Commit 42eb0d54 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

fs: split receive_fd_replace from __receive_fd 



receive_fd_replace shares almost no code with the general case, so split
it out.  Also remove the "Bump the sock usage counts" comment from
both copies, as that is now what __receive_sock actually does.

[AV: ... and make the only user of receive_fd_replace() choose between
it and receive_fd() according to what userland had passed to it in
flags]

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a38fd874

fs/file.c

+19 −20
Original line number Diff line number Diff line
@@ -1068,8 +1068,6 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) 


/**

 * __receive_fd() - Install received file into file descriptor table

 *

 * @fd: fd to install into (if negative, a new fd will be allocated)

 * @file: struct file that was received from another process

 * @ufd: __user pointer to write new fd number to

 * @o_flags: the O_* flags to apply to the new fd entry
@@ -1083,7 +1081,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) 
 *

 * Returns newly install fd or -ve on error.

 */

int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flags)

int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags)

{

	int new_fd;

	int error;
@@ -1092,32 +1090,33 @@ int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flag 
	if (error)

		return error;



	if (fd < 0) {

	new_fd = get_unused_fd_flags(o_flags);

	if (new_fd < 0)

		return new_fd;

	} else {

		new_fd = fd;

	}



	if (ufd) {

		error = put_user(new_fd, ufd);

		if (error) {

			if (fd < 0)

			put_unused_fd(new_fd);

			return error;

		}

	}



	if (fd < 0) {

	fd_install(new_fd, get_file(file));

	} else {

	__receive_sock(file);

	return new_fd;

}



int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)

{

	int error;



	error = security_file_receive(file);

	if (error)

		return error;

	error = replace_fd(new_fd, file, o_flags);

	if (error)

		return error;

	}



	/* Bump the sock usage counts, if any. */

	__receive_sock(file);

	return new_fd;

}

include/linux/file.h

+4 −7
Original line number Diff line number Diff line
@@ -92,23 +92,20 @@ extern void put_unused_fd(unsigned int fd); 


extern void fd_install(unsigned int fd, struct file *file);



extern int __receive_fd(int fd, struct file *file, int __user *ufd,

extern int __receive_fd(struct file *file, int __user *ufd,

			unsigned int o_flags);

static inline int receive_fd_user(struct file *file, int __user *ufd,

				  unsigned int o_flags)

{

	if (ufd == NULL)

		return -EFAULT;

	return __receive_fd(-1, file, ufd, o_flags);

	return __receive_fd(file, ufd, o_flags);

}

static inline int receive_fd(struct file *file, unsigned int o_flags)

{

	return __receive_fd(-1, file, NULL, o_flags);

}

static inline int receive_fd_replace(int fd, struct file *file, unsigned int o_flags)

{

	return __receive_fd(fd, file, NULL, o_flags);

	return __receive_fd(file, NULL, o_flags);

}

int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);



extern void flush_delayed_fput(void);

extern void __fput_sync(struct file *);

kernel/seccomp.c

+12 −5
Original line number Diff line number Diff line
@@ -119,8 +119,11 @@ struct seccomp_kaddfd { 
	int fd;

	unsigned int flags;



	union {

		bool setfd;

		/* To only be set on reply */

		int ret;

	};

	struct completion completion;

	struct list_head list;

};
@@ -1069,7 +1072,11 @@ static void seccomp_handle_addfd(struct seccomp_kaddfd *addfd) 
	 * that it has been handled.

	 */

	list_del_init(&addfd->list);

	addfd->ret = receive_fd_replace(addfd->fd, addfd->file, addfd->flags);

	if (!addfd->setfd)

		addfd->ret = receive_fd(addfd->file, addfd->flags);

	else

		addfd->ret = receive_fd_replace(addfd->fd, addfd->file,

						addfd->flags);

	complete(&addfd->completion);

}
@@ -1583,8 +1590,8 @@ static long seccomp_notify_addfd(struct seccomp_filter *filter, 
		return -EBADF;



	kaddfd.flags = addfd.newfd_flags;

	kaddfd.fd = (addfd.flags & SECCOMP_ADDFD_FLAG_SETFD) ?

		    addfd.newfd : -1;

	kaddfd.setfd = addfd.flags & SECCOMP_ADDFD_FLAG_SETFD;

	kaddfd.fd = addfd.newfd;

	init_completion(&kaddfd.completion);



	ret = mutex_lock_interruptible(&filter->notify_lock);