LXR qemu/linux-user/linuxload.c

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