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