diff --git a/execve2.c b/execve2.c new file mode 100644 index 0000000..27647e7 --- /dev/null +++ b/execve2.c @@ -0,0 +1,178 @@ +int do_execve2(unsigned long * eip,long tmp,char * filename, + char ** argv, char ** envp) +{ + struct m_inode * inode; + struct buffer_head * bh; + struct exec ex; + unsigned long page[MAX_ARG_PAGES]; + int i,argc,envc; + int e_uid, e_gid; + int retval; + int sh_bang = 0; + unsigned long p=PAGE_SIZE*MAX_ARG_PAGES-4; + + if ((0xffff & eip[1]) != 0x000f) + panic("execve called from supervisor mode"); + for (i=0 ; ii_mode)) { /* must be regular file */ + retval = -EACCES; + goto exec_error2; + } + i = inode->i_mode; + e_uid = (i & S_ISUID) ? inode->i_uid : current->euid; + e_gid = (i & S_ISGID) ? inode->i_gid : current->egid; + if (current->euid == inode->i_uid) + i >>= 6; + else if (current->egid == inode->i_gid) + i >>= 3; + if (!(i & 1) && + !((inode->i_mode & 0111) && suser())) { + retval = -ENOEXEC; + goto exec_error2; + } + if (!(bh = bread(inode->i_dev,inode->i_zone[0]))) { + retval = -EACCES; + goto exec_error2; + } + ex = *((struct exec *) bh->b_data); /* read exec-header */ + if ((bh->b_data[0] == '#') && (bh->b_data[1] == '!') && (!sh_bang)) { + /* + * This section does the #! interpretation. + * Sorta complicated, but hopefully it will work. -TYT + */ + + char buf[1023], *cp, *interp, *i_name, *i_arg; + unsigned long old_fs; + + strncpy(buf, bh->b_data+2, 1022); + brelse(bh); + iput(inode); + buf[1022] = '\0'; + if (cp = strchr(buf, '\n')) { + *cp = '\0'; + for (cp = buf; (*cp == ' ') || (*cp == '\t'); cp++); + } + if (!cp || *cp == '\0') { + retval = -ENOEXEC; /* No interpreter name found */ + goto exec_error1; + } + interp = i_name = cp; + i_arg = 0; + for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) { + if (*cp == '/') + i_name = cp+1; + } + if (*cp) { + *cp++ = '\0'; + i_arg = cp; + } + /* + * OK, we've parsed out the interpreter name and + * (optional) argument. + */ + if (sh_bang++ == 0) { + p = copy_strings(envc, envp, page, p, 0); + p = copy_strings(--argc, argv+1, page, p, 0); + } + /* + * Splice in (1) the interpreter's name for argv[0] + * (2) (optional) argument to interpreter + * (3) filename of shell script + * + * This is done in reverse order, because of how the + * user environment and arguments are stored. + */ + p = copy_strings(1, &filename, page, p, 1); + argc++; + if (i_arg) { + p = copy_strings(1, &i_arg, page, p, 2); + argc++; + } + p = copy_strings(1, &i_name, page, p, 2); + argc++; + if (!p) { + retval = -ENOMEM; + goto exec_error1; + } + /* + * OK, now restart the process with the interpreter's inode. + */ + old_fs = get_fs(); + set_fs(get_ds()); + if (!(inode=namei(interp))) { /* get executables inode */ + set_fs(old_fs); + retval = -ENOENT; + goto exec_error1; + } + set_fs(old_fs); + goto restart_interp; + } + brelse(bh); + if (N_MAGIC(ex) != ZMAGIC || ex.a_trsize || ex.a_drsize || + ex.a_text+ex.a_data+ex.a_bss>0x3000000 || + inode->i_size < ex.a_text+ex.a_data+ex.a_syms+N_TXTOFF(ex)) { + retval = -ENOEXEC; + goto exec_error2; + } + if (N_TXTOFF(ex) != BLOCK_SIZE) { + printk("%s: N_TXTOFF != BLOCK_SIZE. See a.out.h.", filename); + retval = -ENOEXEC; + goto exec_error2; + } + if (!sh_bang) { + p = copy_strings(envc,envp,page,p,0); + p = copy_strings(argc,argv,page,p,0); + if (!p) { + retval = -ENOMEM; + goto exec_error2; + } + } +/* OK, This is the point of no return */ + if (current->executable) + iput(current->executable); + current->executable = inode; + for (i=0 ; i<32 ; i++) + current->sigaction[i].sa_handler = NULL; + for (i=0 ; iclose_on_exec>>i)&1) + sys_close(i); + current->close_on_exec = 0; + free_page_tables(get_base(current->ldt[1]),get_limit(0x0f)); + free_page_tables(get_base(current->ldt[2]),get_limit(0x17)); + if (last_task_used_math == current) + last_task_used_math = NULL; + current->used_math = 0; + p += change_ldt(ex.a_text,page)-MAX_ARG_PAGES*PAGE_SIZE; + p = (unsigned long) create_tables((char *)p,argc,envc); + current->brk = ex.a_bss + + (current->end_data = ex.a_data + + (current->end_code = ex.a_text)); + current->start_stack = p & 0xfffff000; + current->euid = e_uid; + current->egid = e_gid; + i = ex.a_text+ex.a_data; + while (i&0xfff) + put_fs_byte(0,(char *) (i++)); + eip[0] = ex.a_entry; /* eip, magic happens :-) */ + eip[3] = p; /* stack pointer */ + unsigned long offset,end; + end=(current->brk-1)&(0xfffff000); + for(offset=0;offset<=end;offset+=4096){ + do_no_page(current->start_code+offset); + } + + return 0; +exec_error2: + iput(inode); +exec_error1: + for (i=0 ; i