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5224f79096
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].
This code was transformed with the help of Coccinelle:
(next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)
@@
identifier S, member, array;
type T1, T2;
@@
struct S {
...
T1 member;
T2 array[
- 0
];
};
UAPI and wireless changes were intentionally excluded from this patch
and will be sent out separately.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/78
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* Copyright (C) 2019 Oracle. All Rights Reserved.
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* Author: Darrick J. Wong <darrick.wong@oracle.com>
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*/
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#ifndef __XFS_SCRUB_ATTR_H__
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#define __XFS_SCRUB_ATTR_H__
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/*
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* Temporary storage for online scrub and repair of extended attributes.
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*/
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struct xchk_xattr_buf {
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/* Size of @buf, in bytes. */
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size_t sz;
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/*
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* Memory buffer -- either used for extracting attr values while
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* walking the attributes; or for computing attr block bitmaps when
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* checking the attribute tree.
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*
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* Each bitmap contains enough bits to track every byte in an attr
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* block (rounded up to the size of an unsigned long). The attr block
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* used space bitmap starts at the beginning of the buffer; the free
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* space bitmap follows immediately after; and we have a third buffer
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* for storing intermediate bitmap results.
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*/
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uint8_t buf[];
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};
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/* A place to store attribute values. */
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static inline uint8_t *
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xchk_xattr_valuebuf(
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struct xfs_scrub *sc)
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{
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struct xchk_xattr_buf *ab = sc->buf;
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return ab->buf;
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}
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/* A bitmap of space usage computed by walking an attr leaf block. */
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static inline unsigned long *
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xchk_xattr_usedmap(
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struct xfs_scrub *sc)
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{
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struct xchk_xattr_buf *ab = sc->buf;
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return (unsigned long *)ab->buf;
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}
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/* A bitmap of free space computed by walking attr leaf block free info. */
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static inline unsigned long *
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xchk_xattr_freemap(
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struct xfs_scrub *sc)
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{
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return xchk_xattr_usedmap(sc) +
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BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
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}
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/* A bitmap used to hold temporary results. */
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static inline unsigned long *
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xchk_xattr_dstmap(
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struct xfs_scrub *sc)
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{
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return xchk_xattr_freemap(sc) +
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BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
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}
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#endif /* __XFS_SCRUB_ATTR_H__ */
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