--- zzzz-none-000/linux-2.4.17/fs/binfmt_misc.c 2001-10-21 02:14:42.000000000 +0000 +++ sangam-fb-322/linux-2.4.17/fs/binfmt_misc.c 2004-11-24 13:22:16.000000000 +0000 @@ -1,722 +1,722 @@ -/* - * binfmt_misc.c - * - * Copyright (C) 1997 Richard Günther - * - * binfmt_misc detects binaries via a magic or filename extension and invokes - * a specified wrapper. This should obsolete binfmt_java, binfmt_em86 and - * binfmt_mz. - * - * 1997-04-25 first version - * [...] - * 1997-05-19 cleanup - * 1997-06-26 hpa: pass the real filename rather than argv[0] - * 1997-06-30 minor cleanup - * 1997-08-09 removed extension stripping, locking cleanup - * 2001-02-28 AV: rewritten into something that resembles C. Original didn't. - */ - -#include -#include - -#include -#include -#include -#include -#include - -#include - -enum { - VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */ -}; - -static LIST_HEAD(entries); -static int enabled = 1; - -enum {Enabled, Magic}; - -typedef struct { - struct list_head list; - int flags; /* type, status, etc. */ - int offset; /* offset of magic */ - int size; /* size of magic/mask */ - char *magic; /* magic or filename extension */ - char *mask; /* mask, NULL for exact match */ - char *interpreter; /* filename of interpreter */ - char *name; - struct dentry *dentry; -} Node; - -static rwlock_t entries_lock __attribute__((unused)) = RW_LOCK_UNLOCKED; - -/* - * Check if we support the binfmt - * if we do, return the node, else NULL - * locking is done in load_misc_binary - */ -static Node *check_file(struct linux_binprm *bprm) -{ - char *p = strrchr(bprm->filename, '.'); - struct list_head *l; - - for (l = entries.next; l != &entries; l = l->next) { - Node *e = list_entry(l, Node, list); - char *s; - int j; - - if (!test_bit(Enabled, &e->flags)) - continue; - - if (!test_bit(Magic, &e->flags)) { - if (p && !strcmp(e->magic, p + 1)) - return e; - continue; - } - - s = bprm->buf + e->offset; - if (e->mask) { - for (j = 0; j < e->size; j++) - if ((*s++ ^ e->magic[j]) & e->mask[j]) - break; - } else { - for (j = 0; j < e->size; j++) - if ((*s++ ^ e->magic[j])) - break; - } - if (j == e->size) - return e; - } - return NULL; -} - -/* - * the loader itself - */ -static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs) -{ - Node *fmt; - struct file * file; - char iname[BINPRM_BUF_SIZE]; - char *iname_addr = iname; - int retval; - - retval = -ENOEXEC; - if (!enabled) - goto _ret; - - /* to keep locking time low, we copy the interpreter string */ - read_lock(&entries_lock); - fmt = check_file(bprm); - if (fmt) { - strncpy(iname, fmt->interpreter, BINPRM_BUF_SIZE - 1); - iname[BINPRM_BUF_SIZE - 1] = '\0'; - } - read_unlock(&entries_lock); - if (!fmt) - goto _ret; - - allow_write_access(bprm->file); - fput(bprm->file); - bprm->file = NULL; - - /* Build args for interpreter */ - remove_arg_zero(bprm); - retval = copy_strings_kernel(1, &bprm->filename, bprm); - if (retval < 0) goto _ret; - bprm->argc++; - retval = copy_strings_kernel(1, &iname_addr, bprm); - if (retval < 0) goto _ret; - bprm->argc++; - bprm->filename = iname; /* for binfmt_script */ - - file = open_exec(iname); - retval = PTR_ERR(file); - if (IS_ERR(file)) - goto _ret; - bprm->file = file; - - retval = prepare_binprm(bprm); - if (retval >= 0) - retval = search_binary_handler(bprm, regs); -_ret: - return retval; -} - -/* Command parsers */ - -/* - * parses and copies one argument enclosed in del from *sp to *dp, - * recognising the \x special. - * returns pointer to the copied argument or NULL in case of an - * error (and sets err) or null argument length. - */ -static char *scanarg(char *s, char del) -{ - char c; - - while ((c = *s++) != del) { - if (c == '\\' && *s == 'x') { - s++; - if (!isxdigit(*s++)) - return NULL; - if (!isxdigit(*s++)) - return NULL; - } - } - return s; -} - -static int unquote(char *from) -{ - char c = 0, *s = from, *p = from; - - while ((c = *s++) != '\0') { - if (c == '\\' && *s == 'x') { - s++; - c = toupper(*s++); - *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4; - c = toupper(*s++); - *p++ |= c - (isdigit(c) ? '0' : 'A' - 10); - continue; - } - *p++ = c; - } - return p - from; -} - -/* - * This registers a new binary format, it recognises the syntax - * ':name:type:offset:magic:mask:interpreter:' - * where the ':' is the IFS, that can be chosen with the first char - */ -static Node *create_entry(const char *buffer, size_t count) -{ - Node *e; - int memsize, err; - char *buf, *p; - char del; - - /* some sanity checks */ - err = -EINVAL; - if ((count < 11) || (count > 256)) - goto out; - - err = -ENOMEM; - memsize = sizeof(Node) + count + 8; - e = (Node *) kmalloc(memsize, GFP_USER); - if (!e) - goto out; - - p = buf = (char *)e + sizeof(Node); - - memset(e, 0, sizeof(Node)); - if (copy_from_user(buf, buffer, count)) - goto Efault; - - del = *p++; /* delimeter */ - - memset(buf+count, del, 8); - - e->name = p; - p = strchr(p, del); - if (!p) - goto Einval; - *p++ = '\0'; - if (!e->name[0] || - !strcmp(e->name, ".") || - !strcmp(e->name, "..") || - strchr(e->name, '/')) - goto Einval; - switch (*p++) { - case 'E': e->flags = 1<flags = (1<flags)) { - char *s = strchr(p, del); - if (!s) - goto Einval; - *s++ = '\0'; - e->offset = simple_strtoul(p, &p, 10); - if (*p++) - goto Einval; - e->magic = p; - p = scanarg(p, del); - if (!p) - goto Einval; - p[-1] = '\0'; - if (!e->magic[0]) - goto Einval; - e->mask = p; - p = scanarg(p, del); - if (!p) - goto Einval; - p[-1] = '\0'; - if (!e->mask[0]) - e->mask = NULL; - e->size = unquote(e->magic); - if (e->mask && unquote(e->mask) != e->size) - goto Einval; - if (e->size + e->offset > BINPRM_BUF_SIZE) - goto Einval; - } else { - p = strchr(p, del); - if (!p) - goto Einval; - *p++ = '\0'; - e->magic = p; - p = strchr(p, del); - if (!p) - goto Einval; - *p++ = '\0'; - if (!e->magic[0] || strchr(e->magic, '/')) - goto Einval; - p = strchr(p, del); - if (!p) - goto Einval; - *p++ = '\0'; - } - e->interpreter = p; - p = strchr(p, del); - if (!p) - goto Einval; - *p++ = '\0'; - if (!e->interpreter[0]) - goto Einval; - - if (*p == '\n') - p++; - if (p != buf + count) - goto Einval; - return e; - -out: - return ERR_PTR(err); - -Efault: - kfree(e); - return ERR_PTR(-EFAULT); -Einval: - kfree(e); - return ERR_PTR(-EINVAL); -} - -/* - * Set status of entry/binfmt_misc: - * '1' enables, '0' disables and '-1' clears entry/binfmt_misc - */ -static int parse_command(const char *buffer, size_t count) -{ - char s[4]; - - if (!count) - return 0; - if (count > 3) - return -EINVAL; - if (copy_from_user(s, buffer, count)) - return -EFAULT; - if (s[count-1] == '\n') - count--; - if (count == 1 && s[0] == '0') - return 1; - if (count == 1 && s[0] == '1') - return 2; - if (count == 2 && s[0] == '-' && s[1] == '1') - return 3; - return -EINVAL; -} - -/* generic stuff */ - -static void entry_status(Node *e, char *page) -{ - char *dp; - char *status = "disabled"; - - if (test_bit(Enabled, &e->flags)) - status = "enabled"; - - if (!VERBOSE_STATUS) { - sprintf(page, "%s\n", status); - return; - } - - sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter); - dp = page + strlen(page); - if (!test_bit(Magic, &e->flags)) { - sprintf(dp, "extension .%s\n", e->magic); - } else { - int i; - - sprintf(dp, "offset %i\nmagic ", e->offset); - dp = page + strlen(page); - for (i = 0; i < e->size; i++) { - sprintf(dp, "%02x", 0xff & (int) (e->magic[i])); - dp += 2; - } - if (e->mask) { - sprintf(dp, "\nmask "); - dp += 6; - for (i = 0; i < e->size; i++) { - sprintf(dp, "%02x", 0xff & (int) (e->mask[i])); - dp += 2; - } - } - *dp++ = '\n'; - *dp = '\0'; - } -} - -static struct inode *bm_get_inode(struct super_block *sb, int mode) -{ - struct inode * inode = new_inode(sb); - - if (inode) { - inode->i_mode = mode; - inode->i_uid = 0; - inode->i_gid = 0; - inode->i_blksize = PAGE_CACHE_SIZE; - inode->i_blocks = 0; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; - } - return inode; -} - -static void bm_clear_inode(struct inode *inode) -{ - Node *e = inode->u.generic_ip; - - if (e) { - write_lock(&entries_lock); - list_del(&e->list); - write_unlock(&entries_lock); - kfree(e); - } -} - -static void kill_node(Node *e) -{ - struct dentry *dentry; - - write_lock(&entries_lock); - dentry = e->dentry; - if (dentry) { - list_del(&e->list); - INIT_LIST_HEAD(&e->list); - e->dentry = NULL; - } - write_unlock(&entries_lock); - - if (dentry) { - dentry->d_inode->i_nlink--; - d_drop(dentry); - dput(dentry); - } -} - -/* / */ - -static ssize_t -bm_entry_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos) -{ - Node *e = file->f_dentry->d_inode->u.generic_ip; - loff_t pos = *ppos; - ssize_t res; - char *page; - int len; - - if (!(page = (char*) __get_free_page(GFP_KERNEL))) - return -ENOMEM; - - entry_status(e, page); - len = strlen(page); - - res = -EINVAL; - if (pos < 0) - goto out; - res = 0; - if (pos >= len) - goto out; - if (len < pos + nbytes) - nbytes = len - pos; - res = -EFAULT; - if (copy_to_user(buf, page + pos, nbytes)) - goto out; - *ppos = pos + nbytes; - res = nbytes; -out: - free_page((unsigned long) page); - return res; -} - -static ssize_t bm_entry_write(struct file *file, const char *buffer, - size_t count, loff_t *ppos) -{ - struct dentry *root; - Node *e = file->f_dentry->d_inode->u.generic_ip; - int res = parse_command(buffer, count); - - switch (res) { - case 1: clear_bit(Enabled, &e->flags); - break; - case 2: set_bit(Enabled, &e->flags); - break; - case 3: root = dget(file->f_vfsmnt->mnt_sb->s_root); - down(&root->d_inode->i_sem); - down(&root->d_inode->i_zombie); - - kill_node(e); - - up(&root->d_inode->i_zombie); - up(&root->d_inode->i_sem); - dput(root); - break; - default: return res; - } - return count; -} - -static struct file_operations bm_entry_operations = { - read: bm_entry_read, - write: bm_entry_write, -}; - -/* /register */ - -static ssize_t bm_register_write(struct file *file, const char *buffer, - size_t count, loff_t *ppos) -{ - Node *e; - struct dentry *root, *dentry; - struct super_block *sb = file->f_vfsmnt->mnt_sb; - int err = 0; - - e = create_entry(buffer, count); - - if (IS_ERR(e)) - return PTR_ERR(e); - - root = dget(sb->s_root); - down(&root->d_inode->i_sem); - dentry = lookup_one_len(e->name, root, strlen(e->name)); - err = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { - down(&root->d_inode->i_zombie); - if (dentry->d_inode) { - err = -EEXIST; - } else { - struct inode * inode = bm_get_inode(sb, S_IFREG | 0644); - err = -ENOMEM; - - if (inode) { - write_lock(&entries_lock); - - e->dentry = dget(dentry); - inode->u.generic_ip = e; - inode->i_fop = &bm_entry_operations; - d_instantiate(dentry, inode); - - list_add(&e->list, &entries); - write_unlock(&entries_lock); - - err = 0; - } - } - up(&root->d_inode->i_zombie); - dput(dentry); - } - up(&root->d_inode->i_sem); - dput(root); - - if (err) { - kfree(e); - return -EINVAL; - } - return count; -} - -static struct file_operations bm_register_operations = { - write: bm_register_write, -}; - -/* /status */ - -static ssize_t -bm_status_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos) -{ - char *s = enabled ? "enabled" : "disabled"; - int len = strlen(s); - loff_t pos = *ppos; - - if (pos < 0) - return -EINVAL; - if (pos >= len) - return 0; - if (len < pos + nbytes) - nbytes = len - pos; - if (copy_to_user(buf, s + pos, nbytes)) - return -EFAULT; - *ppos = pos + nbytes; - return nbytes; -} - -static ssize_t bm_status_write(struct file * file, const char * buffer, - size_t count, loff_t *ppos) -{ - int res = parse_command(buffer, count); - struct dentry *root; - - switch (res) { - case 1: enabled = 0; break; - case 2: enabled = 1; break; - case 3: root = dget(file->f_vfsmnt->mnt_sb->s_root); - down(&root->d_inode->i_sem); - down(&root->d_inode->i_zombie); - - while (!list_empty(&entries)) - kill_node(list_entry(entries.next, Node, list)); - - up(&root->d_inode->i_zombie); - up(&root->d_inode->i_sem); - dput(root); - default: return res; - } - return count; -} - -static struct file_operations bm_status_operations = { - read: bm_status_read, - write: bm_status_write, -}; - -/* / */ - -static struct dentry * bm_lookup(struct inode *dir, struct dentry *dentry) -{ - d_add(dentry, NULL); - return NULL; -} - -static struct file_operations bm_dir_operations = { - read: generic_read_dir, - readdir: dcache_readdir, -}; - -static struct inode_operations bm_dir_inode_operations = { - lookup: bm_lookup, -}; - -/* Superblock handling */ - -static int bm_statfs(struct super_block *sb, struct statfs *buf) -{ - buf->f_type = sb->s_magic; - buf->f_bsize = PAGE_CACHE_SIZE; - buf->f_namelen = 255; - return 0; -} - -static struct super_operations s_ops = { - statfs: bm_statfs, - put_inode: force_delete, - clear_inode: bm_clear_inode, -}; - -static struct super_block *bm_read_super(struct super_block * sb, void * data, int silent) -{ - struct qstr names[2] = {{name:"status"}, {name:"register"}}; - struct inode * inode; - struct dentry * dentry[3]; - int i; - - for (i=0; is_blocksize = PAGE_CACHE_SIZE; - sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = 0x42494e4d; - sb->s_op = &s_ops; - - inode = bm_get_inode(sb, S_IFDIR | 0755); - if (!inode) - return NULL; - inode->i_op = &bm_dir_inode_operations; - inode->i_fop = &bm_dir_operations; - dentry[0] = d_alloc_root(inode); - if (!dentry[0]) { - iput(inode); - return NULL; - } - dentry[1] = d_alloc(dentry[0], &names[0]); - if (!dentry[1]) - goto out1; - dentry[2] = d_alloc(dentry[0], &names[1]); - if (!dentry[2]) - goto out2; - inode = bm_get_inode(sb, S_IFREG | 0644); - if (!inode) - goto out3; - inode->i_fop = &bm_status_operations; - d_add(dentry[1], inode); - inode = bm_get_inode(sb, S_IFREG | 0400); - if (!inode) - goto out3; - inode->i_fop = &bm_register_operations; - d_add(dentry[2], inode); - - sb->s_root = dentry[0]; - return sb; - -out3: - dput(dentry[2]); -out2: - dput(dentry[1]); -out1: - dput(dentry[0]); - return NULL; -} - -static struct linux_binfmt misc_format = { - NULL, THIS_MODULE, load_misc_binary, NULL, NULL, 0 -}; - -static DECLARE_FSTYPE(bm_fs_type, "binfmt_misc", bm_read_super, FS_SINGLE|FS_LITTER); - -static struct vfsmount *bm_mnt; - -static int __init init_misc_binfmt(void) -{ - int err = register_filesystem(&bm_fs_type); - if (!err) { - bm_mnt = kern_mount(&bm_fs_type); - err = PTR_ERR(bm_mnt); - if (IS_ERR(bm_mnt)) - unregister_filesystem(&bm_fs_type); - else { - err = register_binfmt(&misc_format); - if (err) { - unregister_filesystem(&bm_fs_type); - kern_umount(bm_mnt); - } - } - } - return err; -} - -static void __exit exit_misc_binfmt(void) -{ - unregister_binfmt(&misc_format); - unregister_filesystem(&bm_fs_type); - kern_umount(bm_mnt); -} - -EXPORT_NO_SYMBOLS; - -module_init(init_misc_binfmt); -module_exit(exit_misc_binfmt); -MODULE_LICENSE("GPL"); +/* + * binfmt_misc.c + * + * Copyright (C) 1997 Richard Günther + * + * binfmt_misc detects binaries via a magic or filename extension and invokes + * a specified wrapper. This should obsolete binfmt_java, binfmt_em86 and + * binfmt_mz. + * + * 1997-04-25 first version + * [...] + * 1997-05-19 cleanup + * 1997-06-26 hpa: pass the real filename rather than argv[0] + * 1997-06-30 minor cleanup + * 1997-08-09 removed extension stripping, locking cleanup + * 2001-02-28 AV: rewritten into something that resembles C. Original didn't. + */ + +#include +#include + +#include +#include +#include +#include +#include + +#include + +enum { + VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */ +}; + +static LIST_HEAD(entries); +static int enabled = 1; + +enum {Enabled, Magic}; + +typedef struct { + struct list_head list; + int flags; /* type, status, etc. */ + int offset; /* offset of magic */ + int size; /* size of magic/mask */ + char *magic; /* magic or filename extension */ + char *mask; /* mask, NULL for exact match */ + char *interpreter; /* filename of interpreter */ + char *name; + struct dentry *dentry; +} Node; + +static rwlock_t entries_lock __attribute__((unused)) = RW_LOCK_UNLOCKED; + +/* + * Check if we support the binfmt + * if we do, return the node, else NULL + * locking is done in load_misc_binary + */ +static Node *check_file(struct linux_binprm *bprm) +{ + char *p = strrchr(bprm->filename, '.'); + struct list_head *l; + + for (l = entries.next; l != &entries; l = l->next) { + Node *e = list_entry(l, Node, list); + char *s; + int j; + + if (!test_bit(Enabled, &e->flags)) + continue; + + if (!test_bit(Magic, &e->flags)) { + if (p && !strcmp(e->magic, p + 1)) + return e; + continue; + } + + s = bprm->buf + e->offset; + if (e->mask) { + for (j = 0; j < e->size; j++) + if ((*s++ ^ e->magic[j]) & e->mask[j]) + break; + } else { + for (j = 0; j < e->size; j++) + if ((*s++ ^ e->magic[j])) + break; + } + if (j == e->size) + return e; + } + return NULL; +} + +/* + * the loader itself + */ +static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs) +{ + Node *fmt; + struct file * file; + char iname[BINPRM_BUF_SIZE]; + char *iname_addr = iname; + int retval; + + retval = -ENOEXEC; + if (!enabled) + goto _ret; + + /* to keep locking time low, we copy the interpreter string */ + read_lock(&entries_lock); + fmt = check_file(bprm); + if (fmt) { + strncpy(iname, fmt->interpreter, BINPRM_BUF_SIZE - 1); + iname[BINPRM_BUF_SIZE - 1] = '\0'; + } + read_unlock(&entries_lock); + if (!fmt) + goto _ret; + + allow_write_access(bprm->file); + fput(bprm->file); + bprm->file = NULL; + + /* Build args for interpreter */ + remove_arg_zero(bprm); + retval = copy_strings_kernel(1, &bprm->filename, bprm); + if (retval < 0) goto _ret; + bprm->argc++; + retval = copy_strings_kernel(1, &iname_addr, bprm); + if (retval < 0) goto _ret; + bprm->argc++; + bprm->filename = iname; /* for binfmt_script */ + + file = open_exec(iname); + retval = PTR_ERR(file); + if (IS_ERR(file)) + goto _ret; + bprm->file = file; + + retval = prepare_binprm(bprm); + if (retval >= 0) + retval = search_binary_handler(bprm, regs); +_ret: + return retval; +} + +/* Command parsers */ + +/* + * parses and copies one argument enclosed in del from *sp to *dp, + * recognising the \x special. + * returns pointer to the copied argument or NULL in case of an + * error (and sets err) or null argument length. + */ +static char *scanarg(char *s, char del) +{ + char c; + + while ((c = *s++) != del) { + if (c == '\\' && *s == 'x') { + s++; + if (!isxdigit(*s++)) + return NULL; + if (!isxdigit(*s++)) + return NULL; + } + } + return s; +} + +static int unquote(char *from) +{ + char c = 0, *s = from, *p = from; + + while ((c = *s++) != '\0') { + if (c == '\\' && *s == 'x') { + s++; + c = toupper(*s++); + *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4; + c = toupper(*s++); + *p++ |= c - (isdigit(c) ? '0' : 'A' - 10); + continue; + } + *p++ = c; + } + return p - from; +} + +/* + * This registers a new binary format, it recognises the syntax + * ':name:type:offset:magic:mask:interpreter:' + * where the ':' is the IFS, that can be chosen with the first char + */ +static Node *create_entry(const char *buffer, size_t count) +{ + Node *e; + int memsize, err; + char *buf, *p; + char del; + + /* some sanity checks */ + err = -EINVAL; + if ((count < 11) || (count > 256)) + goto out; + + err = -ENOMEM; + memsize = sizeof(Node) + count + 8; + e = (Node *) kmalloc(memsize, GFP_USER); + if (!e) + goto out; + + p = buf = (char *)e + sizeof(Node); + + memset(e, 0, sizeof(Node)); + if (copy_from_user(buf, buffer, count)) + goto Efault; + + del = *p++; /* delimeter */ + + memset(buf+count, del, 8); + + e->name = p; + p = strchr(p, del); + if (!p) + goto Einval; + *p++ = '\0'; + if (!e->name[0] || + !strcmp(e->name, ".") || + !strcmp(e->name, "..") || + strchr(e->name, '/')) + goto Einval; + switch (*p++) { + case 'E': e->flags = 1<flags = (1<flags)) { + char *s = strchr(p, del); + if (!s) + goto Einval; + *s++ = '\0'; + e->offset = simple_strtoul(p, &p, 10); + if (*p++) + goto Einval; + e->magic = p; + p = scanarg(p, del); + if (!p) + goto Einval; + p[-1] = '\0'; + if (!e->magic[0]) + goto Einval; + e->mask = p; + p = scanarg(p, del); + if (!p) + goto Einval; + p[-1] = '\0'; + if (!e->mask[0]) + e->mask = NULL; + e->size = unquote(e->magic); + if (e->mask && unquote(e->mask) != e->size) + goto Einval; + if (e->size + e->offset > BINPRM_BUF_SIZE) + goto Einval; + } else { + p = strchr(p, del); + if (!p) + goto Einval; + *p++ = '\0'; + e->magic = p; + p = strchr(p, del); + if (!p) + goto Einval; + *p++ = '\0'; + if (!e->magic[0] || strchr(e->magic, '/')) + goto Einval; + p = strchr(p, del); + if (!p) + goto Einval; + *p++ = '\0'; + } + e->interpreter = p; + p = strchr(p, del); + if (!p) + goto Einval; + *p++ = '\0'; + if (!e->interpreter[0]) + goto Einval; + + if (*p == '\n') + p++; + if (p != buf + count) + goto Einval; + return e; + +out: + return ERR_PTR(err); + +Efault: + kfree(e); + return ERR_PTR(-EFAULT); +Einval: + kfree(e); + return ERR_PTR(-EINVAL); +} + +/* + * Set status of entry/binfmt_misc: + * '1' enables, '0' disables and '-1' clears entry/binfmt_misc + */ +static int parse_command(const char *buffer, size_t count) +{ + char s[4]; + + if (!count) + return 0; + if (count > 3) + return -EINVAL; + if (copy_from_user(s, buffer, count)) + return -EFAULT; + if (s[count-1] == '\n') + count--; + if (count == 1 && s[0] == '0') + return 1; + if (count == 1 && s[0] == '1') + return 2; + if (count == 2 && s[0] == '-' && s[1] == '1') + return 3; + return -EINVAL; +} + +/* generic stuff */ + +static void entry_status(Node *e, char *page) +{ + char *dp; + char *status = "disabled"; + + if (test_bit(Enabled, &e->flags)) + status = "enabled"; + + if (!VERBOSE_STATUS) { + sprintf(page, "%s\n", status); + return; + } + + sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter); + dp = page + strlen(page); + if (!test_bit(Magic, &e->flags)) { + sprintf(dp, "extension .%s\n", e->magic); + } else { + int i; + + sprintf(dp, "offset %i\nmagic ", e->offset); + dp = page + strlen(page); + for (i = 0; i < e->size; i++) { + sprintf(dp, "%02x", 0xff & (int) (e->magic[i])); + dp += 2; + } + if (e->mask) { + sprintf(dp, "\nmask "); + dp += 6; + for (i = 0; i < e->size; i++) { + sprintf(dp, "%02x", 0xff & (int) (e->mask[i])); + dp += 2; + } + } + *dp++ = '\n'; + *dp = '\0'; + } +} + +static struct inode *bm_get_inode(struct super_block *sb, int mode) +{ + struct inode * inode = new_inode(sb); + + if (inode) { + inode->i_mode = mode; + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = 0; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + } + return inode; +} + +static void bm_clear_inode(struct inode *inode) +{ + Node *e = inode->u.generic_ip; + + if (e) { + write_lock(&entries_lock); + list_del(&e->list); + write_unlock(&entries_lock); + kfree(e); + } +} + +static void kill_node(Node *e) +{ + struct dentry *dentry; + + write_lock(&entries_lock); + dentry = e->dentry; + if (dentry) { + list_del(&e->list); + INIT_LIST_HEAD(&e->list); + e->dentry = NULL; + } + write_unlock(&entries_lock); + + if (dentry) { + dentry->d_inode->i_nlink--; + d_drop(dentry); + dput(dentry); + } +} + +/* / */ + +static ssize_t +bm_entry_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos) +{ + Node *e = file->f_dentry->d_inode->u.generic_ip; + loff_t pos = *ppos; + ssize_t res; + char *page; + int len; + + if (!(page = (char*) __get_free_page(GFP_KERNEL))) + return -ENOMEM; + + entry_status(e, page); + len = strlen(page); + + res = -EINVAL; + if (pos < 0) + goto out; + res = 0; + if (pos >= len) + goto out; + if (len < pos + nbytes) + nbytes = len - pos; + res = -EFAULT; + if (copy_to_user(buf, page + pos, nbytes)) + goto out; + *ppos = pos + nbytes; + res = nbytes; +out: + free_page((unsigned long) page); + return res; +} + +static ssize_t bm_entry_write(struct file *file, const char *buffer, + size_t count, loff_t *ppos) +{ + struct dentry *root; + Node *e = file->f_dentry->d_inode->u.generic_ip; + int res = parse_command(buffer, count); + + switch (res) { + case 1: clear_bit(Enabled, &e->flags); + break; + case 2: set_bit(Enabled, &e->flags); + break; + case 3: root = dget(file->f_vfsmnt->mnt_sb->s_root); + down(&root->d_inode->i_sem); + down(&root->d_inode->i_zombie); + + kill_node(e); + + up(&root->d_inode->i_zombie); + up(&root->d_inode->i_sem); + dput(root); + break; + default: return res; + } + return count; +} + +static struct file_operations bm_entry_operations = { + read: bm_entry_read, + write: bm_entry_write, +}; + +/* /register */ + +static ssize_t bm_register_write(struct file *file, const char *buffer, + size_t count, loff_t *ppos) +{ + Node *e; + struct dentry *root, *dentry; + struct super_block *sb = file->f_vfsmnt->mnt_sb; + int err = 0; + + e = create_entry(buffer, count); + + if (IS_ERR(e)) + return PTR_ERR(e); + + root = dget(sb->s_root); + down(&root->d_inode->i_sem); + dentry = lookup_one_len(e->name, root, strlen(e->name)); + err = PTR_ERR(dentry); + if (!IS_ERR(dentry)) { + down(&root->d_inode->i_zombie); + if (dentry->d_inode) { + err = -EEXIST; + } else { + struct inode * inode = bm_get_inode(sb, S_IFREG | 0644); + err = -ENOMEM; + + if (inode) { + write_lock(&entries_lock); + + e->dentry = dget(dentry); + inode->u.generic_ip = e; + inode->i_fop = &bm_entry_operations; + d_instantiate(dentry, inode); + + list_add(&e->list, &entries); + write_unlock(&entries_lock); + + err = 0; + } + } + up(&root->d_inode->i_zombie); + dput(dentry); + } + up(&root->d_inode->i_sem); + dput(root); + + if (err) { + kfree(e); + return -EINVAL; + } + return count; +} + +static struct file_operations bm_register_operations = { + write: bm_register_write, +}; + +/* /status */ + +static ssize_t +bm_status_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos) +{ + char *s = enabled ? "enabled" : "disabled"; + int len = strlen(s); + loff_t pos = *ppos; + + if (pos < 0) + return -EINVAL; + if (pos >= len) + return 0; + if (len < pos + nbytes) + nbytes = len - pos; + if (copy_to_user(buf, s + pos, nbytes)) + return -EFAULT; + *ppos = pos + nbytes; + return nbytes; +} + +static ssize_t bm_status_write(struct file * file, const char * buffer, + size_t count, loff_t *ppos) +{ + int res = parse_command(buffer, count); + struct dentry *root; + + switch (res) { + case 1: enabled = 0; break; + case 2: enabled = 1; break; + case 3: root = dget(file->f_vfsmnt->mnt_sb->s_root); + down(&root->d_inode->i_sem); + down(&root->d_inode->i_zombie); + + while (!list_empty(&entries)) + kill_node(list_entry(entries.next, Node, list)); + + up(&root->d_inode->i_zombie); + up(&root->d_inode->i_sem); + dput(root); + default: return res; + } + return count; +} + +static struct file_operations bm_status_operations = { + read: bm_status_read, + write: bm_status_write, +}; + +/* / */ + +static struct dentry * bm_lookup(struct inode *dir, struct dentry *dentry) +{ + d_add(dentry, NULL); + return NULL; +} + +static struct file_operations bm_dir_operations = { + read: generic_read_dir, + readdir: dcache_readdir, +}; + +static struct inode_operations bm_dir_inode_operations = { + lookup: bm_lookup, +}; + +/* Superblock handling */ + +static int bm_statfs(struct super_block *sb, struct statfs *buf) +{ + buf->f_type = sb->s_magic; + buf->f_bsize = PAGE_CACHE_SIZE; + buf->f_namelen = 255; + return 0; +} + +static struct super_operations s_ops = { + statfs: bm_statfs, + put_inode: force_delete, + clear_inode: bm_clear_inode, +}; + +static struct super_block *bm_read_super(struct super_block * sb, void * data, int silent) +{ + struct qstr names[2] = {{name:"status"}, {name:"register"}}; + struct inode * inode; + struct dentry * dentry[3]; + int i; + + for (i=0; is_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = 0x42494e4d; + sb->s_op = &s_ops; + + inode = bm_get_inode(sb, S_IFDIR | 0755); + if (!inode) + return NULL; + inode->i_op = &bm_dir_inode_operations; + inode->i_fop = &bm_dir_operations; + dentry[0] = d_alloc_root(inode); + if (!dentry[0]) { + iput(inode); + return NULL; + } + dentry[1] = d_alloc(dentry[0], &names[0]); + if (!dentry[1]) + goto out1; + dentry[2] = d_alloc(dentry[0], &names[1]); + if (!dentry[2]) + goto out2; + inode = bm_get_inode(sb, S_IFREG | 0644); + if (!inode) + goto out3; + inode->i_fop = &bm_status_operations; + d_add(dentry[1], inode); + inode = bm_get_inode(sb, S_IFREG | 0400); + if (!inode) + goto out3; + inode->i_fop = &bm_register_operations; + d_add(dentry[2], inode); + + sb->s_root = dentry[0]; + return sb; + +out3: + dput(dentry[2]); +out2: + dput(dentry[1]); +out1: + dput(dentry[0]); + return NULL; +} + +static struct linux_binfmt misc_format = { + NULL, THIS_MODULE, load_misc_binary, NULL, NULL, 0 +}; + +static DECLARE_FSTYPE(bm_fs_type, "binfmt_misc", bm_read_super, FS_SINGLE|FS_LITTER); + +static struct vfsmount *bm_mnt; + +static int __init init_misc_binfmt(void) +{ + int err = register_filesystem(&bm_fs_type); + if (!err) { + bm_mnt = kern_mount(&bm_fs_type); + err = PTR_ERR(bm_mnt); + if (IS_ERR(bm_mnt)) + unregister_filesystem(&bm_fs_type); + else { + err = register_binfmt(&misc_format); + if (err) { + unregister_filesystem(&bm_fs_type); + kern_umount(bm_mnt); + } + } + } + return err; +} + +static void __exit exit_misc_binfmt(void) +{ + unregister_binfmt(&misc_format); + unregister_filesystem(&bm_fs_type); + kern_umount(bm_mnt); +} + +EXPORT_NO_SYMBOLS; + +module_init(init_misc_binfmt); +module_exit(exit_misc_binfmt); +MODULE_LICENSE("GPL");