1 // SPDX-License-Identifier: GPL-2.0-only
10 #include <linux/backing-dev.h>
17 				     void __user *buf, u64 offset, int length)  in fsverity_read_merkle_tree()  argument
19 	const struct fsverity_operations *vops = inode->i_sb->s_vop;  in fsverity_read_merkle_tree()
26 	end_offset = min(offset + length, vi->tree_params.tree_size);  in fsverity_read_merkle_tree()
27 	if (offset >= end_offset)  in fsverity_read_merkle_tree()
29 	offs_in_page = offset_in_page(offset);  in fsverity_read_merkle_tree()
30 	last_index = (end_offset - 1) >> PAGE_SHIFT;  in fsverity_read_merkle_tree()
33 	 * Iterate through each Merkle tree page in the requested range and copy  in fsverity_read_merkle_tree()
38 	for (index = offset >> PAGE_SHIFT; index <= last_index; index++) {  in fsverity_read_merkle_tree()
40 			min_t(unsigned long, last_index - index + 1,  in fsverity_read_merkle_tree()
41 			      inode->i_sb->s_bdi->io_pages);  in fsverity_read_merkle_tree()
42 		unsigned int bytes_to_copy = min_t(u64, end_offset - offset,  in fsverity_read_merkle_tree()
43 						   PAGE_SIZE - offs_in_page);  in fsverity_read_merkle_tree()
44 		struct page *page;  in fsverity_read_merkle_tree()  local
47 		page = vops->read_merkle_tree_page(inode, index, num_ra_pages);  in fsverity_read_merkle_tree()
48 		if (IS_ERR(page)) {  in fsverity_read_merkle_tree()
49 			err = PTR_ERR(page);  in fsverity_read_merkle_tree()
51 				     "Error %d reading Merkle tree page %lu",  in fsverity_read_merkle_tree()
56 		virt = kmap_local_page(page);  in fsverity_read_merkle_tree()
59 			put_page(page);  in fsverity_read_merkle_tree()
60 			err = -EFAULT;  in fsverity_read_merkle_tree()
64 		put_page(page);  in fsverity_read_merkle_tree()
68 		offset += bytes_to_copy;  in fsverity_read_merkle_tree()
71 			err = -EINTR;  in fsverity_read_merkle_tree()
81 static int fsverity_read_buffer(void __user *dst, u64 offset, int length,  in fsverity_read_buffer()  argument
84 	if (offset >= src_length)  in fsverity_read_buffer()
86 	src += offset;  in fsverity_read_buffer()
87 	src_length -= offset;  in fsverity_read_buffer()
92 		return -EFAULT;  in fsverity_read_buffer()
98 				    void __user *buf, u64 offset, int length)  in fsverity_read_descriptor()  argument
110 	desc->sig_size = 0;  in fsverity_read_descriptor()
112 	res = fsverity_read_buffer(buf, offset, length, desc, desc_size);  in fsverity_read_descriptor()
119 				   void __user *buf, u64 offset, int length)  in fsverity_read_signature()  argument
128 	if (desc->sig_size == 0) {  in fsverity_read_signature()
129 		res = -ENODATA;  in fsverity_read_signature()
135 	 * already verified that sig_size is in-bounds.  in fsverity_read_signature()
137 	res = fsverity_read_buffer(buf, offset, length, desc->signature,  in fsverity_read_signature()
138 				   le32_to_cpu(desc->sig_size));  in fsverity_read_signature()
145  * fsverity_ioctl_read_metadata() - read verity metadata from a file
149  * Return: length read on success, 0 on EOF, -errno on failure
161 		return -ENODATA; /* not a verity file */  in fsverity_ioctl_read_metadata()
168 		return -EFAULT;  in fsverity_ioctl_read_metadata()
171 		return -EINVAL;  in fsverity_ioctl_read_metadata()
173 	/* offset + length must not overflow. */  in fsverity_ioctl_read_metadata()
174 	if (arg.offset + arg.length < arg.offset)  in fsverity_ioctl_read_metadata()
175 		return -EINVAL;  in fsverity_ioctl_read_metadata()
184 		return fsverity_read_merkle_tree(inode, vi, buf, arg.offset,  in fsverity_ioctl_read_metadata()
187 		return fsverity_read_descriptor(inode, buf, arg.offset, length);  in fsverity_ioctl_read_metadata()
189 		return fsverity_read_signature(inode, buf, arg.offset, length);  in fsverity_ioctl_read_metadata()
191 		return -EINVAL;  in fsverity_ioctl_read_metadata()