Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 267 insertions, 0 deletions

diff --git a/drivers/extcon/devres.c b/drivers/extcon/devres.c
new file mode 100644
index 000000000..f9d52e8ec
--- /dev/null
+++ b/drivers/extcon/devres.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/extcon/devres.c - EXTCON device's resource management
+ *
+ * Copyright (C) 2016 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ */
+
+#include "extcon.h"
+
+static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
+{
+	struct extcon_dev **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_extcon_dev_release(struct device *dev, void *res)
+{
+	extcon_dev_free(*(struct extcon_dev **)res);
+}
+
+
+static void devm_extcon_dev_unreg(struct device *dev, void *res)
+{
+	extcon_dev_unregister(*(struct extcon_dev **)res);
+}
+
+struct extcon_dev_notifier_devres {
+	struct extcon_dev *edev;
+	unsigned int id;
+	struct notifier_block *nb;
+};
+
+static void devm_extcon_dev_notifier_unreg(struct device *dev, void *res)
+{
+	struct extcon_dev_notifier_devres *this = res;
+
+	extcon_unregister_notifier(this->edev, this->id, this->nb);
+}
+
+static void devm_extcon_dev_notifier_all_unreg(struct device *dev, void *res)
+{
+	struct extcon_dev_notifier_devres *this = res;
+
+	extcon_unregister_notifier_all(this->edev, this->nb);
+}
+
+/**
+ * devm_extcon_dev_allocate - Allocate managed extcon device
+ * @dev:		the device owning the extcon device being created
+ * @supported_cable:	the array of the supported external connectors
+ *			ending with EXTCON_NONE.
+ *
+ * This function manages automatically the memory of extcon device using device
+ * resource management and simplify the control of freeing the memory of extcon
+ * device.
+ *
+ * Returns the pointer memory of allocated extcon_dev if success
+ * or ERR_PTR(err) if fail
+ */
+struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
+					const unsigned int *supported_cable)
+{
+	struct extcon_dev **ptr, *edev;
+
+	ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	edev = extcon_dev_allocate(supported_cable);
+	if (IS_ERR(edev)) {
+		devres_free(ptr);
+		return edev;
+	}
+
+	edev->dev.parent = dev;
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
+
+/**
+ * devm_extcon_dev_free() - Resource-managed extcon_dev_unregister()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device to be freed
+ *
+ * Free the memory that is allocated with devm_extcon_dev_allocate()
+ * function.
+ */
+void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_extcon_dev_release,
+			       devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
+
+/**
+ * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device to be registered
+ *
+ * this function, that extcon device is automatically unregistered on driver
+ * detach. Internally this function calls extcon_dev_register() function.
+ * To get more information, refer that function.
+ *
+ * If extcon device is registered with this function and the device needs to be
+ * unregistered separately, devm_extcon_dev_unregister() should be used.
+ *
+ * Returns 0 if success or negaive error number if failure.
+ */
+int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
+{
+	struct extcon_dev **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = extcon_dev_register(edev);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
+
+/**
+ * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device to unregistered
+ *
+ * Unregister extcon device that is registered with devm_extcon_dev_register()
+ * function.
+ */
+void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
+			       devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
+
+/**
+ * devm_extcon_register_notifier() - Resource-managed extcon_register_notifier()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device
+ * @id:		the unique id among the extcon enumeration
+ * @nb:		a notifier block to be registered
+ *
+ * This function manages automatically the notifier of extcon device using
+ * device resource management and simplify the control of unregistering
+ * the notifier of extcon device.
+ *
+ * Note that the second parameter given to the callback of nb (val) is
+ * "old_state", not the current state. The current state can be retrieved
+ * by looking at the third pameter (edev pointer)'s state value.
+ *
+ * Returns 0 if success or negaive error number if failure.
+ */
+int devm_extcon_register_notifier(struct device *dev, struct extcon_dev *edev,
+				unsigned int id, struct notifier_block *nb)
+{
+	struct extcon_dev_notifier_devres *ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_extcon_dev_notifier_unreg, sizeof(*ptr),
+				GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = extcon_register_notifier(edev, id, nb);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	ptr->edev = edev;
+	ptr->id = id;
+	ptr->nb = nb;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_extcon_register_notifier);
+
+/**
+ * devm_extcon_unregister_notifier()
+ *			- Resource-managed extcon_unregister_notifier()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device
+ * @id:		the unique id among the extcon enumeration
+ * @nb:		a notifier block to be registered
+ */
+void devm_extcon_unregister_notifier(struct device *dev,
+				struct extcon_dev *edev, unsigned int id,
+				struct notifier_block *nb)
+{
+	WARN_ON(devres_release(dev, devm_extcon_dev_notifier_unreg,
+			       devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL(devm_extcon_unregister_notifier);
+
+/**
+ * devm_extcon_register_notifier_all()
+ *		- Resource-managed extcon_register_notifier_all()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device
+ * @nb:		a notifier block to be registered
+ *
+ * This function manages automatically the notifier of extcon device using
+ * device resource management and simplify the control of unregistering
+ * the notifier of extcon device. To get more information, refer that function.
+ *
+ * Returns 0 if success or negaive error number if failure.
+ */
+int devm_extcon_register_notifier_all(struct device *dev, struct extcon_dev *edev,
+				struct notifier_block *nb)
+{
+	struct extcon_dev_notifier_devres *ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_extcon_dev_notifier_all_unreg, sizeof(*ptr),
+				GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = extcon_register_notifier_all(edev, nb);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	ptr->edev = edev;
+	ptr->nb = nb;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_extcon_register_notifier_all);
+
+/**
+ * devm_extcon_unregister_notifier_all()
+ *		- Resource-managed extcon_unregister_notifier_all()
+ * @dev:	the device owning the extcon device being created
+ * @edev:	the extcon device
+ * @nb:		a notifier block to be registered
+ */
+void devm_extcon_unregister_notifier_all(struct device *dev,
+				struct extcon_dev *edev,
+				struct notifier_block *nb)
+{
+	WARN_ON(devres_release(dev, devm_extcon_dev_notifier_all_unreg,
+			       devm_extcon_dev_match, edev));
+}
+EXPORT_SYMBOL(devm_extcon_unregister_notifier_all);