From 722102274ab1206634d31abe4f438a911a0945d2 Mon Sep 17 00:00:00 2001 From: Chunyan Zhang Date: Fri, 31 Jul 2015 09:37:26 -0600 Subject: [PATCH] Coresight: Add an interface for supporting ETM3/4 Context ID tracing 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 Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- include/linux/coresight.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 3486b9082adb..626da6948ca2 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 -- 2.39.5