treewide: 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:
(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>

1 files changed, 5 insertions, 5 deletions

diff --git a/arch/sparc/include/asm/vio.h b/arch/sparc/include/asm/vio.h
index 8a1a83bbb6d5..2d7bdf665fd3 100644
--- a/arch/sparc/include/asm/vio.h
+++ b/arch/sparc/include/asm/vio.h
@@ -70,7 +70,7 @@ struct vio_dring_register {
 #define VIO_RX_DRING_DATA	0x0004
 	u16			resv;
 	u32			num_cookies;
-	struct ldc_trans_cookie	cookies[0];
+	struct ldc_trans_cookie	cookies[];
 };
 
 struct vio_dring_unregister {
@@ -161,7 +161,7 @@ struct vio_disk_desc {
 	u64			size;
 	u32			ncookies;
 	u32			resv2;
-	struct ldc_trans_cookie	cookies[0];
+	struct ldc_trans_cookie	cookies[];
 };
 
 #define VIO_DISK_VNAME_LEN	8
@@ -200,13 +200,13 @@ struct vio_disk_devid {
 	u16			resv;
 	u16			type;
 	u32			len;
-	char			id[0];
+	char			id[];
 };
 
 struct vio_disk_efi {
 	u64			lba;
 	u64			len;
-	char			data[0];
+	char			data[];
 };
 
 /* VIO net specific structures and defines */
@@ -246,7 +246,7 @@ struct vio_net_desc {
 	struct vio_dring_hdr	hdr;
 	u32			size;
 	u32			ncookies;
-	struct ldc_trans_cookie	cookies[0];
+	struct ldc_trans_cookie	cookies[];
 };
 
 struct vio_net_dext {