ASoC: SOF: 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].

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

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

Link: https://github.com/KSPP/linux/issues/78
Link: https://github.com/KSPP/linux/issues/180
Suggested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Stephen Kitt <steve@sk2.org>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20220217132755.1786130-1-steve@sk2.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/include/sound/sof/topology.h b/include/sound/sof/topology.h
index d12736e..adee6af 100644 (file)
--- a/include/sound/sof/topology.h
+++ b/include/sound/sof/topology.h
@@ -237,7 +237,7 @@ struct sof_ipc_comp_process {
        /* reserved for future use */
        uint32_t reserved[7];
 
-       uint8_t data[0];
+       uint8_t data[];
 } __packed;
 
 /* frees components, buffers and pipelines

diff --git a/sound/soc/sof/topology.c b/sound/soc/sof/topology.c
index e72dcae..1d119d1 100644 (file)
--- a/sound/soc/sof/topology.c
+++ b/sound/soc/sof/topology.c
@@ -2164,7 +2164,7 @@ static int sof_process_load(struct snd_soc_component *scomp, int index,
         */
        if (ipc_data_size) {
                for (i = 0; i < widget->num_kcontrols; i++) {
-                       memcpy(&process->data + offset,
+                       memcpy(&process->data[offset],
                               wdata[i].pdata->data,
                               wdata[i].pdata->size);
                        offset += wdata[i].pdata->size;