If PID namespace is enabled, everytime users configure the Context ID
register to trace the specific process, there needs to be a translation
between the real PID seen from the kernel and VPID seen from the
namespace in which the user's process resides .
This patch just adds the translation interface for ETMs.
Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
---
include/linux/coresight.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 3486b90..626da69 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -248,4 +248,24 @@ static inline struct coresight_platform_data *of_get_coresight_platform_data(
struct device *dev, struct device_node *node) { return NULL; }
#endif
+#ifdef CONFIG_PID_NS
+static inline unsigned long
+coresight_vpid_to_pid(unsigned long vpid)
+{
+ struct task_struct *task = NULL;
+ unsigned long pid = 0;
+
+ rcu_read_lock();
+ task = find_task_by_vpid(vpid);
+ if (task)
+ pid = task_pid_nr(task);
+ rcu_read_unlock();
+
+ return pid;
+}
+#else
+static inline unsigned long
+coresight_vpid_to_pid(unsigned long vpid) { return vpid; }
+#endif
+
#endif
--
1.9.1
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