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. */ 16 abi_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 29 static int count(char ** vec) 30 { 31 int i; 32 33 for(i = 0; *vec; i++) { 34 vec++; 35 } 36 37 return(i); 38 } 39 40 static 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. */ 89 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, 90 abi_ulong stringp, int push_ptr) 91 { 92 TaskState *ts = (TaskState *)thread_env->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 } 132 133 int loader_exec(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 int i; 139 140 bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int); 141 memset(bprm->page, 0, sizeof(bprm->page)); 142 retval = open(filename, O_RDONLY); 143 if (retval < 0) { 144 return -errno; 145 } 146 bprm->fd = retval; 147 bprm->filename = (char *)filename; 148 bprm->argc = count(argv); 149 bprm->argv = argv; 150 bprm->envc = count(envp); 151 bprm->envp = envp; 152 153 retval = prepare_binprm(bprm); 154 155 if(retval>=0) { 156 if (bprm->buf[0] == 0x7f 157 && bprm->buf[1] == 'E' 158 && bprm->buf[2] == 'L' 159 && bprm->buf[3] == 'F') { 160 retval = load_elf_binary(bprm, regs, infop); 161 #if defined(TARGET_HAS_BFLT) 162 } else if (bprm->buf[0] == 'b' 163 && bprm->buf[1] == 'F' 164 && bprm->buf[2] == 'L' 165 && bprm->buf[3] == 'T') { 166 retval = load_flt_binary(bprm,regs,infop); 167 #endif 168 } else { 169 return -ENOEXEC; 170 } 171 } 172 173 if(retval>=0) { 174 /* success. Initialize important registers */ 175 do_init_thread(regs, infop); 176 return retval; 177 } 178 179 /* Something went wrong, return the inode and free the argument pages*/ 180 for (i=0 ; i<MAX_ARG_PAGES ; i++) { 181 g_free(bprm->page[i]); 182 } 183 return(retval); 184 } 185