Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 326 insertions, 0 deletions

diff --git a/drivers/base/base.h b/drivers/base/base.h
new file mode 100644
index 000000000..a5b7abc10
--- /dev/null
+++ b/drivers/base/base.h
@@ -0,0 +1,326 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
+ * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2008-2012 Novell Inc.
+ * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (c) 2012-2019 Linux Foundation
+ *
+ * Core driver model functions and structures that should not be
+ * shared outside of the drivers/base/ directory.
+ *
+ */
+#include <linux/notifier.h>
+
+/**
+ * struct subsys_private - structure to hold the private to the driver core
+ *			   portions of the bus_type/class structure.
+ * @subsys: the struct kset that defines this subsystem
+ * @devices_kset: the subsystem's 'devices' directory
+ * @interfaces: list of subsystem interfaces associated
+ * @mutex: protect the devices, and interfaces lists.
+ * @drivers_kset: the list of drivers associated
+ * @klist_devices: the klist to iterate over the @devices_kset
+ * @klist_drivers: the klist to iterate over the @drivers_kset
+ * @bus_notifier: the bus notifier list for anything that cares about things
+ *		  on this bus.
+ * @drivers_autoprobe: gate whether new devices are automatically attached to
+ *		       registered drivers, or new drivers automatically attach
+ *		       to existing devices.
+ * @bus: pointer back to the struct bus_type that this structure is associated
+ *	 with.
+ * @dev_root: Default device to use as the parent.
+ * @glue_dirs: "glue" directory to put in-between the parent device to
+ *	       avoid namespace conflicts
+ * @class: pointer back to the struct class that this structure is associated
+ *	   with.
+ * @lock_key: Lock class key for use by the lock validator
+ *
+ * This structure is the one that is the actual kobject allowing struct
+ * bus_type/class to be statically allocated safely.  Nothing outside of the
+ * driver core should ever touch these fields.
+ */
+struct subsys_private {
+	struct kset subsys;
+	struct kset *devices_kset;
+	struct list_head interfaces;
+	struct mutex mutex;
+
+	struct kset *drivers_kset;
+	struct klist klist_devices;
+	struct klist klist_drivers;
+	struct blocking_notifier_head bus_notifier;
+	unsigned int drivers_autoprobe:1;
+	const struct bus_type *bus;
+	struct device *dev_root;
+
+	struct kset glue_dirs;
+	const struct class *class;
+
+	struct lock_class_key lock_key;
+};
+#define to_subsys_private(obj) container_of_const(obj, struct subsys_private, subsys.kobj)
+
+static inline struct subsys_private *subsys_get(struct subsys_private *sp)
+{
+	if (sp)
+		kset_get(&sp->subsys);
+	return sp;
+}
+
+static inline void subsys_put(struct subsys_private *sp)
+{
+	if (sp)
+		kset_put(&sp->subsys);
+}
+
+struct subsys_private *bus_to_subsys(const struct bus_type *bus);
+struct subsys_private *class_to_subsys(const struct class *class);
+
+struct driver_private {
+	struct kobject kobj;
+	struct klist klist_devices;
+	struct klist_node knode_bus;
+	struct module_kobject *mkobj;
+	struct device_driver *driver;
+};
+#define to_driver(obj) container_of(obj, struct driver_private, kobj)
+
+/**
+ * struct device_private - structure to hold the private to the driver core
+ *			   portions of the device structure.
+ * @klist_children: klist containing all children of this device
+ * @knode_parent: node in sibling list
+ * @knode_driver: node in driver list
+ * @knode_bus: node in bus list
+ * @knode_class: node in class list
+ * @deferred_probe: entry in deferred_probe_list which is used to retry the
+ *		    binding of drivers which were unable to get all the
+ *		    resources needed by the device; typically because it depends
+ *		    on another driver getting probed first.
+ * @async_driver: pointer to device driver awaiting probe via async_probe
+ * @deferred_probe_reason: capture the -EPROBE_DEFER message emitted with
+ *			   dev_err_probe() for later retrieval via debugfs
+ * @device: pointer back to the struct device that this structure is
+ *	    associated with.
+ * @dead: This device is currently either in the process of or has been
+ *	  removed from the system. Any asynchronous events scheduled for this
+ *	  device should exit without taking any action.
+ *
+ * Nothing outside of the driver core should ever touch these fields.
+ */
+struct device_private {
+	struct klist klist_children;
+	struct klist_node knode_parent;
+	struct klist_node knode_driver;
+	struct klist_node knode_bus;
+	struct klist_node knode_class;
+	struct list_head deferred_probe;
+	const struct device_driver *async_driver;
+	char *deferred_probe_reason;
+	struct device *device;
+	u8 dead:1;
+};
+#define to_device_private_parent(obj)	\
+	container_of(obj, struct device_private, knode_parent)
+#define to_device_private_driver(obj)	\
+	container_of(obj, struct device_private, knode_driver)
+#define to_device_private_bus(obj)	\
+	container_of(obj, struct device_private, knode_bus)
+#define to_device_private_class(obj)	\
+	container_of(obj, struct device_private, knode_class)
+
+/* initialisation functions */
+int devices_init(void);
+int buses_init(void);
+int classes_init(void);
+int firmware_init(void);
+#ifdef CONFIG_SYS_HYPERVISOR
+int hypervisor_init(void);
+#else
+static inline int hypervisor_init(void) { return 0; }
+#endif
+int platform_bus_init(void);
+int faux_bus_init(void);
+void cpu_dev_init(void);
+void container_dev_init(void);
+#ifdef CONFIG_AUXILIARY_BUS
+void auxiliary_bus_init(void);
+#else
+static inline void auxiliary_bus_init(void) { }
+#endif
+
+struct kobject *virtual_device_parent(void);
+
+int bus_add_device(struct device *dev);
+void bus_probe_device(struct device *dev);
+void bus_remove_device(struct device *dev);
+void bus_notify(struct device *dev, enum bus_notifier_event value);
+bool bus_is_registered(const struct bus_type *bus);
+
+int bus_add_driver(struct device_driver *drv);
+void bus_remove_driver(struct device_driver *drv);
+void device_release_driver_internal(struct device *dev, const struct device_driver *drv,
+				    struct device *parent);
+
+void driver_detach(const struct device_driver *drv);
+void driver_deferred_probe_del(struct device *dev);
+void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf);
+static inline int driver_match_device(const struct device_driver *drv,
+				      struct device *dev)
+{
+	return drv->bus->match ? drv->bus->match(dev, drv) : 1;
+}
+
+static inline bool dev_has_sync_state(struct device *dev)
+{
+	struct device_driver *drv;
+
+	if (!dev)
+		return false;
+	drv = READ_ONCE(dev->driver);
+	if (drv && drv->sync_state)
+		return true;
+	if (dev->bus && dev->bus->sync_state)
+		return true;
+	return false;
+}
+
+static inline void dev_sync_state(struct device *dev)
+{
+	if (dev->bus->sync_state)
+		dev->bus->sync_state(dev);
+	else if (dev->driver && dev->driver->sync_state)
+		dev->driver->sync_state(dev);
+}
+
+int driver_add_groups(const struct device_driver *drv,
+		      const struct attribute_group *const *groups);
+void driver_remove_groups(const struct device_driver *drv,
+			  const struct attribute_group *const *groups);
+void device_driver_detach(struct device *dev);
+
+static inline void device_set_driver(struct device *dev, const struct device_driver *drv)
+{
+	/*
+	 * Majority (all?) read accesses to dev->driver happens either
+	 * while holding device lock or in bus/driver code that is only
+	 * invoked when the device is bound to a driver and there is no
+	 * concern of the pointer being changed while it is being read.
+	 * However when reading device's uevent file we read driver pointer
+	 * without taking device lock (so we do not block there for
+	 * arbitrary amount of time). We use WRITE_ONCE() here to prevent
+	 * tearing so that READ_ONCE() can safely be used in uevent code.
+	 */
+	// FIXME - this cast should not be needed "soon"
+	WRITE_ONCE(dev->driver, (struct device_driver *)drv);
+}
+
+struct devres_node;
+typedef void (*dr_node_release_t)(struct device *dev, struct devres_node *node);
+typedef void (*dr_node_free_t)(struct devres_node *node);
+
+struct devres_node {
+	struct list_head		entry;
+	dr_node_release_t		release;
+	dr_node_free_t			free_node;
+	const char			*name;
+	size_t				size;
+};
+
+void devres_node_init(struct devres_node *node, dr_node_release_t release,
+		      dr_node_free_t free_node);
+void devres_node_add(struct device *dev, struct devres_node *node);
+bool devres_node_remove(struct device *dev, struct devres_node *node);
+void devres_set_node_dbginfo(struct devres_node *node, const char *name,
+			     size_t size);
+void devres_for_each_res(struct device *dev, dr_release_t release,
+			 dr_match_t match, void *match_data,
+			 void (*fn)(struct device *, void *, void *),
+			 void *data);
+int devres_release_all(struct device *dev);
+void device_block_probing(void);
+void device_unblock_probing(void);
+void deferred_probe_extend_timeout(void);
+void driver_deferred_probe_trigger(void);
+const char *device_get_devnode(const struct device *dev, umode_t *mode,
+			       kuid_t *uid, kgid_t *gid, const char **tmp);
+
+/* /sys/devices directory */
+extern struct kset *devices_kset;
+void devices_kset_move_last(struct device *dev);
+
+#if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
+int module_add_driver(struct module *mod, const struct device_driver *drv);
+void module_remove_driver(const struct device_driver *drv);
+#else
+static inline int module_add_driver(struct module *mod,
+				    struct device_driver *drv)
+{
+	return 0;
+}
+static inline void module_remove_driver(struct device_driver *drv) { }
+#endif
+
+#ifdef CONFIG_DEVTMPFS
+int devtmpfs_init(void);
+#else
+static inline int devtmpfs_init(void) { return 0; }
+#endif
+
+#ifdef CONFIG_BLOCK
+extern const struct class block_class;
+static inline bool is_blockdev(struct device *dev)
+{
+	return dev->class == &block_class;
+}
+#else
+static inline bool is_blockdev(struct device *dev) { return false; }
+#endif
+
+/* Device links support */
+int device_links_read_lock(void);
+void device_links_read_unlock(int idx);
+int device_links_read_lock_held(void);
+int device_links_check_suppliers(struct device *dev);
+void device_links_force_bind(struct device *dev);
+void device_links_driver_bound(struct device *dev);
+void device_links_driver_cleanup(struct device *dev);
+void device_links_no_driver(struct device *dev);
+bool device_links_busy(struct device *dev);
+void device_links_unbind_consumers(struct device *dev);
+bool device_link_flag_is_sync_state_only(u32 flags);
+void fw_devlink_drivers_done(void);
+void fw_devlink_probing_done(void);
+
+#define dev_for_each_link_to_supplier(__link, __dev)	\
+	list_for_each_entry_srcu(__link, &(__dev)->links.suppliers, c_node, \
+				 device_links_read_lock_held())
+
+#define dev_for_each_link_to_consumer(__link, __dev)	\
+	list_for_each_entry_srcu(__link, &(__dev)->links.consumers, s_node, \
+				 device_links_read_lock_held())
+
+/* device pm support */
+void device_pm_move_to_tail(struct device *dev);
+
+#ifdef CONFIG_DEVTMPFS
+int devtmpfs_create_node(struct device *dev);
+int devtmpfs_delete_node(struct device *dev);
+#else
+static inline int devtmpfs_create_node(struct device *dev) { return 0; }
+static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
+#endif
+
+void software_node_init(void);
+void software_node_notify(struct device *dev);
+void software_node_notify_remove(struct device *dev);
+
+#ifdef CONFIG_PINCTRL
+int pinctrl_bind_pins(struct device *dev);
+#else
+static inline int pinctrl_bind_pins(struct device *dev)
+{
+	return 0;
+}
+#endif /* CONFIG_PINCTRL */