6.18-stable review patch. If anyone has any objections, please let me know.
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From: Carl Worth carl@os.amperecomputing.com
[ Upstream commit aaa5abcc9d44d2c8484f779ab46d242d774cabcb ]
The handle is essential for retrieving the AUX_EVENT of each CPU and is required in perf mode. It has been added to the coresight_path so that dependent devices can access it from the path when needed.
The existing bug can be reproduced with: perf record -e cs_etm//k -C 0-9 dd if=/dev/zero of=/dev/null
Showing an oops as follows: Unable to handle kernel paging request at virtual address 000f6e84934ed19e
Call trace: tmc_etr_get_buffer+0x30/0x80 [coresight_tmc] (P) catu_enable_hw+0xbc/0x3d0 [coresight_catu] catu_enable+0x70/0xe0 [coresight_catu] coresight_enable_path+0xb0/0x258 [coresight]
Fixes: 080ee83cc361 ("Coresight: Change functions to accept the coresight_path") Signed-off-by: Carl Worth carl@os.amperecomputing.com Reviewed-by: Leo Yan leo.yan@arm.com Co-developed-by: Jie Gan jie.gan@oss.qualcomm.com Signed-off-by: Jie Gan jie.gan@oss.qualcomm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250925-fix_helper_data-v2-1-edd8a07c1646@oss.qua... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-etm-perf.c | 1 + drivers/hwtracing/coresight/coresight-tmc-etr.c | 3 ++- include/linux/coresight.h | 10 ++++++---- 3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index f677c08233ba1..5c256af6e54af 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -520,6 +520,7 @@ static void etm_event_start(struct perf_event *event, int flags) goto out;
path = etm_event_cpu_path(event_data, cpu); + path->handle = handle; /* We need a sink, no need to continue without one */ sink = coresight_get_sink(path); if (WARN_ON_ONCE(!sink)) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 800be06598c1b..60b0e0a6da057 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1334,7 +1334,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev, enum cs_mode mode, void *data) { - struct perf_output_handle *handle = data; + struct coresight_path *path = data; + struct perf_output_handle *handle = path->handle; struct etr_perf_buffer *etr_perf;
switch (mode) { diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 6de59ce8ef8ca..2626105e37191 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -332,12 +332,14 @@ static struct coresight_dev_list (var) = { \
/** * struct coresight_path - data needed by enable/disable path - * @path_list: path from source to sink. - * @trace_id: trace_id of the whole path. + * @path_list: path from source to sink. + * @trace_id: trace_id of the whole path. + * @handle: handle of the aux_event. */ struct coresight_path { - struct list_head path_list; - u8 trace_id; + struct list_head path_list; + u8 trace_id; + struct perf_output_handle *handle; };
enum cs_mode {