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freebsd_exec_elf32.c revision 1.7 
      1 /*	$NetBSD: freebsd_exec_elf32.c,v 1.7 2002/11/19 22:38:07 christos 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 <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: freebsd_exec_elf32.c,v 1.7 2002/11/19 22:38:07 christos 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/exec.h>
     42 #ifndef ELFSIZE
     43 #  define ELFSIZE 32
     44 #endif /* !ELFSIZE */
     45 #include <sys/exec_elf.h>
     46 
     47 #include <machine/freebsd_machdep.h>
     48 
     49 #include <compat/freebsd/freebsd_exec.h>
     50 #include <compat/common/compat_util.h>
     51 
     52 int
     53 ELFNAME2(freebsd,probe)(p, epp, veh, itp, pos)
     54 	struct proc *p;
     55 	struct exec_package *epp;
     56 	void *veh;
     57 	char *itp;
     58 	vaddr_t *pos;
     59 {
     60 	int error;
     61 	size_t i;
     62 	size_t phsize;
     63 	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
     64 	Elf_Phdr *ph;
     65 	Elf_Phdr *ephp;
     66 	Elf_Nhdr *np;
     67 	const char *bp;
     68 
     69         static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
     70         static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;
     71 
     72 #ifndef EI_BRAND
     73 #define EI_BRAND 8
     74 #endif
     75 	/*
     76 	 * If a binary has a brand, make sure that it is "FreeBSD".
     77 	 * Newer FreeBSD binaries have OSABI set to ELFOSABI_FREEBSD. This
     78 	 * is arguably broken, but they seem to think they need it, for
     79 	 * whatever reason. If the OSABI field is set, insist that it is
     80 	 * ELFOSABI_FREEBSD.
     81 	 */
     82 	if ((eh->e_ident[EI_BRAND] != '\0' &&
     83 	    strcmp(&eh->e_ident[EI_BRAND], wantBrand) != 0) ||
     84 	    (eh->e_ident[EI_OSABI] != 0 &&
     85 	    eh->e_ident[EI_OSABI] != ELFOSABI_FREEBSD))
     86 		return ENOEXEC;
     87 
     88 	i = eh->e_phnum;
     89 	if (i != 0) {
     90 		phsize = i * sizeof(Elf_Phdr);
     91 		ph = (Elf_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
     92 		if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph,
     93 		    phsize)) != 0)
     94 			goto bad1;
     95 
     96 		for (ephp = ph; i--; ephp++) {
     97 			if (ephp->p_type != PT_INTERP)
     98 				continue;
     99 
    100 			/* Check for "legal" intepreter name. */
    101 			if (ephp->p_filesz < sizeof wantInterp)
    102 				goto bad1;
    103 
    104 			np = (Elf_Nhdr *) malloc(ephp->p_filesz+1,
    105 			    M_TEMP, M_WAITOK);
    106 
    107 			if (((error = exec_read_from(p, epp->ep_vp,
    108 			    ephp->p_offset, np, ephp->p_filesz)) != 0))
    109 				goto bad2;
    110 
    111 			if (strncmp((char *)np, wantInterp,
    112 			    sizeof wantInterp - 1))
    113 				goto bad2;
    114 
    115 			free(np, M_TEMP);
    116 			break;
    117 		}
    118 		free(ph, M_TEMP);
    119 	}
    120 
    121 	if (itp[0]) {
    122 		if ((error = emul_find(p, NULL, epp->ep_esch->es_emul->e_path,
    123 		    itp, &bp, 0)))
    124 			return error;
    125 		if ((error = copystr(bp, itp, MAXPATHLEN, &i)) != 0)
    126 			return error;
    127 		free((void *)bp, M_TEMP);
    128 	}
    129 	*pos = ELF_NO_ADDR;
    130 #ifdef DEBUG_FREEBSD_ELF
    131 	printf("freebsd_elf32_probe: returning 0\n");
    132 #endif
    133 	return 0;
    134 
    135 bad2:
    136 	free(np, M_TEMP);
    137 bad1:
    138 	free(ph, M_TEMP);
    139 	return ENOEXEC;
    140 }
    141