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
  ...

3 files changed, 330 insertions, 0 deletions

diff --git a/Documentation/driver-api/pldmfw/driver-ops.rst b/Documentation/driver-api/pldmfw/driver-ops.rst
new file mode 100644
index 000000000..f0654783d
--- /dev/null
+++ b/Documentation/driver-api/pldmfw/driver-ops.rst
@@ -0,0 +1,56 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+=========================
+Driver-specific callbacks
+=========================
+
+The ``pldmfw`` module relies on the device driver for implementing device
+specific behavior using the following operations.
+
+``.match_record``
+-----------------
+
+The ``.match_record`` operation is used to determine whether a given PLDM
+record matches the device being updated. This requires comparing the record
+descriptors in the record with information from the device. Many record
+descriptors are defined by the PLDM standard, but it is also allowed for
+devices to implement their own descriptors.
+
+The ``.match_record`` operation should return true if a given record matches
+the device.
+
+``.send_package_data``
+----------------------
+
+The ``.send_package_data`` operation is used to send the device-specific
+package data in a record to the device firmware. If the matching record
+provides package data, ``pldmfw`` will call the ``.send_package_data``
+function with a pointer to the package data and with the package data
+length. The device driver should send this data to firmware.
+
+``.send_component_table``
+-------------------------
+
+The ``.send_component_table`` operation is used to forward component
+information to the device. It is called once for each applicable component,
+that is, for each component indicated by the matching record. The
+device driver should send the component information to the device firmware,
+and wait for a response. The provided transfer flag indicates whether this
+is the first, last, or a middle component, and is expected to be forwarded
+to firmware as part of the component table information. The driver should an
+error in the case when the firmware indicates that the component cannot be
+updated, or return zero if the component can be updated.
+
+``.flash_component``
+--------------------
+
+The ``.flash_component`` operation is used to inform the device driver to
+flash a given component. The driver must perform any steps necessary to send
+the component data to the device.
+
+``.finalize_update``
+--------------------
+
+The ``.finalize_update`` operation is used by the ``pldmfw`` library in
+order to allow the device driver to perform any remaining device specific
+logic needed to finish the update.
diff --git a/Documentation/driver-api/pldmfw/file-format.rst b/Documentation/driver-api/pldmfw/file-format.rst
new file mode 100644
index 000000000..b7a9cebe0
--- /dev/null
+++ b/Documentation/driver-api/pldmfw/file-format.rst
@@ -0,0 +1,203 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+==================================
+PLDM Firmware file format overview
+==================================
+
+A PLDM firmware package is a binary file which contains a header that
+describes the contents of the firmware package. This includes an initial
+package header, one or more firmware records, and one or more components
+describing the actual flash contents to program.
+
+This diagram provides an overview of the file format::
+
+        overall file layout
+      +----------------------+
+      |                      |
+      |  Package Header      |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Device Records      |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Component Info      |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Package Header CRC  |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Component Image 1   |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Component Image 2   |
+      |                      |
+      +----------------------+
+      |                      |
+      |         ...          |
+      |                      |
+      +----------------------+
+      |                      |
+      |  Component Image N   |
+      |                      |
+      +----------------------+
+
+Package Header
+==============
+
+The package header begins with the UUID of the PLDM file format, and
+contains information about the version of the format that the file uses. It
+also includes the total header size, a release date, the size of the
+component bitmap, and an overall package version.
+
+The following diagram provides an overview of the package header::
+
+             header layout
+      +-------------------------+
+      | PLDM UUID               |
+      +-------------------------+
+      | Format Revision         |
+      +-------------------------+
+      | Header Size             |
+      +-------------------------+
+      | Release Date            |
+      +-------------------------+
+      | Component Bitmap Length |
+      +-------------------------+
+      | Package Version Info    |
+      +-------------------------+
+
+Device Records
+==============
+
+The device firmware records area starts with a count indicating the total
+number of records in the file, followed by each record. A single device
+record describes what device matches this record. All valid PLDM firmware
+files must contain at least one record, but optionally may contain more than
+one record if they support multiple devices.
+
+Each record will identify the device it supports via TLVs that describe the
+device, such as the PCI device and vendor information. It will also indicate
+which set of components that are used by this device. It is possible that
+only subset of provided components will be used by a given record. A record
+may also optionally contain device-specific package data that will be used
+by the device firmware during the update process.
+
+The following diagram provides an overview of the device record area::
+
+         area layout
+      +---------------+
+      |               |
+      |  Record Count |
+      |               |
+      +---------------+
+      |               |
+      |  Record 1     |
+      |               |
+      +---------------+
+      |               |
+      |  Record 2     |
+      |               |
+      +---------------+
+      |               |
+      |      ...      |
+      |               |
+      +---------------+
+      |               |
+      |  Record N     |
+      |               |
+      +---------------+
+
+           record layout
+      +-----------------------+
+      | Record Length         |
+      +-----------------------+
+      | Descriptor Count      |
+      +-----------------------+
+      | Option Flags          |
+      +-----------------------+
+      | Version Settings      |
+      +-----------------------+
+      | Package Data Length   |
+      +-----------------------+
+      | Applicable Components |
+      +-----------------------+
+      | Version String        |
+      +-----------------------+
+      | Descriptor TLVs       |
+      +-----------------------+
+      | Package Data          |
+      +-----------------------+
+
+Component Info
+==============
+
+The component information area begins with a count of the number of
+components. Following this count is a description for each component. The
+component information points to the location in the file where the component
+data is stored, and includes version data used to identify the version of
+the component.
+
+The following diagram provides an overview of the component area::
+
+         area layout
+      +-----------------+
+      |                 |
+      | Component Count |
+      |                 |
+      +-----------------+
+      |                 |
+      | Component 1     |
+      |                 |
+      +-----------------+
+      |                 |
+      | Component 2     |
+      |                 |
+      +-----------------+
+      |                 |
+      |     ...         |
+      |                 |
+      +-----------------+
+      |                 |
+      | Component N     |
+      |                 |
+      +-----------------+
+
+           component layout
+      +------------------------+
+      | Classification         |
+      +------------------------+
+      | Component Identifier   |
+      +------------------------+
+      | Comparison Stamp       |
+      +------------------------+
+      | Component Options      |
+      +------------------------+
+      | Activation Method      |
+      +------------------------+
+      | Location Offset        |
+      +------------------------+
+      | Component Size         |
+      +------------------------+
+      | Component Version Info |
+      +------------------------+
+      | Package Data           |
+      +------------------------+
+
+
+Package Header CRC
+==================
+
+Following the component information is a short 4-byte CRC calculated over
+the contents of all of the header information.
+
+Component Images
+================
+
+The component images follow the package header information in the PLDM
+firmware file. Each of these is simply a binary chunk with its start and
+size defined by the matching component structure in the component info area.
diff --git a/Documentation/driver-api/pldmfw/index.rst b/Documentation/driver-api/pldmfw/index.rst
new file mode 100644
index 000000000..e59beca37
--- /dev/null
+++ b/Documentation/driver-api/pldmfw/index.rst
@@ -0,0 +1,71 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+==================================
+PLDM Firmware Flash Update Library
+==================================
+
+``pldmfw`` implements functionality for updating the flash on a device using
+the PLDM for Firmware Update standard
+<https://www.dmtf.org/documents/pmci/pldm-firmware-update-specification-100>.
+
+.. toctree::
+   :maxdepth: 1
+
+   file-format
+   driver-ops
+
+Overview of the ``pldmfw`` library
+==================================
+
+The ``pldmfw`` library is intended to be used by device drivers for
+implementing device flash update based on firmware files following the PLDM
+firmware file format.
+
+It is implemented using an ops table that allows device drivers to provide
+the underlying device specific functionality.
+
+``pldmfw`` implements logic to parse the packed binary format of the PLDM
+firmware file into data structures, and then uses the provided function
+operations to determine if the firmware file is a match for the device. If
+so, it sends the record and component data to the firmware using the device
+specific implementations provided by device drivers. Once the device
+firmware indicates that the update may be performed, the firmware data is
+sent to the device for programming.
+
+Parsing the PLDM file
+=====================
+
+The PLDM file format uses packed binary data, with most multi-byte fields
+stored in the Little Endian format. Several pieces of data are variable
+length, including version strings and the number of records and components.
+Due to this, it is not straight forward to index the record, record
+descriptors, or components.
+
+To avoid proliferating access to the packed binary data, the ``pldmfw``
+library parses and extracts this data into simpler structures for ease of
+access.
+
+In order to safely process the firmware file, care is taken to avoid
+unaligned access of multi-byte fields, and to properly convert from Little
+Endian to CPU host format. Additionally the records, descriptors, and
+components are stored in linked lists.
+
+Performing a flash update
+=========================
+
+To perform a flash update, the ``pldmfw`` module performs the following
+steps
+
+1. Parse the firmware file for record and component information
+2. Scan through the records and determine if the device matches any record
+   in the file. The first matched record will be used.
+3. If the matching record provides package data, send this package data to
+   the device.
+4. For each component that the record indicates, send the component data to
+   the device. For each component, the firmware may respond with an
+   indication of whether the update is suitable or not. If any component is
+   not suitable, the update is canceled.
+5. For each component, send the binary data to the device firmware for
+   updating.
+6. After all components are programmed, perform any final device-specific
+   actions to finalize the update.