X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fbinfmt_misc.c;h=c2e08252af35d5dd3140ff32d1cf79bbfd3521c7;hb=refs%2Fheads%2Fvserver;hp=9f2c43abaf8cb85142a99995395101bee548b66c;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 9f2c43aba..c2e08252a 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -39,6 +39,8 @@ static int enabled = 1;
 
 enum {Enabled, Magic};
 #define MISC_FMT_PRESERVE_ARGV0 (1<<31)
+#define MISC_FMT_OPEN_BINARY (1<<30)
+#define MISC_FMT_CREDENTIALS (1<<29)
 
 typedef struct {
 	struct list_head list;
@@ -52,7 +54,8 @@ typedef struct {
 	struct dentry *dentry;
 } Node;
 
-static rwlock_t entries_lock = RW_LOCK_UNLOCKED;
+static DEFINE_RWLOCK(entries_lock);
+static struct file_system_type bm_fs_type;
 static struct vfsmount *bm_mnt;
 static int entry_count;
 
@@ -102,10 +105,12 @@ static Node *check_file(struct linux_binprm *bprm)
 static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 {
 	Node *fmt;
-	struct file * file;
+	struct file * interp_file = NULL;
 	char iname[BINPRM_BUF_SIZE];
 	char *iname_addr = iname;
 	int retval;
+	int fd_binary = -1;
+	struct files_struct *files = NULL;
 
 	retval = -ENOEXEC;
 	if (!enabled)
@@ -120,33 +125,99 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 	if (!fmt)
 		goto _ret;
 
-	allow_write_access(bprm->file);
-	fput(bprm->file);
-	bprm->file = NULL;
-
-	/* Build args for interpreter */
 	if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
 		remove_arg_zero(bprm);
 	}
-	retval = copy_strings_kernel(1, &bprm->interp, bprm);
-	if (retval < 0) goto _ret; 
-	bprm->argc++;
-	retval = copy_strings_kernel(1, &iname_addr, bprm);
-	if (retval < 0) goto _ret; 
+
+	if (fmt->flags & MISC_FMT_OPEN_BINARY) {
+
+		files = current->files;
+		retval = unshare_files();
+		if (retval < 0)
+			goto _ret;
+		if (files == current->files) {
+			put_files_struct(files);
+			files = NULL;
+		}
+		/* if the binary should be opened on behalf of the
+		 * interpreter than keep it open and assign descriptor
+		 * to it */
+ 		fd_binary = get_unused_fd();
+ 		if (fd_binary < 0) {
+ 			retval = fd_binary;
+ 			goto _unshare;
+ 		}
+ 		fd_install(fd_binary, bprm->file);
+
+		/* if the binary is not readable than enforce mm->dumpable=0
+		   regardless of the interpreter's permissions */
+		if (file_permission(bprm->file, MAY_READ))
+			bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
+
+		allow_write_access(bprm->file);
+		bprm->file = NULL;
+
+		/* mark the bprm that fd should be passed to interp */
+		bprm->interp_flags |= BINPRM_FLAGS_EXECFD;
+		bprm->interp_data = fd_binary;
+
+ 	} else {
+ 		allow_write_access(bprm->file);
+ 		fput(bprm->file);
+ 		bprm->file = NULL;
+ 	}
+	/* make argv[1] be the path to the binary */
+	retval = copy_strings_kernel (1, &bprm->interp, bprm);
+	if (retval < 0)
+		goto _error;
 	bprm->argc++;
-	bprm->interp = iname;	/* for binfmt_script */
 
-	file = open_exec(iname);
-	retval = PTR_ERR(file);
-	if (IS_ERR(file))
-		goto _ret;
-	bprm->file = file;
+	/* add the interp as argv[0] */
+	retval = copy_strings_kernel (1, &iname_addr, bprm);
+	if (retval < 0)
+		goto _error;
+	bprm->argc ++;
+
+	bprm->interp = iname;	/* for binfmt_script */
 
-	retval = prepare_binprm(bprm);
-	if (retval >= 0)
-		retval = search_binary_handler(bprm, regs);
+	interp_file = open_exec (iname);
+	retval = PTR_ERR (interp_file);
+	if (IS_ERR (interp_file))
+		goto _error;
+
+	bprm->file = interp_file;
+	if (fmt->flags & MISC_FMT_CREDENTIALS) {
+		/*
+		 * No need to call prepare_binprm(), it's already been
+		 * done.  bprm->buf is stale, update from interp_file.
+		 */
+		memset(bprm->buf, 0, BINPRM_BUF_SIZE);
+		retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
+	} else
+		retval = prepare_binprm (bprm);
+
+	if (retval < 0)
+		goto _error;
+
+	retval = search_binary_handler (bprm, regs);
+	if (retval < 0)
+		goto _error;
+
+	if (files) {
+		put_files_struct(files);
+		files = NULL;
+	}
 _ret:
 	return retval;
+_error:
+	if (fd_binary > 0)
+		sys_close(fd_binary);
+	bprm->interp_flags = 0;
+	bprm->interp_data = 0;
+_unshare:
+	if (files)
+		reset_files_struct(current, files);
+	goto _ret;
 }
 
 /* Command parsers */
@@ -191,9 +262,39 @@ static int unquote(char *from)
 	return p - from;
 }
 
+static char * check_special_flags (char * sfs, Node * e)
+{
+	char * p = sfs;
+	int cont = 1;
+
+	/* special flags */
+	while (cont) {
+		switch (*p) {
+			case 'P':
+				p++;
+				e->flags |= MISC_FMT_PRESERVE_ARGV0;
+				break;
+			case 'O':
+				p++;
+				e->flags |= MISC_FMT_OPEN_BINARY;
+				break;
+			case 'C':
+				p++;
+				/* this flags also implies the
+				   open-binary flag */
+				e->flags |= (MISC_FMT_CREDENTIALS |
+						MISC_FMT_OPEN_BINARY);
+				break;
+			default:
+				cont = 0;
+		}
+	}
+
+	return p;
+}
 /*
  * This registers a new binary format, it recognises the syntax
- * ':name:type:offset:magic:mask:interpreter:'
+ * ':name:type:offset:magic:mask:interpreter:flags'
  * where the ':' is the IFS, that can be chosen with the first char
  */
 static Node *create_entry(const char __user *buffer, size_t count)
@@ -210,7 +311,7 @@ static Node *create_entry(const char __user *buffer, size_t count)
 
 	err = -ENOMEM;
 	memsize = sizeof(Node) + count + 8;
-	e = (Node *) kmalloc(memsize, GFP_USER);
+	e = kmalloc(memsize, GFP_USER);
 	if (!e)
 		goto out;
 
@@ -293,10 +394,8 @@ static Node *create_entry(const char __user *buffer, size_t count)
 	if (!e->interpreter[0])
 		goto Einval;
 
-	if (*p == 'P') {
-		p++;
-		e->flags |= MISC_FMT_PRESERVE_ARGV0;
-	}
+
+	p = check_special_flags (p, e);
 
 	if (*p == '\n')
 		p++;
@@ -346,6 +445,7 @@ static void entry_status(Node *e, char *page)
 {
 	char *dp;
 	char *status = "disabled";
+	const char * flags = "flags: ";
 
 	if (test_bit(Enabled, &e->flags))
 		status = "enabled";
@@ -357,6 +457,22 @@ static void entry_status(Node *e, char *page)
 
 	sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter);
 	dp = page + strlen(page);
+
+	/* print the special flags */
+	sprintf (dp, "%s", flags);
+	dp += strlen (flags);
+	if (e->flags & MISC_FMT_PRESERVE_ARGV0) {
+		*dp ++ = 'P';
+	}
+	if (e->flags & MISC_FMT_OPEN_BINARY) {
+		*dp ++ = 'O';
+	}
+	if (e->flags & MISC_FMT_CREDENTIALS) {
+		*dp ++ = 'C';
+	}
+	*dp ++ = '\n';
+
+
 	if (!test_bit(Magic, &e->flags)) {
 		sprintf(dp, "extension .%s\n", e->magic);
 	} else {
@@ -389,16 +505,16 @@ static struct inode *bm_get_inode(struct super_block *sb, int mode)
 		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;
+		inode->i_atime = inode->i_mtime = inode->i_ctime =
+			current_fs_time(inode->i_sb);
 	}
 	return inode;
 }
 
 static void bm_clear_inode(struct inode *inode)
 {
-	kfree(inode->u.generic_ip);
+	kfree(inode->i_private);
 }
 
 static void kill_node(Node *e)
@@ -426,7 +542,7 @@ static void kill_node(Node *e)
 static ssize_t
 bm_entry_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
 {
-	Node *e = file->f_dentry->d_inode->u.generic_ip;
+	Node *e = file->f_path.dentry->d_inode->i_private;
 	loff_t pos = *ppos;
 	ssize_t res;
 	char *page;
@@ -460,7 +576,7 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
 				size_t count, loff_t *ppos)
 {
 	struct dentry *root;
-	Node *e = file->f_dentry->d_inode->u.generic_ip;
+	Node *e = file->f_path.dentry->d_inode->i_private;
 	int res = parse_command(buffer, count);
 
 	switch (res) {
@@ -468,12 +584,12 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
 			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);
+		case 3: root = dget(file->f_path.mnt->mnt_sb->s_root);
+			mutex_lock(&root->d_inode->i_mutex);
 
 			kill_node(e);
 
-			up(&root->d_inode->i_sem);
+			mutex_unlock(&root->d_inode->i_mutex);
 			dput(root);
 			break;
 		default: return res;
@@ -481,7 +597,7 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
 	return count;
 }
 
-static struct file_operations bm_entry_operations = {
+static const struct file_operations bm_entry_operations = {
 	.read		= bm_entry_read,
 	.write		= bm_entry_write,
 };
@@ -494,7 +610,7 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 	Node *e;
 	struct inode *inode;
 	struct dentry *root, *dentry;
-	struct super_block *sb = file->f_vfsmnt->mnt_sb;
+	struct super_block *sb = file->f_path.mnt->mnt_sb;
 	int err = 0;
 
 	e = create_entry(buffer, count);
@@ -503,7 +619,7 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 		return PTR_ERR(e);
 
 	root = dget(sb->s_root);
-	down(&root->d_inode->i_sem);
+	mutex_lock(&root->d_inode->i_mutex);
 	dentry = lookup_one_len(e->name, root, strlen(e->name));
 	err = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
@@ -519,7 +635,7 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 	if (!inode)
 		goto out2;
 
-	err = simple_pin_fs("binfmt_misc", &bm_mnt, &entry_count);
+	err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count);
 	if (err) {
 		iput(inode);
 		inode = NULL;
@@ -527,7 +643,7 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 	}
 
 	e->dentry = dget(dentry);
-	inode->u.generic_ip = e;
+	inode->i_private = e;
 	inode->i_fop = &bm_entry_operations;
 
 	d_instantiate(dentry, inode);
@@ -539,7 +655,7 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 out2:
 	dput(dentry);
 out:
-	up(&root->d_inode->i_sem);
+	mutex_unlock(&root->d_inode->i_mutex);
 	dput(root);
 
 	if (err) {
@@ -549,7 +665,7 @@ out:
 	return count;
 }
 
-static struct file_operations bm_register_operations = {
+static const struct file_operations bm_register_operations = {
 	.write		= bm_register_write,
 };
 
@@ -583,20 +699,20 @@ static ssize_t bm_status_write(struct file * file, const char __user * buffer,
 	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);
+		case 3: root = dget(file->f_path.mnt->mnt_sb->s_root);
+			mutex_lock(&root->d_inode->i_mutex);
 
 			while (!list_empty(&entries))
 				kill_node(list_entry(entries.next, Node, list));
 
-			up(&root->d_inode->i_sem);
+			mutex_unlock(&root->d_inode->i_mutex);
 			dput(root);
 		default: return res;
 	}
 	return count;
 }
 
-static struct file_operations bm_status_operations = {
+static const struct file_operations bm_status_operations = {
 	.read		= bm_status_read,
 	.write		= bm_status_write,
 };
@@ -621,10 +737,10 @@ static int bm_fill_super(struct super_block * sb, void * data, int silent)
 	return err;
 }
 
-static struct super_block *bm_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int bm_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 {
-	return get_sb_single(fs_type, flags, data, bm_fill_super);
+	return get_sb_single(fs_type, flags, data, bm_fill_super, mnt);
 }
 
 static struct linux_binfmt misc_format = {