Commit | Line | Data |
---|---|---|
15637ed4 | 1 | /* |
317350b1 | 2 | * Copyright (c) 1993, David Greenman |
15637ed4 RG |
3 | * All rights reserved. |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
317350b1 DG |
15 | * This product includes software developed by David Greenman |
16 | * 4. The name of the developer may be used to endorse or promote products | |
17 | * derived from this software without specific prior written permission. | |
15637ed4 | 18 | * |
317350b1 | 19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
15637ed4 RG |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
67c9e20b | 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
15637ed4 RG |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
29 | * SUCH DAMAGE. | |
30 | * | |
05d53854 | 31 | * $Id: kern_execve.c,v 1.19 1994/03/21 09:35:30 davidg Exp $ |
15637ed4 RG |
32 | */ |
33 | ||
34 | #include "param.h" | |
35 | #include "systm.h" | |
36 | #include "signalvar.h" | |
37 | #include "resourcevar.h" | |
317350b1 | 38 | #include "imgact.h" |
3228baa0 | 39 | #include "kernel.h" |
15637ed4 | 40 | #include "mount.h" |
15637ed4 | 41 | #include "file.h" |
7d69de6f | 42 | #include "acct.h" |
15637ed4 RG |
43 | #include "exec.h" |
44 | #include "stat.h" | |
45 | #include "wait.h" | |
46 | #include "mman.h" | |
47 | #include "malloc.h" | |
317350b1 | 48 | #include "syslog.h" |
15637ed4 RG |
49 | |
50 | #include "vm/vm.h" | |
51 | #include "vm/vm_param.h" | |
52 | #include "vm/vm_map.h" | |
53 | #include "vm/vm_kern.h" | |
fde1aeb2 | 54 | #include "vm/vm_user.h" |
15637ed4 RG |
55 | |
56 | #include "machine/reg.h" | |
57 | ||
317350b1 | 58 | int exec_extract_strings __P((struct image_params *)); |
65e8cb73 | 59 | int *exec_copyout_strings __P((struct image_params *)); |
317350b1 | 60 | |
3228baa0 GW |
61 | /* |
62 | * execsw_set is constructed for us by the linker. Each of the items | |
63 | * is a pointer to a `const struct execsw', hence the double pointer here. | |
64 | */ | |
65 | extern const struct linker_set execsw_set; | |
66 | const struct execsw **execsw = (const struct execsw **)&execsw_set.ls_items[0]; | |
15637ed4 RG |
67 | |
68 | /* | |
69 | * execve() system call. | |
70 | */ | |
4c45483e | 71 | int |
15637ed4 RG |
72 | execve(p, uap, retval) |
73 | struct proc *p; | |
3c7eb27c | 74 | register struct execve_args *uap; |
15637ed4 RG |
75 | int *retval; |
76 | { | |
317350b1 | 77 | struct nameidata nd, *ndp; |
65e8cb73 DG |
78 | char *stringbase, *stringp; |
79 | int *stack_base; | |
317350b1 | 80 | int error, resid, len, i; |
317350b1 DG |
81 | struct image_params image_params, *iparams; |
82 | struct vnode *vnodep; | |
15637ed4 | 83 | struct vattr attr; |
317350b1 DG |
84 | char *image_header; |
85 | ||
86 | iparams = &image_params; | |
87 | bzero((caddr_t)iparams, sizeof(struct image_params)); | |
88 | image_header = (char *)0; | |
15637ed4 RG |
89 | |
90 | /* | |
317350b1 DG |
91 | * Initialize a few constants in the common area |
92 | */ | |
93 | iparams->proc = p; | |
94 | iparams->uap = uap; | |
95 | iparams->attr = &attr; | |
96 | ||
97 | /* | |
98 | * Allocate temporary demand zeroed space for argument and | |
99 | * environment strings | |
100 | */ | |
fde1aeb2 GW |
101 | error = vm_allocate(kernel_map, (vm_offset_t *)&iparams->stringbase, |
102 | ARG_MAX, TRUE); | |
317350b1 DG |
103 | if (error) { |
104 | log(LOG_WARNING, "execve: failed to allocate string space\n"); | |
105 | return (error); | |
106 | } | |
107 | ||
108 | if (!iparams->stringbase) { | |
109 | error = ENOMEM; | |
110 | goto exec_fail; | |
111 | } | |
112 | iparams->stringp = iparams->stringbase; | |
113 | iparams->stringspace = ARG_MAX; | |
114 | ||
115 | /* | |
116 | * Translate the file name. namei() returns a vnode pointer | |
117 | * in ni_vp amoung other things. | |
15637ed4 RG |
118 | */ |
119 | ndp = &nd; | |
317350b1 | 120 | ndp->ni_nameiop = LOOKUP | LOCKLEAF | FOLLOW | SAVENAME; |
15637ed4 RG |
121 | ndp->ni_segflg = UIO_USERSPACE; |
122 | ndp->ni_dirp = uap->fname; | |
123 | ||
317350b1 | 124 | interpret: |
15637ed4 | 125 | |
317350b1 DG |
126 | error = namei(ndp, p); |
127 | if (error) { | |
fde1aeb2 GW |
128 | vm_deallocate(kernel_map, (vm_offset_t)iparams->stringbase, |
129 | ARG_MAX); | |
317350b1 | 130 | goto exec_fail; |
15637ed4 | 131 | } |
15637ed4 | 132 | |
317350b1 | 133 | iparams->vnodep = vnodep = ndp->ni_vp; |
15637ed4 | 134 | |
317350b1 DG |
135 | if (vnodep == NULL) { |
136 | error = ENOEXEC; | |
137 | goto exec_fail_dealloc; | |
15637ed4 RG |
138 | } |
139 | ||
140 | /* | |
317350b1 | 141 | * Check file permissions (also 'opens' file) |
15637ed4 | 142 | */ |
317350b1 DG |
143 | error = exec_check_permissions(iparams); |
144 | if (error) | |
145 | goto exec_fail_dealloc; | |
15637ed4 | 146 | |
317350b1 DG |
147 | /* |
148 | * Map the image header (first page) of the file into | |
149 | * kernel address space | |
150 | */ | |
fde1aeb2 GW |
151 | error = vm_mmap(kernel_map, /* map */ |
152 | (vm_offset_t *)&image_header, /* address */ | |
05d53854 | 153 | PAGE_SIZE, /* size */ |
fde1aeb2 GW |
154 | VM_PROT_READ, /* protection */ |
155 | VM_PROT_READ, /* max protection */ | |
156 | MAP_FILE, /* flags */ | |
157 | (caddr_t)vnodep, /* vnode */ | |
158 | 0); /* offset */ | |
317350b1 | 159 | if (error) { |
67c9e20b | 160 | uprintf("mmap failed: %d\n",error); |
317350b1 | 161 | goto exec_fail_dealloc; |
15637ed4 | 162 | } |
317350b1 DG |
163 | iparams->image_header = image_header; |
164 | ||
165 | /* | |
166 | * Loop through list of image activators, calling each one. | |
167 | * If there is no match, the activator returns -1. If there | |
168 | * is a match, but there was an error during the activation, | |
169 | * the error is returned. Otherwise 0 means success. If the | |
170 | * image is interpreted, loop back up and try activating | |
171 | * the interpreter. | |
172 | */ | |
3228baa0 GW |
173 | for (i = 0; execsw[i]; ++i) { |
174 | if (execsw[i]->ex_imgact) | |
175 | error = (*execsw[i]->ex_imgact)(iparams); | |
317350b1 DG |
176 | else |
177 | continue; | |
178 | ||
179 | if (error == -1) | |
180 | continue; | |
181 | if (error) | |
182 | goto exec_fail_dealloc; | |
183 | if (iparams->interpreted) { | |
184 | /* free old vnode and name buffer */ | |
33f2dd50 DG |
185 | vput(ndp->ni_vp); |
186 | FREE(ndp->ni_pnbuf, M_NAMEI); | |
fde1aeb2 | 187 | if (vm_deallocate(kernel_map, |
05d53854 | 188 | (vm_offset_t)image_header, PAGE_SIZE)) |
317350b1 | 189 | panic("execve: header dealloc failed (1)"); |
33f2dd50 | 190 | |
317350b1 | 191 | /* set new name to that of the interpreter */ |
33f2dd50 | 192 | ndp->ni_segflg = UIO_SYSSPACE; |
317350b1 DG |
193 | ndp->ni_dirp = iparams->interpreter_name; |
194 | ndp->ni_nameiop = LOOKUP | LOCKLEAF | FOLLOW | SAVENAME; | |
195 | goto interpret; | |
15637ed4 | 196 | } |
317350b1 DG |
197 | break; |
198 | } | |
199 | /* If we made it through all the activators and none matched, exit. */ | |
200 | if (error == -1) { | |
201 | error = ENOEXEC; | |
202 | goto exec_fail_dealloc; | |
15637ed4 RG |
203 | } |
204 | ||
317350b1 DG |
205 | /* |
206 | * Copy out strings (args and env) and initialize stack base | |
207 | */ | |
208 | stack_base = exec_copyout_strings(iparams); | |
65e8cb73 | 209 | p->p_vmspace->vm_minsaddr = (char *)stack_base; |
15637ed4 | 210 | |
317350b1 DG |
211 | /* |
212 | * Stuff argument count as first item on stack | |
213 | */ | |
65e8cb73 | 214 | *(--stack_base) = iparams->argc; |
15637ed4 | 215 | |
05d53854 | 216 | /* close files on exec */ |
317350b1 | 217 | fdcloseexec(p); |
05d53854 DG |
218 | |
219 | /* reset caught signals */ | |
317350b1 | 220 | execsigs(p); |
15637ed4 | 221 | |
317350b1 DG |
222 | /* name this process - nameiexec(p, ndp) */ |
223 | len = MIN(ndp->ni_namelen,MAXCOMLEN); | |
224 | bcopy(ndp->ni_ptr, p->p_comm, len); | |
225 | p->p_comm[len] = 0; | |
15637ed4 RG |
226 | |
227 | /* | |
317350b1 DG |
228 | * mark as executable, wakeup any process that was vforked and tell |
229 | * it that it now has it's own resources back | |
15637ed4 | 230 | */ |
317350b1 DG |
231 | p->p_flag |= SEXEC; |
232 | if (p->p_pptr && (p->p_flag & SPPWAIT)) { | |
233 | p->p_flag &= ~SPPWAIT; | |
234 | wakeup((caddr_t)p->p_pptr); | |
235 | } | |
236 | ||
237 | /* implement set userid/groupid */ | |
d03b71c0 GW |
238 | p->p_flag &= ~SUGID; |
239 | ||
24b27a4b GW |
240 | /* |
241 | * Turn off kernel tracing for set-id programs, except for | |
242 | * root. | |
243 | */ | |
244 | if (p->p_tracep && (attr.va_mode & (VSUID | VSGID)) && | |
245 | suser(p->p_ucred, &p->p_acflag)) { | |
246 | p->p_traceflag = 0; | |
247 | vrele(p->p_tracep); | |
248 | p->p_tracep = 0; | |
249 | } | |
05d53854 | 250 | if ((attr.va_mode & VSUID) && (p->p_flag & STRC) == 0) { |
317350b1 | 251 | p->p_ucred = crcopy(p->p_ucred); |
9e85cc83 | 252 | p->p_ucred->cr_uid = attr.va_uid; |
d03b71c0 | 253 | p->p_flag |= SUGID; |
317350b1 | 254 | } |
05d53854 | 255 | if ((attr.va_mode & VSGID) && (p->p_flag & STRC) == 0) { |
317350b1 | 256 | p->p_ucred = crcopy(p->p_ucred); |
9e85cc83 | 257 | p->p_ucred->cr_groups[0] = attr.va_gid; |
d03b71c0 | 258 | p->p_flag |= SUGID; |
317350b1 DG |
259 | } |
260 | ||
9e85cc83 GW |
261 | /* |
262 | * Implement correct POSIX saved uid behavior. | |
263 | */ | |
264 | p->p_cred->p_svuid = p->p_ucred->cr_uid; | |
265 | p->p_cred->p_svgid = p->p_ucred->cr_gid; | |
266 | ||
317350b1 DG |
267 | /* mark vnode pure text */ |
268 | ndp->ni_vp->v_flag |= VTEXT; | |
15637ed4 RG |
269 | |
270 | /* | |
317350b1 DG |
271 | * If tracing the process, trap to debugger so breakpoints |
272 | * can be set before the program executes. | |
15637ed4 | 273 | */ |
317350b1 DG |
274 | if (p->p_flag & STRC) |
275 | psignal(p, SIGTRAP); | |
15637ed4 | 276 | |
317350b1 DG |
277 | /* clear "fork but no exec" flag, as we _are_ execing */ |
278 | p->p_acflag &= ~AFORK; | |
15637ed4 | 279 | |
317350b1 | 280 | /* Set entry address */ |
65e8cb73 | 281 | setregs(p, iparams->entry_addr, stack_base); |
15637ed4 | 282 | |
317350b1 DG |
283 | /* |
284 | * free various allocated resources | |
285 | */ | |
05d53854 | 286 | if (vm_deallocate(kernel_map, (vm_offset_t)iparams->stringbase, ARG_MAX)) |
317350b1 | 287 | panic("execve: string buffer dealloc failed (1)"); |
05d53854 | 288 | if (vm_deallocate(kernel_map, (vm_offset_t)image_header, PAGE_SIZE)) |
317350b1 DG |
289 | panic("execve: header dealloc failed (2)"); |
290 | vput(ndp->ni_vp); | |
291 | FREE(ndp->ni_pnbuf, M_NAMEI); | |
15637ed4 | 292 | |
317350b1 | 293 | return (0); |
15637ed4 | 294 | |
317350b1 DG |
295 | exec_fail_dealloc: |
296 | if (iparams->stringbase && iparams->stringbase != (char *)-1) | |
fde1aeb2 GW |
297 | if (vm_deallocate(kernel_map, (vm_offset_t)iparams->stringbase, |
298 | ARG_MAX)) | |
317350b1 DG |
299 | panic("execve: string buffer dealloc failed (2)"); |
300 | if (iparams->image_header && iparams->image_header != (char *)-1) | |
fde1aeb2 | 301 | if (vm_deallocate(kernel_map, |
05d53854 | 302 | (vm_offset_t)iparams->image_header, PAGE_SIZE)) |
317350b1 DG |
303 | panic("execve: header dealloc failed (3)"); |
304 | vput(ndp->ni_vp); | |
305 | FREE(ndp->ni_pnbuf, M_NAMEI); | |
15637ed4 | 306 | |
317350b1 DG |
307 | exec_fail: |
308 | if (iparams->vmspace_destroyed) { | |
309 | /* sorry, no more process anymore. exit gracefully */ | |
310 | #if 0 /* XXX */ | |
311 | vm_deallocate(&vs->vm_map, USRSTACK - MAXSSIZ, MAXSSIZ); | |
312 | #endif | |
313 | kexit(p, W_EXITCODE(0, SIGABRT)); | |
314 | /* NOT REACHED */ | |
315 | return(0); | |
316 | } else { | |
317 | return(error); | |
15637ed4 | 318 | } |
317350b1 | 319 | } |
15637ed4 | 320 | |
317350b1 DG |
321 | /* |
322 | * Destroy old address space, and allocate a new stack | |
4c321944 | 323 | * The new stack is only SGROWSIZ large because it is grown |
317350b1 DG |
324 | * automatically in trap.c. |
325 | */ | |
326 | int | |
327 | exec_new_vmspace(iparams) | |
328 | struct image_params *iparams; | |
329 | { | |
330 | int error; | |
331 | struct vmspace *vmspace = iparams->proc->p_vmspace; | |
4c321944 | 332 | caddr_t stack_addr = (caddr_t) (USRSTACK - SGROWSIZ); |
15637ed4 | 333 | |
317350b1 | 334 | iparams->vmspace_destroyed = 1; |
15637ed4 | 335 | |
317350b1 DG |
336 | /* Blow away entire process VM */ |
337 | vm_deallocate(&vmspace->vm_map, 0, USRSTACK); | |
15637ed4 | 338 | |
317350b1 | 339 | /* Allocate a new stack */ |
fde1aeb2 | 340 | error = vm_allocate(&vmspace->vm_map, (vm_offset_t *)&stack_addr, |
4c321944 | 341 | SGROWSIZ, FALSE); |
317350b1 DG |
342 | if (error) |
343 | return(error); | |
15637ed4 | 344 | |
4c321944 DG |
345 | vmspace->vm_ssize = SGROWSIZ >> PAGE_SHIFT; |
346 | ||
317350b1 DG |
347 | /* Initialize maximum stack address */ |
348 | vmspace->vm_maxsaddr = (char *)USRSTACK - MAXSSIZ; | |
15637ed4 | 349 | |
317350b1 DG |
350 | return(0); |
351 | } | |
15637ed4 | 352 | |
317350b1 DG |
353 | /* |
354 | * Copy out argument and environment strings from the old process | |
355 | * address space into the temporary string buffer. | |
356 | */ | |
357 | int | |
358 | exec_extract_strings(iparams) | |
359 | struct image_params *iparams; | |
360 | { | |
361 | char **argv, **envv; | |
362 | char *argp, *envp; | |
363 | int length; | |
33f2dd50 | 364 | |
317350b1 DG |
365 | /* |
366 | * extract arguments first | |
367 | */ | |
33f2dd50 | 368 | |
317350b1 DG |
369 | argv = iparams->uap->argv; |
370 | ||
371 | if (argv) | |
372 | while (argp = (caddr_t) fuword(argv++)) { | |
373 | if (argp == (caddr_t) -1) | |
374 | return (EFAULT); | |
375 | if (copyinstr(argp, iparams->stringp, iparams->stringspace, | |
376 | &length) == ENAMETOOLONG) | |
377 | return(E2BIG); | |
378 | iparams->stringspace -= length; | |
379 | iparams->stringp += length; | |
380 | iparams->argc++; | |
381 | } | |
15637ed4 | 382 | |
317350b1 DG |
383 | /* |
384 | * extract environment strings | |
385 | */ | |
15637ed4 | 386 | |
317350b1 DG |
387 | envv = iparams->uap->envv; |
388 | ||
389 | if (envv) | |
390 | while (envp = (caddr_t) fuword(envv++)) { | |
391 | if (envp == (caddr_t) -1) | |
392 | return (EFAULT); | |
393 | if (copyinstr(envp, iparams->stringp, iparams->stringspace, | |
394 | &length) == ENAMETOOLONG) | |
395 | return(E2BIG); | |
396 | iparams->stringspace -= length; | |
397 | iparams->stringp += length; | |
398 | iparams->envc++; | |
399 | } | |
33f2dd50 | 400 | |
317350b1 DG |
401 | return (0); |
402 | } | |
15637ed4 | 403 | |
317350b1 DG |
404 | /* |
405 | * Copy strings out to the new process address space, constructing | |
406 | * new arg and env vector tables. Return a pointer to the base | |
407 | * so that it can be used as the initial stack pointer. | |
408 | */ | |
65e8cb73 | 409 | int * |
317350b1 DG |
410 | exec_copyout_strings(iparams) |
411 | struct image_params *iparams; | |
412 | { | |
413 | int argc, envc; | |
414 | char **vectp; | |
65e8cb73 DG |
415 | char *stringp, *destp; |
416 | int *stack_base; | |
317350b1 | 417 | int vect_table_size, string_table_size; |
15637ed4 RG |
418 | |
419 | /* | |
317350b1 DG |
420 | * Calculate string base and vector table pointers. |
421 | */ | |
422 | destp = (caddr_t) ((caddr_t)USRSTACK - | |
423 | roundup((ARG_MAX - iparams->stringspace), sizeof(char *))); | |
424 | /* | |
425 | * The '+ 2' is for the null pointers at the end of each of the | |
426 | * arg and env vector sets | |
15637ed4 | 427 | */ |
317350b1 DG |
428 | vectp = (char **) (destp - |
429 | (iparams->argc + iparams->envc + 2) * sizeof(char *)); | |
15637ed4 | 430 | |
317350b1 DG |
431 | /* |
432 | * vectp also becomes our initial stack base | |
433 | */ | |
65e8cb73 | 434 | stack_base = (int *)vectp; |
15637ed4 | 435 | |
317350b1 DG |
436 | stringp = iparams->stringbase; |
437 | argc = iparams->argc; | |
438 | envc = iparams->envc; | |
15637ed4 | 439 | |
317350b1 DG |
440 | for (; argc > 0; --argc) { |
441 | *(vectp++) = destp; | |
442 | while (*destp++ = *stringp++); | |
15637ed4 | 443 | } |
317350b1 DG |
444 | |
445 | /* a null vector table pointer seperates the argp's from the envp's */ | |
446 | *(vectp++) = NULL; | |
447 | ||
448 | for (; envc > 0; --envc) { | |
449 | *(vectp++) = destp; | |
450 | while (*destp++ = *stringp++); | |
15637ed4 RG |
451 | } |
452 | ||
317350b1 DG |
453 | /* end of vector table is a null pointer */ |
454 | *vectp = NULL; | |
15637ed4 | 455 | |
317350b1 DG |
456 | return (stack_base); |
457 | } | |
15637ed4 | 458 | |
317350b1 DG |
459 | /* |
460 | * Check permissions of file to execute. | |
461 | * Return 0 for success or error code on failure. | |
462 | */ | |
463 | int | |
464 | exec_check_permissions(iparams) | |
465 | struct image_params *iparams; | |
466 | { | |
467 | struct proc *p = iparams->proc; | |
468 | struct vnode *vnodep = iparams->vnodep; | |
469 | struct vattr *attr = iparams->attr; | |
470 | int error; | |
15637ed4 | 471 | |
317350b1 DG |
472 | /* |
473 | * Check number of open-for-writes on the file and deny execution | |
474 | * if there are any. | |
475 | */ | |
476 | if (vnodep->v_writecount) { | |
477 | return (ETXTBSY); | |
478 | } | |
15637ed4 | 479 | |
317350b1 DG |
480 | /* Get file attributes */ |
481 | error = VOP_GETATTR(vnodep, attr, p->p_ucred, p); | |
482 | if (error) | |
483 | return (error); | |
15637ed4 | 484 | |
317350b1 DG |
485 | /* |
486 | * 1) Check if file execution is disabled for the filesystem that this | |
487 | * file resides on. | |
488 | * 2) Insure that at least one execute bit is on - otherwise root | |
489 | * will always succeed, and we don't want to happen unless the | |
490 | * file really is executable. | |
491 | * 3) Insure that the file is a regular file. | |
492 | */ | |
493 | if ((vnodep->v_mount->mnt_flag & MNT_NOEXEC) || | |
494 | ((attr->va_mode & 0111) == 0) || | |
495 | (attr->va_type != VREG)) { | |
496 | return (EACCES); | |
497 | } | |
15637ed4 | 498 | |
20fcbdf2 DG |
499 | /* |
500 | * Zero length files can't be exec'd | |
501 | */ | |
502 | if (attr->va_size == 0) | |
503 | return (ENOEXEC); | |
504 | ||
317350b1 DG |
505 | /* |
506 | * Disable setuid/setgid if the filesystem prohibits it or if | |
507 | * the process is being traced. | |
508 | */ | |
509 | if ((vnodep->v_mount->mnt_flag & MNT_NOSUID) || (p->p_flag & STRC)) | |
510 | attr->va_mode &= ~(VSUID | VSGID); | |
15637ed4 | 511 | |
317350b1 DG |
512 | /* |
513 | * Check for execute permission to file based on current credentials. | |
514 | * Then call filesystem specific open routine (which does nothing | |
515 | * in the general case). | |
516 | */ | |
517 | error = VOP_ACCESS(vnodep, VEXEC, p->p_ucred, p); | |
518 | if (error) | |
519 | return (error); | |
15637ed4 | 520 | |
317350b1 DG |
521 | error = VOP_OPEN(vnodep, FREAD, p->p_ucred, p); |
522 | if (error) | |
523 | return (error); | |
15637ed4 | 524 | |
317350b1 | 525 | return (0); |
15637ed4 | 526 | } |