On 5/12/2021 1:12 PM, Colin Ian King wrote:

Hi,

Static analysis with Coverity on linux-next has detected an issue with the following commit:

commit 5f1b95d08de712327e452d082a50fded435ec884 Author: Yang Li yang.lee@linux.alibaba.com Date: Sun Apr 25 18:12:33 2021 +0800

 ASoC: q6dsp: q6afe: remove unneeded dead-store initialization

the analysis is as follows:

1181 int q6afe_port_stop(struct q6afe_port *port) 1182 { 1183 struct afe_port_cmd_device_stop *stop; 1184 struct q6afe *afe = port->afe; 1185 struct apr_pkt *pkt;

 1. var_decl: Declaring variable port_id without initializer.

1186 int port_id; 1187 int ret = 0; 1188 int index, pkt_size; 1189 void *p; 1190 1191 index = port->token;

 2. Condition index < 0, taking false branch.
 3. Condition index >= 127, taking false branch.

1192 if (index < 0 || index >= AFE_PORT_MAX) { 1193 dev_err(afe->dev, "AFE port index[%d] invalid!\n", index); 1194 return -EINVAL; 1195 } 1196 1197 pkt_size = APR_HDR_SIZE + sizeof(*stop); 1198 p = kzalloc(pkt_size, GFP_KERNEL);

 4. Condition !p, taking false branch.

1199 if (!p) 1200 return -ENOMEM; 1201 1202 pkt = p; 1203 stop = p + APR_HDR_SIZE; 1204 1205 pkt->hdr.hdr_field = APR_HDR_FIELD(APR_MSG_TYPE_SEQ_CMD, 1206 APR_HDR_LEN(APR_HDR_SIZE), 1207 APR_PKT_VER); 1208 pkt->hdr.pkt_size = pkt_size; 1209 pkt->hdr.src_port = 0; 1210 pkt->hdr.dest_port = 0; 1211 pkt->hdr.token = index; 1212 pkt->hdr.opcode = AFE_PORT_CMD_DEVICE_STOP;

 Uninitialized scalar variable (UNINIT)
 5. uninit_use: Using uninitialized value port_id.

1213 stop->port_id = port_id; 1214 stop->reserved = 0;

the commit removed the initialization of port_id = port->id, and now we have a regression where stop->port_id is being assigned with a garbage uninitialized value in port_id. Perhaps the fix needs reverting. As it stands, I don't know why clang was reporting this as an error.

Colin

I suspect this patch was not made against a current tree. I sent a patch that resolved this and Mark picked it up so it should be in the next -next version:

https://lore.kernel.org/r/20210511190306.2418917-1-nathan@kernel.org/

Cheers, Nathan