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, 457 insertions, 0 deletions

diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
new file mode 100644
index 000000000..9bef9248a
--- /dev/null
+++ b/drivers/base/power/common.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drivers/base/power/common.c - Common device power management code.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/pm_clock.h>
+#include <linux/acpi.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+
+#include "power.h"
+
+/**
+ * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
+ * @dev: Device to handle.
+ *
+ * If power.subsys_data is NULL, point it to a new object, otherwise increment
+ * its reference counter.  Return 0 if new object has been created or refcount
+ * increased, otherwise negative error code.
+ */
+int dev_pm_get_subsys_data(struct device *dev)
+{
+	struct pm_subsys_data *psd;
+
+	psd = kzalloc_obj(*psd);
+	if (!psd)
+		return -ENOMEM;
+
+	spin_lock_irq(&dev->power.lock);
+
+	if (dev->power.subsys_data) {
+		dev->power.subsys_data->refcount++;
+	} else {
+		spin_lock_init(&psd->lock);
+		psd->refcount = 1;
+		dev->power.subsys_data = psd;
+		pm_clk_init(dev);
+		psd = NULL;
+	}
+
+	spin_unlock_irq(&dev->power.lock);
+
+	/* kfree() verifies that its argument is nonzero. */
+	kfree(psd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
+
+/**
+ * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
+ * @dev: Device to handle.
+ *
+ * If the reference counter of power.subsys_data is zero after dropping the
+ * reference, power.subsys_data is removed.
+ */
+void dev_pm_put_subsys_data(struct device *dev)
+{
+	struct pm_subsys_data *psd;
+
+	spin_lock_irq(&dev->power.lock);
+
+	psd = dev_to_psd(dev);
+	if (!psd)
+		goto out;
+
+	if (--psd->refcount == 0)
+		dev->power.subsys_data = NULL;
+	else
+		psd = NULL;
+
+ out:
+	spin_unlock_irq(&dev->power.lock);
+	kfree(psd);
+}
+EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
+
+/**
+ * dev_pm_domain_attach - Attach a device to its PM domain.
+ * @dev: Device to attach.
+ * @flags: indicate whether we should power on/off the device on attach/detach
+ *
+ * The @dev may only be attached to a single PM domain. By iterating through
+ * the available alternatives we try to find a valid PM domain for the device.
+ * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
+ * should be assigned by the corresponding attach function.
+ *
+ * This function should typically be invoked from subsystem level code during
+ * the probe phase. Especially for those that holds devices which requires
+ * power management through PM domains.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns 0 on successfully attached PM domain, or when it is found that the
+ * device doesn't need a PM domain, else a negative error code.
+ */
+int dev_pm_domain_attach(struct device *dev, u32 flags)
+{
+	int ret;
+
+	if (dev->pm_domain)
+		return 0;
+
+	ret = acpi_dev_pm_attach(dev, !!(flags & PD_FLAG_ATTACH_POWER_ON));
+	if (!ret)
+		ret = genpd_dev_pm_attach(dev);
+
+	if (dev->pm_domain)
+		dev->power.detach_power_off = !!(flags & PD_FLAG_DETACH_POWER_OFF);
+
+	return ret < 0 ? ret : 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
+
+/**
+ * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
+ * @dev: The device used to lookup the PM domain.
+ * @index: The index of the PM domain.
+ *
+ * As @dev may only be attached to a single PM domain, the backend PM domain
+ * provider creates a virtual device to attach instead. If attachment succeeds,
+ * the ->detach() callback in the struct dev_pm_domain are assigned by the
+ * corresponding backend attach function, as to deal with detaching of the
+ * created virtual device.
+ *
+ * This function should typically be invoked by a driver during the probe phase,
+ * in case its device requires power management through multiple PM domains. The
+ * driver may benefit from using the received device, to configure device-links
+ * towards its original device. Depending on the use-case and if needed, the
+ * links may be dynamically changed by the driver, which allows it to control
+ * the power to the PM domains independently from each other.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns the virtual created device when successfully attached to its PM
+ * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR().
+ * Note that, to detach the returned virtual device, the driver shall call
+ * dev_pm_domain_detach() on it, typically during the remove phase.
+ */
+struct device *dev_pm_domain_attach_by_id(struct device *dev,
+					  unsigned int index)
+{
+	if (dev->pm_domain)
+		return ERR_PTR(-EEXIST);
+
+	return genpd_dev_pm_attach_by_id(dev, index);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_id);
+
+/**
+ * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains.
+ * @dev: The device used to lookup the PM domain.
+ * @name: The name of the PM domain.
+ *
+ * For a detailed function description, see dev_pm_domain_attach_by_id().
+ */
+struct device *dev_pm_domain_attach_by_name(struct device *dev,
+					    const char *name)
+{
+	if (dev->pm_domain)
+		return ERR_PTR(-EEXIST);
+
+	return genpd_dev_pm_attach_by_name(dev, name);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name);
+
+/**
+ * dev_pm_domain_attach_list - Associate a device with its PM domains.
+ * @dev: The device used to lookup the PM domains for.
+ * @data: The data used for attaching to the PM domains.
+ * @list: An out-parameter with an allocated list of attached PM domains.
+ *
+ * This function helps to attach a device to its multiple PM domains. The
+ * caller, which is typically a driver's probe function, may provide a list of
+ * names for the PM domains that we should try to attach the device to, but it
+ * may also provide an empty list, in case the attach should be done for all of
+ * the available PM domains.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns the number of attached PM domains or a negative error code in case of
+ * a failure. Note that, to detach the list of PM domains, the driver shall call
+ * dev_pm_domain_detach_list(), typically during the remove phase.
+ */
+int dev_pm_domain_attach_list(struct device *dev,
+			      const struct dev_pm_domain_attach_data *data,
+			      struct dev_pm_domain_list **list)
+{
+	struct device_node *np = dev->of_node;
+	struct dev_pm_domain_list *pds;
+	struct device *pd_dev = NULL;
+	int ret, i, num_pds = 0;
+	bool by_id = true;
+	size_t size;
+	u32 pd_flags = data ? data->pd_flags : 0;
+	u32 link_flags = pd_flags & PD_FLAG_NO_DEV_LINK ? 0 :
+			DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME;
+
+	if (dev->pm_domain)
+		return -EEXIST;
+
+	/* For now this is limited to OF based platforms. */
+	if (!np)
+		return 0;
+
+	if (data && data->pd_names) {
+		num_pds = data->num_pd_names;
+		by_id = false;
+	} else {
+		num_pds = of_count_phandle_with_args(np, "power-domains",
+						     "#power-domain-cells");
+	}
+
+	if (num_pds <= 0)
+		return 0;
+
+	pds = kzalloc_obj(*pds);
+	if (!pds)
+		return -ENOMEM;
+
+	size = sizeof(*pds->pd_devs) + sizeof(*pds->pd_links) +
+	       sizeof(*pds->opp_tokens);
+	pds->pd_devs = kcalloc(num_pds, size, GFP_KERNEL);
+	if (!pds->pd_devs) {
+		ret = -ENOMEM;
+		goto free_pds;
+	}
+	pds->pd_links = (void *)(pds->pd_devs + num_pds);
+	pds->opp_tokens = (void *)(pds->pd_links + num_pds);
+
+	if (link_flags && pd_flags & PD_FLAG_DEV_LINK_ON)
+		link_flags |= DL_FLAG_RPM_ACTIVE;
+
+	for (i = 0; i < num_pds; i++) {
+		if (by_id)
+			pd_dev = dev_pm_domain_attach_by_id(dev, i);
+		else
+			pd_dev = dev_pm_domain_attach_by_name(dev,
+							data->pd_names[i]);
+		if (IS_ERR_OR_NULL(pd_dev)) {
+			ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV;
+			goto err_attach;
+		}
+
+		if (pd_flags & PD_FLAG_REQUIRED_OPP) {
+			struct dev_pm_opp_config config = {
+				.required_dev = pd_dev,
+				.required_dev_index = i,
+			};
+
+			ret = dev_pm_opp_set_config(dev, &config);
+			if (ret < 0)
+				goto err_link;
+
+			pds->opp_tokens[i] = ret;
+		}
+
+		if (link_flags) {
+			struct device_link *link;
+
+			link = device_link_add(dev, pd_dev, link_flags);
+			if (!link) {
+				ret = -ENODEV;
+				goto err_link;
+			}
+
+			pds->pd_links[i] = link;
+		}
+
+		pds->pd_devs[i] = pd_dev;
+	}
+
+	pds->num_pds = num_pds;
+	*list = pds;
+	return num_pds;
+
+err_link:
+	dev_pm_opp_clear_config(pds->opp_tokens[i]);
+	dev_pm_domain_detach(pd_dev, true);
+err_attach:
+	while (--i >= 0) {
+		dev_pm_opp_clear_config(pds->opp_tokens[i]);
+		if (pds->pd_links[i])
+			device_link_del(pds->pd_links[i]);
+		dev_pm_domain_detach(pds->pd_devs[i], true);
+	}
+	kfree(pds->pd_devs);
+free_pds:
+	kfree(pds);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_list);
+
+/**
+ * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
+ * @_list: The list of PM domains to detach.
+ *
+ * This function reverse the actions from devm_pm_domain_attach_list().
+ * it will be invoked during the remove phase from drivers implicitly if driver
+ * uses devm_pm_domain_attach_list() to attach the PM domains.
+ */
+static void devm_pm_domain_detach_list(void *_list)
+{
+	struct dev_pm_domain_list *list = _list;
+
+	dev_pm_domain_detach_list(list);
+}
+
+/**
+ * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
+ * @dev: The device used to lookup the PM domains for.
+ * @data: The data used for attaching to the PM domains.
+ * @list: An out-parameter with an allocated list of attached PM domains.
+ *
+ * NOTE: this will also handle calling devm_pm_domain_detach_list() for
+ * you during remove phase.
+ *
+ * Returns the number of attached PM domains or a negative error code in case of
+ * a failure.
+ */
+int devm_pm_domain_attach_list(struct device *dev,
+			       const struct dev_pm_domain_attach_data *data,
+			       struct dev_pm_domain_list **list)
+{
+	int ret, num_pds;
+
+	num_pds = dev_pm_domain_attach_list(dev, data, list);
+	if (num_pds <= 0)
+		return num_pds;
+
+	ret = devm_add_action_or_reset(dev, devm_pm_domain_detach_list, *list);
+	if (ret)
+		return ret;
+
+	return num_pds;
+}
+EXPORT_SYMBOL_GPL(devm_pm_domain_attach_list);
+
+/**
+ * dev_pm_domain_detach - Detach a device from its PM domain.
+ * @dev: Device to detach.
+ * @power_off: Used to indicate whether we should power off the device.
+ *
+ * This functions will reverse the actions from dev_pm_domain_attach(),
+ * dev_pm_domain_attach_by_id() and dev_pm_domain_attach_by_name(), thus it
+ * detaches @dev from its PM domain.  Typically it should be invoked during the
+ * remove phase, either from subsystem level code or from drivers.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ */
+void dev_pm_domain_detach(struct device *dev, bool power_off)
+{
+	if (dev->pm_domain && dev->pm_domain->detach)
+		dev->pm_domain->detach(dev, power_off);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
+
+/**
+ * dev_pm_domain_detach_list - Detach a list of PM domains.
+ * @list: The list of PM domains to detach.
+ *
+ * This function reverse the actions from dev_pm_domain_attach_list().
+ * Typically it should be invoked during the remove phase from drivers.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ */
+void dev_pm_domain_detach_list(struct dev_pm_domain_list *list)
+{
+	int i;
+
+	if (!list)
+		return;
+
+	for (i = 0; i < list->num_pds; i++) {
+		dev_pm_opp_clear_config(list->opp_tokens[i]);
+		if (list->pd_links[i])
+			device_link_del(list->pd_links[i]);
+		dev_pm_domain_detach(list->pd_devs[i], true);
+	}
+
+	kfree(list->pd_devs);
+	kfree(list);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_detach_list);
+
+/**
+ * dev_pm_domain_start - Start the device through its PM domain.
+ * @dev: Device to start.
+ *
+ * This function should typically be called during probe by a subsystem/driver,
+ * when it needs to start its device from the PM domain's perspective. Note
+ * that, it's assumed that the PM domain is already powered on when this
+ * function is called.
+ *
+ * Returns 0 on success and negative error values on failures.
+ */
+int dev_pm_domain_start(struct device *dev)
+{
+	if (dev->pm_domain && dev->pm_domain->start)
+		return dev->pm_domain->start(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_start);
+
+/**
+ * dev_pm_domain_set - Set PM domain of a device.
+ * @dev: Device whose PM domain is to be set.
+ * @pd: PM domain to be set, or NULL.
+ *
+ * Sets the PM domain the device belongs to. The PM domain of a device needs
+ * to be set before its probe finishes (it's bound to a driver).
+ *
+ * This function must be called with the device lock held.
+ */
+void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
+{
+	if (dev->pm_domain == pd)
+		return;
+
+	WARN(pd && device_is_bound(dev),
+	     "PM domains can only be changed for unbound devices\n");
+	dev->pm_domain = pd;
+	device_pm_check_callbacks(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_set);
+
+/**
+ * dev_pm_domain_set_performance_state - Request a new performance state.
+ * @dev: The device to make the request for.
+ * @state: Target performance state for the device.
+ *
+ * This function should be called when a new performance state needs to be
+ * requested for a device that is attached to a PM domain. Note that, the
+ * support for performance scaling for PM domains is optional.
+ *
+ * Returns 0 on success and when performance scaling isn't supported, negative
+ * error code on failure.
+ */
+int dev_pm_domain_set_performance_state(struct device *dev, unsigned int state)
+{
+	if (dev->pm_domain && dev->pm_domain->set_performance_state)
+		return dev->pm_domain->set_performance_state(dev, state);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_set_performance_state);