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