linux/include/uapi/sound/sof/header.h
Gustavo A. R. Silva 94dfc73e7c treewide: uapi: Replace zero-length arrays with flexible-array members
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:
(linux-5.19-rc2$ 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
  ];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
		strcpy(de3->name, ".");
		^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[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
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-06-28 21:26:05 +02:00

30 lines
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C

/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* Copyright(c) 2018 Intel Corporation. All rights reserved.
*/
#ifndef __INCLUDE_UAPI_SOUND_SOF_USER_HEADER_H__
#define __INCLUDE_UAPI_SOUND_SOF_USER_HEADER_H__
#include <linux/types.h>
/*
* Header for all non IPC ABI data.
*
* Identifies data type, size and ABI.
* Used by any bespoke component data structures or binary blobs.
*/
struct sof_abi_hdr {
__u32 magic; /**< 'S', 'O', 'F', '\0' */
__u32 type; /**< component specific type */
__u32 size; /**< size in bytes of data excl. this struct */
__u32 abi; /**< SOF ABI version */
__u32 reserved[4]; /**< reserved for future use */
__u32 data[]; /**< Component data - opaque to core */
} __packed;
#endif