On Fri, Mar 6, 2026 at 3:35 PM Rosen Penev <[email protected]> wrote:
>
> The former is just a nice macro and the latter allows runtime analysis
> of the allocation and its size.
>
> Signed-off-by: Rosen Penev <[email protected]>
> ---
> fs/smb/server/transport_ipc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/fs/smb/server/transport_ipc.c b/fs/smb/server/transport_ipc.c
> index 2dbabe2d8005..f7aa427a06fe 100644
> --- a/fs/smb/server/transport_ipc.c
> +++ b/fs/smb/server/transport_ipc.c
> @@ -55,7 +55,7 @@ static bool ksmbd_ipc_validate_version(struct genl_info *m)
> struct ksmbd_ipc_msg {
> unsigned int type;
> unsigned int sz;
> - unsigned char payload[];
> + unsigned char payload[] __counted_by(sz);
> };
>
> struct ipc_msg_table_entry {
> @@ -242,9 +242,8 @@ static void ipc_update_last_active(void)
> static struct ksmbd_ipc_msg *ipc_msg_alloc(size_t sz)
> {
> struct ksmbd_ipc_msg *msg;
> - size_t msg_sz = sz + sizeof(struct ksmbd_ipc_msg);
>
> - msg = kvzalloc(msg_sz, KSMBD_DEFAULT_GFP);
> + msg = kvzalloc_flex(*msg, payload, sz, KSMBD_DEFAULT_GFP);
> if (msg)
> msg->sz = sz;
We don't need to manually set msg->sz if the flexible array member is
properly annotated with __counted_by(sz) ?
kvmalloc_flex() automatically sets the counter via internal
__set_flex_counter().
