sys/compat/freebsd/freebsd_exec_elf32.c

   1 /*      $NetBSD: freebsd_exec_elf32.c,v 1.16 2006/11/16 01:32:42 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 1.16 2006/11/16 01:32:42 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)(
  58         struct lwp *l,
  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(l, 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(l, 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(l, epp, itp)))
 124                         return error;
 125         }
 126 #ifdef DEBUG_FREEBSD_ELF
 127         printf("freebsd_elf32_probe: returning 0\n");
 128 #endif
 129         return 0;
 130
 131 bad2:
 132         free(np, M_TEMP);
 133 bad1:
 134         free(ph, M_TEMP);
 135         return ENOEXEC;
 136 }