diff mbox series

[v4,4/5] usb: gadget: add trace event of configfs link/unlink operation

Message ID 1648621087-14948-5-git-send-email-quic_linyyuan@quicinc.com
State Superseded
Headers show
Series usb: gadget: configfs: new trace events | expand

Commit Message

Linyu Yuan March 30, 2022, 6:18 a.m. UTC 
Add API trace_usb_configfs_link_group() and trace_usb_configfs_unlink_group()
to trace user link/unlink a group like add function to configuration or
remove function from configuration.
If a specific function need link/unlink, it also can be used.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
---
v2: no change
v3: add API in trace.c
v4: fix memory leak

 drivers/usb/gadget/configfs.c              |  8 ++++++
 drivers/usb/gadget/function/uvc_configfs.c | 12 ++++++++
 drivers/usb/gadget/trace.c                 | 46 ++++++++++++++++++++++++++++++
 include/linux/usb/composite.h              |  6 ++++
 4 files changed, 72 insertions(+)
diff mbox series

Patch

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index a0599fb..a304d29 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -422,6 +422,8 @@  static int config_usb_cfg_link(
 	struct usb_function *f;
 	int ret;
 
+	trace_usb_configfs_link_group(usb_cfg_ci, usb_func_ci);
+
 	mutex_lock(&gi->lock);
 	/*
 	 * Make sure this function is from within our _this_ gadget and not
@@ -471,6 +473,8 @@  static void config_usb_cfg_unlink(
 			to_usb_function_instance(usb_func_ci);
 	struct usb_function *f;
 
+	trace_usb_configfs_unlink_group(usb_cfg_ci, usb_func_ci);
+
 	/*
 	 * ideally I would like to forbid to unlink functions while a gadget is
 	 * bound to an UDC. Since this isn't possible at the moment, we simply
@@ -893,6 +897,8 @@  static int os_desc_link(struct config_item *os_desc_ci,
 	struct usb_configuration *c = NULL, *iter;
 	int ret;
 
+	trace_usb_configfs_link_group(os_desc_ci, usb_cfg_ci);
+
 	mutex_lock(&gi->lock);
 	list_for_each_entry(iter, &cdev->configs, list) {
 		if (iter != &c_target->c)
@@ -924,6 +930,8 @@  static void os_desc_unlink(struct config_item *os_desc_ci,
 	struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
 	struct usb_composite_dev *cdev = &gi->cdev;
 
+	trace_usb_configfs_unlink_group(os_desc_ci, usb_cfg_ci);
+
 	mutex_lock(&gi->lock);
 	if (gi->composite.gadget_driver.udc_name)
 		unregister_gadget(gi);
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index cc0f2eb..fc139f3 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -598,6 +598,8 @@  static int uvcg_control_class_allow_link(struct config_item *src,
 	struct uvcg_control_header *target_hdr;
 	int ret = -EINVAL;
 
+	trace_usb_configfs_link_group(src, target);
+
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
 	control = src->ci_parent->ci_parent;
@@ -639,6 +641,8 @@  static void uvcg_control_class_drop_link(struct config_item *src,
 	struct uvc_descriptor_header **class_array;
 	struct uvcg_control_header *target_hdr;
 
+	trace_usb_configfs_unlink_group(src, target);
+
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
 	control = src->ci_parent->ci_parent;
@@ -883,6 +887,8 @@  static int uvcg_streaming_header_allow_link(struct config_item *src,
 	struct uvcg_format_ptr *format_ptr;
 	int i, ret = -EINVAL;
 
+	trace_usb_configfs_link_group(src, target);
+
 	src_hdr = to_uvcg_streaming_header(src);
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
@@ -946,6 +952,8 @@  static void uvcg_streaming_header_drop_link(struct config_item *src,
 	struct uvcg_format *target_fmt = NULL;
 	struct uvcg_format_ptr *format_ptr, *tmp;
 
+	trace_usb_configfs_unlink_group(src, target);
+
 	src_hdr = to_uvcg_streaming_header(src);
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
@@ -2171,6 +2179,8 @@  static int uvcg_streaming_class_allow_link(struct config_item *src,
 	size_t size = 0, count = 0;
 	int ret = -EINVAL;
 
+	trace_usb_configfs_link_group(src, target);
+
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
 	streaming = src->ci_parent->ci_parent;
@@ -2242,6 +2252,8 @@  static void uvcg_streaming_class_drop_link(struct config_item *src,
 	struct uvc_descriptor_header ***class_array;
 	struct uvcg_streaming_header *target_hdr;
 
+	trace_usb_configfs_unlink_group(src, target);
+
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */
 
 	streaming = src->ci_parent->ci_parent;
diff --git a/drivers/usb/gadget/trace.c b/drivers/usb/gadget/trace.c
index f4708c0..68e747b 100644
--- a/drivers/usb/gadget/trace.c
+++ b/drivers/usb/gadget/trace.c
@@ -88,4 +88,50 @@  void trace_usb_configfs_drop_group(struct config_item *parent,
 	trace_usb_configfs_make_drop_group(parent, item, "rmdir");
 }
 EXPORT_SYMBOL(trace_usb_configfs_drop_group);
+
+static void trace_usb_configfs_link_unlink_group(struct config_item *dest,
+		struct config_item *src, char *link_unlink)
+{
+	char *group, *dest_group, *src_group;
+	int ret;
+
+	group = kzalloc(4 * GROUP_LEN, GFP_KERNEL);
+	if (!group)
+		return;
+
+	dest_group = group + 2 * GROUP_LEN;
+	ret = gadget_configfs_group(dest_group, dest);
+	if (ret) {
+		kfree(group);
+		return;
+	}
+
+	src_group = group + 3 * GROUP_LEN;
+	ret = gadget_configfs_group(src_group, src);
+	if (ret) {
+		kfree(group);
+		return;
+	}
+
+	snprintf(group, 2 * GROUP_LEN, "%s %s %s",
+			link_unlink, dest_group, src_group);
+
+	trace_gadget_configfs(group);
+
+	kfree(group);
+}
+
+void trace_usb_configfs_link_group(struct config_item *dest,
+		struct config_item *src)
+{
+	trace_usb_configfs_link_unlink_group(dest, src, "link");
+}
+EXPORT_SYMBOL(trace_usb_configfs_link_group);
+
+void trace_usb_configfs_unlink_group(struct config_item *dest,
+		struct config_item *src)
+{
+	trace_usb_configfs_link_unlink_group(dest, src, "unlink");
+}
+EXPORT_SYMBOL(trace_usb_configfs_unlink_group);
 #endif
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index e904527..df74bd5 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -608,9 +608,15 @@  void trace_usb_configfs_make_group(struct config_item *parent,
 		struct config_item *item);
 void trace_usb_configfs_drop_group(struct config_item *parent,
 		struct config_item *item);
+void trace_usb_configfs_link_group(struct config_item *dest,
+		struct config_item *src);
+void trace_usb_configfs_unlink_group(struct config_item *dest,
+		struct config_item *src);
 #else
 #define trace_usb_configfs_make_group(parent, item) do {} while(0)
 #define trace_usb_configfs_drop_group(parent, item) do {} while(0)
+#define trace_usb_configfs_link_group(dest, src) do {} while(0)
+#define trace_usb_configfs_unlink_group(dest, src) do {} while(0)
 #endif
 
 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,