coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()

This code generates a Smatch warning:

    drivers/hwtracing/coresight/coresight-tmc-etr.c:947 tmc_etr_buf_insert_barrier_packet()
    error: uninitialized symbol 'bufp'.

The problem is that if tmc_sg_table_get_data() returns -EINVAL, then
when we test if "len < CORESIGHT_BARRIER_PKT_SIZE", the negative "len"
value is type promoted to a high unsigned long value which is greater
than CORESIGHT_BARRIER_PKT_SIZE.  Fix this bug by adding an explicit
check for error codes.

Fixes: 75f4e3619f ("coresight: tmc-etr: Add transparent buffer management")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/7d33e244-d8b9-4c27-9653-883a13534b01@kili.mountain
This commit is contained in:
Dan Carpenter 2023-04-21 13:42:41 +03:00 committed by Suzuki K Poulose
parent ac9a78681b
commit f67bc15e52

View File

@ -942,7 +942,7 @@ tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
len = tmc_etr_buf_get_data(etr_buf, offset,
CORESIGHT_BARRIER_PKT_SIZE, &bufp);
if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE))
return -EINVAL;
coresight_insert_barrier_packet(bufp);
return offset + CORESIGHT_BARRIER_PKT_SIZE;