641 Commits

Author SHA1 Message Date
Linus Torvalds
fdbfee9fc5 Merge tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verification updates from Steven Rostedt:

 - Refactor da_monitor header to share handlers across monitor types

   No functional changes, only less code duplication.

 - Add Hybrid Automata model class

   Add a new model class that extends deterministic automata by adding
   constraints on transitions and states. Those constraints can take
   into account wall-clock time and as such allow RV monitor to make
   assertions on real time. Add documentation and code generation
   scripts.

 - Add stall monitor as hybrid automaton example

   Add a monitor that triggers a violation when a task is stalling as an
   example of automaton working with real time variables.

 - Convert the opid monitor to a hybrid automaton

   The opid monitor can be heavily simplified if written as a hybrid
   automaton: instead of tracking preempt and interrupt enable/disable
   events, it can just run constraints on the preemption/interrupt
   states when events like wakeup and need_resched verify.

 - Add support for per-object monitors in DA/HA

   Allow writing deterministic and hybrid automata monitors for generic
   objects (e.g. any struct), by exploiting a hash table where objects
   are saved. This allows to track more than just tasks in RV. For
   instance it will be used to track deadline entities in deadline
   monitors.

 - Add deadline tracepoints and move some deadline utilities

   Prepare the ground for deadline monitors by defining events and
   exporting helpers.

 - Add nomiss deadline monitor

   Add first example of deadline monitor asserting all entities complete
   before their deadline.

 - Improve rvgen error handling

   Introduce AutomataError exception class and better handle expected
   exceptions while showing a backtrace for unexpected ones.

 - Improve python code quality in rvgen

   Refactor the rvgen generation scripts to align with python best
   practices: use f-strings instead of %, use len() instead of
   __len__(), remove semicolons, use context managers for file
   operations, fix whitespace violations, extract magic strings into
   constants, remove unused imports and methods.

 - Fix small bugs in rvgen

   The generator scripts presented some corner case bugs: logical error
   in validating what a correct dot file looks like, fix an isinstance()
   check, enforce a dot file has an initial state, fix type annotations
   and typos in comments.

 - rvgen refactoring

   Refactor automata.py to use iterator-based parsing and handle
   required arguments directly in argparse.

 - Allow epoll in rtapp-sleep monitor

   The epoll_wait call is now rt-friendly so it should be allowed in the
   sleep monitor as a valid sleep method.

* tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (32 commits)
  rv: Allow epoll in rtapp-sleep monitor
  rv/rvgen: fix _fill_states() return type annotation
  rv/rvgen: fix unbound loop variable warning
  rv/rvgen: enforce presence of initial state
  rv/rvgen: extract node marker string to class constant
  rv/rvgen: fix isinstance check in Variable.expand()
  rv/rvgen: make monitor arguments required in rvgen
  rv/rvgen: remove unused __get_main_name method
  rv/rvgen: remove unused sys import from dot2c
  rv/rvgen: refactor automata.py to use iterator-based parsing
  rv/rvgen: use class constant for init marker
  rv/rvgen: fix DOT file validation logic error
  rv/rvgen: fix PEP 8 whitespace violations
  rv/rvgen: fix typos in automata and generator docstring and comments
  rv/rvgen: use context managers for file operations
  rv/rvgen: remove unnecessary semicolons
  rv/rvgen: replace __len__() calls with len()
  rv/rvgen: replace % string formatting with f-strings
  rv/rvgen: remove bare except clauses in generator
  rv/rvgen: introduce AutomataError exception class
  ...
2026-04-15 17:15:18 -07:00
Linus Torvalds
e4bf304f00 Merge tag 'trace-ringbuffer-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:

 - Add remote buffers for pKVM

   pKVM has a hypervisor component that is used to protect the guest
   from the host kernel. This hypervisor is a black box to the kernel as
   the kernel is to user space. The remote buffers are used to have a
   memory mapping between the hypervisor and the kernel where kernel may
   send commands to enable tracing within the hypervisor. Then the
   kernel will read this memory mapping just like user space can read
   the memory mapped ring buffer of the kernel tracing system.

   Since the hypervisor only has a single context, it doesn't need to
   worry about races between normal context, interrupt context and NMIs
   like the kernel does. The ring buffer it uses doesn't need to be as
   complex. The remote buffers are a simple version of the ring buffer
   that works in a single context. They are still per-CPU and use sub
   buffers. The data layout is the same as the kernel's ring buffer to
   share the same parsing.

   Currently, only ARM64 implements pKVM, but there's work to implement
   it also in x86. The remote buffer code is separated out from the ARM
   implementation so that it can be used in the future by x86.

   The ARM64 updates for pKVM is in the ARM/KVM tree and it merged in
   the remote buffers of this tree.

 - Make the backup instance non reusable

   The backup instance is a copy of the persistent ring buffer so that
   the persistent ring buffer could start recording again without using
   the data from the previous boot. The backup isn't for normal tracing.
   It is made read-only, and after it is consumed, it is automatically
   removed.

 - Have backup copy persistent instance before it starts recording

   To allow the persistent ring buffer to start recording from the
   kernel command line commands, move the copy of the backup instance to
   before the the command line options start recording.

 - Report header_page overwrite field as "char" and not "int'

   The rust parser of the header_page file was triggering a warning when
   it defined the overwrite variable as "int" but it was only a single
   byte in size.

 - Fix memory barriers for the trace_buffer CPU mask

   When a CPU comes online, the bit is set to allow readers to know that
   the CPU buffer is allocated. The bit is set after the allocation is
   done, and a smp_wmb() is performed after the allocation and before
   the setting of the bit. But instead of adding a smp_rmb() to all
   readers, since once a buffer is created for a CPU it is not deleted
   if that CPU goes offline, so this allocation is almost always done at
   boot up before any readers exist.

   If for the unlikely case where a CPU comes online for the first time
   after the system boot has finished, send an IPI to all CPUs to force
   the smp_rmb() for each CPU.

 - Show clock function being used in debugging ring buffer data

   When the ring buffer checks are enabled and the ring buffer detects
   an inconsistency in the times of the invents, print out the clock
   being used when the error occurred. There was a very hard to hit bug
   that would happen every so often and it ended up being only triggered
   when the jiffies clock was being used. If the bug showed the clock
   being used, it would have been much easier to find the problem (which
   was an internal function was being traced which caused the clock
   accounting to go off).

* tag 'trace-ringbuffer-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
  ring-buffer: Prevent off-by-one array access in ring_buffer_desc_page()
  ring-buffer: Report header_page overwrite as char
  tracing: Allow backup to save persistent ring buffer before it starts
  tracing/Documentation: Add a section about backup instance
  tracing: Remove the backup instance automatically after read
  tracing: Make the backup instance non-reusable
  ring-buffer: Enforce read ordering of trace_buffer cpumask and buffers
  ring-buffer: Show what clock function is used on timestamp errors
  tracing: Check for undefined symbols in simple_ring_buffer
  tracing: load/unload page callbacks for simple_ring_buffer
  Documentation: tracing: Add tracing remotes
  tracing: selftests: Add trace remote tests
  tracing: Add a trace remote module for testing
  tracing: Introduce simple_ring_buffer
  ring-buffer: Export buffer_data_page and macros
  tracing: Add helpers to create trace remote events
  tracing: Add events/ root files to trace remotes
  tracing: Add events to trace remotes
  tracing: Add init callback to trace remotes
  tracing: Add non-consuming read to trace remotes
  ...
2026-04-15 15:59:46 -07:00
Linus Torvalds
40286d6379 Merge tag 'pci-v7.1-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull pci updates from Bjorn Helgaas:
 "Enumeration:

   - Allow TLP Processing Hints to be enabled for RCiEPs (George Abraham
     P)

   - Enable AtomicOps only if we know the Root Port supports them (Gerd
     Bayer)

   - Don't enable AtomicOps for RCiEPs since none of them need Atomic
     Ops and we can't tell whether the Root Complex would support them
     (Gerd Bayer)

   - Leave Precision Time Measurement disabled until a driver enables it
     to avoid PCIe errors (Mika Westerberg)

   - Make pci_set_vga_state() fail if bridge doesn't support VGA
     routing, i.e., PCI_BRIDGE_CTL_VGA is not writable, and return
     errors to vga_get() callers including userspace via
     /dev/vga_arbiter (Simon Richter)

   - Validate max-link-speed from DT in j721e, brcmstb, mediatek-gen3,
     rzg3s drivers (where the actual controller constraints are known),
     and remove validation from the generic OF DT accessor (Hans Zhang)

   - Remove pc110pad driver (no longer useful after 486 CPU support
     removed) and no_pci_devices() (pc110pad was the last user) (Dmitry
     Torokhov, Heiner Kallweit)

  Resource management:

   - Prevent assigning space to unimplemented bridge windows; previously
     we mistakenly assumed prefetchable window existed and assigned
     space and put a BAR there (Ahmed Naseef)

   - Avoid shrinking bridge windows to fit in the initial Root Port
     window; fixes one problem with devices with large BARs connected
     via switches, e.g., Thunderbolt (Ilpo Järvinen)

   - Pass full extent of empty space, not just the aligned space, to
     resource_alignf callback so free space before the requested
     alignment can be used (Ilpo Järvinen)

   - Place small resources before larger ones for better utilization of
     address space (Ilpo Järvinen)

   - Fix alignment calculation for resource size larger than align,
     e.g., bridge windows larger than the 1MB required alignment (Ilpo
     Järvinen)

  Reset:

   - Update slot handling so all ARI functions are treated as being in
     the same slot. They're all reset by Secondary Bus Reset, but
     previously drivers of ARI functions that appeared to be on a
     non-zero device weren't notified and fatal hardware errors could
     result (Keith Busch)

   - Make sysfs reset_subordinate hotplug safe to avoid spurious hotplug
     events (Keith Busch)

   - Hide Secondary Bus Reset ('bus') from sysfs reset_methods if masked
     by CXL because it has no effect (Vidya Sagar)

   - Avoid FLR for AMD NPU device, where it causes the device to hang
     (Lizhi Hou)

  Error handling:

   - Clear only error bits in PCIe Device Status to avoid accidentally
     clearing Emergency Power Reduction Detected (Shuai Xue)

   - Check for AER errors even in devices without drivers (Lukas Wunner)

   - Initialize ratelimit info so DPC and EDR paths log AER error
     information (Kuppuswamy Sathyanarayanan)

  Power control:

   - Add UPD720201/UPD720202 USB 3.0 xHCI Host Controller .compatible so
     generic pwrctrl driver can control it (Neil Armstrong)

  Hotplug:

   - Set LED_HW_PLUGGABLE for NPEM hotplug-capable ports so LED core
     doesn't complain when setting brightness fails because the endpoint
     is gone (Richard Cheng)

  Peer-to-peer DMA:

   - Allow wildcards in list of host bridges that support peer-to-peer
     DMA between hierarchy domains and add all Google SoCs (Jacob
     Moroni)

  Endpoint framework:

   - Advertise dynamic inbound mapping support in pci-epf-test and
     update host pci_endpoint_test to skip doorbell testing if not
     advertised by endpoint (Koichiro Den)

   - Return 0, not remaining timeout, when MHI eDMA ops complete so
     mhi_ep_ring_add_element() doesn't interpret non-zero as failure
     (Daniel Hodges)

   - Remove vntb and ntb duplicate resource teardown that leads to oops
     when .allow_link() fails or .drop_link() is called (Koichiro Den)

   - Disable vntb delayed work before clearing BAR mappings and
     doorbells to avoid oops caused by doing the work after resources
     have been torn down (Koichiro Den)

   - Add a way to describe reserved subregions within BARs, e.g.,
     platform-owned fixed register windows, and use it for the RK3588
     BAR4 DMA ctrl window (Koichiro Den)

   - Add BAR_DISABLED for BARs that will never be available to an EPF
     driver, and change some BAR_RESERVED annotations to BAR_DISABLED
     (Niklas Cassel)

   - Add NTB .get_dma_dev() callback for cases where DMA API requires a
     different device, e.g., vNTB devices (Koichiro Den)

   - Add reserved region types for MSI-X Table and PBA so Endpoint
     controllers can them as describe hardware-owned regions in a
     BAR_RESERVED BAR (Manikanta Maddireddy)

   - Make Tegra194/234 BAR0 programmable and remove 1MB size limit
     (Manikanta Maddireddy)

   - Expose Tegra BAR2 (MSI-X) and BAR4 (DMA) as 64-bit BAR_RESERVED
     (Manikanta Maddireddy)

   - Add Tegra194 and Tegra234 device table entries to pci_endpoint_test
     (Manikanta Maddireddy)

   - Skip the BAR subrange selftest if there are not enough inbound
     window resources to run the test (Christian Bruel)

  New native PCIe controller drivers:

   - Add DT binding and driver for Andes QiLai SoC PCIe host controller
     (Randolph Lin)

   - Add DT binding and driver for ESWIN PCIe Root Complex (Senchuan
     Zhang)

  Baikal T-1 PCIe controller driver:

   - Remove driver since it never quite became usable (Andy Shevchenko)

  Cadence PCIe controller driver:

   - Implement byte/word config reads with dword (32-bit) reads because
     some Cadence controllers don't support sub-dword accesses (Aksh
     Garg)

  CIX Sky1 PCIe controller driver:

   - Add 'power-domains' to DT binding for SCMI power domain (Gary Yang)

  Freescale i.MX6 PCIe controller driver:

   - Add i.MX94 and i.MX943 to fsl,imx6q-pcie-ep DT binding (Richard
     Zhu)

   - Delay instead of polling for L2/L3 Ready after PME_Turn_off when
     suspending i.MX6SX because LTSSM registers are inaccessible
     (Richard Zhu)

   - Separate PERST# assertion (for resetting endpoints) from core reset
     (for resetting the RC itself) to prepare for new DTs with PERST#
     GPIO in per-Root Port nodes (Sherry Sun)

   - Retain Root Port MSI capability on i.MX7D, i.MX8MM, and i.MX8MQ so
     MSI from downstream devices will work (Richard Zhu)

   - Fix i.MX95 reference clock source selection when internal refclk is
     used (Franz Schnyder)

  Freescale Layerscape PCIe controller driver:

   - Allow building as a removable module (Sascha Hauer)

  MediaTek PCIe Gen3 controller driver:

   - Use dev_err_probe() to simplify error paths and make deferred probe
     messages visible in /sys/kernel/debug/devices_deferred (Chen-Yu
     Tsai)

   - Power off device if setup fails (Chen-Yu Tsai)

   - Integrate new pwrctrl API to enable power control for WiFi/BT
     adapters on mainboard or in PCIe or M.2 slots (Chen-Yu Tsai)

  NVIDIA Tegra194 PCIe controller driver:

   - Poll less aggressively and non-atomically for PME_TO_Ack during
     transition to L2 (Vidya Sagar)

   - Disable LTSSM after transition to Detect on surprise link down to
     stop toggling between Polling and Detect (Manikanta Maddireddy)

   - Don't force the device into the D0 state before L2 when suspending
     or shutting down the controller (Vidya Sagar)

   - Disable PERST# IRQ only in Endpoint mode because it's not
     registered in Root Port mode (Manikanta Maddireddy)

   - Handle 'nvidia,refclk-select' as optional (Vidya Sagar)

   - Disable direct speed change in Endpoint mode so link speed change
     is controlled by the host (Vidya Sagar)

   - Set LTR values before link up to avoid bogus LTR messages with 0
     latency (Vidya Sagar)

   - Allow system suspend when the Endpoint link is down (Vidya Sagar)

   - Use DWC IP core version, not Tegra custom values, to avoid DWC core
     version check warnings (Manikanta Maddireddy)

   - Apply ECRC workaround to devices based on DesignWare 5.00a as well
     as 4.90a (Manikanta Maddireddy)

   - Disable PM Substate L1.2 in Endpoint mode to work around Tegra234
     erratum (Vidya Sagar)

   - Delay post-PERST# cleanup until core is powered on to avoid CBB
     timeout (Manikanta Maddireddy)

   - Assert CLKREQ# so switches that forward it to their downstream side
     can bring up those links successfully (Vidya Sagar)

   - Calibrate pipe to UPHY for Endpoint mode to reset stale PLL state
     from any previous bad link state (Vidya Sagar)

   - Remove IRQF_ONESHOT flag from Endpoint interrupt registration so
     DMA driver and Endpoint controller driver can share the interrupt
     line (Vidya Sagar)

   - Enable DMA interrupt to support DMA in both Root Port and Endpoint
     modes (Vidya Sagar)

   - Enable hardware link retraining after link goes down in Endpoint
     mode (Vidya Sagar)

   - Add DT binding and driver support for core clock monitoring (Vidya
     Sagar)

  Qualcomm PCIe controller driver:

   - Advertise 'Hot-Plug Capable' and set 'No Command Completed Support'
     since Qcom Root Ports support hotplug events like DL_Up/Down and
     can accept writes to Slot Control without delays between writes
     (Krishna Chaitanya Chundru)

  Renesas R-Car PCIe controller driver:

   - Mark Endpoint BAR0 and BAR2 as Resizable (Koichiro Den)

   - Reduce EPC BAR alignment requirement to 4K (Koichiro Den)

  Renesas RZ/G3S PCIe controller driver:

   - Add RZ/G3E to DT binding and to driver (John Madieu)

   - Assert (not deassert) resets in probe error path (John Madieu)

   - Assert resets in suspend path in reverse order they were deasserted
     during probe (John Madieu)

   - Rework inbound window algorithm to prevent mapping more than
     intended region and enforce alignment on size, to prepare for
     RZ/G3E support (John Madieu)

  Rockchip DesignWare PCIe controller driver:

   - Add tracepoints for PCIe controller LTSSM transitions and link rate
     changes (Shawn Lin)

   - Trace LTSSM events collected by the dw-rockchip debug FIFO (Shawn
     Lin)

  SOPHGO PCIe controller driver:

   - Disable ASPM L0s and L1 on Sophgo 2042 PCIe Root Ports that
     advertise support for them (Yao Zi)

  Synopsys DesignWare PCIe controller driver:

   - Continue with system suspend even if an Endpoint doesn't respond
     with PME_TO_Ack message (Manivannan Sadhasivam)

   - Set Endpoint MSI-X Table Size in the correct function of a
     multi-function device when configuring MSI-X, not in Function 0
     (Aksh Garg)

   - Set Max Link Width and Max Link Speed for all functions of a
     multi-function device, not just Function 0 (Aksh Garg)

   - Expose PCIe event counters in groups 5-7 in debugfs (Hans Zhang)

  Miscellaneous:

   - Warn only once about invalid ACS kernel parameter format (Richard
     Cheng)

   - Suppress FW_BUG warning when writing sysfs 'numa_node' with the
     current value (Li RongQing)

   - Drop redundant 'depends on PCI' from Kconfig (Julian Braha)"

* tag 'pci-v7.1-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (165 commits)
  PCI/P2PDMA: Add Google SoCs to the P2P DMA host bridge list
  PCI/P2PDMA: Allow wildcard Device IDs in host bridge list
  PCI: sg2042: Avoid L0s and L1 on Sophgo 2042 PCIe Root Ports
  PCI: cadence: Add flags for disabling ASPM capability for broken Root Ports
  PCI: tegra194: Add core monitor clock support
  dt-bindings: PCI: tegra194: Add monitor clock support
  PCI: tegra194: Enable hardware hot reset mode in Endpoint mode
  PCI: tegra194: Enable DMA interrupt
  PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration
  PCI: tegra194: Calibrate pipe to UPHY for Endpoint mode
  PCI: tegra194: Assert CLKREQ# explicitly by default
  PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on
  PCI: tegra194: Disable L1.2 capability of Tegra234 EP
  PCI: dwc: Apply ECRC workaround to DesignWare 5.00a as well
  PCI: tegra194: Use DWC IP core version
  PCI: tegra194: Free up Endpoint resources during remove()
  PCI: tegra194: Allow system suspend when the Endpoint link is not up
  PCI: tegra194: Set LTR message request before PCIe link up in Endpoint mode
  PCI: tegra194: Disable direct speed change for Endpoint mode
  PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select"
  ...
2026-04-15 14:41:21 -07:00
Steven Rostedt
1eab6493f5 tracing: Documentation: Update histogram-design.rst for fn() handling
The histogram documentation describes the old method of the histogram
triggers using the fn() field of the histogram field structure to process
the field. But due to Spectre mitigation, the function pointer to handle
the fields at runtime caused a noticeable overhead. It was converted over
to a fn_num and hist_fn_call() is now used to call the specific functions
for the fields via a switch statement based on the field's fn_num value.

Update the documentation to reflect this change.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260126181742.03e8f0d5@gandalf.local.home>
2026-04-09 08:46:39 -06:00
Shawn Lin
a3966a6f91 Documentation: tracing: Add PCI controller event documentation
The PCI controller tracepoint, pcie_ltssm_state_transition, monitors the
LTSSM state transition and data rate changes for debugging purposes. Add
documentation for it.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[mani: added MAINTAINERS entry]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/1774403912-210670-3-git-send-email-shawn.lin@rock-chips.com
2026-04-07 20:13:12 +05:30
Masami Hiramatsu (Google)
e53ba177c2 tracing/Documentation: Add a section about backup instance
Add a section about backup instance to the debugging.rst.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/177502548479.1311542.7062269603547001007.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-04-02 13:27:21 -04:00
Gabriele Monaco
b133207deb rv: Add nomiss deadline monitor
Add the deadline monitors collection to validate the deadline scheduler,
both for deadline tasks and servers.

The currently implemented monitors are:
* nomiss:
    validate dl entities run to completion before their deadiline

Reviewed-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20260330111010.153663-13-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-03-31 16:47:18 +02:00
Gabriele Monaco
2b406fdb33 rv: Convert the opid monitor to a hybrid automaton
The opid monitor validates that wakeup and need_resched events only
occur with interrupts and preemption disabled by following the
preemptirq tracepoints.
As reported in [1], those tracepoints might be inaccurate in some
situations (e.g. NMIs).

Since the monitor doesn't validate other ordering properties, remove the
dependency on preemptirq tracepoints and convert the monitor to a hybrid
automaton to validate the constraint during event handling.
This makes the monitor more robust by also removing the workaround for
interrupts missing the preemption tracepoints, which was working on
PREEMPT_RT only and allows the monitor to be built on kernels without
the preemptirqs tracepoints.

[1] - https://lore.kernel.org/lkml/20250625120823.60600-1-gmonaco@redhat.com

Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260330111010.153663-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-03-31 16:47:17 +02:00
Gabriele Monaco
13578a0871 rv: Add sample hybrid monitor stall
Add a sample monitor to showcase hybrid/timed automata.
The stall monitor identifies tasks stalled for longer than a threshold
and reacts when that happens.

Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260330111010.153663-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-03-31 16:47:17 +02:00
Gabriele Monaco
708340c271 Documentation/rv: Add documentation about hybrid automata
Describe theory and implementation of hybrid automata in the dedicated
page hybrid_automata.rst
Include a section on how to integrate a hybrid automaton in
monitor_synthesis.rst
Also remove a hanging $ in deterministic_automata.rst

Reviewed-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20260330111010.153663-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-03-31 16:47:17 +02:00
Vincent Donnefort
c88d510584 Documentation: tracing: Add tracing remotes
Add documentation about the newly introduced tracing remotes framework.

Link: https://patch.msgid.link/20260309162516.2623589-17-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09 12:33:55 -04:00
Linus Torvalds
505d195b0f Merge tag 'char-misc-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc/IIO driver updates from Greg KH:
 "Here is the big set of char/misc/iio and other smaller driver
  subsystem changes for 7.0-rc1. Lots of little things in here,
  including:

   - Loads of iio driver changes and updates and additions

   - gpib driver updates

   - interconnect driver updates

   - i3c driver updates

   - hwtracing (coresight and intel) driver updates

   - deletion of the obsolete mwave driver

   - binder driver updates (rust and c versions)

   - mhi driver updates (causing a merge conflict, see below)

   - mei driver updates

   - fsi driver updates

   - eeprom driver updates

   - lots of other small char and misc driver updates and cleanups

  All of these have been in linux-next for a while, with no reported
  issues"

* tag 'char-misc-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (297 commits)
  mux: mmio: fix regmap leak on probe failure
  rust_binder: return p from rust_binder_transaction_target_node()
  drivers: android: binder: Update ARef imports from sync::aref
  rust_binder: fix needless borrow in context.rs
  iio: magn: mmc5633: Fix Kconfig for combination of I3C as module and driver builtin
  iio: sca3000: Fix a resource leak in sca3000_probe()
  iio: proximity: rfd77402: Add interrupt handling support
  iio: proximity: rfd77402: Document device private data structure
  iio: proximity: rfd77402: Use devm-managed mutex initialization
  iio: proximity: rfd77402: Use kernel helper for result polling
  iio: proximity: rfd77402: Align polling timeout with datasheet
  iio: cros_ec: Allow enabling/disabling calibration mode
  iio: frequency: ad9523: correct kernel-doc bad line warning
  iio: buffer: buffer_impl.h: fix kernel-doc warnings
  iio: gyro: itg3200: Fix unchecked return value in read_raw
  MAINTAINERS: add entry for ADE9000 driver
  iio: accel: sca3000: remove unused last_timestamp field
  iio: accel: adxl372: remove unused int2_bitmask field
  iio: adc: ad7766: Use iio_trigger_generic_data_rdy_poll()
  iio: magnetometer: Remove IRQF_ONESHOT
  ...
2026-02-17 09:11:04 -08:00
Linus Torvalds
3c6e577d5a Merge tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
 "User visible changes:

   - Add an entry into MAINTAINERS file for RUST versions of code

     There's now RUST code for tracing and static branches. To
     differentiate that code from the C code, add entries in for the
     RUST version (with "[RUST]" around it) so that the right
     maintainers get notified on changes.

   - New bitmask-list option added to tracefs

     When this is set, bitmasks in trace event are not displayed as hex
     numbers, but instead as lists: e.g. 0-5,7,9 instead of 0000015f

   - New show_event_filters file in tracefs

     Instead of having to search all events/*/*/filter for any active
     filters enabled in the trace instance, the file show_event_filters
     will list them so that there's only one file that needs to be
     examined to see if any filters are active.

   - New show_event_triggers file in tracefs

     Instead of having to search all events/*/*/trigger for any active
     triggers enabled in the trace instance, the file
     show_event_triggers will list them so that there's only one file
     that needs to be examined to see if any triggers are active.

   - Have traceoff_on_warning disable trace pintk buffer too

     Recently recording of trace_printk() could go to other trace
     instances instead of the top level instance. But if
     traceoff_on_warning triggers, it doesn't stop the buffer with
     trace_printk() and that data can easily be lost by being
     overwritten. Have traceoff_on_warning also disable the instance
     that has trace_printk() being written to it.

   - Update the hist_debug file to show what function the field uses

     When CONFIG_HIST_TRIGGERS_DEBUG is enabled, a hist_debug file
     exists for every event. This displays the internal data of any
     histogram enabled for that event. But it is lacking the function
     that is called to process one of its fields. This is very useful
     information that was missing when debugging histograms.

   - Up the histogram stack size from 16 to 31

     Stack traces can be used as keys for event histograms. Currently
     the size of the stack that is stored is limited to just 16 entries.
     But the storage space in the histogram is 256 bytes, meaning that
     it can store up to 31 entries (plus one for the count of entries).
     Instead of letting that space go to waste, up the limit from 16 to
     31. This makes the keys much more useful.

   - Fix permissions of per CPU file buffer_size_kb

     The per CPU file of buffer_size_kb was incorrectly set to read only
     in a previous cleanup. It should be writable.

   - Reset "last_boot_info" if the persistent buffer is cleared

     The last_boot_info shows address information of a persistent ring
     buffer if it contains data from a previous boot. It is cleared when
     recording starts again, but it is not cleared when the buffer is
     reset. The data is useless after a reset so clear it on reset too.

  Internal changes:

   - A change was made to allow tracepoint callbacks to have preemption
     enabled, and instead be protected by SRCU. This required some
     updates to the callbacks for perf and BPF.

     perf needed to disable preemption directly in its callback because
     it expects preemption disabled in the later code.

     BPF needed to disable migration, as its code expects to run
     completely on the same CPU.

   - Have irq_work wake up other CPU if current CPU is "isolated"

     When there's a waiter waiting on ring buffer data and a new event
     happens, an irq work is triggered to wake up that waiter. This is
     noisy on isolated CPUs (running NO_HZ_FULL). Trigger an IPI to a
     house keeping CPU instead.

   - Use proper free of trigger_data instead of open coding it in.

   - Remove redundant call of event_trigger_reset_filter()

     It was called immediately in a function that was called right after
     it.

   - Workqueue cleanups

   - Report errors if tracing_update_buffers() were to fail.

   - Make the enum update workqueue generic for other parts of tracing

     On boot up, a work queue is created to convert enum names into
     their numbers in the trace event format files. This work queue can
     also be used for other aspects of tracing that takes some time and
     shouldn't be called by the init call code.

     The blk_trace initialization takes a bit of time. Have the
     initialization code moved to the new tracing generic work queue
     function.

   - Skip kprobe boot event creation call if there's no kprobes defined
     on cmdline

     The kprobe initialization to set up kprobes if they are defined on
     the cmdline requires taking the event_mutex lock. This can be held
     by other tracing code doing initialization for a long time. Since
     kprobes added to the kernel command line need to be setup
     immediately, as they may be tracing early initialization code, they
     cannot be postponed in a work queue and must be setup in the
     initcall code.

     If there's no kprobe on the kernel cmdline, there's no reason to
     take the mutex and slow down the boot up code waiting to get the
     lock only to find out there's nothing to do. Simply exit out early
     if there's no kprobes on the kernel cmdline.

     If there are kprobes on the cmdline, then someone cares more about
     tracing over the speed of boot up.

   - Clean up the trigger code a bit

   - Move code out of trace.c and into their own files

     trace.c is now over 11,000 lines of code and has become more
     difficult to maintain. Start splitting it up so that related code
     is in their own files.

     Move all the trace_printk() related code into trace_printk.c.

     Move the __always_inline stack functions into trace.h.

     Move the pid filtering code into a new trace_pid.c file.

   - Better define the max latency and snapshot code

     The latency tracers have a "max latency" buffer that is a copy of
     the main buffer and gets swapped with it when a new high latency is
     detected. This keeps the trace up to the highest latency around
     where this max_latency buffer is never written to. It is only used
     to save the last max latency trace.

     A while ago a snapshot feature was added to tracefs to allow user
     space to perform the same logic. It could also enable events to
     trigger a "snapshot" if one of their fields hit a new high. This
     was built on top of the latency max_latency buffer logic.

     Because snapshots came later, they were dependent on the latency
     tracers to be enabled. In reality, the latency tracers depend on
     the snapshot code and not the other way around. It was just that
     they came first.

     Restructure the code and the kconfigs to have the latency tracers
     depend on snapshot code instead. This actually simplifies the logic
     a bit and allows to disable more when the latency tracers are not
     defined and the snapshot code is.

   - Fix a "false sharing" in the hwlat tracer code

     The loop to search for latency in hardware was using a variable
     that could be changed by user space for each sample. If the user
     change this variable, it could cause a bus contention, and reading
     that variable can show up as a large latency in the trace causing a
     false positive. Read this variable at the start of the sample with
     a READ_ONCE() into a local variable and keep the code from sharing
     cache lines with readers.

   - Fix function graph tracer static branch optimization code

     When only one tracer is defined for function graph tracing, it uses
     a static branch to call that tracer directly. When another tracer
     is added, it goes into loop logic to call all the registered
     callbacks.

     The code was incorrect when going back to one tracer and never
     re-enabled the static branch again to do the optimization code.

   - And other small fixes and cleanups"

* tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (46 commits)
  function_graph: Restore direct mode when callbacks drop to one
  tracing: Fix indentation of return statement in print_trace_fmt()
  tracing: Reset last_boot_info if ring buffer is reset
  tracing: Fix to set write permission to per-cpu buffer_size_kb
  tracing: Fix false sharing in hwlat get_sample()
  tracing: Move d_max_latency out of CONFIG_FSNOTIFY protection
  tracing: Better separate SNAPSHOT and MAX_TRACE options
  tracing: Add tracer_uses_snapshot() helper to remove #ifdefs
  tracing: Rename trace_array field max_buffer to snapshot_buffer
  tracing: Move pid filtering into trace_pid.c
  tracing: Move trace_printk functions out of trace.c and into trace_printk.c
  tracing: Use system_state in trace_printk_init_buffers()
  tracing: Have trace_printk functions use flags instead of using global_trace
  tracing: Make tracing_update_buffers() take NULL for global_trace
  tracing: Make printk_trace global for tracing system
  tracing: Move ftrace_trace_stack() out of trace.c and into trace.h
  tracing: Move __trace_buffer_{un}lock_*() functions to trace.h
  tracing: Make tracing_selftest_running global to the tracing subsystem
  tracing: Make tracing_disabled global for tracing system
  tracing: Clean up use of trace_create_maxlat_file()
  ...
2026-02-13 19:25:16 -08:00
Linus Torvalds
f75c03a761 Merge tag 'trace-rv-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verifier updates from Steven Rostedt:

 - Refactor da_monitor to minimize macros

   Complete refactor of da_monitor.h to reduce reliance on macros
   generating functions. Use generic static functions and uses the
   preprocessor only when strictly necessary (e.g. for tracepoint
   handlers).

   The change essentially relies on functions with generic names (e.g.
   da_handle) instead of monitor-specific as well adding the need to
   define constant (e.g. MONITOR_NAME, MONITOR_TYPE) before including
   the header rather than calling macros that would define functions.
   Also adapt monitors and documentation accordingly.

 - Cleanup DA code generation scripts

   Clean up functions in dot2c removing reimplementations of trivial
   library functions (__buff_to_string) and removing some other unused
   intermediate steps.

 - Annotate functions with types in the rvgen python scripts

 - Remove superfluous assignments and cleanup generated code

   The rvgen scripts generate a superfluous assignment to 0 for enum
   variables and don't add commas to the last elements, which is against
   the kernel coding standards. Change the generation process for a
   better compliance and slightly simpler logic.

 - Remove superfluous declarations from generated code

   The monitor container source files contained a declaration and a
   definition for the rv_monitor variable. The former is superfluous and
   was removed.

 - Fix reference to outdated documentation

   s/da_monitor_synthesis.rst/monitor_synthesis.rst in comment in
   da_monitor.h

* tag 'trace-rv-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rv: Fix documentation reference in da_monitor.h
  verification/rvgen: Remove unused variable declaration from containers
  verification/dot2c: Remove superfluous enum assignment and add last comma
  verification/dot2c: Remove __buff_to_string() and cleanup
  verification/rvgen: Annotate DA functions with types
  verification/rvgen: Adapt dot2k and templates after refactoring da_monitor.h
  Documentation/rv: Adapt documentation after da_monitor refactoring
  rv: Cleanup da_monitor after refactor
  rv: Refactor da_monitor to minimise macros
2026-02-12 14:08:49 -08:00
Linus Torvalds
1c2b4a4c2b Merge tag 'pci-v7.0-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Don't try to enable Extended Tags on VFs since that bit is Reserved
     and causes misleading log messages (Håkon Bugge)

   - Initialize Endpoint Read Completion Boundary to match Root Port,
     regardless of ACPI _HPX (Håkon Bugge)

   - Apply _HPX PCIe Setting Record only to AER configuration, and only
     when OS owns PCIe hotplug but not AER, to avoid clobbering Extended
     Tag and Relaxed Ordering settings (Håkon Bugge)

  Resource management:

   - Move CardBus code to setup-cardbus.c and only build it when
     CONFIG_CARDBUS is set (Ilpo Järvinen)

   - Fix bridge window alignment with optional resources, where
     additional alignment requirement was previously lost (Ilpo
     Järvinen)

   - Stop over-estimating bridge window size since they are now assigned
     without any gaps between them (Ilpo Järvinen)

   - Increase resource MAX_IORES_LEVEL to avoid /proc/iomem flattening
     for nested bridges and endpoints (Ilpo Järvinen)

   - Add pbus_mem_size_optional() to handle sizes of optional resources
     (SR-IOV VF BARs, expansion ROMs, bridge windows) (Ilpo Järvinen)

   - Don't claim disabled bridge windows to avoid spurious claim
     failures (Ilpo Järvinen)

  Driver binding:

   - Fix device reference leak in pcie_port_remove_service() (Uwe
     Kleine-König)

   - Move pcie_port_bus_match() and pcie_port_bus_type to PCIe-specific
     portdrv.c (Uwe Kleine-König)

   - Convert portdrv to use pcie_port_bus_type.probe() and .remove()
     callbacks so .probe() and .remove() can eventually be removed from
     struct device_driver (Uwe Kleine-König)

  Error handling:

   - Clear stale errors on reporting agents upon probe so they don't
     look like recent errors (Lukas Wunner)

   - Add generic RAS tracepoint for hotplug events (Shuai Xue)

   - Add RAS tracepoint for link speed changes (Shuai Xue)

  Power management:

   - Avoid redundant delay on transition from D3hot to D3cold if the
     device was already in D3hot (Brian Norris)

   - Prevent runtime suspend until devices are fully initialized to
     avoid saving incompletely configured device state (Brian Norris)

  Power control:

   - Add power_on/off callbacks with generic signature to pwrseq,
     tc9563, and slot drivers so they can be used by pwrctrl core
     (Manivannan Sadhasivam)

   - Add PCIe M.2 connector support to the slot pwrctrl driver
     (Manivannan Sadhasivam)

   - Switch to pwrctrl interfaces to create, destroy, and power on/off
     devices, calling them from host controller drivers instead of the
     PCI core (Manivannan Sadhasivam)

   - Drop qcom .assert_perst() callbacks since this is now done by the
     controller driver instead of the pwrctrl driver (Manivannan
     Sadhasivam)

  Virtualization:

   - Remove an incorrect unlock in pci_slot_trylock() error handling
     (Jinhui Guo)

   - Lock the bridge device for slot reset (Keith Busch)

   - Enable ACS after IOMMU configuration on OF platforms so ACS is
     enabled an all devices; previously the first device enumerated
     (typically a Root Port) didn't have ACS enabled (Manivannan
     Sadhasivam)

   - Disable ACS Source Validation for IDT 0x80b5 and 0x8090 switches to
     work around hardware erratum; previously ACS SV was only
     temporarily disabled, which worked for enumeration but not after
     reset (Manivannan Sadhasivam)

  Peer-to-peer DMA:

   - Release per-CPU pgmap ref when vm_insert_page() fails to avoid hang
     when removing the PCI device (Hou Tao)

   - Remove incorrect p2pmem_alloc_mmap() warning about page refcount
     (Hou Tao)

  Endpoint framework:

   - Add configfs sub-groups synchronously to avoid NULL pointer
     dereference when racing with removal (Liu Song)

   - Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink()
     functions (Manikanta Maddireddy)

  ASPEED PCIe controller driver:

   - Add ASPEED Root Complex DT binding and driver (Jacky Chou)

  Freescale i.MX6 PCIe controller driver:

   - Add DT binding and driver support for an optional external refclock
     in addition to the refclock from the internal PLL (Richard Zhu)

   - Fix CLKREQ# control so host asserts it during enumeration and
     Endpoints can use it afterwards to exit the L1.2 link state
     (Richard Zhu)

  NVIDIA Tegra PCIe controller driver:

   - Export irq_domain_free_irqs() to allow PCI/MSI drivers that tear
     down MSI domains to be built as modules (Aaron Kling)

   - Allow pci-tegra to be built as a module (Aaron Kling)

  NVIDIA Tegra194 PCIe controller driver:

   - Relax Kconfig so tegra194 can be built for platforms beyond
     Tegra194 (Vidya Sagar)

  Qualcomm PCIe controller driver:

   - Merge SC8180x DT binding into SM8150 (Krzysztof Kozlowski)

   - Move SDX55, SDM845, QCS404, IPQ5018, IPQ6018, IPQ8074 Gen3,
     IPQ8074, IPQ4019, IPQ9574, APQ8064, MSM8996, APQ8084 to dedicated
     schema (Krzysztof Kozlowski)

   - Add DT binding and driver support for SA8255p Endpoint being
     configured by firmware (Mrinmay Sarkar)

   - Parse PERST# from all PCIe bridge nodes for future platforms that
     will have PERST# in Switch Downstream Ports as well as in Root
     Ports (Manivannan Sadhasivam)

  Renesas RZ/G3S PCIe controller driver:

   - Use pci_generic_config_write() since the writability provided by
     the custom wrapper is unnecessary (Claudiu Beznea)

  SOPHGO PCIe controller driver:

   - Disable ASPM L0s and L1 on Sophgo 2044 PCIe Root Ports (Inochi
     Amaoto)

  Synopsys DesignWare PCIe controller driver:

   - Extend PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP() to return a
     pointer to the preceding Capability, to allow removal of
     Capabilities that are advertised but not fully implemented (Qiang
     Yu)

   - Remove MSI and MSI-X Capabilities in platforms that can't support
     them, so the PCI core automatically falls back to INTx (Qiang Yu)

   - Add ASPM L1.1 and L1.2 Substates context to debugfs ltssm_status
     for drivers that support this (Shawn Lin)

   - Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if
     link is not up to avoid an unnecessary timeout (Manivannan
     Sadhasivam)

   - Revert dw-rockchip, qcom, and DWC core changes that used link-up
     IRQs to trigger enumeration instead of waiting for link to be up
     because the PCI core doesn't allocate bus number space for
     hierarchies that might be attached (Niklas Cassel)

   - Make endpoint iATU entry for MSI permanent instead of programming
     it dynamically, which is slow and racy with respect to other
     concurrent traffic, e.g., eDMA (Koichiro Den)

   - Use iMSI-RX MSI target address when possible to fix endpoints using
     32-bit MSI (Shawn Lin)

   - Allow DWC host controller driver probe to continue if device is not
     found or found but inactive; only fail when there's an error with
     the link (Manivannan Sadhasivam)

   - For controllers like NXP i.MX6QP and i.MX7D, where LTSSM registers
     are not accessible after PME_Turn_Off, simply wait 10ms instead of
     polling for L2/L3 Ready (Richard Zhu)

   - Use multiple iATU entries to map large bridge windows and DMA
     ranges when necessary instead of failing (Samuel Holland)

   - Add EPC dynamic_inbound_mapping feature bit for Endpoint
     Controllers that can update BAR inbound address translation without
     requiring EPF driver to clear/reset the BAR first, and advertise it
     for DWC-based Endpoints (Koichiro Den)

   - Add EPC subrange_mapping feature bit for Endpoint Controllers that
     can map multiple independent inbound regions in a single BAR,
     implement subrange mapping, advertise it for DWC-based Endpoints,
     and add Endpoint selftests for it (Koichiro Den)

   - Make resizable BARs work for Endpoint multi-PF configurations;
     previously it only worked for PF 0 (Aksh Garg)

   - Fix Endpoint non-PF 0 support for BAR configuration, ATU mappings,
     and Address Match Mode (Aksh Garg)

   - Set up iATU when ECAM is enabled; previously IO and MEM outbound
     windows weren't programmed, and ECAM-related iATU entries weren't
     restored after suspend/resume, so config accesses failed (Krishna
     Chaitanya Chundru)

  Miscellaneous:

   - Use system_percpu_wq and WQ_PERCPU to explicitly request per-CPU
     work so WQ_UNBOUND can eventually be removed (Marco Crivellari)"

* tag 'pci-v7.0-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (176 commits)
  PCI/bwctrl: Disable BW controller on Intel P45 using a quirk
  PCI: Disable ACS SV for IDT 0x8090 switch
  PCI: Disable ACS SV for IDT 0x80b5 switch
  PCI: Cache ACS Capabilities register
  PCI: Enable ACS after configuring IOMMU for OF platforms
  PCI: Add ACS quirk for Pericom PI7C9X2G404 switches [12d8:b404]
  PCI: Add ACS quirk for Qualcomm Hamoa & Glymur
  PCI: Use device_lock_assert() to verify device lock is held
  PCI: Use lockdep_assert_held(pci_bus_sem) to verify lock is held
  PCI: Fix pci_slot_lock () device locking
  PCI: Fix pci_slot_trylock() error handling
  PCI: Mark Nvidia GB10 to avoid bus reset
  PCI: Mark ASM1164 SATA controller to avoid bus reset
  PCI: host-generic: Avoid reporting incorrect 'missing reg property' error
  PCI/PME: Replace RMW of Root Status register with direct write
  PCI/AER: Clear stale errors on reporting agents upon probe
  PCI: Don't claim disabled bridge windows
  PCI: rzg3s-host: Fix device node reference leak in rzg3s_pcie_host_parse_port()
  PCI: dwc: Fix missing iATU setup when ECAM is enabled
  PCI: dwc: Clean up iATU index usage in dw_pcie_iatu_setup()
  ...
2026-02-11 17:20:38 -08:00
Aaron Tomlin
6a80838814 tracing: Add show_event_triggers to expose active event triggers
To audit active event triggers, userspace currently must traverse the
events/ directory and read each individual trigger file. This is
cumbersome for system-wide auditing or debugging.

Introduce "show_event_triggers" at the trace root directory. This file
displays all events that currently have one or more triggers applied,
alongside the trigger configuration, in a consolidated
system:event [tab] trigger format.

The implementation leverages the existing trace_event_file iterators
and uses the trigger's own print() operation to ensure output
consistency with the per-event trigger files.

Link: https://patch.msgid.link/20260105142939.2655342-3-atomlin@atomlin.com
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-26 17:44:24 -05:00
Aaron Tomlin
729757b96a tracing: Add show_event_filters to expose active event filters
Currently, to audit active Ftrace event filters, userspace must
recursively traverse the events/ directory and read each individual
filter file. This is inefficient for monitoring tools and debugging.

Introduce "show_event_filters" at the trace root directory. This file
displays all events that currently have a filter applied, alongside the
actual filter string, in a consolidated system:event [tab] filter
format.

The implementation reuses the existing trace_event_file iterators to
ensure atomic traversal of the event list and utilises guard(rcu)() for
automatic, scope-based protection when accessing volatile filter
strings.

Link: https://patch.msgid.link/20260105142939.2655342-2-atomlin@atomlin.com
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-26 17:44:15 -05:00
Aaron Tomlin
2cddfc2e8f tracing: Add bitmask-list option for human-readable bitmask display
Add support for displaying bitmasks in human-readable list format (e.g.,
0,2-5,7) in addition to the default hexadecimal bitmap representation.
This is particularly useful when tracing CPU masks and other large
bitmasks where individual bit positions are more meaningful than their
hexadecimal encoding.

When the "bitmask-list" option is enabled, the printk "%*pbl" format
specifier is used to render bitmasks as comma-separated ranges, making
trace output easier to interpret for complex CPU configurations and
large bitmask values.

Link: https://patch.msgid.link/20251226160724.2246493-2-atomlin@atomlin.com
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-01-26 17:00:50 -05:00
Jani Nikula
a592a36e49 Documentation: use a source-read extension for the index link boilerplate
The root document usually has a special :ref:`genindex` link to the
generated index. This is also the case for Documentation/index.rst. The
other index.rst files deeper in the directory hierarchy usually don't.

For SPHINXDIRS builds, the root document isn't Documentation/index.rst,
but some other index.rst in the hierarchy. Currently they have a
".. only::" block to add the index link when doing SPHINXDIRS html
builds.

This is obviously very tedious and repetitive. The link is also added to
all index.rst files in the hierarchy for SPHINXDIRS builds, not just the
root document.

Put the boilerplate in a sphinx-includes/subproject-index.rst file, and
include it at the end of the root document for subproject builds in an
ad-hoc source-read extension defined in conf.py.

For now, keep having the boilerplate in translations, because this
approach currently doesn't cover translated index link headers.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
[jc: did s/doctree/kern_doc_dir/ ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260123143149.2024303-1-jani.nikula@intel.com>
2026-01-23 11:59:34 -07:00
Petr Vorel
a02857e734 Documentation/trace: Fix links to other documents
Link to another document does not require 'file:'. Removing it fixes
links in generated html docs.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260111223643.174812-2-pvorel@suse.cz>
2026-01-12 09:31:19 -07:00
Gabriele Monaco
e4a1e415eb Documentation/rv: Adapt documentation after da_monitor refactoring
Previous changes refactored the da_monitor header file to avoid using
macros. This implies a few changes in how to import and use da_monitor
helpers:

 DECLARE_DA_MON_<TYPE>(name, type) is substituted by
 #define RV_MON_TYPE RV_MON_<TYPE>

 da_handle_event_<name>() is substituted by
 da_handle_event()

Update the documentation to reflect the changes.

Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251126104241.291258-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-01-12 07:43:50 +01:00
Shuai Xue
8236fc613d Documentation: tracing: Add PCI tracepoint documentation
The PCI tracing system provides tracepoints to monitor critical hardware
events that can impact system performance and reliability. Add
documentation about it.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
[bhelgaas: squash fixes:
https://lore.kernel.org/r/20260108013956.14351-2-bagasdotme@gmail.com
https://lore.kernel.org/r/20260108013956.14351-3-bagasdotme@gmail.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20251210132907.58799-4-xueshuai@linux.alibaba.com
2026-01-08 10:06:19 -06:00
Soham Metha
7508b208f1 Documentation/rv: Fix dead link to monitor_synthesis.rst
The file 'da_monitor_synthesis.rst' was renamed to 'monitor_synthesis.rst' in
commit f40a7c0602
("Documentation/rv: Prepare monitor synthesis document for LTL inclusion").

Signed-off-by: Soham Metha <sohammetha01@gmail.com>
Fixes: f40a7c0602 ("Documentation/rv: Prepare monitor synthesis document for LTL inclusion")
Acked-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251204032452.9523-1-sohammetha01@gmail.com>
2025-12-22 15:30:26 -07:00
James Clark
19214ad0a4 coresight: docs: Document etm4x timestamp interval option
Document how the new field is used, maximum value and the interaction
with SYNC timestamps.

Tested-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20251128-james-cs-syncfreq-v8-13-4d319764cc58@linaro.org
2025-12-22 15:30:54 +00:00
Linus Torvalds
69c5079b49 Merge tag 'trace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:

 - Extend tracing option mask to 64 bits

   The trace options were defined by a 32 bit variable. This limits the
   tracing instances to have a total of 32 different options. As that
   limit has been hit, and more options are being added, increase the
   option mask to a 64 bit number, doubling the number of options
   available.

   As this is required for the kprobe topic branches as well as the
   tracing topic branch, a separate branch was created and merged into
   both.

 - Make trace_user_fault_read() available for the rest of tracing

   The function trace_user_fault_read() is used by trace_marker file
   read to allow reading user space to be done fast and without locking
   or allocations. Make this available so that the system call trace
   events can use it too.

 - Have system call trace events read user space values

   Now that the system call trace events callbacks are called in a
   faultable context, take advantage of this and read the user space
   buffers for various system calls. For example, show the path name of
   the openat system call instead of just showing the pointer to that
   path name in user space. Also show the contents of the buffer of the
   write system call. Several system call trace events are updated to
   make tracing into a light weight strace tool for all applications in
   the system.

 - Update perf system call tracing to do the same

 - And a config and syscall_user_buf_size file to control the size of
   the buffer

   Limit the amount of data that can be read from user space. The
   default size is 63 bytes but that can be expanded to 165 bytes.

 - Allow the persistent ring buffer to print system calls normally

   The persistent ring buffer prints trace events by their type and
   ignores the print_fmt. This is because the print_fmt may change from
   kernel to kernel. As the system call output is fixed by the system
   call ABI itself, there's no reason to limit that. This makes reading
   the system call events in the persistent ring buffer much nicer and
   easier to understand.

 - Add options to show text offset to function profiler

   The function profiler that counts the number of times a function is
   hit currently lists all functions by its name and offset. But this
   becomes ambiguous when there are several functions with the same
   name.

   Add a tracing option that changes the output to be that of
   '_text+offset' instead. Now a user space tool can use this
   information to map the '_text+offset' to the unique function it is
   counting.

 - Report bad dynamic event command

   If a bad command is passed to the dynamic_events file, report it
   properly in the error log.

 - Clean up tracer options

   Clean up the tracer option code a bit, by removing some useless code
   and also using switch statements instead of a series of if
   statements.

 - Have tracing options be instance specific

   Tracers can have their own options (function tracer, irqsoff tracer,
   function graph tracer, etc). But now that the same tracer can be
   enabled in multiple trace instances, their options are still global.
   The API is per instance, thus changing one affects other instances.
   This isn't even consistent, as the option take affect differently
   depending on when an tracer started in an instance. Make the options
   for instances only affect the instance it is changed under.

 - Optimize pid_list lock contention

   Whenever the pid_list is read, it uses a spin lock. This happens at
   every sched switch. Taking the lock at sched switch can be removed by
   instead using a seqlock counter.

 - Clean up the trace trigger structures

   The trigger code uses two different structures to implement a single
   tigger. This was due to trying to reuse code for the two different
   types of triggers (always on trigger, and count limited trigger). But
   by adding a single field to one structure, the other structure could
   be absorbed into the first structure making he code easier to
   understand.

 - Create a bulk garbage collector for trace triggers

   If user space has triggers for several hundreds of events and then
   removes them, it can take several seconds to complete. This is
   because each removal calls tracepoint_synchronize_unregister() that
   can take hundreds of milliseconds to complete.

   Instead, create a helper thread that will do the clean up. When a
   trigger is removed, it will create the kthread if it isn't already
   created, and then add the trigger to a llist. The kthread will take
   the items off the llist, call tracepoint_synchronize_unregister(),
   and then remove the items it took off. It will then check if there's
   more items to free before sleeping.

   This makes user space removing all these triggers to finish in less
   than a second.

 - Allow function tracing of some of the tracing infrastructure code

   Because the tracing code can cause recursion issues if it is traced
   by the function tracer the entire tracing directory disables function
   tracing. But not all of tracing causes issues if it is traced.
   Namely, the event tracing code. Add a config that enables some of the
   tracing code to be traced to help in debugging it. Note, when this is
   enabled, it does add noise to general function tracing, especially if
   events are enabled as well (which is a common case).

 - Add boot-time backup instance for persistent buffer

   The persistent ring buffer is used mostly for kernel crash analysis
   in the field. One issue is that if there's a crash, the data in the
   persistent ring buffer must be read before tracing can begin using
   it. This slows down the boot process. Once tracing starts in the
   persistent ring buffer, the old data must be freed and the addresses
   no longer match and old events can't be in the buffer with new
   events.

   Create a way to create a backup buffer that copies the persistent
   ring buffer at boot up. Then after a crash, the always on tracer can
   begin immediately as well as the normal boot process while the crash
   analysis tooling uses the backup buffer. After the backup buffer is
   finished being read, it can be removed.

 - Enable function graph args and return address options at the same
   time

   Currently the when reading of arguments in the function graph tracer
   is enabled, the option to record the parent function in the entry
   event can not be enabled. Update the code so that it can.

 - Add new struct_offset() helper macro

   Add a new macro that takes a pointer to a structure and a name of one
   of its members and it will return the offset of that member. This
   allows the ring buffer code to simplify the following:

   From:  size = struct_size(entry, buf, cnt - sizeof(entry->id));
     To:  size = struct_offset(entry, id) + cnt;

   There should be other simplifications that this macro can help out
   with as well

* tag 'trace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (42 commits)
  overflow: Introduce struct_offset() to get offset of member
  function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously
  tracing: Add boot-time backup of persistent ring buffer
  ftrace: Allow tracing of some of the tracing code
  tracing: Use strim() in trigger_process_regex() instead of skip_spaces()
  tracing: Add bulk garbage collection of freeing event_trigger_data
  tracing: Remove unneeded event_mutex lock in event_trigger_regex_release()
  tracing: Merge struct event_trigger_ops into struct event_command
  tracing: Remove get_trigger_ops() and add count_func() from trigger ops
  tracing: Show the tracer options in boot-time created instance
  ftrace: Avoid redundant initialization in register_ftrace_direct
  tracing: Remove unused variable in tracing_trace_options_show()
  fgraph: Make fgraph_no_sleep_time signed
  tracing: Convert function graph set_flags() to use a switch() statement
  tracing: Have function graph tracer option sleep-time be per instance
  tracing: Move graph-time out of function graph options
  tracing: Have function graph tracer option funcgraph-irqs be per instance
  trace/pid_list: optimize pid_list->lock contention
  tracing: Have function graph tracer define options per instance
  tracing: Have function tracer define options per instance
  ...
2025-12-05 09:51:37 -08:00
Tomas Glozar
b9f6a40dc3 Documentation/trace: Specify exact priority for timerlat
The timerlat tracer documentation mentions that threads are created with
real-time priority, but does not mention which priority and scheduling
class is used.

Add the information so that users do not have to look it up in
trace_osnoise.c.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251010083338.478961-9-tglozar@redhat.com>
2025-11-05 11:19:20 -07:00
Steven Rostedt
299ea67e6a tracing: Add a config and syscall_user_buf_size file to limit amount written
When a system call that can copy user space addresses into the ring
buffer, it can copy up to 511 bytes of data. This can waste precious ring
buffer space if the user isn't interested in the output. Add a new file
"syscall_user_buf_size" that gets initialized to a new config
CONFIG_SYSCALL_BUF_SIZE_DEFAULT that defaults to 63.

The config also is used to limit how much perf can read from user space.

Also lower the max down to 165, as this isn't to record everything that a
system call may be passing through to the kernel. 165 is more than enough.

The reason for 165 is because adding one for the nul terminating byte, as
well as possibly needing to append the "..." string turns it into 170
bytes. As this needs to save up to 3 arguments and 3 * 170 is 510 which
fits nicely in 512 bytes (a power of 2).

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/20251028231148.260068913@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-10-28 20:10:59 -04:00
Bagas Sanjaya
b8874ea3d0 Documentation: trace: histogram: Convert ftrace docs cross-reference
In brief "Extended error information" section, details on error
condition is referred to ftrace docs, which is written in :file:
directive instead of a proper cross-reference. Convert it.

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250916054202.582074-7-bagasdotme@gmail.com>
2025-09-18 11:49:26 -06:00
Bagas Sanjaya
fa06220f34 Documentation: trace: histogram-design: Wrap introductory note in note:: directive
Use Sphinx note:: directive for the introductory note at the beginning
of docs, instead of aligned-text paragraph that renders as definition
list.

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250916054202.582074-6-bagasdotme@gmail.com>
2025-09-18 11:49:26 -06:00
Bagas Sanjaya
8c716e87ea Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram
Section heading for sched_waking histogram is shown as normal paragraph
instead due to codeblock marker for the following diagram being in the
same line as the section underline. Separate them.

Fixes: daceabf1b4 ("tracing/doc: Fix ascii-art in histogram-design.rst")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250916054202.582074-5-bagasdotme@gmail.com>
2025-09-18 11:49:26 -06:00
Bagas Sanjaya
f867a298ac Documentation: trace: histogram-design: Trim trailing vertices in diagram explanation text
Diagram explanation text is supposed to be interleaved commentary
between diagram parts that are spread out, but it outputs ugly in
htmldocs due to trailing vertices as if both the explanation and the
diagram are in the same literal code block.

Trim trailing vertices.

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250916054202.582074-4-bagasdotme@gmail.com>
2025-09-18 11:49:26 -06:00
Bagas Sanjaya
348b7ca8d3 Documentation: trace: histogram: Fix histogram trigger subsection number order
Section numbering in subsections of "Histogram Trigger Command" sections
is inconsistent in order. In particular, "'hist' trigger examples" is
erroneously numbered as 6.2, which is a leftover from  b8df4a3634
("tracing: Move hist trigger Documentation to histogram.txt").

Fix the order.

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250916054202.582074-3-bagasdotme@gmail.com>
2025-09-18 11:49:26 -06:00
Ryan Chung
b65988af71 tracing: fix grammar error in debugging.rst
Signed-off-by: Ryan Chung <seokwoo.chung130@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250831101736.11519-3-seokwoo.chung130@gmail.com
2025-09-03 15:31:48 -06:00
Ryan Chung
d5958c8a09 tracing: rephrase for clearer documentation
Signed-off-by: Ryan Chung <seokwoo.chung130@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250831101736.11519-2-seokwoo.chung130@gmail.com
2025-09-03 15:31:30 -06:00
Mehdi Ben Hadj Khelifa
915fb5caad docs: Corrected typo in trace/events
-Changed 'Dyamically' to 'Dynamically' in trace/events.rst

under sections 7.1 and 7.3

Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250819085040.974388-1-mehdi.benhadjkhelifa@gmail.com
2025-08-21 11:59:11 -06:00
Jonathan Corbet
4e18a0b090 Merge branch 'bjorn' into docs-mw
A big set of typo fixes from Bjorn Helgaas
2025-08-18 10:40:16 -06:00
Bjorn Helgaas
29fe206065 Documentation: Fix trace typos
Fix typos.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250813200526.290420-9-helgaas@kernel.org
2025-08-18 10:31:20 -06:00
Gopi Krishna Menon
70d476b63a Documentation/rv: Fix minor typo in monitor_synthesis page
Specifically, fix spelling of "practice"

Signed-off-by: Gopi Krishna Menon <krishnagopi487@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250810111249.93181-1-krishnagopi487@gmail.com
2025-08-12 12:41:20 -06:00
Linus Torvalds
d6f38c1239 Merge tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:

 - Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing

   When tracefs was first introduced back in 2014, the directory
   /sys/kernel/tracing was added and is the designated location to mount
   tracefs. To keep backward compatibility, tracefs was auto-mounted in
   /sys/kernel/debug/tracing as well.

   All distros now mount tracefs on /sys/kernel/tracing. Having it seen
   in two different locations has lead to various issues and
   inconsistencies.

   The VFS folks have to also maintain debugfs_create_automount() for
   this single user.

   It's been over 10 years. Tooling and scripts should start replacing
   the debugfs location with the tracefs one. The reason tracefs was
   created in the first place was to allow access to the tracing
   facilities without the need to configure debugfs into the kernel.
   Using tracefs should now be more robust.

   A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED which is
   default y, so that the kernel is still built with the automount. This
   config allows those that want to remove the automount from debugfs to
   do so.

   When tracefs is accessed from /sys/kernel/debug/tracing, the
   following printk is triggerd:

     pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n");

   This gives users another 5 years to fix their scripts.

 - Use queue_rcu_work() instead of call_rcu() for freeing event filters

   The number of filters to be free can be many depending on the number
   of events within an event system. Freeing them from softirq context
   can potentially cause undesired latency. Use the RCU workqueue to
   free them instead.

 - Remove pointless memory barriers in latency code

   Memory barriers were added to some of the latency code a long time
   ago with the idea of "making them visible", but that's not what
   memory barriers are for. They are to synchronize access between
   different variables. There was no synchronization here making them
   pointless.

 - Remove "__attribute__()" from the type field of event format

   When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y
   and PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with
   the following:

     field:const char * filename;      offset:24;      size:8; signed:0;

   Turns into:

     field:const char __attribute__((btf_type_tag("user"))) * filename;      offset:24;      size:8; signed:0;

   This confuses parsers. Add code to strip these tags from the strings.

 - Add eprobe config option CONFIG_EPROBE_EVENTS

   Eprobes were added back in 5.15 but were only enabled when another
   probe was enabled (kprobe, fprobe, uprobe, etc). The eprobes had no
   config option of their own. Add one as they should be a separate
   entity.

   It's default y to keep with the old kernels but still has
   dependencies on TRACING and HAVE_REGS_AND_STACK_ACCESS_API.

 - Add eprobe documentation

   When eprobes were added back in 5.15 no documentation was added to
   describe them. This needs to be rectified.

 - Replace open coded cpumask_next_wrap() in move_to_next_cpu()

 - Have preemptirq_delay_run() use off-stack CPU mask

 - Remove obsolete comment about pelt_cfs event

   DECLARE_TRACE() appends "_tp" to trace events now, but the comment
   above pelt_cfs still mentioned appending it manually.

 - Remove EVENT_FILE_FL_SOFT_MODE flag

   The SOFT_MODE flag was required when the soft enabling and disabling
   of trace events was first introduced. But there was a bug with this
   approach as it only worked for a single instance. When multiple users
   required soft disabling and disabling the code was changed to have a
   ref count. The SOFT_MODE flag is now set iff the ref count is non
   zero. This is redundant and just reading the ref count is good
   enough.

 - Fix typo in comment

* tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add documentation about eprobes
  tracing: Have eprobes have their own config option
  tracing: Remove "__attribute__()" from the type field of event format
  tracing: Deprecate auto-mounting tracefs in debugfs
  tracing: Fix comment in trace_module_remove_events()
  tracing: Remove EVENT_FILE_FL_SOFT_MODE flag
  tracing: Remove pointless memory barriers
  tracing/sched: Remove obsolete comment on suffixes
  kernel: trace: preemptirq_delay_test: use offstack cpu mask
  tracing: Use queue_rcu_work() to free filters
  tracing: Replace opencoded cpumask_next_wrap() in move_to_next_cpu()
2025-08-01 10:29:36 -07:00
Linus Torvalds
b1cce98493 Merge tag 'docs-6.17' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It has been a relatively busy cycle for docs, especially the build
  system:

   - The Perl kernel-doc script was added to 2.3.52pre1 just after the
     turn of the millennium. Over the following 25 years, it accumulated
     a vast amount of cruft, all in a language few people want to deal
     with anymore. Mauro's Python replacement in 6.16 faithfully
     reproduced all of the cruft in the hope of avoiding regressions.

     Now that we have a more reasonable code base, though, we can work
     on cleaning it up; many of the changes this time around are toward
     that end.

   - A reorganization of the ext4 docs into the usual TOC format.

   - Various Chinese translations and updates.

   - A new script from Mauro to help with docs-build testing.

   - A new document for linked lists

   - A sweep through MAINTAINERS fixing broken GitHub git:// repository
     links.

  ...and lots of fixes and updates"

* tag 'docs-6.17' of git://git.lwn.net/linux: (147 commits)
  scripts: add origin commit identification based on specific patterns
  sphinx: kernel_abi: fix performance regression with O=<dir>
  Documentation: core-api: entry: Replace deprecated KVM entry/exit functions
  docs: fault-injection: drop reference to md-faulty
  docs: document linked lists
  scripts: kdoc: make it backward-compatible with Python 3.7
  docs: kernel-doc: emit warnings for ancient versions of Python
  Documentation/rtla: Describe exit status
  Documentation/rtla: Add include common_appendix.rst
  docs: kernel: Clarify printk_ratelimit_burst reset behavior
  Documentation: ioctl-number: Don't repeat macro names
  Documentation: ioctl-number: Shorten macros table
  Documentation: ioctl-number: Correct full path to papr-physical-attestation.h
  Documentation: ioctl-number: Extend "Include File" column width
  Documentation: ioctl-number: Fix linuxppc-dev mailto link
  overlayfs.rst: fix typos
  docs: kdoc: emit a warning for ancient versions of Python
  docs: kdoc: clean up check_sections()
  docs: kdoc: directly access the always-there KdocItem fields
  docs: kdoc: straighten up dump_declaration()
  ...
2025-07-31 08:36:51 -07:00
Linus Torvalds
4ff261e725 Merge tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verification updates from Steven Rostedt:

 - Added Linear temporal logic monitors for RT application

   Real-time applications may have design flaws causing them to have
   unexpected latency. For example, the applications may raise page
   faults, or may be blocked trying to take a mutex without priority
   inheritance.

   However, while attempting to implement DA monitors for these
   real-time rules, deterministic automaton is found to be inappropriate
   as the specification language. The automaton is complicated, hard to
   understand, and error-prone.

   For these cases, linear temporal logic is found to be more suitable.
   The LTL is more concise and intuitive.

 - Make printk_deferred() public

   The new monitors needed access to printk_deferred(). Make them
   visible for the entire kernel.

 - Add a vpanic() to allow for va_list to be passed to panic.

 - Add rtapp container monitor.

   A collection of monitors that check for common problems with
   real-time applications that cause unexpected latency.

 - Add page fault tracepoints to risc-v

   These tracepoints are necessary to for the RV monitor to run on
   risc-v.

 - Fix the behaviour of the rv tool with -s and idle tasks.

 - Allow the rv tool to gracefully terminate with SIGTERM

 - Adjusts dot2c not to create lines over 100 columns

 - Properly order nested monitors in the RV Kconfig file

 - Return the registration error in all DA monitor instead of 0

 - Update and add new sched collection monitors

   Replace tss and sncid monitors with more complete sts:

   Not only prove that switches occur in scheduling context and scheduling
   needs interrupt disabled but also that each call to the scheduler
   disables interrupts to (optionally) switch.

   New monitor: nrp
     Preemption requires need resched which is cleared by any switch
     (includes a non optimal workaround for /nested/ preemptions)

   New monitor: sssw
     suspension requires setting the task to sleepable and, after the
     switch occurs, the task requires a wakeup to come back to runnable

   New monitor: opid
      waking and need-resched operations occur with interrupts and
      preemption disabled or in IRQ without explicitly disabling
      preemption"

* tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits)
  rv: Add opid per-cpu monitor
  rv: Add nrp and sssw per-task monitors
  rv: Replace tss and sncid monitors with more complete sts
  sched: Adapt sched tracepoints for RV task model
  rv: Retry when da monitor detects race conditions
  rv: Adjust monitor dependencies
  rv: Use strings in da monitors tracepoints
  rv: Remove trailing whitespace from tracepoint string
  rv: Add da_handle_start_run_event_ to per-task monitors
  rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()
  rv: Fix wrong type cast in monitors_show()
  rv: Remove struct rv_monitor::reacting
  rv: Remove rv_reactor's reference counter
  rv: Merge struct rv_reactor_def into struct rv_reactor
  rv: Merge struct rv_monitor_def into struct rv_monitor
  rv: Remove unused field in struct rv_monitor_def
  rv: Return init error when registering monitors
  verification/rvgen: Organise Kconfig entries for nested monitors
  tools/dot2c: Fix generated files going over 100 column limit
  tools/rv: Stop gracefully also on SIGTERM
  ...
2025-07-30 16:23:12 -07:00
Steven Rostedt
623526ba89 Documentation: tracing: Add documentation about eprobes
Eprobes was added back in 5.15, but was never documented. It became a
"secret" interface even though it has been a topic of several
presentations. For some reason, when eprobes was added, documenting it
never became a priority, until now.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/20250730140945.528135548@kernel.org
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-30 10:38:43 -04:00
Gabriele Monaco
614384533d rv: Add opid per-cpu monitor
Add a per-cpu monitor as part of the sched model:
* opid: operations with preemption and irq disabled
    Monitor to ensure wakeup and need_resched occur with irq and
    preemption disabled or in irq handlers.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-10-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Nam Cao <namcao@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28 16:47:35 -04:00
Gabriele Monaco
e8440a88e5 rv: Add nrp and sssw per-task monitors
Add 2 per-task monitors as part of the sched model:

* nrp: need-resched preempts
    Monitor to ensure preemption requires need resched.
* sssw: set state sleep and wakeup
    Monitor to ensure sched_set_state to sleepable leads to sleeping and
    sleeping tasks require wakeup.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250728135022.255578-9-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Nam Cao <namcao@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28 16:47:34 -04:00
Gabriele Monaco
d0096c2f9c rv: Replace tss and sncid monitors with more complete sts
The tss monitor currently guarantees task switches can happen only while
scheduling, whereas the sncid monitor enforces scheduling occurs with
interrupt disabled.

Replace the monitors with a more comprehensive specification which
implies both but also ensures that:
* each scheduler call disable interrupts to switch
* each task switch happens with interrupts disabled

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250728135022.255578-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-28 16:47:34 -04:00
Nam Cao
8cfcf9b0e9 verification/rvgen: Support the 'next' operator
The 'next' operator is a unary operator. It is defined as: "next time, the
operand must be true".

Support this operator. For RV monitors, "next time" means the next
invocation of ltl_validate().

Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/9c32cec04dd18d2e956fddd84b0e0a2503daa75a.1752239482.git.namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Tested-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24 10:43:23 -04:00
Nam Cao
e93648e862 Documentation/rv: Add documentation for linear temporal logic monitors
Add documents describing linear temporal logic runtime verification
monitors and how to generate them using rvgen.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/be13719e66fd8da147d7c69d5365aa23c52b743f.1751634289.git.namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24 10:42:47 -04:00
Nam Cao
f40a7c0602 Documentation/rv: Prepare monitor synthesis document for LTL inclusion
Monitor synthesis from deterministic automaton and linear temporal logic
have a lot in common. Therefore a single document should describe both.

Change da_monitor_synthesis.rst to monitor_synthesis.rst. LTL monitor
synthesis will be added to this file by a follow-up commit.

This makes the diff far easier to read. If renaming and adding LTL info is
done in a single commit, git wouldn't recognize it as a rename, but a file
removal and a file addition.

While at it, correct the old dot2k commands to the new rvgen commands.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/d91c6e4600287f4732d68a014219e576a75ce6dc.1751634289.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-24 10:42:46 -04:00
Steven Rostedt
4d6d0a6263 tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
Ftrace is tightly coupled with architecture specific code because it
requires the use of trampolines written in assembly. This means that when
a new feature or optimization is made, it must be done for all
architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are
added to denote which architecture has the new enhancement so that other
architectures can still function until they too have been updated.

The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.

Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where
applicable.

Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-22 20:15:56 -04:00
Nam Cao
670ff946b9 rv: Add documentation for rtapp monitor
Add documentation describing the rtapp monitor.

Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/df0242d74c12511e82cc9d73c082def91a160c74.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-09 15:27:02 -04:00