Hi Dan

On 21/04/2023 11:42, Dan Carpenter wrote:

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: 75f4e3619fe2 ("coresight: tmc-etr: Add transparent buffer management") Signed-off-by: Dan Carpenter dan.carpenter@linaro.org

---

drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 918d461fcf4a..eaa296ced167 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -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;

Thanks for the fix, I will send this as fixes at 6.4-rc1, as I have already sent the PULL request for 6.4

Suzuki