unless you're root), or... 127 */ 128 if ((t->p_cred->p_ruid != p->p_cred->p_ruid || 129 ISSET(t->p_flag, P_SUGID)) && 130 (error = suser(p->p_ucred, &p->p_acflag)) != 0) 131 return (error); 132 133 /* 134 * (2) ...it's init, which controls the security level 135 * of the entire system, and the system was not 136 * compiled with permanetly insecure mode turned on. 137 */ 138 if (t == initproc && securelevel > -1) 139 return (EPERM); 140 141 /* 142 * (3) the tracer is chrooted, and its root directory is 143 * not at or above the root directory of the tracee 144 */ 145 146 if (!proc_isunder(t, p)) 147 return EPERM; 148 149 return (0); 150 } 151