1 /* $OpenBSD: exec_subr.c,v 1.6 1999/02/26 05:14:27 art 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 #if defined(UVM) 47 #include <uvm/uvm.h> 48 #endif 49 50 #ifdef DEBUG 51 /* 52 * new_vmcmd(): 53 * create a new vmcmd structure and fill in its fields based 54 * on function call arguments. make sure objects ref'd by 55 * the vmcmd are 'held'. 56 * 57 * If not debugging, this is a macro, so it's expanded inline. 58 */ 59 60 void 61 new_vmcmd(evsp, proc, len, addr, vp, offset, prot) 62 struct exec_vmcmd_set *evsp; 63 int (*proc) __P((struct proc * p, struct exec_vmcmd *)); 64 u_long len; 65 u_long addr; 66 struct vnode *vp; 67 u_long offset; 68 u_int prot; 69 { 70 struct exec_vmcmd *vcp; 71 72 if (evsp->evs_used >= evsp->evs_cnt) 73 vmcmdset_extend(evsp); 74 vcp = &evsp->evs_cmds[evsp->evs_used++]; 75 vcp->ev_proc = proc; 76 vcp->ev_len = len; 77 vcp->ev_addr = addr; 78 if ((vcp->ev_vp = vp) != NULL) 79 vref(vp); 80 vcp->ev_offset = offset; 81 vcp->ev_prot = prot; 82 } 83 #endif /* DEBUG */ 84 85 void 86 vmcmdset_extend(evsp) 87 struct exec_vmcmd_set *evsp; 88 { 89 struct exec_vmcmd *nvcp; 90 u_int ocnt; 91 92 #ifdef DIAGNOSTIC 93 if (evsp->evs_used < evsp->evs_cnt) 94 panic("vmcmdset_extend: not necessary"); 95 #endif 96 97 /* figure out number of entries in new set */ 98 ocnt = evsp->evs_cnt; 99 evsp->evs_cnt += ocnt ? ocnt : EXEC_DEFAULT_VMCMD_SETSIZE; 100 101 /* allocate it */ 102 MALLOC(nvcp, struct exec_vmcmd *, 103 (evsp->evs_cnt * sizeof(struct exec_vmcmd)), M_EXEC, M_WAITOK); 104 105 /* free the old struct, if there was one, and record the new one */ 106 if (ocnt) { 107 bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd))); 108 FREE(evsp->evs_cmds, M_EXEC); 109 } 110 evsp->evs_cmds = nvcp; 111 } 112 113 void 114 kill_vmcmds(evsp) 115 struct exec_vmcmd_set *evsp; 116 { 117 struct exec_vmcmd *vcp; 118 int i; 119 120 if (evsp->evs_cnt == 0) 121 return; 122 123 for (i = 0; i < evsp->evs_used; i++) { 124 vcp = &evsp->evs_cmds[i]; 125 if (vcp->ev_vp != NULLVP) 126 vrele(vcp->ev_vp); 127 } 128 evsp->evs_used = evsp->evs_cnt = 0; 129 FREE(evsp->evs_cmds, M_EXEC); 130 } 131 132 /* 133 * vmcmd_map_pagedvn(): 134 * handle vmcmd which specifies that a vnode should be mmap'd. 135 * appropriate for handling demand-paged text and data segments. 136 */ 137 138 int 139 vmcmd_map_pagedvn(p, cmd) 140 struct proc *p; 141 struct exec_vmcmd *cmd; 142 { 143 /* 144 * note that if you're going to map part of an process as being 145 * paged from a vnode, that vnode had damn well better be marked as 146 * VTEXT. that's handled in the routine which sets up the vmcmd to 147 * call this routine. 148 */ 149 #if defined(UVM) 150 struct uvm_object *uobj; 151 int retval; 152 153 /* 154 * map the vnode in using uvm_map. 155 */ 156 157 /* checks imported from uvm_mmap, needed? */ 158 if (cmd->ev_len == 0) 159 return(0); 160 if (cmd->ev_offset & PAGE_MASK) 161 return(EINVAL); 162 if (cmd->ev_addr & PAGE_MASK) 163 return(EINVAL); 164 165 /* 166 * first, attach to the object 167 */ 168 169 uobj = uvn_attach((void *) cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 170 if (uobj == NULL) 171 return(ENOMEM); 172 173 /* 174 * do the map 175 */ 176 177 retval = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 178 uobj, cmd->ev_offset, 179 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 180 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); 181 182 /* 183 * check for error 184 */ 185 186 if (retval == KERN_SUCCESS) 187 return(0); 188 189 /* 190 * error: detach from object 191 */ 192 193 uobj->pgops->pgo_detach(uobj); 194 return(EINVAL); 195 #else 196 return vm_mmap(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 197 cmd->ev_prot, VM_PROT_ALL, MAP_FIXED|MAP_COPY, (caddr_t)cmd->ev_vp, 198 cmd->ev_offset); 199 #endif 200 } 201 202 /* 203 * vmcmd_map_readvn(): 204 * handle vmcmd which specifies that a vnode should be read from. 205 * appropriate for non-demand-paged text/data segments, i.e. impure 206 * objects (a la OMAGIC and NMAGIC). 207 */ 208 int 209 vmcmd_map_readvn(p, cmd) 210 struct proc *p; 211 struct exec_vmcmd *cmd; 212 { 213 int error; 214 215 #if defined(UVM) 216 if (cmd->ev_len == 0) 217 return(KERN_SUCCESS); /* XXXCDC: should it happen? */ 218 219 cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */ 220 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 221 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 222 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY, 223 UVM_ADV_NORMAL, 224 UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 225 226 #else 227 error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr, 228 cmd->ev_len, 0); 229 #endif 230 if (error) 231 return error; 232 233 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 234 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT|IO_NODELOCKED, 235 p->p_ucred, NULL, p); 236 if (error) 237 return error; 238 239 #if defined(UVM) 240 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 241 /* 242 * we had to map in the area at PROT_ALL so that vn_rdwr() 243 * could write to it. however, the caller seems to want 244 * it mapped read-only, so now we are going to have to call 245 * uvm_map_protect() to fix up the protection. ICK. 246 */ 247 return(uvm_map_protect(&p->p_vmspace->vm_map, 248 trunc_page(cmd->ev_addr), 249 round_page(cmd->ev_addr + cmd->ev_len), 250 cmd->ev_prot, FALSE)); 251 } else { 252 return(KERN_SUCCESS); 253 } 254 #else 255 return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), 256 round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE); 257 #endif 258 } 259 260 /* 261 * vmcmd_map_zero(): 262 * handle vmcmd which specifies a zero-filled address space region. The 263 * address range must be first allocated, then protected appropriately. 264 */ 265 266 int 267 vmcmd_map_zero(p, cmd) 268 struct proc *p; 269 struct exec_vmcmd *cmd; 270 { 271 int error; 272 273 #if defined(UVM) 274 if (cmd->ev_len == 0) 275 return(KERN_SUCCESS); /* XXXCDC: should it happen? */ 276 277 cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */ 278 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 279 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 280 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 281 UVM_ADV_NORMAL, 282 UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); 283 284 #else 285 error = vm_allocate(&p->p_vmspace->vm_map, &cmd->ev_addr, 286 cmd->ev_len, 0); 287 #endif 288 if (error) 289 return error; 290 291 #if !defined(UVM) 292 return vm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), 293 round_page(cmd->ev_addr + cmd->ev_len), cmd->ev_prot, FALSE); 294 #else 295 return(KERN_SUCCESS); 296 #endif 297 } 298 299 /* 300 * exec_setup_stack(): Set up the stack segment for an a.out 301 * executable. 302 * 303 * Note that the ep_ssize parameter must be set to be the current stack 304 * limit; this is adjusted in the body of execve() to yield the 305 * appropriate stack segment usage once the argument length is 306 * calculated. 307 * 308 * This function returns an int for uniformity with other (future) formats' 309 * stack setup functions. They might have errors to return. 310 */ 311 312 int 313 exec_setup_stack(p, epp) 314 struct proc *p; 315 struct exec_package *epp; 316 { 317 318 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 319 epp->ep_minsaddr = USRSTACK; 320 epp->ep_ssize = round_page(p->p_rlimit[RLIMIT_STACK].rlim_cur); 321 322 /* 323 * set up commands for stack. note that this takes *two*, one to 324 * map the part of the stack which we can access, and one to map 325 * the part which we can't. 326 * 327 * arguably, it could be made into one, but that would require the 328 * addition of another mapping proc, which is unnecessary 329 * 330 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 331 * <stack> ep_minsaddr 332 */ 333 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 334 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 335 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 336 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 337 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 338 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 339 340 return 0; 341 } 342