On 09/05/2026 1:58 am, Jie Gan wrote:
When coresight_path_assign_trace_id() cannot assign a valid trace ID, coresight_enable_sysfs() takes the err_path goto with ret still 0, returning success to the caller despite no trace session being started.
Fix this by changing coresight_path_assign_trace_id() to return int. Move the IS_VALID_CS_TRACE_ID() check inside the function so it returns -EINVAL on failure and 0 on success. Update coresight_enable_sysfs() to check the return value directly instead of inspecting path->trace_id after the call.
The other caller in coresight-etm-perf.c discards the return value and continues to check path->trace_id via IS_VALID_CS_TRACE_ID() directly. This is unaffected: on failure path->trace_id is no longer written, so it remains 0, which IS_VALID_CS_TRACE_ID() rejects the same as before.
Fixes: d87d76d823d1 ("Coresight: Allocate trace ID after building the path") Signed-off-by: Jie Gan jie.gan@oss.qualcomm.com
Changes in v2:
- Refactor the coresight_path_assign_trace_id function.
- Link to v1: https://lore.kernel.org/r/20260508-fix-trace-id-error-v1-1-5f11a5456fdf@oss....
drivers/hwtracing/coresight/coresight-core.c | 14 ++++++++++---- drivers/hwtracing/coresight/coresight-priv.h | 2 +- drivers/hwtracing/coresight/coresight-sysfs.c | 4 ++-- 3 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 46f247f73cf6..cabdc0c72f38 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -739,12 +739,12 @@ static int coresight_get_trace_id(struct coresight_device *csdev,
- Call this after creating the path and before enabling it. This leaves
- the trace ID set on the path, or it remains 0 if it couldn't be assigned.
*/ -void coresight_path_assign_trace_id(struct coresight_path *path, +int coresight_path_assign_trace_id(struct coresight_path *path, enum cs_mode mode) { struct coresight_device *sink = coresight_get_sink(path); struct coresight_node *nd;
- int trace_id;
- int trace_id, ret = -EINVAL;
list_for_each_entry(nd, &path->path_list, link) { /* Assign a trace ID to the path for the first device that wants to do it */ @@ -755,10 +755,16 @@ void coresight_path_assign_trace_id(struct coresight_path *path, * Non 0 is either success or fail. */ if (trace_id != 0) {
path->trace_id = trace_id;return;
if (IS_VALID_CS_TRACE_ID(trace_id)) {path->trace_id = trace_id;ret = 0;
Reviewed-by: James Clark james.clark@linaro.org
Minor nit, but just "return 0" here is a bit simpler.
}return ret;
And then "return -EINVAL" for these ones.
}}
- return ret; > }
/** diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 1ea882dffd70..34c7e792adbd 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -153,7 +153,7 @@ int coresight_make_links(struct coresight_device *orig, void coresight_remove_links(struct coresight_device *orig, struct coresight_connection *conn); u32 coresight_get_sink_id(struct coresight_device *csdev); -void coresight_path_assign_trace_id(struct coresight_path *path, +int coresight_path_assign_trace_id(struct coresight_path *path, enum cs_mode mode); #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X) diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index d2a6ed8bcc74..b6a870399e83 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -211,8 +211,8 @@ int coresight_enable_sysfs(struct coresight_device *csdev) goto out; }
- coresight_path_assign_trace_id(path, CS_MODE_SYSFS);
- if (!IS_VALID_CS_TRACE_ID(path->trace_id))
- ret = coresight_path_assign_trace_id(path, CS_MODE_SYSFS);
- if (ret) goto err_path;
ret = coresight_enable_path(path, CS_MODE_SYSFS);
base-commit: 17c7841d09ee7d33557fd075562d9289b6018c90 change-id: 20260508-fix-trace-id-error-dbfdd4d8f2d1
Best regards,