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netbsd32_execve.c revision 1.4.2.2
      1 /*	$NetBSD: netbsd32_execve.c,v 1.4.2.2 2002/01/10 19:51:54 thorpej 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 1.4.2.2 2002/01/10 19:51:54 thorpej 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 #if defined(LKM) || defined(_LKM)
     64 extern struct lock exec_lock;
     65 #endif
     66 
     67 /*
     68  * Need to completly reimplement this syscall due to argument copying.
     69  */
     70 /* ARGSUSED */
     71 int
     72 netbsd32_execve(p, v, retval)
     73 	struct proc *p;
     74 	void *v;
     75 	register_t *retval;
     76 {
     77 	struct netbsd32_execve_args /* {
     78 		syscallarg(const netbsd32_charp) path;
     79 		syscallarg(netbsd32_charpp) argp;
     80 		syscallarg(netbsd32_charpp) envp;
     81 	} */ *uap = v;
     82 	struct sys_execve_args ua;
     83 	caddr_t sg;
     84 
     85 	NETBSD32TOP_UAP(path, const char);
     86 	NETBSD32TOP_UAP(argp, char *);
     87 	NETBSD32TOP_UAP(envp, char *);
     88 	sg = stackgap_init(p->p_emul);
     89 	CHECK_ALT_EXIST(p, &sg, SCARG(&ua, path));
     90 
     91 	return netbsd32_execve2(p, &ua, retval);
     92 }
     93 
     94 int
     95 netbsd32_execve2(p, uap, retval)
     96 	struct proc *p;
     97 	struct sys_execve_args *uap;
     98 	register_t *retval;
     99 {
    100 	/* Function args */
    101 	int error, i;
    102 	struct exec_package pack;
    103 	struct nameidata nid;
    104 	struct vattr attr;
    105 	struct ucred *cred = p->p_ucred;
    106 	char *argp;
    107 	netbsd32_charp const *cpp;
    108 	char *dp;
    109 	netbsd32_charp sp;
    110 	long argc, envc;
    111 	size_t len;
    112 	char *stack;
    113 	struct ps_strings arginfo;
    114 	struct vmspace *vm;
    115 	char **tmpfap;
    116 	int szsigcode;
    117 	struct exec_vmcmd *base_vcp = NULL;
    118 
    119 	/*
    120 	 * Init the namei data to point the file user's program name.
    121 	 * This is done here rather than in check_exec(), so that it's
    122 	 * possible to override this settings if any of makecmd/probe
    123 	 * functions call check_exec() recursively - for example,
    124 	 * see exec_script_makecmds().
    125 	 */
    126 	NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
    127 
    128 	/*
    129 	 * initialize the fields of the exec package.
    130 	 */
    131 	pack.ep_name = SCARG(uap, path);
    132 	pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK);
    133 	pack.ep_hdrlen = exec_maxhdrsz;
    134 	pack.ep_hdrvalid = 0;
    135 	pack.ep_ndp = &nid;
    136 	pack.ep_emul_arg = NULL;
    137 	pack.ep_vmcmds.evs_cnt = 0;
    138 	pack.ep_vmcmds.evs_used = 0;
    139 	pack.ep_vap = &attr;
    140 	pack.ep_flags = 0;
    141 
    142 #if defined(LKM) || defined(_LKM)
    143 	lockmgr(&exec_lock, LK_SHARED, NULL);
    144 #endif
    145 
    146 	/* see if we can run it. */
    147 	if ((error = check_exec(p, &pack)) != 0)
    148 		goto freehdr;
    149 
    150 	/* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
    151 
    152 	/* allocate an argument buffer */
    153 	argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS);
    154 #ifdef DIAGNOSTIC
    155 	if (argp == (vaddr_t) 0)
    156 		panic("netbsd32_execve: argp == NULL");
    157 #endif
    158 	dp = argp;
    159 	argc = 0;
    160 
    161 	/* copy the fake args list, if there's one, freeing it as we go */
    162 	if (pack.ep_flags & EXEC_HASARGL) {
    163 		tmpfap = pack.ep_fa;
    164 		while (*tmpfap != NULL) {
    165 			char *cp;
    166 
    167 			cp = *tmpfap;
    168 			while (*cp)
    169 				*dp++ = *cp++;
    170 			dp++;
    171 
    172 			FREE(*tmpfap, M_EXEC);
    173 			tmpfap++; argc++;
    174 		}
    175 		FREE(pack.ep_fa, M_EXEC);
    176 		pack.ep_flags &= ~EXEC_HASARGL;
    177 	}
    178 
    179 	/* Now get argv & environment */
    180 	if (!(cpp = (netbsd32_charp *)SCARG(uap, argp))) {
    181 		error = EINVAL;
    182 		goto bad;
    183 	}
    184 
    185 	if (pack.ep_flags & EXEC_SKIPARG)
    186 		cpp++;
    187 
    188 	while (1) {
    189 		len = argp + ARG_MAX - dp;
    190 		if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
    191 			goto bad;
    192 		if (!sp)
    193 			break;
    194 		if ((error = copyinstr((char *)(u_long)sp, dp,
    195 				       len, &len)) != 0) {
    196 			if (error == ENAMETOOLONG)
    197 				error = E2BIG;
    198 			goto bad;
    199 		}
    200 		dp += len;
    201 		cpp++;
    202 		argc++;
    203 	}
    204 
    205 	envc = 0;
    206 	/* environment need not be there */
    207 	if ((cpp = (netbsd32_charp *)SCARG(uap, envp)) != NULL ) {
    208 		while (1) {
    209 			len = argp + ARG_MAX - dp;
    210 			if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
    211 				goto bad;
    212 			if (!sp)
    213 				break;
    214 			if ((error = copyinstr((char *)(u_long)sp,
    215 					       dp, len, &len)) != 0) {
    216 				if (error == ENAMETOOLONG)
    217 					error = E2BIG;
    218 				goto bad;
    219 			}
    220 			dp += len;
    221 			cpp++;
    222 			envc++;
    223 		}
    224 	}
    225 
    226 	dp = (char *) ALIGN(dp);
    227 
    228 	szsigcode = pack.ep_es->es_emul->e_esigcode -
    229 	    pack.ep_es->es_emul->e_sigcode;
    230 
    231 	/* Now check if args & environ fit into new stack */
    232 	if (pack.ep_flags & EXEC_32)
    233 		len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
    234 		    sizeof(int) + sizeof(int) + dp + STACKGAPLEN +
    235 		    szsigcode + sizeof(struct ps_strings)) - argp;
    236 	else
    237 		len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
    238 		    sizeof(char *) + sizeof(int) + dp + STACKGAPLEN +
    239 		    szsigcode + sizeof(struct ps_strings)) - argp;
    240 
    241 	len = ALIGN(len);	/* make the stack "safely" aligned */
    242 
    243 	if (len > pack.ep_ssize) { /* in effect, compare to initial limit */
    244 		error = ENOMEM;
    245 		goto bad;
    246 	}
    247 
    248 	/* adjust "active stack depth" for process VSZ */
    249 	pack.ep_ssize = len;	/* maybe should go elsewhere, but... */
    250 
    251 	/*
    252 	 * Do whatever is necessary to prepare the address space
    253 	 * for remapping.  Note that this might replace the current
    254 	 * vmspace with another!
    255 	 */
    256 	uvmspace_exec(p, VM_MIN_ADDRESS, (vaddr_t)pack.ep_minsaddr);
    257 
    258 	/* Now map address space */
    259 	vm = p->p_vmspace;
    260 	vm->vm_taddr = (char *) pack.ep_taddr;
    261 	vm->vm_tsize = btoc(pack.ep_tsize);
    262 	vm->vm_daddr = (char *) pack.ep_daddr;
    263 	vm->vm_dsize = btoc(pack.ep_dsize);
    264 	vm->vm_ssize = btoc(pack.ep_ssize);
    265 	vm->vm_maxsaddr = (char *) pack.ep_maxsaddr;
    266 	vm->vm_minsaddr = (char *) pack.ep_minsaddr;
    267 
    268 	/* create the new process's VM space by running the vmcmds */
    269 #ifdef DIAGNOSTIC
    270 	if (pack.ep_vmcmds.evs_used == 0)
    271 		panic("netbsd32_execve: no vmcmds");
    272 #endif
    273 	for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) {
    274 		struct exec_vmcmd *vcp;
    275 
    276 		vcp = &pack.ep_vmcmds.evs_cmds[i];
    277 		if (vcp->ev_flags & VMCMD_RELATIVE) {
    278 #ifdef DIAGNOSTIC
    279 			if (base_vcp == NULL)
    280 				panic("netbsd32_execve: relative vmcmd with no base");
    281 			if (vcp->ev_flags & VMCMD_BASE)
    282 				panic("netbsd32_execve: illegal base & relative vmcmd");
    283 #endif
    284 			vcp->ev_addr += base_vcp->ev_addr;
    285 		}
    286 		error = (*vcp->ev_proc)(p, vcp);
    287 #ifdef DEBUG
    288 		if (error) {
    289 			int j;
    290 
    291 			for (j = 0; j <= i; j++)
    292 				printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", j,
    293 				       vcp[j-i].ev_addr, vcp[j-i].ev_len,
    294 				       vcp[j-i].ev_offset);
    295 		}
    296 #endif
    297 		if (vcp->ev_flags & VMCMD_BASE)
    298 			base_vcp = vcp;
    299 	}
    300 
    301 	/* free the vmspace-creation commands, and release their references */
    302 	kill_vmcmds(&pack.ep_vmcmds);
    303 
    304 	/* if an error happened, deallocate and punt */
    305 	if (error) {
    306 #ifdef DEBUG
    307 		printf("netbsd32_execve: vmcmd %i failed: %d\n", i-1, error);
    308 #endif
    309 		goto exec_abort;
    310 	}
    311 
    312 	/* remember information about the process */
    313 	arginfo.ps_nargvstr = argc;
    314 	arginfo.ps_nenvstr = envc;
    315 
    316 	stack = (char *) (vm->vm_minsaddr - len);
    317 	/* Now copy argc, args & environ to new stack */
    318 	error = (*pack.ep_es->es_copyargs)(&pack, &arginfo,
    319 	    &stack, argp);
    320 	if (error) {
    321 #ifdef DEBUG
    322 		printf("netbsd32_execve: copyargs failed\n");
    323 #endif
    324 		goto exec_abort;
    325 	}
    326 	/* restore the stack back to its original point */
    327 	stack = (char *) (vm->vm_minsaddr - len);
    328 
    329 	/* fill process ps_strings info */
    330 	p->p_psstr = (struct ps_strings *)(stack - sizeof(struct ps_strings));
    331 	p->p_psargv = offsetof(struct ps_strings, ps_argvstr);
    332 	p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr);
    333 	p->p_psenv = offsetof(struct ps_strings, ps_envstr);
    334 	p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr);
    335 
    336 	/* copy out the process's ps_strings structure */
    337 	if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) {
    338 #ifdef DEBUG
    339 		printf("netbsd32_execve: ps_strings copyout failed\n");
    340 #endif
    341 		goto exec_abort;
    342 	}
    343 
    344 	/* copy out the process's signal trapoline code */
    345 	if (szsigcode) {
    346 		if (copyout((char *)pack.ep_es->es_emul->e_sigcode,
    347 		    p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode,
    348 		    szsigcode)) {
    349 #ifdef DEBUG
    350 			printf("netbsd32_execve: sig trampoline copyout failed\n");
    351 #endif
    352 			goto exec_abort;
    353 		}
    354 #ifdef PMAP_NEED_PROCWR
    355 		/* This is code. Let the pmap do what is needed. */
    356 		pmap_procwr(p, (vaddr_t)p->p_sigacts->ps_sigcode, szsigcode);
    357 #endif
    358 	}
    359 
    360 	stopprofclock(p);	/* stop profiling */
    361 	fdcloseexec(p);		/* handle close on exec */
    362 	execsigs(p);		/* reset catched signals */
    363 	p->p_ctxlink = NULL;	/* reset ucontext link */
    364 
    365 	/* set command name & other accounting info */
    366 	len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN);
    367 	memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len);
    368 	p->p_comm[len] = 0;
    369 	p->p_acflag &= ~AFORK;
    370 
    371 	/* record proc's vnode, for use by procfs and others */
    372         if (p->p_textvp)
    373                 vrele(p->p_textvp);
    374 	VREF(pack.ep_vp);
    375 	p->p_textvp = pack.ep_vp;
    376 
    377 	p->p_flag |= P_EXEC;
    378 	if (p->p_flag & P_PPWAIT) {
    379 		p->p_flag &= ~P_PPWAIT;
    380 		wakeup((caddr_t) p->p_pptr);
    381 	}
    382 
    383 	/*
    384 	 * deal with set[ug]id.
    385 	 * MNT_NOSUID has already been used to disable s[ug]id.
    386 	 */
    387 	if ((p->p_flag & P_TRACED) == 0 &&
    388 
    389 	    (((attr.va_mode & S_ISUID) != 0 &&
    390 	      p->p_ucred->cr_uid != attr.va_uid) ||
    391 
    392 	     ((attr.va_mode & S_ISGID) != 0 &&
    393 	      p->p_ucred->cr_gid != attr.va_gid))) {
    394 		/*
    395 		 * Mark the process as SUGID before we do
    396 		 * anything that might block.
    397 		 */
    398 		p_sugid(p);
    399 
    400 		p->p_ucred = crcopy(cred);
    401 #ifdef KTRACE
    402 		/*
    403 		 * If process is being ktraced, turn off - unless
    404 		 * root set it.
    405 		 */
    406 		if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT))
    407 			ktrderef(p);
    408 #endif
    409 		if (attr.va_mode & S_ISUID)
    410 			p->p_ucred->cr_uid = attr.va_uid;
    411 		if (attr.va_mode & S_ISGID)
    412 			p->p_ucred->cr_gid = attr.va_gid;
    413 	} else
    414 		p->p_flag &= ~P_SUGID;
    415 	p->p_cred->p_svuid = p->p_ucred->cr_uid;
    416 	p->p_cred->p_svgid = p->p_ucred->cr_gid;
    417 
    418 	doexechooks(p);
    419 
    420 	uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
    421 
    422 	PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
    423 	vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
    424 	VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
    425 	vput(pack.ep_vp);
    426 
    427 	/* setup new registers and do misc. setup. */
    428 	(*pack.ep_es->es_setregs)(p, &pack, (u_long) stack);
    429 
    430 	if (p->p_flag & P_TRACED)
    431 		psignal(p, SIGTRAP);
    432 
    433 	free(pack.ep_hdr, M_EXEC);
    434 
    435 	/*
    436 	 * Call emulation specific exec hook. This can setup setup per-process
    437 	 * p->p_emuldata or do any other per-process stuff an emulation needs.
    438 	 *
    439 	 * If we are executing process of different emulation than the
    440 	 * original forked process, call e_proc_exit() of the old emulation
    441 	 * first, then e_proc_exec() of new emulation. If the emulation is
    442 	 * same, the exec hook code should deallocate any old emulation
    443 	 * resources held previously by this process.
    444 	 */
    445 	if (p->p_emul && p->p_emul->e_proc_exit
    446 	    && p->p_emul != pack.ep_es->es_emul)
    447 		(*p->p_emul->e_proc_exit)(p);
    448 
    449 	/*
    450 	 * Call exec hook. Emulation code may NOT store reference to anything
    451 	 * from &pack.
    452 	 */
    453         if (pack.ep_es->es_emul->e_proc_exec)
    454                 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack);
    455 
    456 	/* update p_emul, the old value is no longer needed */
    457 	p->p_emul = pack.ep_es->es_emul;
    458 
    459 #ifdef KTRACE
    460 	if (KTRPOINT(p, KTR_EMUL))
    461 		ktremul(p);
    462 #endif
    463 
    464 #if defined(LKM) || defined(_LKM)
    465 	lockmgr(&exec_lock, LK_RELEASE, NULL);
    466 #endif
    467 
    468 	return (EJUSTRETURN);
    469 
    470 bad:
    471 	/* free the vmspace-creation commands, and release their references */
    472 	kill_vmcmds(&pack.ep_vmcmds);
    473 	/* kill any opened file descriptor, if necessary */
    474 	if (pack.ep_flags & EXEC_HASFD) {
    475 		pack.ep_flags &= ~EXEC_HASFD;
    476 		(void) fdrelease(p, pack.ep_fd);
    477 	}
    478 	/* close and put the exec'd file */
    479 	vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
    480 	VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
    481 	vput(pack.ep_vp);
    482 	PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
    483 	uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
    484 
    485 freehdr:
    486 #if defined(LKM) || defined(_LKM)
    487 	lockmgr(&exec_lock, LK_RELEASE, NULL);
    488 #endif
    489 
    490 	free(pack.ep_hdr, M_EXEC);
    491 	return error;
    492 
    493 exec_abort:
    494 #if defined(LKM) || defined(_LKM)
    495 	lockmgr(&exec_lock, LK_RELEASE, NULL);
    496 #endif
    497 
    498 	/*
    499 	 * the old process doesn't exist anymore.  exit gracefully.
    500 	 * get rid of the (new) address space we have created, if any, get rid
    501 	 * of our namei data and vnode, and exit noting failure
    502 	 */
    503 	uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
    504 		VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
    505 	if (pack.ep_emul_arg)
    506 		FREE(pack.ep_emul_arg, M_TEMP);
    507 	PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
    508 	vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
    509 	VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
    510 	vput(pack.ep_vp);
    511 	uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
    512 	free(pack.ep_hdr, M_EXEC);
    513 	exit1(p, W_EXITCODE(error, SIGABRT));
    514 
    515 	/* NOTREACHED */
    516 	return 0;
    517 }
    518