On 2/17/22 10:44, Gustavo A. R. Silva wrote:

On Thu, Feb 17, 2022 at 02:27:55PM +0100, Stephen Kitt 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].

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-a...

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

Reviewed-by: Gustavo A. R. Silva gustavoars@kernel.org

Thanks for the patch

Acked-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

I just realized we have additional cases in this directory (interface between kernel and firmware), I'll send a follow-up patch a

channel_map.h: int32_t ch_coeffs[0]; channel_map.h: struct sof_ipc_channel_map ch_map[0]; control.h: struct sof_ipc_ctrl_value_chan chanv[0]; control.h: struct sof_ipc_ctrl_value_comp compv[0]; control.h: struct sof_abi_hdr data[0]; control.h: struct sof_abi_hdr data[0];

Thanks!

Gustavo

...

---

include/sound/sof/topology.h | 2 +- sound/soc/sof/topology.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/sound/sof/topology.h b/include/sound/sof/topology.h index d12736e14b69..adee6afd1490 100644 --- 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 e72dcae5e7ee..1d119d1dd69d 100644 --- 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;
  
  

base-commit: f71077a4d84bbe8c7b91b7db7c4ef815755ac5e3

2.27.0