firmware: arm_scmi: Fix base agent discover response

According to scmi specification, the response of the discover agent request
is made of:
- int32 status
- uint32 agent_id
- uint8 name[16]

but the current implementation doesn't take into account the agent_id field
and only allocates a rx buffer of SCMI_MAX_STR_SIZE length

Allocate the correct length for rx buffer and copy the name from the
correct offset in the response.

While no error were returned until v5.15, v5.16-rc1 fails with virtio_scmi
transport channel:

 | arm-scmi firmware:scmi0: SCMI Notifications - Core Enabled.
 | arm-scmi firmware:scmi0: SCMI Protocol v2.0 'Linaro:PMWG' Firmware version 0x2090000
 | scmi-virtio virtio0: tx:used len 28 is larger than in buflen 24

Link: https://lore.kernel.org/r/20211117081856.9932-1-vincent.guittot@linaro.org
Fixes: b6f20ff8bd ("firmware: arm_scmi: add common infrastructure and support for base protocol")
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Vincent Guittot 2021-11-17 09:18:56 +01:00 committed by Sudeep Holla
parent 9516116572
commit d1cbd9e0f7

View File

@ -34,6 +34,12 @@ struct scmi_msg_resp_base_attributes {
__le16 reserved;
};
struct scmi_msg_resp_base_discover_agent {
__le32 agent_id;
u8 name[SCMI_MAX_STR_SIZE];
};
struct scmi_msg_base_error_notify {
__le32 event_control;
#define BASE_TP_NOTIFY_ALL BIT(0)
@ -225,18 +231,21 @@ static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
int id, char *name)
{
int ret;
struct scmi_msg_resp_base_discover_agent *agent_info;
struct scmi_xfer *t;
ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
sizeof(__le32), SCMI_MAX_STR_SIZE, &t);
sizeof(__le32), sizeof(*agent_info), &t);
if (ret)
return ret;
put_unaligned_le32(id, t->tx.buf);
ret = ph->xops->do_xfer(ph, t);
if (!ret)
strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
if (!ret) {
agent_info = t->rx.buf;
strlcpy(name, agent_info->name, SCMI_MAX_STR_SIZE);
}
ph->xops->xfer_put(ph, t);