netbsd32_execve.c revision 1.2.2.3 1 /* $NetBSD: netbsd32_execve.c,v 1.2.2.3 2001/11/14 19:13:16 nathanw Exp $ */
2
3 /*
4 * Copyright (c) 1998, 2001 Matthew R. Green
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. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: netbsd32_execve.c,v 1.2.2.3 2001/11/14 19:13:16 nathanw Exp $");
33
34 #if defined(_KERNEL_OPT)
35 #include "opt_ktrace.h"
36 #endif
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/mount.h>
42 #include <sys/stat.h>
43 #include <sys/wait.h>
44 #include <sys/ktrace.h>
45 #include <sys/vnode.h>
46 #include <sys/file.h>
47 #include <sys/filedesc.h>
48 #include <sys/namei.h>
49
50 #include <uvm/uvm_extern.h>
51
52 #include <sys/syscallargs.h>
53 #include <sys/proc.h>
54 #include <sys/acct.h>
55 #include <sys/exec.h>
56
57 #include <compat/netbsd32/netbsd32.h>
58 #include <compat/netbsd32/netbsd32_syscall.h>
59 #include <compat/netbsd32/netbsd32_syscallargs.h>
60
61 /* this is provided by kern/kern_exec.c */
62 extern int exec_maxhdrsz;
63 extern struct lock exec_lock;
64
65 /*
66 * Need to completly reimplement this syscall due to argument copying.
67 */
68 /* ARGSUSED */
69 int
70 netbsd32_execve(p, v, retval)
71 struct proc *p;
72 void *v;
73 register_t *retval;
74 {
75 struct netbsd32_execve_args /* {
76 syscallarg(const netbsd32_charp) path;
77 syscallarg(netbsd32_charpp) argp;
78 syscallarg(netbsd32_charpp) envp;
79 } */ *uap = v;
80 struct sys_execve_args ua;
81 caddr_t sg;
82
83 NETBSD32TOP_UAP(path, const char);
84 NETBSD32TOP_UAP(argp, char *);
85 NETBSD32TOP_UAP(envp, char *);
86 sg = stackgap_init(p->p_emul);
87 CHECK_ALT_EXIST(p, &sg, SCARG(&ua, path));
88
89 return netbsd32_execve2(p, &ua, retval);
90 }
91
92 int
93 netbsd32_execve2(p, uap, retval)
94 struct proc *p;
95 struct sys_execve_args *uap;
96 register_t *retval;
97 {
98 /* Function args */
99 int error, i;
100 struct exec_package pack;
101 struct nameidata nid;
102 struct vattr attr;
103 struct ucred *cred = p->p_ucred;
104 char *argp;
105 netbsd32_charp const *cpp;
106 char *dp;
107 netbsd32_charp sp;
108 long argc, envc;
109 size_t len;
110 char *stack;
111 struct ps_strings arginfo;
112 struct vmspace *vm;
113 char **tmpfap;
114 int szsigcode;
115 struct exec_vmcmd *base_vcp = NULL;
116
117 /*
118 * Init the namei data to point the file user's program name.
119 * This is done here rather than in check_exec(), so that it's
120 * possible to override this settings if any of makecmd/probe
121 * functions call check_exec() recursively - for example,
122 * see exec_script_makecmds().
123 */
124 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
125
126 /*
127 * initialize the fields of the exec package.
128 */
129 pack.ep_name = SCARG(uap, path);
130 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK);
131 pack.ep_hdrlen = exec_maxhdrsz;
132 pack.ep_hdrvalid = 0;
133 pack.ep_ndp = &nid;
134 pack.ep_emul_arg = NULL;
135 pack.ep_vmcmds.evs_cnt = 0;
136 pack.ep_vmcmds.evs_used = 0;
137 pack.ep_vap = &attr;
138 pack.ep_flags = 0;
139
140 lockmgr(&exec_lock, LK_SHARED, NULL);
141
142 /* see if we can run it. */
143 if ((error = check_exec(p, &pack)) != 0)
144 goto freehdr;
145
146 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
147
148 /* allocate an argument buffer */
149 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS);
150 #ifdef DIAGNOSTIC
151 if (argp == (vaddr_t) 0)
152 panic("netbsd32_execve: argp == NULL");
153 #endif
154 dp = argp;
155 argc = 0;
156
157 /* copy the fake args list, if there's one, freeing it as we go */
158 if (pack.ep_flags & EXEC_HASARGL) {
159 tmpfap = pack.ep_fa;
160 while (*tmpfap != NULL) {
161 char *cp;
162
163 cp = *tmpfap;
164 while (*cp)
165 *dp++ = *cp++;
166 dp++;
167
168 FREE(*tmpfap, M_EXEC);
169 tmpfap++; argc++;
170 }
171 FREE(pack.ep_fa, M_EXEC);
172 pack.ep_flags &= ~EXEC_HASARGL;
173 }
174
175 /* Now get argv & environment */
176 if (!(cpp = (netbsd32_charp *)SCARG(uap, argp))) {
177 error = EINVAL;
178 goto bad;
179 }
180
181 if (pack.ep_flags & EXEC_SKIPARG)
182 cpp++;
183
184 while (1) {
185 len = argp + ARG_MAX - dp;
186 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
187 goto bad;
188 if (!sp)
189 break;
190 if ((error = copyinstr((char *)(u_long)sp, dp,
191 len, &len)) != 0) {
192 if (error == ENAMETOOLONG)
193 error = E2BIG;
194 goto bad;
195 }
196 dp += len;
197 cpp++;
198 argc++;
199 }
200
201 envc = 0;
202 /* environment need not be there */
203 if ((cpp = (netbsd32_charp *)SCARG(uap, envp)) != NULL ) {
204 while (1) {
205 len = argp + ARG_MAX - dp;
206 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
207 goto bad;
208 if (!sp)
209 break;
210 if ((error = copyinstr((char *)(u_long)sp,
211 dp, len, &len)) != 0) {
212 if (error == ENAMETOOLONG)
213 error = E2BIG;
214 goto bad;
215 }
216 dp += len;
217 cpp++;
218 envc++;
219 }
220 }
221
222 dp = (char *) ALIGN(dp);
223
224 szsigcode = pack.ep_es->es_emul->e_esigcode -
225 pack.ep_es->es_emul->e_sigcode;
226
227 /* Now check if args & environ fit into new stack */
228 if (pack.ep_flags & EXEC_32)
229 len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
230 sizeof(int) + sizeof(int) + dp + STACKGAPLEN +
231 szsigcode + sizeof(struct ps_strings)) - argp;
232 else
233 len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
234 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN +
235 szsigcode + sizeof(struct ps_strings)) - argp;
236
237 len = ALIGN(len); /* make the stack "safely" aligned */
238
239 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */
240 error = ENOMEM;
241 goto bad;
242 }
243
244 /* adjust "active stack depth" for process VSZ */
245 pack.ep_ssize = len; /* maybe should go elsewhere, but... */
246
247 /*
248 * Do whatever is necessary to prepare the address space
249 * for remapping. Note that this might replace the current
250 * vmspace with another!
251 */
252 uvmspace_exec(p, VM_MIN_ADDRESS, (vaddr_t)pack.ep_minsaddr);
253
254 /* Now map address space */
255 vm = p->p_vmspace;
256 vm->vm_taddr = (char *) pack.ep_taddr;
257 vm->vm_tsize = btoc(pack.ep_tsize);
258 vm->vm_daddr = (char *) pack.ep_daddr;
259 vm->vm_dsize = btoc(pack.ep_dsize);
260 vm->vm_ssize = btoc(pack.ep_ssize);
261 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr;
262 vm->vm_minsaddr = (char *) pack.ep_minsaddr;
263
264 /* create the new process's VM space by running the vmcmds */
265 #ifdef DIAGNOSTIC
266 if (pack.ep_vmcmds.evs_used == 0)
267 panic("netbsd32_execve: no vmcmds");
268 #endif
269 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) {
270 struct exec_vmcmd *vcp;
271
272 vcp = &pack.ep_vmcmds.evs_cmds[i];
273 if (vcp->ev_flags & VMCMD_RELATIVE) {
274 #ifdef DIAGNOSTIC
275 if (base_vcp == NULL)
276 panic("netbsd32_execve: relative vmcmd with no base");
277 if (vcp->ev_flags & VMCMD_BASE)
278 panic("netbsd32_execve: illegal base & relative vmcmd");
279 #endif
280 vcp->ev_addr += base_vcp->ev_addr;
281 }
282 error = (*vcp->ev_proc)(p, vcp);
283 #ifdef DEBUG
284 if (error) {
285 int j;
286
287 for (j = 0; j <= i; j++)
288 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", j,
289 vcp[j-i].ev_addr, vcp[j-i].ev_len,
290 vcp[j-i].ev_offset);
291 }
292 #endif
293 if (vcp->ev_flags & VMCMD_BASE)
294 base_vcp = vcp;
295 }
296
297 /* free the vmspace-creation commands, and release their references */
298 kill_vmcmds(&pack.ep_vmcmds);
299
300 /* if an error happened, deallocate and punt */
301 if (error) {
302 #ifdef DEBUG
303 printf("netbsd32_execve: vmcmd %i failed: %d\n", i-1, error);
304 #endif
305 goto exec_abort;
306 }
307
308 /* remember information about the process */
309 arginfo.ps_nargvstr = argc;
310 arginfo.ps_nenvstr = envc;
311
312 stack = (char *) (vm->vm_minsaddr - len);
313 /* Now copy argc, args & environ to new stack */
314 error = (*pack.ep_es->es_copyargs)(&pack, &arginfo,
315 &stack, argp);
316 if (error) {
317 #ifdef DEBUG
318 printf("netbsd32_execve: copyargs failed\n");
319 #endif
320 goto exec_abort;
321 }
322 /* restore the stack back to its original point */
323 stack = (char *) (vm->vm_minsaddr - len);
324
325 /* fill process ps_strings info */
326 p->p_psstr = (struct ps_strings *)(stack - sizeof(struct ps_strings));
327 p->p_psargv = offsetof(struct ps_strings, ps_argvstr);
328 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr);
329 p->p_psenv = offsetof(struct ps_strings, ps_envstr);
330 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr);
331
332 /* copy out the process's ps_strings structure */
333 if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) {
334 #ifdef DEBUG
335 printf("netbsd32_execve: ps_strings copyout failed\n");
336 #endif
337 goto exec_abort;
338 }
339
340 /* copy out the process's signal trapoline code */
341 if (szsigcode) {
342 if (copyout((char *)pack.ep_es->es_emul->e_sigcode,
343 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode,
344 szsigcode)) {
345 #ifdef DEBUG
346 printf("netbsd32_execve: sig trampoline copyout failed\n");
347 #endif
348 goto exec_abort;
349 }
350 #ifdef PMAP_NEED_PROCWR
351 /* This is code. Let the pmap do what is needed. */
352 pmap_procwr(p, (vaddr_t)p->p_sigacts->ps_sigcode, szsigcode);
353 #endif
354 }
355
356 stopprofclock(p); /* stop profiling */
357 fdcloseexec(p); /* handle close on exec */
358 execsigs(p); /* reset catched signals */
359 p->p_ctxlink = NULL; /* reset ucontext link */
360
361 /* set command name & other accounting info */
362 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN);
363 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len);
364 p->p_comm[len] = 0;
365 p->p_acflag &= ~AFORK;
366
367 /* record proc's vnode, for use by procfs and others */
368 if (p->p_textvp)
369 vrele(p->p_textvp);
370 VREF(pack.ep_vp);
371 p->p_textvp = pack.ep_vp;
372
373 p->p_flag |= P_EXEC;
374 if (p->p_flag & P_PPWAIT) {
375 p->p_flag &= ~P_PPWAIT;
376 wakeup((caddr_t) p->p_pptr);
377 }
378
379 /*
380 * deal with set[ug]id.
381 * MNT_NOSUID has already been used to disable s[ug]id.
382 */
383 if ((p->p_flag & P_TRACED) == 0 &&
384
385 (((attr.va_mode & S_ISUID) != 0 &&
386 p->p_ucred->cr_uid != attr.va_uid) ||
387
388 ((attr.va_mode & S_ISGID) != 0 &&
389 p->p_ucred->cr_gid != attr.va_gid))) {
390 /*
391 * Mark the process as SUGID before we do
392 * anything that might block.
393 */
394 p_sugid(p);
395
396 p->p_ucred = crcopy(cred);
397 #ifdef KTRACE
398 /*
399 * If process is being ktraced, turn off - unless
400 * root set it.
401 */
402 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT))
403 ktrderef(p);
404 #endif
405 if (attr.va_mode & S_ISUID)
406 p->p_ucred->cr_uid = attr.va_uid;
407 if (attr.va_mode & S_ISGID)
408 p->p_ucred->cr_gid = attr.va_gid;
409 } else
410 p->p_flag &= ~P_SUGID;
411 p->p_cred->p_svuid = p->p_ucred->cr_uid;
412 p->p_cred->p_svgid = p->p_ucred->cr_gid;
413
414 doexechooks(p);
415
416 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
417
418 PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
419 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
420 VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
421 vput(pack.ep_vp);
422
423 /* setup new registers and do misc. setup. */
424 (*pack.ep_es->es_setregs)(p, &pack, (u_long) stack);
425
426 if (p->p_flag & P_TRACED)
427 psignal(p, SIGTRAP);
428
429 free(pack.ep_hdr, M_EXEC);
430
431 /*
432 * Call emulation specific exec hook. This can setup setup per-process
433 * p->p_emuldata or do any other per-process stuff an emulation needs.
434 *
435 * If we are executing process of different emulation than the
436 * original forked process, call e_proc_exit() of the old emulation
437 * first, then e_proc_exec() of new emulation. If the emulation is
438 * same, the exec hook code should deallocate any old emulation
439 * resources held previously by this process.
440 */
441 if (p->p_emul && p->p_emul->e_proc_exit
442 && p->p_emul != pack.ep_es->es_emul)
443 (*p->p_emul->e_proc_exit)(p);
444
445 /*
446 * Call exec hook. Emulation code may NOT store reference to anything
447 * from &pack.
448 */
449 if (pack.ep_es->es_emul->e_proc_exec)
450 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack);
451
452 /* update p_emul, the old value is no longer needed */
453 p->p_emul = pack.ep_es->es_emul;
454
455 #ifdef KTRACE
456 if (KTRPOINT(p, KTR_EMUL))
457 ktremul(p);
458 #endif
459
460 lockmgr(&exec_lock, LK_RELEASE, NULL);
461
462 return (EJUSTRETURN);
463
464 bad:
465 /* free the vmspace-creation commands, and release their references */
466 kill_vmcmds(&pack.ep_vmcmds);
467 /* kill any opened file descriptor, if necessary */
468 if (pack.ep_flags & EXEC_HASFD) {
469 pack.ep_flags &= ~EXEC_HASFD;
470 (void) fdrelease(p, pack.ep_fd);
471 }
472 /* close and put the exec'd file */
473 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
474 VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
475 vput(pack.ep_vp);
476 PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
477 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
478
479 freehdr:
480 lockmgr(&exec_lock, LK_RELEASE, NULL);
481
482 free(pack.ep_hdr, M_EXEC);
483 return error;
484
485 exec_abort:
486 lockmgr(&exec_lock, LK_RELEASE, NULL);
487
488 /*
489 * the old process doesn't exist anymore. exit gracefully.
490 * get rid of the (new) address space we have created, if any, get rid
491 * of our namei data and vnode, and exit noting failure
492 */
493 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
494 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
495 if (pack.ep_emul_arg)
496 FREE(pack.ep_emul_arg, M_TEMP);
497 PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
498 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
499 VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
500 vput(pack.ep_vp);
501 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
502 free(pack.ep_hdr, M_EXEC);
503 exit1(p, W_EXITCODE(error, SIGABRT));
504
505 /* NOTREACHED */
506 return 0;
507 }
508