2021-05-15 10:56:41

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH][next] misc: bcm-vk: Replace zero-length array with flexible array member

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].

Also, make use of the struct_size() helper in kzalloc().

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/misc/bcm-vk/bcm_vk_msg.c | 3 +--
drivers/misc/bcm-vk/bcm_vk_msg.h | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c
index f40cf08a6192..6efc52b49af6 100644
--- a/drivers/misc/bcm-vk/bcm_vk_msg.c
+++ b/drivers/misc/bcm-vk/bcm_vk_msg.c
@@ -701,8 +701,7 @@ int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, u32 shut_type,
return -EINVAL;
}

- entry = kzalloc(sizeof(*entry) +
- sizeof(struct vk_msg_blk), GFP_KERNEL);
+ entry = kzalloc(struct_size(entry, to_v_msg, 1), GFP_KERNEL);
if (!entry)
return -ENOMEM;

diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.h b/drivers/misc/bcm-vk/bcm_vk_msg.h
index 4eaad84825d6..56784c8896d8 100644
--- a/drivers/misc/bcm-vk/bcm_vk_msg.h
+++ b/drivers/misc/bcm-vk/bcm_vk_msg.h
@@ -116,7 +116,7 @@ struct bcm_vk_wkent {
u32 usr_msg_id;
u32 to_v_blks;
u32 seq_num;
- struct vk_msg_blk to_v_msg[0];
+ struct vk_msg_blk to_v_msg[];
};

/* queue stats counters */
--
2.27.0