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 in_group_p(gid_t g) 30 { 31 /* return TRUE if we're in the specified group, FALSE otherwise */ 32 int ngroup; 33 int i; 34 gid_t grouplist[NGROUPS]; 35 36 ngroup = getgroups(NGROUPS, grouplist); 37 for(i = 0; i < ngroup; i++) { 38 if(grouplist[i] == g) { 39 return 1; 40 } 41 } 42 return 0; 43 } 44 45 static int count(char ** vec) 46 { 47 int i; 48 49 for(i = 0; *vec; i++) { 50 vec++; 51 } 52 53 return(i); 54 } 55 56 static int prepare_binprm(struct linux_binprm *bprm) 57 { 58 struct stat st; 59 int mode; 60 int retval, id_change; 61 62 if(fstat(bprm->fd, &st) < 0) { 63 return(-errno); 64 } 65 66 mode = st.st_mode; 67 if(!S_ISREG(mode)) { /* Must be regular file */ 68 return(-EACCES); 69 } 70 if(!(mode & 0111)) { /* Must have at least one execute bit set */ 71 return(-EACCES); 72 } 73 74 bprm->e_uid = geteuid(); 75 bprm->e_gid = getegid(); 76 id_change = 0; 77 78 /* Set-uid? */ 79 if(mode & S_ISUID) { 80 bprm->e_uid = st.st_uid; 81 if(bprm->e_uid != geteuid()) { 82 id_change = 1; 83 } 84 } 85 86 /* Set-gid? */ 87 /* 88 * If setgid is set but no group execute bit then this 89 * is a candidate for mandatory locking, not a setgid 90 * executable. 91 */ 92 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { 93 bprm->e_gid = st.st_gid; 94 if (!in_group_p(bprm->e_gid)) { 95 id_change = 1; 96 } 97 } 98 99 retval = read(bprm->fd, bprm->buf, BPRM_BUF_SIZE); 100 if (retval < 0) { 101 perror("prepare_binprm"); 102 exit(-1); 103 } 104 if (retval < BPRM_BUF_SIZE) { 105 /* Make sure the rest of the loader won't read garbage. */ 106 memset(bprm->buf + retval, 0, BPRM_BUF_SIZE - retval); 107 } 108 return retval; 109 } 110 111 /* Construct the envp and argv tables on the target stack. */ 112 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, 113 abi_ulong stringp, int push_ptr) 114 { 115 TaskState *ts = (TaskState *)thread_env->opaque; 116 int n = sizeof(abi_ulong); 117 abi_ulong envp; 118 abi_ulong argv; 119 120 sp -= (envc + 1) * n; 121 envp = sp; 122 sp -= (argc + 1) * n; 123 argv = sp; 124 if (push_ptr) { 125 /* FIXME - handle put_user() failures */ 126 sp -= n; 127 put_user_ual(envp, sp); 128 sp -= n; 129 put_user_ual(argv, sp); 130 } 131 sp -= n; 132 /* FIXME - handle put_user() failures */ 133 put_user_ual(argc, sp); 134 ts->info->arg_start = stringp; 135 while (argc-- > 0) { 136 /* FIXME - handle put_user() failures */ 137 put_user_ual(stringp, argv); 138 argv += n; 139 stringp += target_strlen(stringp) + 1; 140 } 141 ts->info->arg_end = stringp; 142 /* FIXME - handle put_user() failures */ 143 put_user_ual(0, argv); 144 while (envc-- > 0) { 145 /* FIXME - handle put_user() failures */ 146 put_user_ual(stringp, envp); 147 envp += n; 148 stringp += target_strlen(stringp) + 1; 149 } 150 /* FIXME - handle put_user() failures */ 151 put_user_ual(0, envp); 152 153 return sp; 154 } 155 156 int loader_exec(const char * filename, char ** argv, char ** envp, 157 struct target_pt_regs * regs, struct image_info *infop, 158 struct linux_binprm *bprm) 159 { 160 int retval; 161 int i; 162 163 bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int); 164 memset(bprm->page, 0, sizeof(bprm->page)); 165 retval = open(filename, O_RDONLY); 166 if (retval < 0) 167 return retval; 168 bprm->fd = retval; 169 bprm->filename = (char *)filename; 170 bprm->argc = count(argv); 171 bprm->argv = argv; 172 bprm->envc = count(envp); 173 bprm->envp = envp; 174 175 retval = prepare_binprm(bprm); 176 177 infop->host_argv = argv; 178 179 if(retval>=0) { 180 if (bprm->buf[0] == 0x7f 181 && bprm->buf[1] == 'E' 182 && bprm->buf[2] == 'L' 183 && bprm->buf[3] == 'F') { 184 retval = load_elf_binary(bprm, regs, infop); 185 #if defined(TARGET_HAS_BFLT) 186 } else if (bprm->buf[0] == 'b' 187 && bprm->buf[1] == 'F' 188 && bprm->buf[2] == 'L' 189 && bprm->buf[3] == 'T') { 190 retval = load_flt_binary(bprm,regs,infop); 191 #endif 192 } else { 193 fprintf(stderr, "Unknown binary format\n"); 194 return -1; 195 } 196 } 197 198 if(retval>=0) { 199 /* success. Initialize important registers */ 200 do_init_thread(regs, infop); 201 return retval; 202 } 203 204 /* Something went wrong, return the inode and free the argument pages*/ 205 for (i=0 ; i<MAX_ARG_PAGES ; i++) { 206 free(bprm->page[i]); 207 } 208 return(retval); 209 } 210