bsd-user/bsdload.c

   1 /* Code for loading BSD executables.  Mostly linux kernel code.  */
   2
   3 #include "qemu/osdep.h"
   4
   5 #include "qemu.h"
   6
   7 #define TARGET_NGROUPS 32
   8
   9 /* ??? This should really be somewhere else.  */
  10 abi_long memcpy_to_target(abi_ulong dest, const void *src,
  11                           unsigned long len)
  12 {
  13     void *host_ptr;
  14
  15     host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
  16     if (!host_ptr) {
  17         return -TARGET_EFAULT;
  18     }
  19     memcpy(host_ptr, src, len);
  20     unlock_user(host_ptr, dest, 1);
  21     return 0;
  22 }
  23
  24 static int count(char **vec)
  25 {
  26     int         i;
  27
  28     for (i = 0; *vec; i++) {
  29         vec++;
  30     }
  31
  32     return i;
  33 }
  34
  35 static int prepare_binprm(struct linux_binprm *bprm)
  36 {
  37     struct stat         st;
  38     int mode;
  39     int retval;
  40
  41     if (fstat(bprm->fd, &st) < 0) {
  42         return -errno;
  43     }
  44
  45     mode = st.st_mode;
  46     if (!S_ISREG(mode)) {        /* Must be regular file */
  47         return -EACCES;
  48     }
  49     if (!(mode & 0111)) {        /* Must have at least one execute bit set */
  50         return -EACCES;
  51     }
  52
  53     bprm->e_uid = geteuid();
  54     bprm->e_gid = getegid();
  55
  56     /* Set-uid? */
  57     if (mode & S_ISUID) {
  58         bprm->e_uid = st.st_uid;
  59     }
  60
  61     /* Set-gid? */
  62     /*
  63      * If setgid is set but no group execute bit then this
  64      * is a candidate for mandatory locking, not a setgid
  65      * executable.
  66      */
  67     if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
  68         bprm->e_gid = st.st_gid;
  69     }
  70
  71     memset(bprm->buf, 0, sizeof(bprm->buf));
  72     retval = lseek(bprm->fd, 0L, SEEK_SET);
  73     if (retval >= 0) {
  74         retval = read(bprm->fd, bprm->buf, 128);
  75     }
  76     if (retval < 0) {
  77         perror("prepare_binprm");
  78         exit(-1);
  79     } else {
  80         return retval;
  81     }
  82 }
  83
  84 /* Construct the envp and argv tables on the target stack.  */
  85 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
  86                               abi_ulong stringp, int push_ptr)
  87 {
  88     int n = sizeof(abi_ulong);
  89     abi_ulong envp;
  90     abi_ulong argv;
  91
  92     sp -= (envc + 1) * n;
  93     envp = sp;
  94     sp -= (argc + 1) * n;
  95     argv = sp;
  96     if (push_ptr) {
  97         /* FIXME - handle put_user() failures */
  98         sp -= n;
  99         put_user_ual(envp, sp);
 100         sp -= n;
 101         put_user_ual(argv, sp);
 102     }
 103     sp -= n;
 104     /* FIXME - handle put_user() failures */
 105     put_user_ual(argc, sp);
 106
 107     while (argc-- > 0) {
 108         /* FIXME - handle put_user() failures */
 109         put_user_ual(stringp, argv);
 110         argv += n;
 111         stringp += target_strlen(stringp) + 1;
 112     }
 113     /* FIXME - handle put_user() failures */
 114     put_user_ual(0, argv);
 115     while (envc-- > 0) {
 116         /* FIXME - handle put_user() failures */
 117         put_user_ual(stringp, envp);
 118         envp += n;
 119         stringp += target_strlen(stringp) + 1;
 120     }
 121     /* FIXME - handle put_user() failures */
 122     put_user_ual(0, envp);
 123
 124     return sp;
 125 }
 126
 127 int loader_exec(const char *filename, char **argv, char **envp,
 128              struct target_pt_regs *regs, struct image_info *infop)
 129 {
 130     struct linux_binprm bprm;
 131     int retval;
 132     int i;
 133
 134     bprm.p = TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(unsigned int);
 135     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {     /* clear page-table */
 136             bprm.page[i] = NULL;
 137     }
 138     retval = open(filename, O_RDONLY);
 139     if (retval < 0) {
 140         return retval;
 141     }
 142     bprm.fd = retval;
 143     bprm.filename = (char *)filename;
 144     bprm.argc = count(argv);
 145     bprm.argv = argv;
 146     bprm.envc = count(envp);
 147     bprm.envp = envp;
 148
 149     retval = prepare_binprm(&bprm);
 150
 151     if (retval >= 0) {
 152         if (bprm.buf[0] == 0x7f
 153                 && bprm.buf[1] == 'E'
 154                 && bprm.buf[2] == 'L'
 155                 && bprm.buf[3] == 'F') {
 156             retval = load_elf_binary(&bprm, regs, infop);
 157         } else {
 158             fprintf(stderr, "Unknown binary format\n");
 159             return -1;
 160         }
 161     }
 162
 163     if (retval >= 0) {
 164         /* success.  Initialize important registers */
 165         do_init_thread(regs, infop);
 166         return retval;
 167     }
 168
 169     /* Something went wrong, return the inode and free the argument pages*/
 170     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 171         g_free(bprm.page[i]);
 172     }
 173     return retval;
 174 }