[PATCH v4 01/16] firmware: arm_scmi: Fix max pending messages boundary check

Cristian Marussi
2021-06-11T17:02:58Z

SCMI message headers carry a sequence number and such field is sized to
allow for MSG_TOKEN_MAX distinct numbers; moreover zero is not really an
acceptable maximum number of pending in-flight messages.

Fix accordignly the checks performed on the value exported by transports
in scmi_desc.max_msg.

Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Fixes: aa4f886f3893 ("firmware: arm_scmi: add basic driver infrastructure for SCMI")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
drivers/firmware/arm_scmi/driver.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 66e5e694be7d..6713b259f1e6 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1025,8 +1025,9 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo,
const struct scmi_desc *desc = sinfo->desc;

/* Pre-allocated messages, no more than what hdr.seq can support */
- if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) {
- dev_err(dev, "Maximum message of %d exceeds supported %ld\n",
+ if (WARN_ON(!desc->max_msg || desc->max_msg > MSG_TOKEN_MAX)) {
+ dev_err(dev,
+ "Invalid max_msg %d. Maximum messages supported %ld.\n",
desc->max_msg, MSG_TOKEN_MAX);
return -EINVAL;
}
--
2.17.1