[PATCH][next] ALSA: virtio: 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-an...
Link: https://github.com/KSPP/linux/issues/78 Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org --- sound/virtio/virtio_pcm_msg.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c index f88c8f29cbd8..aca2dc1989ba 100644 --- a/sound/virtio/virtio_pcm_msg.c +++ b/sound/virtio/virtio_pcm_msg.c @@ -20,7 +20,7 @@ struct virtio_pcm_msg { struct virtio_snd_pcm_xfer xfer; struct virtio_snd_pcm_status status; size_t length; - struct scatterlist sgs[0]; + struct scatterlist sgs[]; };
/** @@ -146,8 +146,7 @@ int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss, int sg_num = virtsnd_pcm_sg_num(data, period_bytes); struct virtio_pcm_msg *msg;
- msg = kzalloc(sizeof(*msg) + sizeof(*msg->sgs) * (sg_num + 2), - GFP_KERNEL); + msg = kzalloc(struct_size(msg, sgs, sg_num + 2), GFP_KERNEL); if (!msg) return -ENOMEM;
On Wed, 29 Sep 2021 21:15:04 +0200, Gustavo A. R. Silva wrote:
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-an...
Link: https://github.com/KSPP/linux/issues/78 Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org
Thanks, applied.
Takashi
participants (2)
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Gustavo A. R. Silva
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Takashi Iwai