[PATCH 06/10] Coresight: Add an interface for supporting ETM3/4 Context ID tracing
From: mathieu.poirier@linaro.org (Mathieu Poirier)
Date: 2015-07-31 15:39:15
Also in:
lkml
Subsystem:
arm/coresight framework and drivers, the rest · Maintainers:
Suzuki K Poulose, Linus Torvalds
From: Chunyan Zhang <redacted> 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 <redacted> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- 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
--
1.9.1