5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilkka Koskinen ilkka@os.amperecomputing.com
[ Upstream commit 0e14e062f5ff98aa15264dfa87c5f5e924028561 ]
Trying to record a trace on kernel with 64k pages resulted in -ENOMEM. This happens due to a bug in calculating the number of table pages, which returns zero. Fix the issue by rounding up.
$ perf record --kcore -e cs_etm/@tmc_etr55,cycacc,branch_broadcast/k --per-thread taskset --cpu-list 1 dd if=/dev/zero of=/dev/null failed to mmap with 12 (Cannot allocate memory)
Fixes: 8ed536b1e283 ("coresight: catu: Add support for scatter gather tables") Signed-off-by: Ilkka Koskinen ilkka@os.amperecomputing.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250109215348.5483-1-ilkka@os.amperecomputing.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-catu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c index 16ebf38a9f664..da205738e8c96 100644 --- a/drivers/hwtracing/coresight/coresight-catu.c +++ b/drivers/hwtracing/coresight/coresight-catu.c @@ -267,7 +267,7 @@ catu_init_sg_table(struct device *catu_dev, int node, * Each table can address upto 1MB and we can have * CATU_PAGES_PER_SYSPAGE tables in a system page. */ - nr_tpages = DIV_ROUND_UP(size, SZ_1M) / CATU_PAGES_PER_SYSPAGE; + nr_tpages = DIV_ROUND_UP(size, CATU_PAGES_PER_SYSPAGE * SZ_1M); catu_table = tmc_alloc_sg_table(catu_dev, node, nr_tpages, size >> PAGE_SHIFT, pages); if (IS_ERR(catu_table))