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freebsd_exec_elf32.c revision 1.13 
      1 /*	$NetBSD: freebsd_exec_elf32.c,v 1.13 2005/09/13 01:42:32 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 1.13 2005/09/13 01:42:32 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 <compat/sys/signal.h>
     48 #include <compat/sys/signalvar.h>
     49 
     50 #include <compat/freebsd/freebsd_exec.h>
     51 #include <compat/common/compat_util.h>
     52 
     53 #include <machine/freebsd_machdep.h>
     54 
     55 
     56 int
     57 ELFNAME2(freebsd,probe)(p, epp, veh, itp, pos)
     58 	struct proc *p;
     59 	struct exec_package *epp;
     60 	void *veh;
     61 	char *itp;
     62 	vaddr_t *pos;
     63 {
     64 	int error;
     65 	size_t i;
     66 	size_t phsize;
     67 	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
     68 	Elf_Phdr *ph;
     69 	Elf_Phdr *ephp;
     70 	Elf_Nhdr *np;
     71 
     72         static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
     73         static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;
     74 
     75         /*
     76 	 * Insist that the executable have a brand, and that it be "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.
     80 	 */
     81 #ifndef EI_BRAND
     82 #define EI_BRAND 8
     83 #endif
     84         if ((eh->e_ident[EI_BRAND] == '\0'
     85 		|| strcmp(&eh->e_ident[EI_BRAND], wantBrand) != 0)
     86 	    && eh->e_ident[EI_OSABI] != ELFOSABI_FREEBSD)
     87 		return ENOEXEC;
     88 
     89 	i = eh->e_phnum;
     90 	if (i != 0) {
     91 		phsize = i * sizeof(Elf_Phdr);
     92 		ph = (Elf_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
     93 		if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph,
     94 		    phsize)) != 0)
     95 			goto bad1;
     96 
     97 		for (ephp = ph; i--; ephp++) {
     98 			if (ephp->p_type != PT_INTERP)
     99 				continue;
    100 
    101 			/* Check for "legal" intepreter name. */
    102 			if (ephp->p_filesz < sizeof wantInterp)
    103 				goto bad1;
    104 
    105 			np = (Elf_Nhdr *) malloc(ephp->p_filesz+1,
    106 			    M_TEMP, M_WAITOK);
    107 
    108 			if (((error = exec_read_from(p, epp->ep_vp,
    109 			    ephp->p_offset, np, ephp->p_filesz)) != 0))
    110 				goto bad2;
    111 
    112 			if (strncmp((char *)np, wantInterp,
    113 			    sizeof wantInterp - 1))
    114 				goto bad2;
    115 
    116 			free(np, M_TEMP);
    117 			break;
    118 		}
    119 		free(ph, M_TEMP);
    120 	}
    121 
    122 	if (itp) {
    123 		if ((error = emul_find_interp(p, epp->ep_esch->es_emul->e_path,
    124 		    itp)))
    125 			return error;
    126 	}
    127 #ifdef DEBUG_FREEBSD_ELF
    128 	printf("freebsd_elf32_probe: returning 0\n");
    129 #endif
    130 	return 0;
    131 
    132 bad2:
    133 	free(np, M_TEMP);
    134 bad1:
    135 	free(ph, M_TEMP);
    136 	return ENOEXEC;
    137 }
    138