1 // SPDX-License-Identifier: GPL-2.0-only
9  * kernel_read_file() - read file contents into a kernel buffer
11  * @file	file to read from
18  * @file_size	if non-NULL, the full size of @file will be
21  *		file contents being read (for LSMs to examine)
23  * @offset must be 0 unless both @buf and @file_size are non-NULL
24  * (i.e. the caller must be expecting to read partial file contents
25  * via an already-allocated @buf, in at most @buf_size chunks, and
26  * will be able to determine when the entire file was read by
27  * checking @file_size). This isn't a recommended way to read a
31  * Returns number of bytes read (no single read will be bigger
46 		return -EINVAL;  in kernel_read_file()
48 	if (!S_ISREG(file_inode(file)->i_mode))  in kernel_read_file()
49 		return -EINVAL;  in kernel_read_file()
57 		ret = -EINVAL;  in kernel_read_file()
58 		goto out;  in kernel_read_file()
62 		ret = -EFBIG;  in kernel_read_file()
63 		goto out;  in kernel_read_file()
65 	/* The entire file cannot be read in one buffer. */  in kernel_read_file()
67 		ret = -EFBIG;  in kernel_read_file()
68 		goto out;  in kernel_read_file()
74 		goto out;  in kernel_read_file()
82 		ret = -ENOMEM;  in kernel_read_file()
83 		goto out;  in kernel_read_file()
90 		size_t wanted = min_t(size_t, buf_size - copied,  in kernel_read_file()
91 					      i_size - pos);  in kernel_read_file()
106 			ret = -EIO;  in kernel_read_file()
121 out:  in kernel_read_file()
135 		return -EINVAL;  in kernel_read_file_from_path()
157 		return -EINVAL;  in kernel_read_file_from_path_initns()
179 	ssize_t ret = -EBADF;  in kernel_read_file_from_fd()
181 	if (!f.file || !(f.file->f_mode & FMODE_READ))  in kernel_read_file_from_fd()
182 		goto out;  in kernel_read_file_from_fd()
185 out:  in kernel_read_file_from_fd()