1 /* $OpenBSD: exec_subr.c,v 1.4 1997/02/24 14:19:56 niklas Exp $ */ 2 /* $NetBSD: exec_subr.c,v 1.9 1994/12/04 03:10:42 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1993, 1994 Christopher G. Demetriou 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Christopher G. Demetriou. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/proc.h> 37 #include <sys/malloc.h> 38 #include <sys/vnode.h> 39 #include <sys/filedesc.h> 40 #include <sys/exec.h> 41 #include <sys/mman.h> 42 #include <sys/resourcevar.h> 43 44 #include <vm/vm.h> 45 46 #ifdef DEBUG 47 /* 48 * new_vmcmd(): 49 * create a new vmcmd structure and fill in its fields based 50 * on function call arguments. make sure objects ref'd by 51 * the vmcmd are 'held'. 52 * 53 * If not debugging, this is a macro, so it's expanded inline. 54 */ 55 56 void 57 new_vmcmd(evsp, proc, len, addr, vp, offset, prot) 58 struct exec_vmcmd_set *evsp; 59 int (*proc) __P((struct proc * p, struct exec_vmcmd *)); 60 u_long len; 61 u_long addr; 62 struct vnode *vp; 63 u_long offset; 64 u_int prot; 65 { 66 struct exec_vmcmd *vcp; 67 68 if (evsp->evs_used >= evsp->evs_cnt) 69 vmcmdset_extend(evsp); 70 vcp = &evsp->evs_cmds[evsp->evs_used++]; 71 vcp->ev_proc = proc; 72 vcp->ev_len = len; 73 vcp->ev_addr = addr; 74 if ((vcp->ev_vp = vp) != NULL) 75 vref(vp); 76 vcp->ev_offset = offset; 77 vcp->ev_prot = prot; 78 } 79 #endif /* DEBUG */ 80 81 void 82 vmcmdset_extend(evsp) 83 struct exec_vmcmd_set *evsp; 84 { 85 struct exec_vmcmd *nvcp; 86 u_int ocnt; 87 88 #ifdef DIAGNOSTIC 89 if (evsp->evs_used < evsp->evs_cnt) 90 panic("vmcmdset_extend: not necessary"); 91 #endif 92 93 /* figure out number of entries in new set */ 94 ocnt = evsp->evs_cnt; 95 evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE; 96 97 /* allocate it */ 98 MALLOC(nvcp, struct exec_vmcmd *, 99 (evsp->evs_cnt * sizeof(struct exec_vmcmd)), M_EXEC, M_WAITOK); 100 101 /* free the old struct, if there was one, and record the new one */ 102 if (ocnt) { 103 bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd))); 104 FREE(evsp->evs_cmds, M_EXEC); 105 } 106 evsp->evs_cmds = nvcp; 107 } 108 109 void 110 kill_vmcmds(evsp) 111 struct exec_vmcmd_set *evsp; 112 { 113 struct exec_vmcmd *vcp; 114 int i; 115 116 if (evsp->evs_cnt == 0) 117 return; 118 119 for (i = 0; i < evsp->evs_used; i++) { 120 vcp = &evsp->evs_cmds[i]; 121 if (vcp->ev_vp != NULLVP) 122 vrele(vcp->ev_vp); 123 } 124 evsp->evs_used = evsp->evs_cnt = 0; 125 FREE(evsp->evs_cmds, M_EXEC); 126 } 127 128 /* 129 * vmcmd_map_pagedvn(): 130 * handle vmcmd which specifies that a vnode should be mmap'd. 131 * appropriate for handling demand-paged text and data segments. 132 */ 133 134 int 135 vmcmd_map_pagedvn(p, cmd) 136 struct proc *p; 137 struct exec_vmcmd *cmd; 138 { 139 /* 140 * note that if you're going to map part of an process as being 141 * paged from a vnode, that vnode had damn well better be marked as 142 * VTEXT. that's handled in the routine which sets up the vmcmd to 143 * call this routine. 144 */ 145 return vm_mmap(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 146 cmd->ev_prot, VM_PROT_ALL, MAP_FIXED|MAP_COPY, (caddr_t)cmd->ev_vp, 147 cmd->ev_offset); 148 } 149 150 /* 151 * vmcmd_map_readvn(): 152 * handle vmcmd which specifies that a vnode should be read from. 153 * appropriate for non-demand-paged text/data segments, i.e. impure 154 * objects (a la OMAGIC and NMAGIC). 155 */ 156 int 157 vmcmd_map_readvn(p, cmd) 158 struct proc *p; 159 struct exec_vmcmd *cmd; 160 { 161 int error; 162 163 error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr, 164 cmd->ev_len, 0); 165 if (error) 166 return error; 167 168 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 169 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT|IO_NODELOCKED, 170 p->p_ucred, (int *)0, p); 171 if (error) 172 return error; 173 174 return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), 175 round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE); 176 } 177 178 /* 179 * vmcmd_map_zero(): 180 * handle vmcmd which specifies a zero-filled address space region. The 181 * address range must be first allocated, then protected appropriately. 182 */ 183 184 int 185 vmcmd_map_zero(p, cmd) 186 struct proc *p; 187 struct exec_vmcmd *cmd; 188 { 189 int error; 190 191 error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr, 192 cmd->ev_len, 0); 193 if (error) 194 return error; 195 196 return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), 197 round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE); 198 } 199 200 /* 201 * exec_setup_stack(): Set up the stack segment for an a.out 202 * executable. 203 * 204 * Note that the ep_ssize parameter must be set to be the current stack 205 * limit; this is adjusted in the body of execve() to yield the 206 * appropriate stack segment usage once the argument length is 207 * calculated. 208 * 209 * This function returns an int for uniformity with other (future) formats' 210 * stack setup functions. They might have errors to return. 211 */ 212 213 int 214 exec_setup_stack(p, epp) 215 struct proc *p; 216 struct exec_package *epp; 217 { 218 219 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 220 epp->ep_minsaddr = USRSTACK; 221 epp->ep_ssize = round_page(p->p_rlimit[RLIMIT_STACK].rlim_cur); 222 223 /* 224 * set up commands for stack. note that this takes *two*, one to 225 * map the part of the stack which we can access, and one to map 226 * the part which we can't. 227 * 228 * arguably, it could be made into one, but that would require the 229 * addition of another mapping proc, which is unnecessary 230 * 231 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 232 * <stack> ep_minsaddr 233 */ 234 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 235 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 236 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 237 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 238 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 239 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 240 241 return 0; 242 } 243