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, 335 insertions, 0 deletions

diff --git a/samples/Kconfig b/samples/Kconfig
new file mode 100644
index 000000000..a75e8e783
--- /dev/null
+++ b/samples/Kconfig
@@ -0,0 +1,335 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig SAMPLES
+	bool "Sample kernel code"
+	help
+	  You can build and test sample kernel code here.
+
+if SAMPLES
+
+config SAMPLE_AUXDISPLAY
+	bool "auxdisplay sample"
+	depends on CC_CAN_LINK
+
+config SAMPLE_TRACE_EVENTS
+	tristate "Build trace_events examples -- loadable modules only"
+	depends on EVENT_TRACING && m
+	help
+	  This builds the trace event example module.
+
+config SAMPLE_TRACE_CUSTOM_EVENTS
+	tristate "Build custom trace event example -- loadable modules only"
+	depends on EVENT_TRACING && m
+	help
+	  This builds the custom trace event example module.
+
+config SAMPLE_TRACE_PRINTK
+	tristate "Build trace_printk module - tests various trace_printk formats"
+	depends on EVENT_TRACING && m
+	help
+	  This builds a module that calls trace_printk() and can be used to
+	  test various trace_printk() calls from a module.
+
+config SAMPLE_FTRACE_DIRECT
+	tristate "Build register_ftrace_direct() example"
+	depends on DYNAMIC_FTRACE_WITH_DIRECT_CALLS && m
+	depends on HAVE_SAMPLE_FTRACE_DIRECT
+	help
+	  This builds an ftrace direct function example
+	  that hooks to wake_up_process and prints the parameters.
+
+config SAMPLE_FTRACE_DIRECT_MULTI
+	tristate "Build register_ftrace_direct() on multiple ips example"
+	depends on DYNAMIC_FTRACE_WITH_DIRECT_CALLS && m
+	depends on HAVE_SAMPLE_FTRACE_DIRECT_MULTI
+	help
+	  This builds an ftrace direct function example
+	  that hooks to wake_up_process and schedule, and prints
+	  the function addresses.
+
+config SAMPLE_FTRACE_OPS
+	tristate "Build custom ftrace ops example"
+	depends on FUNCTION_TRACER
+	help
+	  This builds an ftrace ops example that hooks two functions and
+	  measures the time taken to invoke one function a number of times.
+
+config SAMPLE_TRACE_ARRAY
+	tristate "Build sample module for kernel access to Ftrace instances"
+	depends on EVENT_TRACING && m
+	help
+	  This builds a module that demonstrates the use of various APIs to
+	  access Ftrace instances from within the kernel.
+
+config SAMPLE_KOBJECT
+	tristate "Build kobject examples"
+	help
+	  This config option will allow you to build a number of
+	  different kobject sample modules showing how to use kobjects,
+	  ksets, and ktypes properly.
+
+	  If in doubt, say "N" here.
+
+config SAMPLE_KPROBES
+	tristate "Build kprobes examples -- loadable modules only"
+	depends on KPROBES && m
+	help
+	  This build several kprobes example modules.
+
+config SAMPLE_KRETPROBES
+	tristate "Build kretprobes example -- loadable modules only"
+	default m
+	depends on SAMPLE_KPROBES && KRETPROBES
+
+config SAMPLE_HW_BREAKPOINT
+	tristate "Build kernel hardware breakpoint examples -- loadable module only"
+	depends on HAVE_HW_BREAKPOINT && m
+	help
+	  This builds kernel hardware breakpoint example modules.
+
+config SAMPLE_FPROBE
+	tristate "Build fprobe examples -- loadable modules only"
+	depends on FPROBE && m
+	help
+	  This builds a fprobe example module. This module has an option 'symbol'.
+	  You can specify a probed symbol or symbols separated with ','.
+
+config SAMPLE_KFIFO
+	tristate "Build kfifo examples -- loadable modules only"
+	depends on m
+	help
+	  This config option will allow you to build a number of
+	  different kfifo sample modules showing how to use the
+	  generic kfifo API.
+
+	  If in doubt, say "N" here.
+
+config SAMPLE_KDB
+	tristate "Build kdb command example -- loadable modules only"
+	depends on KGDB_KDB && m
+	help
+	  Build an example of how to dynamically add the hello
+	  command to the kdb shell.
+
+config SAMPLE_QMI_CLIENT
+	tristate "Build qmi client sample -- loadable modules only"
+	depends on m
+	depends on ARCH_QCOM
+	depends on NET
+	select QCOM_QMI_HELPERS
+	help
+	  Build an QMI client sample driver, which demonstrates how to
+	  communicate with a remote QRTR service, using QMI encoded messages.
+
+config SAMPLE_RPMSG_CLIENT
+	tristate "Build rpmsg client sample -- loadable modules only"
+	depends on RPMSG && m
+	help
+	  Build an rpmsg client sample driver, which demonstrates how
+	  to communicate with an AMP-configured remote processor over
+	  the rpmsg bus.
+
+config SAMPLE_LIVEPATCH
+	tristate "Build live patching samples -- loadable modules only"
+	depends on LIVEPATCH && m
+	help
+	  Build sample live patch demonstrations.
+
+config SAMPLE_CONFIGFS
+	tristate "Build configfs patching sample -- loadable modules only"
+	depends on CONFIGFS_FS && m
+	help
+	  Builds a sample configfs interface.
+
+config SAMPLE_CONNECTOR
+	tristate "Build connector sample -- loadable modules only"
+	depends on CONNECTOR && HEADERS_INSTALL && m
+	help
+	  When enabled, this builds both a sample kernel module for
+	  the connector interface and a user space tool to communicate
+	  with it.
+	  See also Documentation/driver-api/connector.rst
+
+config SAMPLE_FANOTIFY_ERROR
+	bool "Build fanotify error monitoring sample"
+	depends on FANOTIFY && CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  When enabled, this builds an example code that uses the
+	  FAN_FS_ERROR fanotify mechanism to monitor filesystem
+	  errors.
+	  See also Documentation/admin-guide/filesystem-monitoring.rst.
+
+config SAMPLE_HIDRAW
+	bool "hidraw sample"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+
+config SAMPLE_LANDLOCK
+	bool "Landlock example"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build a simple Landlock sandbox manager able to start a process
+	  restricted by a user-defined filesystem access control policy.
+
+config SAMPLE_PIDFD
+	bool "pidfd sample"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+
+config SAMPLE_SECCOMP
+	bool "Build seccomp sample code"
+	depends on SECCOMP_FILTER && CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build samples of seccomp filters using various methods of
+	  BPF filter construction.
+
+config SAMPLE_TIMER
+	bool "Timer sample"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+
+config SAMPLE_TSM_MR
+	tristate "TSM measurement sample"
+	select CRYPTO_LIB_SHA256
+	select CRYPTO_LIB_SHA512
+	select TSM_MEASUREMENTS
+	select VIRT_DRIVERS
+	help
+	  Build a sample module that emulates MRs (Measurement Registers) and
+	  exposes them to user mode applications through the TSM sysfs
+	  interface (/sys/class/misc/tsm_mr_sample/emulated_mr/).
+
+	  The module name will be tsm-mr-sample when built as a module.
+
+config SAMPLE_UHID
+	bool "UHID sample"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build UHID sample program.
+
+config SAMPLE_VFIO_MDEV_MTTY
+	tristate "Build VFIO mtty example mediated device sample code"
+	depends on VFIO
+	select VFIO_MDEV
+	help
+	  Build a virtual tty sample driver for use as a VFIO
+	  mediated device
+
+config SAMPLE_VFIO_MDEV_MDPY
+	tristate "Build VFIO mdpy example mediated device sample code"
+	depends on VFIO
+	select VFIO_MDEV
+	help
+	  Build a virtual display sample driver for use as a VFIO
+	  mediated device.  It is a simple framebuffer and supports
+	  the region display interface (VFIO_GFX_PLANE_TYPE_REGION).
+
+config SAMPLE_VFIO_MDEV_MDPY_FB
+	tristate "Build VFIO mdpy example guest fbdev driver"
+	depends on FB
+	select FB_IOMEM_HELPERS
+	help
+	  Guest fbdev driver for the virtual display sample driver.
+
+config SAMPLE_VFIO_MDEV_MBOCHS
+	tristate "Build VFIO mbochs example mediated device sample code"
+	depends on VFIO
+	select VFIO_MDEV
+	select DMA_SHARED_BUFFER
+	help
+	  Build a virtual display sample driver for use as a VFIO
+	  mediated device.  It supports the region display interface
+	  (VFIO_GFX_PLANE_TYPE_DMABUF).
+	  Emulate enough of qemu stdvga to make bochs-drm.ko happy.
+	  That is basically the vram memory bar and the bochs dispi
+	  interface vbe registers in the mmio register bar.
+	  Specifically it does *not* include any legacy vga stuff.
+	  Device looks a lot like "qemu -device secondary-vga".
+
+config SAMPLE_ANDROID_BINDERFS
+	bool "Build Android binderfs example"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Builds a sample program to illustrate the use of the Android binderfs
+	  filesystem.
+
+config SAMPLE_VFS
+	bool "Build example programs that use new VFS system calls"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build example userspace programs that use new VFS system calls such
+	  as mount API and statx().  Note that this is restricted to the x86
+	  arch whilst it accesses system calls that aren't yet in all arches.
+
+config SAMPLE_INTEL_MEI
+	bool "Build example program working with intel mei driver"
+	depends on INTEL_MEI
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build a sample program to work with mei device.
+
+config SAMPLE_TPS6594_PFSM
+	bool "Build example program working with TPS6594 PFSM driver"
+	depends on HEADERS_INSTALL
+	depends on CC_CAN_LINK
+	help
+	  Build a sample program to work with PFSM devices.
+
+config SAMPLE_WATCHDOG
+	bool "watchdog sample"
+	depends on CC_CAN_LINK
+
+config SAMPLE_WATCH_QUEUE
+	bool "Build example watch_queue notification API consumer"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build example userspace program to use the new mount_notify(),
+	  sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
+
+config SAMPLE_CORESIGHT_SYSCFG
+	tristate "Build example loadable module for CoreSight config"
+	depends on CORESIGHT && m
+	help
+	  Build an example loadable module that adds new CoreSight features
+	  and configuration using the CoreSight system configuration API.
+	  This demonstrates how a user may create their own CoreSight
+	  configurations and easily load them into the system at runtime.
+
+config SAMPLE_KMEMLEAK
+	tristate "Simple test for the kernel memory leak detector"
+	depends on DEBUG_KMEMLEAK && m
+	help
+	  Build a sample program which have explicitly leaks memory to test
+	  kmemleak.
+
+config SAMPLE_CGROUP
+	bool "Build cgroup sample code"
+	depends on CGROUPS && CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build samples that demonstrate the usage of the cgroup API.
+
+config SAMPLE_CHECK_EXEC
+	bool "Exec secure bits examples"
+	depends on CC_CAN_LINK && HEADERS_INSTALL
+	help
+	  Build a tool to easily configure SECBIT_EXEC_RESTRICT_FILE and
+	  SECBIT_EXEC_DENY_INTERACTIVE, and a simple script interpreter to
+	  demonstrate how they should be used with execveat(2) +
+	  AT_EXECVE_CHECK.
+
+config SAMPLE_HUNG_TASK
+	tristate "Hung task detector test code"
+	depends on DETECT_HUNG_TASK && DEBUG_FS
+	help
+	  Build a module that provides debugfs files (e.g., mutex, semaphore,
+	  rw_semaphore_read, rw_semaphore_write) under <debugfs>/hung_task.
+	  Reading these files with multiple processes triggers hung task
+	  detection by holding locks for a long time (256 seconds).
+
+source "samples/rust/Kconfig"
+
+source "samples/damon/Kconfig"
+
+endif # SAMPLES
+
+config HAVE_SAMPLE_FTRACE_DIRECT
+	bool
+
+config HAVE_SAMPLE_FTRACE_DIRECT_MULTI
+	bool