Commit 98836386 authored by Al Viro's avatar Al Viro
Browse files

don't bother with tid_fd_revalidate() in lookups 



what we want it for is actually updating inode metadata;
take _that_ into a separate helper and use it.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 1ae9bd8b

fs/proc/fd.c

+44 −37
Original line number Diff line number Diff line
@@ -98,12 +98,27 @@ static bool tid_fd_mode(struct task_struct *task, unsigned fd, fmode_t *mode) 
	return !!file;

}



static void tid_fd_update_inode(struct task_struct *task, struct inode *inode,

				fmode_t f_mode)

{

	task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);



	if (S_ISLNK(inode->i_mode)) {

		unsigned i_mode = S_IFLNK;

		if (f_mode & FMODE_READ)

			i_mode |= S_IRUSR | S_IXUSR;

		if (f_mode & FMODE_WRITE)

			i_mode |= S_IWUSR | S_IXUSR;

		inode->i_mode = i_mode;

	}

	security_task_to_inode(task, inode);

}



static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)

{

	struct task_struct *task;

	struct inode *inode;

	unsigned int fd;

	fmode_t f_mode;



	if (flags & LOOKUP_RCU)

		return -ECHILD;
@@ -113,18 +128,9 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) 
	fd = proc_fd(inode);



	if (task) {

		fmode_t f_mode;

		if (tid_fd_mode(task, fd, &f_mode)) {

			task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);



			if (S_ISLNK(inode->i_mode)) {

				unsigned i_mode = S_IFLNK;

				if (f_mode & FMODE_READ)

					i_mode |= S_IRUSR | S_IXUSR;

				if (f_mode & FMODE_WRITE)

					i_mode |= S_IWUSR | S_IXUSR;

				inode->i_mode = i_mode;

			}

			security_task_to_inode(task, inode);

			tid_fd_update_inode(task, inode, f_mode);

			put_task_struct(task);

			return 1;

		}
@@ -168,34 +174,35 @@ static int proc_fd_link(struct dentry *dentry, struct path *path) 
	return ret;

}



struct fd_data {

	fmode_t mode;

	unsigned fd;

};



static int

proc_fd_instantiate(struct inode *dir, struct dentry *dentry,

		    struct task_struct *task, const void *ptr)

{

	unsigned fd = (unsigned long)ptr;

	const struct fd_data *data = ptr;

	struct proc_inode *ei;

	struct inode *inode;



	inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK);

	if (!inode)

		goto out;

		return -ENOENT;



	ei = PROC_I(inode);

	ei->fd = fd;

	ei->fd = data->fd;



	inode->i_op = &proc_pid_link_inode_operations;

	inode->i_size = 64;



	ei->op.proc_get_link = proc_fd_link;

	tid_fd_update_inode(task, inode, data->mode);



	d_set_d_op(dentry, &tid_fd_dentry_operations);

	d_add(dentry, inode);



	/* Close the race of the process dying before we return the dentry */

	if (tid_fd_revalidate(dentry, 0))

	return 0;

 out:

	return -ENOENT;

}



static struct dentry *proc_lookupfd_common(struct inode *dir,
@@ -204,17 +211,16 @@ static struct dentry *proc_lookupfd_common(struct inode *dir, 
{

	struct task_struct *task = get_proc_task(dir);

	int result = -ENOENT;

	unsigned fd = name_to_int(&dentry->d_name);

	fmode_t f_mode;

	struct fd_data data = {.fd = name_to_int(&dentry->d_name)};



	if (!task)

		goto out_no_task;

	if (fd == ~0U)

	if (data.fd == ~0U)

		goto out;

	if (!tid_fd_mode(task, fd, &f_mode))

	if (!tid_fd_mode(task, data.fd, &data.mode))

		goto out;



	result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);

	result = instantiate(dir, dentry, task, &data);

out:

	put_task_struct(task);

out_no_task:
@@ -241,17 +247,22 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx, 
	for (fd = ctx->pos - 2;

	     fd < files_fdtable(files)->max_fds;

	     fd++, ctx->pos++) {

		struct file *f;

		struct fd_data data;

		char name[10 + 1];

		int len;



		if (!fcheck_files(files, fd))

		f = fcheck_files(files, fd);

		if (!f)

			continue;

		data.mode = f->f_mode;

		rcu_read_unlock();

		data.fd = fd;



		len = snprintf(name, sizeof(name), "%u", fd);

		if (!proc_fill_cache(file, ctx,

				     name, len, instantiate, p,

				     (void *)(unsigned long)fd))

				     &data))

			goto out_fd_loop;

		cond_resched();

		rcu_read_lock();
@@ -313,27 +324,23 @@ static int 
proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,

			struct task_struct *task, const void *ptr)

{

	unsigned fd = (unsigned long)ptr;

	const struct fd_data *data = ptr;

	struct proc_inode *ei;

	struct inode *inode;



	inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR);

	if (!inode)

		goto out;

		return -ENOENT;



	ei = PROC_I(inode);

	ei->fd = fd;

	ei->fd = data->fd;



	inode->i_fop = &proc_fdinfo_file_operations;

	tid_fd_update_inode(task, inode, 0);



	d_set_d_op(dentry, &tid_fd_dentry_operations);

	d_add(dentry, inode);



	/* Close the race of the process dying before we return the dentry */

	if (tid_fd_revalidate(dentry, 0))

	return 0;

 out:

	return -ENOENT;

}



static struct dentry *