exec_subr.c revision 1.45
1 /* $NetBSD: exec_subr.c,v 1.45 2005/07/06 23:08:57 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1993, 1994, 1996 Christopher G. Demetriou 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christopher G. Demetriou. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: exec_subr.c,v 1.45 2005/07/06 23:08:57 thorpej Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/vnode.h> 41 #include <sys/filedesc.h> 42 #include <sys/exec.h> 43 #include <sys/mman.h> 44 #include <sys/resourcevar.h> 45 #include <sys/device.h> 46 47 #include <uvm/uvm.h> 48 49 #define VMCMD_EVCNT_DECL(name) \ 50 static struct evcnt vmcmd_ev_##name = \ 51 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "vmcmd", #name); \ 52 EVCNT_ATTACH_STATIC(vmcmd_ev_##name) 53 54 #define VMCMD_EVCNT_INCR(name) \ 55 vmcmd_ev_##name.ev_count++ 56 57 VMCMD_EVCNT_DECL(calls); 58 VMCMD_EVCNT_DECL(extends); 59 VMCMD_EVCNT_DECL(kills); 60 61 /* 62 * new_vmcmd(): 63 * create a new vmcmd structure and fill in its fields based 64 * on function call arguments. make sure objects ref'd by 65 * the vmcmd are 'held'. 66 */ 67 68 void 69 new_vmcmd(struct exec_vmcmd_set *evsp, 70 int (*proc)(struct proc * p, struct exec_vmcmd *), 71 u_long len, u_long addr, struct vnode *vp, u_long offset, 72 u_int prot, int flags) 73 { 74 struct exec_vmcmd *vcp; 75 76 VMCMD_EVCNT_INCR(calls); 77 78 if (evsp->evs_used >= evsp->evs_cnt) 79 vmcmdset_extend(evsp); 80 vcp = &evsp->evs_cmds[evsp->evs_used++]; 81 vcp->ev_proc = proc; 82 vcp->ev_len = len; 83 vcp->ev_addr = addr; 84 if ((vcp->ev_vp = vp) != NULL) 85 vref(vp); 86 vcp->ev_offset = offset; 87 vcp->ev_prot = prot; 88 vcp->ev_flags = flags; 89 } 90 91 void 92 vmcmdset_extend(struct exec_vmcmd_set *evsp) 93 { 94 struct exec_vmcmd *nvcp; 95 u_int ocnt; 96 97 #ifdef DIAGNOSTIC 98 if (evsp->evs_used < evsp->evs_cnt) 99 panic("vmcmdset_extend: not necessary"); 100 #endif 101 102 /* figure out number of entries in new set */ 103 if ((ocnt = evsp->evs_cnt) != 0) { 104 evsp->evs_cnt += ocnt; 105 VMCMD_EVCNT_INCR(extends); 106 } else 107 evsp->evs_cnt = EXEC_DEFAULT_VMCMD_SETSIZE; 108 109 /* allocate it */ 110 nvcp = malloc(evsp->evs_cnt * sizeof(struct exec_vmcmd), 111 M_EXEC, M_WAITOK); 112 113 /* free the old struct, if there was one, and record the new one */ 114 if (ocnt) { 115 memcpy(nvcp, evsp->evs_cmds, 116 (ocnt * sizeof(struct exec_vmcmd))); 117 free(evsp->evs_cmds, M_EXEC); 118 } 119 evsp->evs_cmds = nvcp; 120 } 121 122 void 123 kill_vmcmds(struct exec_vmcmd_set *evsp) 124 { 125 struct exec_vmcmd *vcp; 126 u_int i; 127 128 VMCMD_EVCNT_INCR(kills); 129 130 if (evsp->evs_cnt == 0) 131 return; 132 133 for (i = 0; i < evsp->evs_used; i++) { 134 vcp = &evsp->evs_cmds[i]; 135 if (vcp->ev_vp != NULL) 136 vrele(vcp->ev_vp); 137 } 138 evsp->evs_used = evsp->evs_cnt = 0; 139 free(evsp->evs_cmds, M_EXEC); 140 } 141 142 /* 143 * vmcmd_map_pagedvn(): 144 * handle vmcmd which specifies that a vnode should be mmap'd. 145 * appropriate for handling demand-paged text and data segments. 146 */ 147 148 int 149 vmcmd_map_pagedvn(struct proc *p, struct exec_vmcmd *cmd) 150 { 151 struct uvm_object *uobj; 152 int error; 153 154 KASSERT(cmd->ev_vp->v_flag & VTEXT); 155 156 /* 157 * map the vnode in using uvm_map. 158 */ 159 160 if (cmd->ev_len == 0) 161 return(0); 162 if (cmd->ev_offset & PAGE_MASK) 163 return(EINVAL); 164 if (cmd->ev_addr & PAGE_MASK) 165 return(EINVAL); 166 if (cmd->ev_len & PAGE_MASK) 167 return(EINVAL); 168 169 /* 170 * first, attach to the object 171 */ 172 173 uobj = uvn_attach(cmd->ev_vp, VM_PROT_READ|VM_PROT_EXECUTE); 174 if (uobj == NULL) 175 return(ENOMEM); 176 VREF(cmd->ev_vp); 177 178 /* 179 * do the map 180 */ 181 182 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, 183 uobj, cmd->ev_offset, 0, 184 UVM_MAPFLAG(cmd->ev_prot, VM_PROT_ALL, UVM_INH_COPY, 185 UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); 186 if (error) { 187 uobj->pgops->pgo_detach(uobj); 188 } 189 return error; 190 } 191 192 /* 193 * vmcmd_map_readvn(): 194 * handle vmcmd which specifies that a vnode should be read from. 195 * appropriate for non-demand-paged text/data segments, i.e. impure 196 * objects (a la OMAGIC and NMAGIC). 197 */ 198 int 199 vmcmd_map_readvn(struct proc *p, struct exec_vmcmd *cmd) 200 { 201 int error; 202 long diff; 203 204 if (cmd->ev_len == 0) 205 return 0; 206 207 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 208 cmd->ev_addr -= diff; /* required by uvm_map */ 209 cmd->ev_offset -= diff; 210 cmd->ev_len += diff; 211 212 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 213 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 214 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY, 215 UVM_ADV_NORMAL, 216 UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); 217 218 if (error) 219 return error; 220 221 return vmcmd_readvn(p, cmd); 222 } 223 224 int 225 vmcmd_readvn(struct proc *p, struct exec_vmcmd *cmd) 226 { 227 int error; 228 229 error = vn_rdwr(UIO_READ, cmd->ev_vp, (caddr_t)cmd->ev_addr, 230 cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, 231 p->p_ucred, NULL, p); 232 if (error) 233 return error; 234 235 #ifdef PMAP_NEED_PROCWR 236 /* 237 * we had to write the process, make sure the pages are synched 238 * with the instruction cache. 239 */ 240 if (cmd->ev_prot & VM_PROT_EXECUTE) 241 pmap_procwr(p, cmd->ev_addr, cmd->ev_len); 242 #endif 243 244 if (cmd->ev_prot != (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)) { 245 246 /* 247 * we had to map in the area at PROT_ALL so that vn_rdwr() 248 * could write to it. however, the caller seems to want 249 * it mapped read-only, so now we are going to have to call 250 * uvm_map_protect() to fix up the protection. ICK. 251 */ 252 253 return uvm_map_protect(&p->p_vmspace->vm_map, 254 trunc_page(cmd->ev_addr), 255 round_page(cmd->ev_addr + cmd->ev_len), 256 cmd->ev_prot, FALSE); 257 } 258 return 0; 259 } 260 261 /* 262 * vmcmd_map_zero(): 263 * handle vmcmd which specifies a zero-filled address space region. The 264 * address range must be first allocated, then protected appropriately. 265 */ 266 267 int 268 vmcmd_map_zero(struct proc *p, struct exec_vmcmd *cmd) 269 { 270 int error; 271 long diff; 272 273 diff = cmd->ev_addr - trunc_page(cmd->ev_addr); 274 cmd->ev_addr -= diff; /* required by uvm_map */ 275 cmd->ev_len += diff; 276 277 error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, 278 round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, 279 UVM_MAPFLAG(cmd->ev_prot, UVM_PROT_ALL, UVM_INH_COPY, 280 UVM_ADV_NORMAL, 281 UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); 282 return error; 283 } 284 285 /* 286 * exec_read_from(): 287 * 288 * Read from vnode into buffer at offset. 289 */ 290 int 291 exec_read_from(struct proc *p, struct vnode *vp, u_long off, void *bf, 292 size_t size) 293 { 294 int error; 295 size_t resid; 296 297 if ((error = vn_rdwr(UIO_READ, vp, bf, size, off, UIO_SYSSPACE, 298 0, p->p_ucred, &resid, NULL)) != 0) 299 return error; 300 /* 301 * See if we got all of it 302 */ 303 if (resid != 0) 304 return ENOEXEC; 305 return 0; 306 } 307 308 /* 309 * exec_setup_stack(): Set up the stack segment for an elf 310 * executable. 311 * 312 * Note that the ep_ssize parameter must be set to be the current stack 313 * limit; this is adjusted in the body of execve() to yield the 314 * appropriate stack segment usage once the argument length is 315 * calculated. 316 * 317 * This function returns an int for uniformity with other (future) formats' 318 * stack setup functions. They might have errors to return. 319 */ 320 321 int 322 exec_setup_stack(struct proc *p, struct exec_package *epp) 323 { 324 u_long max_stack_size; 325 u_long access_linear_min, access_size; 326 u_long noaccess_linear_min, noaccess_size; 327 328 #ifndef USRSTACK32 329 #define USRSTACK32 (0x00000000ffffffffL&~PGOFSET) 330 #endif 331 332 if (epp->ep_flags & EXEC_32) { 333 epp->ep_minsaddr = USRSTACK32; 334 max_stack_size = MAXSSIZ; 335 } else { 336 epp->ep_minsaddr = USRSTACK; 337 max_stack_size = MAXSSIZ; 338 } 339 epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr, 340 max_stack_size); 341 epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur; 342 343 /* 344 * set up commands for stack. note that this takes *two*, one to 345 * map the part of the stack which we can access, and one to map 346 * the part which we can't. 347 * 348 * arguably, it could be made into one, but that would require the 349 * addition of another mapping proc, which is unnecessary 350 */ 351 access_size = epp->ep_ssize; 352 access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size); 353 noaccess_size = max_stack_size - access_size; 354 noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 355 access_size), noaccess_size); 356 if (noaccess_size > 0) { 357 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size, 358 noaccess_linear_min, NULL, 0, VM_PROT_NONE); 359 } 360 KASSERT(access_size > 0); 361 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, access_size, 362 access_linear_min, NULL, 0, VM_PROT_READ | VM_PROT_WRITE); 363 364 return 0; 365 } 366
Indexes created Tue Sep 23 14:10:03 GMT 2025