6.6-stable review patch. If anyone has any objections, please let me know.
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From: Yuanfang Zhang quic_yuanfang@quicinc.com
[ Upstream commit 12d9a9dd9d8a4f1968073e7f34515896d1e22b78 ]
Ensure that etm_perf_add_symlink_sink() is only called for devices that implement the alloc_buffer operation. This prevents invalid symlink creation for dummy sinks that do not implement alloc_buffer.
Without this check, perf may attempt to use a dummy sink that lacks alloc_buffer operationsu to initialise perf's ring buffer, leading to runtime failures.
Fixes: 9d3ba0b6c0569 ("Coresight: Add coresight dummy driver") Signed-off-by: Yuanfang Zhang quic_yuanfang@quicinc.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250630-etm_perf_sink-v1-1-e4a7211f9ad7@quicinc.c... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 3b57851869eaa..a836952737209 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1638,8 +1638,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) goto out_unlock; }
- if (csdev->type == CORESIGHT_DEV_TYPE_SINK || - csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) { + if ((csdev->type == CORESIGHT_DEV_TYPE_SINK || + csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && + sink_ops(csdev)->alloc_buffer) { ret = etm_perf_add_symlink_sink(csdev);
if (ret) {