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freebsd_exec.c revision 1.4.8.2
      1 /*	$NetBSD: freebsd_exec.c,v 1.4.8.2 2000/11/22 16:02:22 bouyer Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1993, 1994 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 "opt_execfmt.h"
     34 
     35 #include <sys/param.h>
     36 #include <sys/systm.h>
     37 #include <sys/proc.h>
     38 #include <sys/malloc.h>
     39 #include <sys/vnode.h>
     40 #include <sys/exec.h>
     41 #ifdef EXEC_ELF32
     42 # ifndef ELFSIZE
     43 #  define ELFSIZE 32
     44 # endif /* !ELFSIZE */
     45 # include <sys/exec_elf.h>
     46 #endif /* EXEC_ELF32 */
     47 #include <sys/resourcevar.h>
     48 
     49 #include <machine/freebsd_machdep.h>
     50 
     51 #include <compat/freebsd/freebsd_exec.h>
     52 #include <compat/freebsd/freebsd_util.h>
     53 
     54 #include <compat/freebsd/freebsd_syscall.h>
     55 
     56 extern struct sysent freebsd_sysent[];
     57 extern const char * const freebsd_syscallnames[];
     58 
     59 const struct emul emul_freebsd = {
     60 	"freebsd",
     61 	NULL,
     62 	freebsd_sendsig,
     63 	FREEBSD_SYS_syscall,
     64 	FREEBSD_SYS_MAXSYSCALL,
     65 	freebsd_sysent,
     66 	freebsd_syscallnames,
     67 	freebsd_sigcode,
     68 	freebsd_esigcode,
     69 };
     70 
     71 #ifdef EXEC_ELF32
     72 
     73 int
     74 ELFNAME2(freebsd,probe)(p, epp, veh, itp, pos)
     75 	struct proc *p;
     76 	struct exec_package *epp;
     77 	void *veh;
     78 	char *itp;
     79 	vaddr_t *pos;
     80 {
     81 	int error;
     82 	size_t i;
     83 	size_t phsize;
     84 	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
     85 	Elf_Phdr *ph;
     86 	Elf_Phdr *ephp;
     87 	Elf_Nhdr *np;
     88 	const char *bp;
     89 
     90         static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
     91         static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;
     92 
     93         /* Insist that the executable have a brand, and that it be "FreeBSD" */
     94 #ifndef EI_BRAND
     95 #define EI_BRAND 8
     96 #endif
     97         if (eh->e_ident[EI_BRAND] == '\0'
     98 	  || strcmp(&eh->e_ident[EI_BRAND], wantBrand))
     99 		return ENOEXEC;
    100 
    101 	i = eh->e_phnum;
    102 	if (i != 0) {
    103 		phsize = i * sizeof(Elf_Phdr);
    104 		ph = (Elf_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
    105 		if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
    106 		    (caddr_t) ph, phsize)) != 0)
    107 			goto bad1;
    108 
    109 		for (ephp = ph; i--; ephp++) {
    110 			if (ephp->p_type != PT_INTERP)
    111 				continue;
    112 
    113 			/* Check for "legal" intepreter name. */
    114 			if (ephp->p_filesz < sizeof wantInterp)
    115 				goto bad1;
    116 
    117 			np = (Elf_Nhdr *) malloc(ephp->p_filesz+1,
    118 			    M_TEMP, M_WAITOK);
    119 
    120 			if (((error = ELFNAME(read_from)(p, epp->ep_vp,
    121 			    ephp->p_offset, (caddr_t)np, ephp->p_filesz)) != 0))
    122 				goto bad2;
    123 
    124 			if (strncmp((char *)np, wantInterp,
    125 			    sizeof wantInterp - 1))
    126 				goto bad2;
    127 
    128 			free(np, M_TEMP);
    129 			break;
    130 		}
    131 		free(ph, M_TEMP);
    132 	}
    133 
    134 	if (itp[0]) {
    135 		if ((error = emul_find(p, NULL, freebsd_emul_path,
    136 		    itp, &bp, 0)))
    137 			return error;
    138 		if ((error = copystr(bp, itp, MAXPATHLEN, &i)) != 0)
    139 			return error;
    140 		free((void *)bp, M_TEMP);
    141 	}
    142 	*pos = ELF_NO_ADDR;
    143 #ifdef DEBUG_FREEBSD_ELF
    144 	printf("freebsd_elf32_probe: returning 0\n");
    145 #endif
    146 	return 0;
    147 
    148 bad2:
    149 	free(np, M_TEMP);
    150 bad1:
    151 	free(ph, M_TEMP);
    152 	return ENOEXEC;
    153 }
    154 #endif /* EXEC_ELF32 */
    155 
    156 
    157 #ifdef EXEC_AOUT
    158 /*
    159 * exec_aout_makecmds(): Check if it's an a.out-format executable.
    160 *
    161 * Given a proc pointer and an exec package pointer, see if the referent
    162 * of the epp is in a.out format.  First check 'standard' magic numbers for
    163 * this architecture.  If that fails, try a cpu-dependent hook.
    164  *
    165  * This function, in the former case, or the hook, in the latter, is
    166  * responsible for creating a set of vmcmds which can be used to build
    167  * the process's vm space and inserting them into the exec package.
    168  */
    169 
    170 int
    171 exec_freebsd_aout_makecmds(p, epp)
    172 	struct proc *p;
    173 	struct exec_package *epp;
    174 {
    175 	u_long midmag;
    176 	int error = ENOEXEC;
    177 	struct exec *execp = epp->ep_hdr;
    178 
    179 	if (epp->ep_hdrvalid < sizeof(struct exec))
    180 		return ENOEXEC;
    181 
    182 	midmag = FREEBSD_N_GETMID(*execp) << 16 | FREEBSD_N_GETMAGIC(*execp);
    183 
    184 	/* assume FreeBSD's MID_MACHINE and [ZQNO]MAGIC is same as NetBSD's */
    185 	switch (midmag) {
    186 	case (MID_MACHINE << 16) | ZMAGIC:
    187 		error = exec_aout_prep_oldzmagic(p, epp);
    188 		break;
    189 	case (MID_MACHINE << 16) | QMAGIC:
    190 		error = exec_aout_prep_zmagic(p, epp);
    191 		break;
    192 	case (MID_MACHINE << 16) | NMAGIC:
    193 		error = exec_aout_prep_nmagic(p, epp);
    194 		break;
    195 	case (MID_MACHINE << 16) | OMAGIC:
    196 		error = exec_aout_prep_omagic(p, epp);
    197 		break;
    198 	}
    199 	if (error)
    200 		kill_vmcmds(&epp->ep_vmcmds);
    201 
    202 	return error;
    203 }
    204 #endif /* EXEC_AOUT */
    205