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, 259 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-thermal b/Documentation/ABI/testing/sysfs-class-thermal
new file mode 100644
index 000000000..968d89e15
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-thermal
@@ -0,0 +1,259 @@
+What:		/sys/class/thermal/thermal_zoneX/type
+Description:
+		Strings which represent the thermal zone type.
+		This is given by thermal zone driver as part of registration.
+		E.g: "acpitz" indicates it's an ACPI thermal device.
+		In order to keep it consistent with hwmon sys attribute; this
+		should be a short, lowercase string, not containing spaces nor
+		dashes.
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/temp
+Description:
+		Current temperature as reported by thermal zone (sensor).
+
+		Unit: millidegree Celsius
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/mode
+Description:
+		One of the predefined values in [enabled, disabled].
+		This file gives information about the algorithm that is
+		currently managing the thermal zone. It can be either default
+		kernel based algorithm or user space application.
+
+		enabled
+				enable Kernel Thermal management.
+		disabled
+				Preventing kernel thermal zone driver actions upon
+				trip points so that user application can take full
+				charge of the thermal management.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/policy
+Description:
+		One of the various thermal governors used for a particular zone.
+
+		RW, Required
+
+What:		/sys/class/thermal/thermal_zoneX/available_policies
+Description:
+		Available thermal governors which can be used for a
+		particular zone.
+
+		RO, Required
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_temp
+Description:
+		The temperature above which trip point will be fired.
+
+		Unit: millidegree Celsius
+
+		RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_type
+Description:
+		Strings which indicate the type of the trip point.
+
+		E.g. it can be one of critical, hot, passive, `active[0-*]`
+		for ACPI thermal zone.
+
+		RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/trip_point_Y_hyst
+Description:
+		The hysteresis value for a trip point, represented as an
+		integer.
+
+		Unit: Celsius
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY
+Description:
+	Sysfs link to the thermal cooling device node where the sys I/F
+	for cooling device throttling control represents.
+
+	RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY_trip_point
+Description:
+		The trip point in this thermal zone which `cdev[0-*]` is
+		associated with; -1 means the cooling device is not
+		associated with any trip point.
+
+		RO, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/cdevY_weight
+Description:
+		The influence of `cdev[0-*]` in this thermal zone. This value
+		is relative to the rest of cooling devices in the thermal
+		zone. For example, if a cooling device has a weight double
+		than that of other, it's twice as effective in cooling the
+		thermal zone.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/emul_temp
+Description:
+		Interface to set the emulated temperature method in thermal zone
+		(sensor). After setting this temperature, the thermal zone may
+		pass this temperature to platform emulation function if
+		registered or cache it locally. This is useful in debugging
+		different temperature threshold and its associated cooling
+		action. This is write only node and writing 0 on this node
+		should disable emulation.
+
+		Unit: millidegree Celsius
+
+		WO, Optional
+
+		WARNING:
+		    Be careful while enabling this option on production systems,
+		    because userland can easily disable the thermal policy by simply
+		    flooding this sysfs node with low temperature values.
+
+
+What:		/sys/class/thermal/thermal_zoneX/k_d
+Description:
+		The derivative term of the power allocator governor's PID
+		controller. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_i
+Description:
+		The integral term of the power allocator governor's PID
+		controller. This term allows the PID controller to compensate
+		for long term drift. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_po
+Description:
+		The proportional term of the power allocator governor's PID
+		controller during temperature overshoot. Temperature overshoot
+		is when the current temperature is above the "desired
+		temperature" trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/k_pu
+Description:
+		The proportional term of the power allocator governor's PID
+		controller during temperature undershoot. Temperature undershoot
+		is when the current temperature is below the "desired
+		temperature" trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/integral_cutoff
+Description:
+		Temperature offset from the desired temperature trip point
+		above which the integral term of the power allocator
+		governor's PID controller starts accumulating errors. For
+		example, if integral_cutoff is 0, then the integral term only
+		accumulates error when temperature is above the desired
+		temperature trip point. For more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		Unit: millidegree Celsius
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/slope
+Description:
+		The slope constant used in a linear extrapolation model
+		to determine a hotspot temperature based off the sensor's
+		raw readings. It is up to the device driver to determine
+		the usage of these values.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/offset
+Description:
+		The offset constant used in a linear extrapolation model
+		to determine a hotspot temperature based off the sensor's
+		raw readings. It is up to the device driver to determine
+		the usage of these values.
+
+		RW, Optional
+
+What:		/sys/class/thermal/thermal_zoneX/sustainable_power
+Description:
+		An estimate of the sustained power that can be dissipated by
+		the thermal zone. Used by the power allocator governor. For
+		more information see
+		Documentation/driver-api/thermal/power_allocator.rst
+
+		Unit: milliwatts
+
+		RW, Optional
+
+What:		/sys/class/thermal/cooling_deviceX/type
+Description:
+		String which represents the type of device, e.g:
+
+		- for generic ACPI: should be "Fan", "Processor" or "LCD"
+		- for memory controller device on intel_menlow platform:
+		  should be "Memory controller".
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/max_state
+Description:
+		The maximum permissible cooling state of this cooling device.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/cur_state
+Description:
+		The current cooling state of this cooling device.
+		The value can any integer numbers between 0 and max_state:
+
+		- cur_state == 0 means no cooling
+		- cur_state == max_state means the maximum cooling.
+
+		RW, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/reset
+Description:
+		Writing any value resets the cooling device's statistics.
+
+		WO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/time_in_state_ms:
+Description:
+		The amount of time spent by the cooling device in various
+		cooling states. The output will have "<state> <time>" pair
+		in each line, which will mean this cooling device spent <time>
+		msec of time at <state>.
+
+		Output will have one line for each of the supported states.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/total_trans
+Description:
+		A single positive value showing the total number of times
+		the state of a cooling device is changed.
+
+		RO, Required
+
+What:		/sys/class/thermal/cooling_deviceX/stats/trans_table
+Description:
+		This gives fine grained information about all the cooling state
+		transitions. The cat output here is a two dimensional matrix,
+		where an entry <i,j> (row i, column j) represents the number
+		of transitions from State_i to State_j. If the transition
+		table is bigger than PAGE_SIZE, reading this will return
+		an -EFBIG error.
+
+		RO, Required