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Commit c9e6c1fe authored by Ruidong Tian's avatar Ruidong Tian Committed by Greg Kroah-Hartman
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coresight: tmc: Explicit type conversions to prevent integer overflow 



[ Upstream commit fd380097cdb305582b7a1f9476391330299d2c59 ]

Perf cs_etm session executed unexpectedly when AUX buffer > 1G.

  perf record -C 0 -m ,2G -e cs_etm// -- <workload>
  [ perf record: Captured and wrote 2.615 MB perf.data ]

Perf only collect about 2M perf data rather than 2G. This is becasuse
the operation, "nr_pages << PAGE_SHIFT", in coresight tmc driver, will
overflow when nr_pages >= 0x80000(correspond to 1G AUX buffer). The
overflow cause buffer allocation to fail, and TMC driver will alloc
minimal buffer size(1M). You can just get about 2M perf data(1M AUX
buffer + perf data header) at least.

Explicit convert nr_pages to 64 bit to avoid overflow.

Fixes: 22f429f1 ("coresight: etm-perf: Add support for ETR backend")
Fixes: 99443ea1 ("coresight: Add generic TMC sg table framework")
Fixes: 2e499bbc ("coresight: tmc: implementing TMC-ETF AUX space API")
Signed-off-by: default avatarRuidong Tian <tianruidong@linux.alibaba.com>
Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230804081514.120171-2-tianruidong@linux.alibaba.com


Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 463934ca

drivers/hwtracing/coresight/coresight-tmc-etf.c

+1 −1
Original line number Diff line number Diff line
@@ -426,7 +426,7 @@ static int tmc_set_etf_buffer(struct coresight_device *csdev, 
		return -EINVAL;



	/* wrap head around to the amount of space we have */

	head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);

	head = handle->head & (((unsigned long)buf->nr_pages << PAGE_SHIFT) - 1);



	/* find the page to write to */

	buf->cur = head / PAGE_SIZE;

drivers/hwtracing/coresight/coresight-tmc-etr.c

+3 −2
Original line number Diff line number Diff line
@@ -47,7 +47,8 @@ struct etr_perf_buffer { 
};



/* Convert the perf index to an offset within the ETR buffer */

#define PERF_IDX2OFF(idx, buf)	((idx) % ((buf)->nr_pages << PAGE_SHIFT))

#define PERF_IDX2OFF(idx, buf)		\

		((idx) % ((unsigned long)(buf)->nr_pages << PAGE_SHIFT))



/* Lower limit for ETR hardware buffer */

#define TMC_ETR_PERF_MIN_BUF_SIZE	SZ_1M
@@ -1215,7 +1216,7 @@ 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;

drivers/hwtracing/coresight/coresight-tmc.h

+1 −1
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ 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);