bsd-user/bsdload.c

   1 /*
   2  *  Load BSD executables.
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "qemu/osdep.h"
  19
  20 #include "qemu.h"
  21
  22 #define TARGET_NGROUPS 32
  23
  24 /* ??? This should really be somewhere else.  */
  25 abi_long memcpy_to_target(abi_ulong dest, const void *src,
  26                           unsigned long len)
  27 {
  28     void *host_ptr;
  29
  30     host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
  31     if (!host_ptr) {
  32         return -TARGET_EFAULT;
  33     }
  34     memcpy(host_ptr, src, len);
  35     unlock_user(host_ptr, dest, 1);
  36     return 0;
  37 }
  38
  39 static int count(char **vec)
  40 {
  41     int         i;
  42
  43     for (i = 0; *vec; i++) {
  44         vec++;
  45     }
  46
  47     return i;
  48 }
  49
  50 static int prepare_binprm(struct bsd_binprm *bprm)
  51 {
  52     struct stat         st;
  53     int mode;
  54     int retval;
  55
  56     if (fstat(bprm->fd, &st) < 0) {
  57         return -errno;
  58     }
  59
  60     mode = st.st_mode;
  61     if (!S_ISREG(mode)) {        /* Must be regular file */
  62         return -EACCES;
  63     }
  64     if (!(mode & 0111)) {        /* Must have at least one execute bit set */
  65         return -EACCES;
  66     }
  67
  68     bprm->e_uid = geteuid();
  69     bprm->e_gid = getegid();
  70
  71     /* Set-uid? */
  72     if (mode & S_ISUID) {
  73         bprm->e_uid = st.st_uid;
  74     }
  75
  76     /* Set-gid? */
  77     /*
  78      * If setgid is set but no group execute bit then this
  79      * is a candidate for mandatory locking, not a setgid
  80      * executable.
  81      */
  82     if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
  83         bprm->e_gid = st.st_gid;
  84     }
  85
  86     memset(bprm->buf, 0, sizeof(bprm->buf));
  87     retval = lseek(bprm->fd, 0L, SEEK_SET);
  88     if (retval >= 0) {
  89         retval = read(bprm->fd, bprm->buf, 128);
  90     }
  91     if (retval < 0) {
  92         perror("prepare_binprm");
  93         exit(-1);
  94     } else {
  95         return retval;
  96     }
  97 }
  98
  99 /* Construct the envp and argv tables on the target stack.  */
 100 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 101                               abi_ulong stringp, int push_ptr)
 102 {
 103     int n = sizeof(abi_ulong);
 104     abi_ulong envp;
 105     abi_ulong argv;
 106
 107     sp -= (envc + 1) * n;
 108     envp = sp;
 109     sp -= (argc + 1) * n;
 110     argv = sp;
 111     if (push_ptr) {
 112         /* FIXME - handle put_user() failures */
 113         sp -= n;
 114         put_user_ual(envp, sp);
 115         sp -= n;
 116         put_user_ual(argv, sp);
 117     }
 118     sp -= n;
 119     /* FIXME - handle put_user() failures */
 120     put_user_ual(argc, sp);
 121
 122     while (argc-- > 0) {
 123         /* FIXME - handle put_user() failures */
 124         put_user_ual(stringp, argv);
 125         argv += n;
 126         stringp += target_strlen(stringp) + 1;
 127     }
 128     /* FIXME - handle put_user() failures */
 129     put_user_ual(0, argv);
 130     while (envc-- > 0) {
 131         /* FIXME - handle put_user() failures */
 132         put_user_ual(stringp, envp);
 133         envp += n;
 134         stringp += target_strlen(stringp) + 1;
 135     }
 136     /* FIXME - handle put_user() failures */
 137     put_user_ual(0, envp);
 138
 139     return sp;
 140 }
 141
 142 int loader_exec(const char *filename, char **argv, char **envp,
 143              struct target_pt_regs *regs, struct image_info *infop)
 144 {
 145     struct bsd_binprm bprm;
 146     int retval;
 147     int i;
 148
 149     bprm.p = TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(unsigned int);
 150     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {     /* clear page-table */
 151             bprm.page[i] = NULL;
 152     }
 153     retval = open(filename, O_RDONLY);
 154     if (retval < 0) {
 155         return retval;
 156     }
 157     bprm.fd = retval;
 158     bprm.filename = (char *)filename;
 159     bprm.argc = count(argv);
 160     bprm.argv = argv;
 161     bprm.envc = count(envp);
 162     bprm.envp = envp;
 163
 164     retval = prepare_binprm(&bprm);
 165
 166     if (retval >= 0) {
 167         if (bprm.buf[0] == 0x7f
 168                 && bprm.buf[1] == 'E'
 169                 && bprm.buf[2] == 'L'
 170                 && bprm.buf[3] == 'F') {
 171             retval = load_elf_binary(&bprm, regs, infop);
 172         } else {
 173             fprintf(stderr, "Unknown binary format\n");
 174             return -1;
 175         }
 176     }
 177
 178     if (retval >= 0) {
 179         /* success.  Initialize important registers */
 180         do_init_thread(regs, infop);
 181         return retval;
 182     }
 183
 184     /* Something went wrong, return the inode and free the argument pages*/
 185     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 186         g_free(bprm.page[i]);
 187     }
 188     return retval;
 189 }