[RESEND PATCH] coresight: tmc: Explicit type conversions to prevent integer overflow

From: Ruidong Tian
Date: Fri Jul 14 2023 - 04:44:07 EST


Perf cs_etm session will failed when AUX buffer > 1G.

perf record -C 0 -m ,2G -e cs_etm// -- taskset -c 0 ls
failed to mmap with 12 (Cannot allocate memory)

In coresight tmc driver, "nr_pages << PAGE_SHIFT" will overflow when
nr_pages >= 0x80000(correspond to 1G AUX buffer). Explicit convert nr_pages
to 64 bit to avoid overflow.

Signed-off-by: Ruidong Tian <tianruidong@xxxxxxxxxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +-
drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 766325de0e29..1425ecd1cf78 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1267,7 +1267,7 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
* than the size requested via sysfs.
*/
if ((nr_pages << PAGE_SHIFT) > drvdata->size) {
- etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT),
+ etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << PAGE_SHIFT),
0, node, NULL);
if (!IS_ERR(etr_buf))
goto done;
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index b97da39652d2..0ee48c5ba764 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -325,7 +325,7 @@ ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table,
static inline unsigned long
tmc_sg_table_buf_size(struct tmc_sg_table *sg_table)
{
- return sg_table->data_pages.nr_pages << PAGE_SHIFT;
+ return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT;
}

struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
--
2.33.1