Commit 82af599b authored by Al Viro's avatar Al Viro
Browse files

readdir.c: get compat_filldir() more or less in sync with filldir() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 391b7461

fs/readdir.c

+27 −24
Original line number Diff line number Diff line
@@ -473,7 +473,7 @@ struct compat_linux_dirent { 
struct compat_getdents_callback {

	struct dir_context ctx;

	struct compat_linux_dirent __user *current_dir;

	struct compat_linux_dirent __user *previous;

	int prev_reclen;

	int count;

	int error;

};
@@ -481,13 +481,17 @@ struct compat_getdents_callback { 
static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,

		loff_t offset, u64 ino, unsigned int d_type)

{

	struct compat_linux_dirent __user * dirent;

	struct compat_linux_dirent __user *dirent, *prev;

	struct compat_getdents_callback *buf =

		container_of(ctx, struct compat_getdents_callback, ctx);

	compat_ulong_t d_ino;

	int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +

		namlen + 2, sizeof(compat_long_t));

	int prev_reclen;



	buf->error = verify_dirent_name(name, namlen);

	if (unlikely(buf->error))

		return buf->error;

	buf->error = -EINVAL;	/* only used if we fail.. */

	if (reclen > buf->count)

		return -EINVAL;
@@ -496,29 +500,27 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, 
		buf->error = -EOVERFLOW;

		return -EOVERFLOW;

	}

	dirent = buf->previous;

	if (dirent) {

		if (signal_pending(current))

	prev_reclen = buf->prev_reclen;

	if (prev_reclen && signal_pending(current))

		return -EINTR;

		if (__put_user(offset, &dirent->d_off))

			goto efault;

	}

	dirent = buf->current_dir;

	if (__put_user(d_ino, &dirent->d_ino))

		goto efault;

	if (__put_user(reclen, &dirent->d_reclen))

		goto efault;

	if (copy_to_user(dirent->d_name, name, namlen))

		goto efault;

	if (__put_user(0, dirent->d_name + namlen))

		goto efault;

	if (__put_user(d_type, (char  __user *) dirent + reclen - 1))

	prev = (void __user *) dirent - prev_reclen;

	if (!user_write_access_begin(prev, reclen + prev_reclen))

		goto efault;

	buf->previous = dirent;

	dirent = (void __user *)dirent + reclen;

	buf->current_dir = dirent;



	unsafe_put_user(offset, &prev->d_off, efault_end);

	unsafe_put_user(d_ino, &dirent->d_ino, efault_end);

	unsafe_put_user(reclen, &dirent->d_reclen, efault_end);

	unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);

	unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);

	user_write_access_end();



	buf->prev_reclen = reclen;

	buf->current_dir = (void __user *)dirent + reclen;

	buf->count -= reclen;

	return 0;

efault_end:

	user_write_access_end();

efault:

	buf->error = -EFAULT;

	return -EFAULT;
@@ -528,7 +530,6 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, 
		struct compat_linux_dirent __user *, dirent, unsigned int, count)

{

	struct fd f;

	struct compat_linux_dirent __user * lastdirent;

	struct compat_getdents_callback buf = {

		.ctx.actor = compat_filldir,

		.current_dir = dirent,
@@ -546,8 +547,10 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, 
	error = iterate_dir(f.file, &buf.ctx);

	if (error >= 0)

		error = buf.error;

	lastdirent = buf.previous;

	if (lastdirent) {

	if (buf.prev_reclen) {

		struct compat_linux_dirent __user * lastdirent;

		lastdirent = (void __user *)buf.current_dir - buf.prev_reclen;



		if (put_user(buf.ctx.pos, &lastdirent->d_off))

			error = -EFAULT;

		else