change wifi driver to cypress

hc

2024-01-05 071106ecf68c401173c58808b1cf5f68cc50d390

 kernel/Documentation/filesystems/fsverity.rst
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 --------------------
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 The FS_IOC_ENABLE_VERITY ioctl enables fs-verity on a file.  It takes
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-in a pointer to a :c:type:`struct fsverity_enable_arg`, defined as
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+in a pointer to a struct fsverity_enable_arg, defined as
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 follows::
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     struct fsverity_enable_arg {
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   feature enabled on it.  (See `Filesystem support`_.)
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 - ``EOVERFLOW``: the digest is longer than the specified
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   ``digest_size`` bytes.  Try providing a larger buffer.
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+
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+FS_IOC_READ_VERITY_METADATA
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+---------------------------
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+
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+The FS_IOC_READ_VERITY_METADATA ioctl reads verity metadata from a
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+verity file.  This ioctl is available since Linux v5.12.
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+
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+This ioctl allows writing a server program that takes a verity file
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+and serves it to a client program, such that the client can do its own
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+fs-verity compatible verification of the file.  This only makes sense
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+if the client doesn't trust the server and if the server needs to
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+provide the storage for the client.
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+
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+This is a fairly specialized use case, and most fs-verity users won't
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+need this ioctl.
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+
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+This ioctl takes in a pointer to the following structure::
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+
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+   #define FS_VERITY_METADATA_TYPE_MERKLE_TREE     1
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+   #define FS_VERITY_METADATA_TYPE_DESCRIPTOR      2
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+   #define FS_VERITY_METADATA_TYPE_SIGNATURE       3
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+
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+   struct fsverity_read_metadata_arg {
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+           __u64 metadata_type;
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+           __u64 offset;
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+           __u64 length;
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+           __u64 buf_ptr;
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+           __u64 __reserved;
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+   };
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+
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+``metadata_type`` specifies the type of metadata to read:
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+
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+- ``FS_VERITY_METADATA_TYPE_MERKLE_TREE`` reads the blocks of the
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+  Merkle tree.  The blocks are returned in order from the root level
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+  to the leaf level.  Within each level, the blocks are returned in
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+  the same order that their hashes are themselves hashed.
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+  See `Merkle tree`_ for more information.
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+
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+- ``FS_VERITY_METADATA_TYPE_DESCRIPTOR`` reads the fs-verity
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+  descriptor.  See `fs-verity descriptor`_.
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+
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+- ``FS_VERITY_METADATA_TYPE_SIGNATURE`` reads the signature which was
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+  passed to FS_IOC_ENABLE_VERITY, if any.  See `Built-in signature
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+  verification`_.
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+
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+The semantics are similar to those of ``pread()``.  ``offset``
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+specifies the offset in bytes into the metadata item to read from, and
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+``length`` specifies the maximum number of bytes to read from the
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+metadata item.  ``buf_ptr`` is the pointer to the buffer to read into,
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+cast to a 64-bit integer.  ``__reserved`` must be 0.  On success, the
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+number of bytes read is returned.  0 is returned at the end of the
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+metadata item.  The returned length may be less than ``length``, for
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+example if the ioctl is interrupted.
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+
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+The metadata returned by FS_IOC_READ_VERITY_METADATA isn't guaranteed
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+to be authenticated against the file digest that would be returned by
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+`FS_IOC_MEASURE_VERITY`_, as the metadata is expected to be used to
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+implement fs-verity compatible verification anyway (though absent a
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+malicious disk, the metadata will indeed match).  E.g. to implement
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+this ioctl, the filesystem is allowed to just read the Merkle tree
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+blocks from disk without actually verifying the path to the root node.
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+
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+FS_IOC_READ_VERITY_METADATA can fail with the following errors:
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+
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+- ``EFAULT``: the caller provided inaccessible memory
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+- ``EINTR``: the ioctl was interrupted before any data was read
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+- ``EINVAL``: reserved fields were set, or ``offset + length``
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+  overflowed
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+- ``ENODATA``: the file is not a verity file, or
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+  FS_VERITY_METADATA_TYPE_SIGNATURE was requested but the file doesn't
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+  have a built-in signature
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+- ``ENOTTY``: this type of filesystem does not implement fs-verity, or
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+  this ioctl is not yet implemented on it
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+- ``EOPNOTSUPP``: the kernel was not configured with fs-verity
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+  support, or the filesystem superblock has not had the 'verity'
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+  feature enabled on it.  (See `Filesystem support`_.)
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 FS_IOC_GETFLAGS
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 ---------------
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       retrofit existing filesystems with new consistency mechanisms.
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       Data journalling is available on ext4, but is very slow.
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-    - Rebuilding the the Merkle tree after every write, which would be
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+    - Rebuilding the Merkle tree after every write, which would be
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       extremely inefficient.  Alternatively, a different authenticated
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       dictionary structure such as an "authenticated skiplist" could
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       be used.  However, this would be far more complex.