1 /* $OpenBSD: exec_subr.c,v 1.28 2006/11/14 18:00:27 jmc 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 <uvm/uvm.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, flags) 58 struct exec_vmcmd_set *evsp; 59 int (*proc)(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 int flags; 66 { 67 struct exec_vmcmd *vcp; 68 69 if (evsp->evs_used >= evsp->evs_cnt) 70 vmcmdset_extend(evsp); 71 vcp = &evsp->evs_cmds[evsp->evs_used++]; 72 vcp->ev_proc = proc; 73 vcp->ev_len = len; 74 vcp->ev_addr = addr; 75 if ((vcp->ev_vp = vp) != NULL) 76 vref(vp); 77 vcp->ev_offset = offset; 78 vcp->ev_prot = prot; 79 vcp->ev_flags = flags; 80 } 81 #endif /* DEBUG */ 82 83 void 84 vmcmdset_extend(evsp) 85 struct exec_vmcmd_set *evsp; 86 { 87 struct exec_vmcmd *nvcp; 88 u_int ocnt; 89 90 #ifdef DIAGNOSTIC 91 if (evsp->evs_used < evsp->evs_cnt) 92 panic("vmcmdset_extend: not necessary"); 93 #endif 94 95 ocnt = evsp->evs_cnt; 96 KASSERT(ocnt > 0); 97 /* figure out number of entries in new set */ 98 evsp->evs_cnt += ocnt; 99 100 /* reallocate the command set */ 101 nvcp = malloc(evsp->evs_cnt * sizeof(struct exec_vmcmd), M_EXEC, 102 M_WAITOK); 103 bcopy(evsp->evs_cmds, nvcp, (ocnt * sizeof(struct exec_vmcmd))); 104 if (evsp->evs_cmds != evsp->evs_start) 105 free(evsp->evs_cmds, M_EXEC); 106 evsp->evs_cmds = nvcp; 107 } 108 109 void 110 kill_vmcmds(struct exec_vmcmd_set *evsp) 111 { 112 struct exec_vmcmd *vcp; 113 int i; 114 115 for (i = 0; i < evsp->evs_used; i++) { 116 vcp = &evsp->evs_cmds[i]; 117 if (vcp->ev_vp != NULLVP) 118 vrele(vcp->ev_vp); 119 } 120 121 /* 122 * Free old vmcmds and reset the array. 123 */ 124 evsp->evs_used = 0; 125 if (evsp->evs_cmds != evsp->evs_start) 126 free(evsp->evs_cmds, M_EXEC); 127 evsp->evs_cmds = evsp->evs_start; 128 evsp->evs_cnt = EXEC_DEFAULT_VMCMD_SETSIZE; 129 } 130 131 int 132 exec_process_vmcmds(struct proc *p, struct exec_package *epp) 133 { 134 struct exec_vmcmd *base_vc = NULL; 135 int error = 0; 136 int i; 137 138 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 139 struct exec_vmcmd *vcp; 140 141 vcp = &epp->ep_vmcmds.evs_cmds[i]; 142 143 if (vcp->ev_flags & VMCMD_RELATIVE) { 144 #ifdef DIAGNOSTIC 145 if (base_vc == NULL) 146 panic("exec_process_vmcmds: RELATIVE no base"); 147 #endif 148 vcp->ev_addr += base_vc->ev_addr; 149 } 150 error = (*vcp->ev_proc)(p, vcp); 151 if (vcp->ev_flags & VMCMD_BASE) { 152 base_vc = vcp; 153 } 154 } 155 156 kill_vmcmds(&epp->ep_vmcmds); 157 158 return (error); 159 } 160 161 /* 162 * vmcmd_map_pagedvn(): 163 * handle vmcmd which specifies that a vnode should be mmap'd. 164 * appropriate for handling demand-paged text and data segments. 165 */ 166 167 int 168 vmcmd_map_pagedvn(p, cmd) 169 struct proc *p; 170 struct exec_vmcmd *cmd; 171 { 172 /* 173 * note that if you're going to map part of a process as being 174 * paged from a vnode, that vnode had damn well better be marked as 175 * VTEXT. that's handled in the routine which sets up the vmcmd to 176 * call this routine. 177 */ 178 struct uvm_object *uobj; 179 int error; 180 181 /* 182 * map the vnode in using uvm_map. 183 */ 184 185 if (cmd->ev_len == 0) 186 return(0); 187 if (cmd->ev_offset & PAGE_MASK) 188 return(EINVAL); 189 if (cmd->ev_addr & PAGE_MASK) 190 return(EINVAL); 191 if (cmd->ev_len & PAGE_MASK) 192 return(EINVAL); 193 194 /* 195 * first, attach to the object 196 */ 197 198 uobj = uvn_attach((void *) cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 199 if (uobj == NULL) 200 return(ENOMEM); 201 202 /* 203 * do the map 204 */ 205 206 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 207 uobj, cmd->ev_offset, 0, 208 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 209 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); 210 211 /* 212 * check for error 213 */ 214 215 if (error) { 216 /* 217 * error: detach from object 218 */ 219 uobj->pgops->pgo_detach(uobj); 220 } 221 222 return (error); 223 } 224 225 /* 226 * vmcmd_map_readvn(): 227 * handle vmcmd which specifies that a vnode should be read from. 228 * appropriate for non-demand-paged text/data segments, i.e. impure 229 * objects (a la OMAGIC and NMAGIC). 230 */ 231 232 int 233 vmcmd_map_readvn(struct proc *p, struct exec_vmcmd *cmd) 234 { 235 int error; 236 vm_prot_t prot; 237 238 if (cmd->ev_len == 0) 239 return (0); 240 241 prot = cmd->ev_prot; 242 243 cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */ 244 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 245 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 246 UVM_MAPFLAG(prot | UVM_PROT_WRITE, UVM_PROT_ALL, UVM_INH_COPY, 247 UVM_ADV_NORMAL, 248 UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 249 250 if (error) 251 return (error); 252 253 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 254 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, 255 p->p_ucred, NULL, p); 256 if (error) 257 return (error); 258 259 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 260 /* 261 * we had to map in the area at PROT_ALL so that vn_rdwr() 262 * could write to it. however, the caller seems to want 263 * it mapped read-only, so now we are going to have to call 264 * uvm_map_protect() to fix up the protection. ICK. 265 */ 266 return (uvm_map_protect(&p->p_vmspace->vm_map, 267 trunc_page(cmd->ev_addr), 268 round_page(cmd->ev_addr + cmd->ev_len), 269 prot, FALSE)); 270 } 271 return (0); 272 } 273 274 /* 275 * vmcmd_map_zero(): 276 * handle vmcmd which specifies a zero-filled address space region. The 277 * address range must be first allocated, then protected appropriately. 278 */ 279 280 int 281 vmcmd_map_zero(p, cmd) 282 struct proc *p; 283 struct exec_vmcmd *cmd; 284 { 285 int error; 286 287 if (cmd->ev_len == 0) 288 return (0); 289 290 cmd->ev_addr = trunc_page(cmd->ev_addr); /* required by uvm_map */ 291 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 292 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 293 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 294 UVM_ADV_NORMAL, UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); 295 296 if (error) 297 return error; 298 299 return (0); 300 } 301 302 /* 303 * exec_setup_stack(): Set up the stack segment for an a.out 304 * executable. 305 * 306 * Note that the ep_ssize parameter must be set to be the current stack 307 * limit; this is adjusted in the body of execve() to yield the 308 * appropriate stack segment usage once the argument length is 309 * calculated. 310 * 311 * This function returns an int for uniformity with other (future) formats' 312 * stack setup functions. They might have errors to return. 313 */ 314 315 int 316 exec_setup_stack(p, epp) 317 struct proc *p; 318 struct exec_package *epp; 319 { 320 321 #ifdef MACHINE_STACK_GROWS_UP 322 epp->ep_maxsaddr = USRSTACK; 323 epp->ep_minsaddr = USRSTACK + MAXSSIZ; 324 #else 325 epp->ep_maxsaddr = USRSTACK - MAXSSIZ; 326 epp->ep_minsaddr = USRSTACK; 327 #endif 328 epp->ep_ssize = round_page(p->p_rlimit[RLIMIT_STACK].rlim_cur); 329 330 /* 331 * set up commands for stack. note that this takes *two*, one to 332 * map the part of the stack which we can access, and one to map 333 * the part which we can't. 334 * 335 * arguably, it could be made into one, but that would require the 336 * addition of another mapping proc, which is unnecessary 337 * 338 * note that in memory, things assumed to be: 0 ....... ep_maxsaddr 339 * <stack> ep_minsaddr 340 */ 341 #ifdef MACHINE_STACK_GROWS_UP 342 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 343 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 344 epp->ep_maxsaddr + epp->ep_ssize, NULLVP, 0, VM_PROT_NONE); 345 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 346 epp->ep_maxsaddr, NULLVP, 0, 347 VM_PROT_READ|VM_PROT_WRITE); 348 #else 349 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, 350 ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr), 351 epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE); 352 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize, 353 (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0, 354 VM_PROT_READ|VM_PROT_WRITE); 355 #endif 356 357 return 0; 358 } 359