media: venus: Replace one-element arrays with flexible-array members

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
members in multiple structures, and refactor the rest of the code,
accordingly.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

This results in no differences in binary output.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/291
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/qcom/venus/hfi_msgs.c

@@ -233,7 +233,7 @@ static void hfi_sys_init_done(struct venus_core *core, struct venus_inst *inst,
 		goto done;
 	}
 
-	rem_bytes = pkt->hdr.size - sizeof(*pkt) + sizeof(u32);
+	rem_bytes = pkt->hdr.size - sizeof(*pkt);
 	if (rem_bytes <= 0) {
 		/* missing property data */
 		error = HFI_ERR_SYS_INSUFFICIENT_RESOURCES;
@@ -434,7 +434,7 @@ static void hfi_session_init_done(struct venus_core *core,
 	if (!IS_V1(core))
 		goto done;
 
-	rem_bytes = pkt->shdr.hdr.size - sizeof(*pkt) + sizeof(u32);
+	rem_bytes = pkt->shdr.hdr.size - sizeof(*pkt);
 	if (rem_bytes <= 0) {
 		error = HFI_ERR_SESSION_INSUFFICIENT_RESOURCES;
 		goto done;

drivers/media/platform/qcom/venus/hfi_msgs.h

@@ -50,7 +50,7 @@ struct hfi_msg_event_notify_pkt {
 	u32 event_id;
 	u32 event_data1;
 	u32 event_data2;
-	u32 ext_event_data[1];
+	u32 ext_event_data[];
 };
 
 struct hfi_msg_event_release_buffer_ref_pkt {
@@ -63,7 +63,7 @@ struct hfi_msg_sys_init_done_pkt {
 	struct hfi_pkt_hdr hdr;
 	u32 error_type;
 	u32 num_properties;
-	u32 data[1];
+	u32 data[];
 };
 
 struct hfi_msg_sys_pc_prep_done_pkt {
@@ -81,7 +81,7 @@ struct hfi_msg_session_init_done_pkt {
 	struct hfi_session_hdr_pkt shdr;
 	u32 error_type;
 	u32 num_properties;
-	u32 data[1];
+	u32 data[];
 };
 
 struct hfi_msg_session_end_done_pkt {
@@ -228,7 +228,7 @@ struct hfi_msg_session_parse_sequence_header_done_pkt {
 	struct hfi_session_hdr_pkt shdr;
 	u32 error_type;
 	u32 num_properties;
-	u32 data[1];
+	u32 data[];
 };
 
 struct hfi_msg_session_property_info_pkt {
@@ -247,7 +247,7 @@ struct hfi_msg_session_release_buffers_done_pkt {
 	struct hfi_session_hdr_pkt shdr;
 	u32 error_type;
 	u32 num_buffers;
-	u32 buffer_info[1];
+	u32 buffer_info[];
 };
 
 struct hfi_msg_sys_debug_pkt {
@@ -256,7 +256,7 @@ struct hfi_msg_sys_debug_pkt {
 	u32 msg_size;
 	u32 time_stamp_hi;
 	u32 time_stamp_lo;
-	u8 msg_data[1];
+	u8 msg_data[];
 };
 
 struct hfi_msg_sys_coverage_pkt {
@@ -264,7 +264,7 @@ struct hfi_msg_sys_coverage_pkt {
 	u32 msg_size;
 	u32 time_stamp_hi;
 	u32 time_stamp_lo;
-	u8 msg_data[1];
+	u8 msg_data[];
 };
 
 struct venus_core;