linux-stable.git/kernel/trace/Makefile, branch master

tracing: Move pid filtering into trace_pid.c

2026-02-09T02:01:13+00:00

The trace.c file was a dumping ground for most tracing code. Start
organizing it better by moving various functions out into their own files.
Move the PID filtering functions from trace.c into its own trace_pid.c
file.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20260208032450.998330662@kernel.org
Signed-off-by: Steven Rostedt (Google)

ftrace: Allow tracing of some of the tracing code

2025-11-26T20:13:30+00:00

There is times when tracing the tracing infrastructure can be useful for
debugging the tracing code. Currently all files in the tracing directory
are set to "notrace" the functions.

Add a new config option FUNCTION_SELF_TRACING that will allow some of the
files in the tracing infrastructure to be traced. It requires a config to
enable because it will add noise to the function tracer if events and
other tracing features are enabled. Tracing functions and events together
is quite common, so not tracing the event code should be the default.

Cc: Masami Hiramatsu 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Cc: Mark Rutland 
Cc: Tom Zanussi 
Link: https://patch.msgid.link/20251120181514.736f2d5f@gandalf.local.home
Signed-off-by: Steven Rostedt (Google)

tracing: Have eprobes have their own config option

2025-07-30T14:38:43+00:00

Eprobes were added in 5.15 and were selected whenever any of the other
probe events were selected. If kprobe events were enabled (which it is by
default if kprobes are enabled) it would enable eprobe events as well. The
same for uprobes and fprobes.

Have eprobes have its own config and it gets enabled by default if tracing
is enabled.

Link: https://lore.kernel.org/all/20250729102636.b7cce553e7cc263722b12365@kernel.org/

Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Cc: Namhyung Kim 
Cc: Jonathan Corbet 
Cc: Randy Dunlap 
Link: https://lore.kernel.org/20250730140945.360286733@kernel.org
Suggested-by: Masami Hiramatsu (Google) 
Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Steven Rostedt (Google)

tracing/probes: Move finding func-proto API and getting func-param API to trace_btf

2023-08-23T00:39:45+00:00

Move generic function-proto find API and getting function parameter API
to BTF library code from trace_probe.c. This will avoid redundant efforts
on different feature.

Link: https://lore.kernel.org/all/169272155255.160970.719426926348706349.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) 
Acked-by: Steven Rostedt (Google)

tracing/probes: Add fprobe events for tracing function entry and exit.

2023-06-06T12:39:55+00:00

Add fprobe events for tracing function entry and exit instead of kprobe
events. With this change, we can continue to trace function entry/exit
even if the CONFIG_KPROBES_ON_FTRACE is not available. Since
CONFIG_KPROBES_ON_FTRACE requires the CONFIG_DYNAMIC_FTRACE_WITH_REGS,
it is not available if the architecture only supports
CONFIG_DYNAMIC_FTRACE_WITH_ARGS. And that means kprobe events can not
probe function entry/exit effectively on such architecture.
But this can be solved if the dynamic events supports fprobe events.

The fprobe event is a new dynamic events which is only for the function
(symbol) entry and exit. This event accepts non register fetch arguments
so that user can trace the function arguments and return values.

The fprobe events syntax is here;

 f[:[GRP/][EVENT]] FUNCTION [FETCHARGS]
 f[MAXACTIVE][:[GRP/][EVENT]] FUNCTION%return [FETCHARGS]

E.g.

 # echo 'f vfs_read $arg1'  >> dynamic_events
 # echo 'f vfs_read%return $retval'  >> dynamic_events
 # cat dynamic_events
 f:fprobes/vfs_read__entry vfs_read arg1=$arg1
 f:fprobes/vfs_read__exit vfs_read%return arg1=$retval
 # echo 1 > events/fprobes/enable
 # head -n 20 trace | tail
 #           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
 #              | |         |   |||||     |         |
              sh-142     [005] ...1.   448.386420: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386436: vfs_read__exit: (ksys_read+0x75/0x100 <- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.386451: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386458: vfs_read__exit: (ksys_read+0x75/0x100 <- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.386469: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386476: vfs_read__exit: (ksys_read+0x75/0x100 <- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.602073: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.602089: vfs_read__exit: (ksys_read+0x75/0x100 <- vfs_read) arg1=0x1

Link: https://lore.kernel.org/all/168507469754.913472.6112857614708350210.stgit@mhiramat.roam.corp.google.com/

Reported-by: kernel test robot 
Link: https://lore.kernel.org/all/202302011530.7vm4O8Ro-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google)

rv: Add Runtime Verification (RV) interface

2022-07-30T18:01:28+00:00

RV is a lightweight (yet rigorous) method that complements classical
exhaustive verification techniques (such as model checking and
theorem proving) with a more practical approach to complex systems.

RV works by analyzing the trace of the system's actual execution,
comparing it against a formal specification of the system behavior.
RV can give precise information on the runtime behavior of the
monitored system while enabling the reaction for unexpected
events, avoiding, for example, the propagation of a failure on
safety-critical systems.

The development of this interface roots in the development of the
paper:

De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.

And:

De Oliveira, Daniel Bristot. Automata-based formal analysis
and verification of the real-time Linux kernel. PhD Thesis, 2020.

The RV interface resembles the tracing/ interface on purpose. The current
path for the RV interface is /sys/kernel/tracing/rv/.

It presents these files:

 "available_monitors"
   - List the available monitors, one per line.

   For example:
     # cat available_monitors
     wip
     wwnr

 "enabled_monitors"
   - Lists the enabled monitors, one per line;
   - Writing to it enables a given monitor;
   - Writing a monitor name with a '!' prefix disables it;
   - Truncating the file disables all enabled monitors.

   For example:
     # cat enabled_monitors
     # echo wip > enabled_monitors
     # echo wwnr >> enabled_monitors
     # cat enabled_monitors
     wip
     wwnr
     # echo '!wip' >> enabled_monitors
     # cat enabled_monitors
     wwnr
     # echo > enabled_monitors
     # cat enabled_monitors
     #

   Note that more than one monitor can be enabled concurrently.

 "monitoring_on"
   - It is an on/off general switcher for monitoring. Note
   that it does not disable enabled monitors or detach events,
   but stop the per-entity monitors of monitoring the events
   received from the system. It resembles the "tracing_on" switcher.

 "monitors/"
   Each monitor will have its one directory inside "monitors/". There
   the monitor specific files will be presented.
   The "monitors/" directory resembles the "events" directory on
   tracefs.

   For example:
     # cd monitors/wip/
     # ls
     desc  enable
     # cat desc
     wakeup in preemptive per-cpu testing monitor.
     # cat enable
     0

For further information, see the comments in the header of
kernel/trace/rv/rv.c from this patch.

Link: https://lkml.kernel.org/r/a4bfe038f50cb047bfb343ad0e12b0e646ab308b.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck 
Cc: Guenter Roeck 
Cc: Jonathan Corbet 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Cc: Catalin Marinas 
Cc: Marco Elver 
Cc: Dmitry Vyukov 
Cc: "Paul E. McKenney" 
Cc: Shuah Khan 
Cc: Gabriele Paoloni 
Cc: Juri Lelli 
Cc: Clark Williams 
Cc: Tao Zhou 
Cc: Randy Dunlap 
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira 
Signed-off-by: Steven Rostedt (Google)

tracing: Disable kcov on trace_preemptirq.c

2022-05-27T01:13:00+00:00

Functions in trace_preemptirq.c could be invoked from early interrupt
code that bypasses kcov trace function's in_task() check. Disable kcov
on this file to reduce random code coverage.

Link: https://lkml.kernel.org/r/20220523063033.1778974-1-liu3101@purdue.edu

Acked-by: Dmitry Vyukov 
Signed-off-by: Congyu Liu 
Signed-off-by: Steven Rostedt (Google)

Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2022-03-24T20:13:26+00:00

Pull networking updates from Jakub Kicinski:
"The sprinkling of SPI drivers is because we added a new one and Mark
sent us a SPI driver interface conversion pull request.

Core
----

- Introduce XDP multi-buffer support, allowing the use of XDP with
jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

- Speed up netns dismantling (5x) and lower the memory cost a little.
Remove unnecessary per-netns sockets. Scope some lists to a netns.
Cut down RCU syncing. Use batch methods. Allow netdev registration
to complete out of order.

- Support distinguishing timestamp types (ingress vs egress) and
maintaining them across packet scrubbing points (e.g. redirect).

- Continue the work of annotating packet drop reasons throughout the
stack.

- Switch netdev error counters from an atomic to dynamically
allocated per-CPU counters.

- Rework a few preempt_disable(), local_irq_save() and busy waiting
sections problematic on PREEMPT_RT.

- Extend the ref_tracker to allow catching use-after-free bugs.

BPF
---

- Introduce "packing allocator" for BPF JIT images. JITed code is
marked read only, and used to be allocated at page granularity.
Custom allocator allows for more efficient memory use, lower iTLB
pressure and prevents identity mapping huge pages from getting
split.

- Make use of BTF type annotations (e.g. __user, __percpu) to enforce
the correct probe read access method, add appropriate helpers.

- Convert the BPF preload to use light skeleton and drop the
user-mode-driver dependency.

- Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
its use as a packet generator.

- Allow local storage memory to be allocated with GFP_KERNEL if
called from a hook allowed to sleep.

- Introduce fprobe (multi kprobe) to speed up mass attachment (arch
bits to come later).

- Add unstable conntrack lookup helpers for BPF by using the BPF
kfunc infra.

- Allow cgroup BPF progs to return custom errors to user space.

- Add support for AF_UNIX iterator batching.

- Allow iterator programs to use sleepable helpers.

- Support JIT of add, and, or, xor and xchg atomic ops on arm64.

- Add BTFGen support to bpftool which allows to use CO-RE in kernels
without BTF info.

- Large number of libbpf API improvements, cleanups and deprecations.

Protocols
---------

- Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

- Adjust TSO packet sizes based on min_rtt, allowing very low latency
links (data centers) to always send full-sized TSO super-frames.

- Make IPv6 flow label changes (AKA hash rethink) more configurable,
via sysctl and setsockopt. Distinguish between server and client
behavior.

- VxLAN support to "collect metadata" devices to terminate only
configured VNIs. This is similar to VLAN filtering in the bridge.

- Support inserting IPv6 IOAM information to a fraction of frames.

- Add protocol attribute to IP addresses to allow identifying where
given address comes from (kernel-generated, DHCP etc.)

- Support setting socket and IPv6 options via cmsg on ping6 sockets.

- Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
Define dscp_t and stop taking ECN bits into account in fib-rules.

- Add support for locked bridge ports (for 802.1X).

- tun: support NAPI for packets received from batched XDP buffs,
doubling the performance in some scenarios.

- IPv6 extension header handling in Open vSwitch.

- Support IPv6 control message load balancing in bonding, prevent
neighbor solicitation and advertisement from using the wrong port.
Support NS/NA monitor selection similar to existing ARP monitor.

- SMC
- improve performance with TCP_CORK and sendfile()
- support auto-corking
- support TCP_NODELAY

- MCTP (Management Component Transport Protocol)
- add user space tag control interface
- I2C binding driver (as specified by DMTF DSP0237)

- Multi-BSSID beacon handling in AP mode for WiFi.

- Bluetooth:
- handle MSFT Monitor Device Event
- add MGMT Adv Monitor Device Found/Lost events

- Multi-Path TCP:
- add support for the SO_SNDTIMEO socket option
- lots of selftest cleanups and improvements

- Increase the max PDU size in CAN ISOTP to 64 kB.

Driver API
----------

- Add HW counters for SW netdevs, a mechanism for devices which
offload packet forwarding to report packet statistics back to
software interfaces such as tunnels.

- Select the default NIC queue count as a fraction of number of
physical CPU cores, instead of hard-coding to 8.

- Expose devlink instance locks to drivers. Allow device layer of
drivers to use that lock directly instead of creating their own
which always runs into ordering issues in devlink callbacks.

- Add header/data split indication to guide user space enabling of
TCP zero-copy Rx.

- Allow configuring completion queue event size.

- Refactor page_pool to enable fragmenting after allocation.

- Add allocation and page reuse statistics to page_pool.

- Improve Multiple Spanning Trees support in the bridge to allow
reuse of topologies across VLANs, saving HW resources in switches.

- DSA (Distributed Switch Architecture):
- replay and offload of host VLAN entries
- offload of static and local FDB entries on LAG interfaces
- FDB isolation and unicast filtering

New hardware / drivers
----------------------

- Ethernet:
- LAN937x T1 PHYs
- Davicom DM9051 SPI NIC driver
- Realtek RTL8367S, RTL8367RB-VB switch and MDIO
- Microchip ksz8563 switches
- Netronome NFP3800 SmartNICs
- Fungible SmartNICs
- MediaTek MT8195 switches

- WiFi:
- mt76: MediaTek mt7916
- mt76: MediaTek mt7921u USB adapters
- brcmfmac: Broadcom BCM43454/6

- Mobile:
- iosm: Intel M.2 7360 WWAN card

Drivers
-------

- Convert many drivers to the new phylink API built for split PCS
designs but also simplifying other cases.

- Intel Ethernet NICs:
- add TTY for GNSS module for E810T device
- improve AF_XDP performance
- GTP-C and GTP-U filter offload
- QinQ VLAN support

- Mellanox Ethernet NICs (mlx5):
- support xdp->data_meta
- multi-buffer XDP
- offload tc push_eth and pop_eth actions

- Netronome Ethernet NICs (nfp):
- flow-independent tc action hardware offload (police / meter)
- AF_XDP

- Other Ethernet NICs:
- at803x: fiber and SFP support
- xgmac: mdio: preamble suppression and custom MDC frequencies
- r8169: enable ASPM L1.2 if system vendor flags it as safe
- macb/gem: ZynqMP SGMII
- hns3: add TX push mode
- dpaa2-eth: software TSO
- lan743x: multi-queue, mdio, SGMII, PTP
- axienet: NAPI and GRO support

- Mellanox Ethernet switches (mlxsw):
- source and dest IP address rewrites
- RJ45 ports

- Marvell Ethernet switches (prestera):
- basic routing offload
- multi-chain TC ACL offload

- NXP embedded Ethernet switches (ocelot & felix):
- PTP over UDP with the ocelot-8021q DSA tagging protocol
- basic QoS classification on Felix DSA switch using dcbnl
- port mirroring for ocelot switches

- Microchip high-speed industrial Ethernet (sparx5):
- offloading of bridge port flooding flags
- PTP Hardware Clock

- Other embedded switches:
- lan966x: PTP Hardward Clock
- qca8k: mdio read/write operations via crafted Ethernet packets

- Qualcomm 802.11ax WiFi (ath11k):
- add LDPC FEC type and 802.11ax High Efficiency data in radiotap
- enable RX PPDU stats in monitor co-exist mode

- Intel WiFi (iwlwifi):
- UHB TAS enablement via BIOS
- band disablement via BIOS
- channel switch offload
- 32 Rx AMPDU sessions in newer devices

- MediaTek WiFi (mt76):
- background radar detection
- thermal management improvements on mt7915
- SAR support for more mt76 platforms
- MBSSID and 6 GHz band on mt7915

- RealTek WiFi:
- rtw89: AP mode
- rtw89: 160 MHz channels and 6 GHz band
- rtw89: hardware scan

- Bluetooth:
- mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

- Microchip CAN (mcp251xfd):
- multiple RX-FIFOs and runtime configurable RX/TX rings
- internal PLL, runtime PM handling simplification
- improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
llc: fix netdevice reference leaks in llc_ui_bind()
drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
ice: don't allow to run ice_send_event_to_aux() in atomic ctx
ice: fix 'scheduling while atomic' on aux critical err interrupt
net/sched: fix incorrect vlan_push_eth dest field
net: bridge: mst: Restrict info size queries to bridge ports
net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
drivers: net: xgene: Fix regression in CRC stripping
net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
net: dsa: fix missing host-filtered multicast addresses
net/mlx5e: Fix build warning, detected write beyond size of field
iwlwifi: mvm: Don't fail if PPAG isn't supported
selftests/bpf: Fix kprobe_multi test.
Revert "rethook: x86: Add rethook x86 implementation"
Revert "arm64: rethook: Add arm64 rethook implementation"
Revert "powerpc: Add rethook support"
Revert "ARM: rethook: Add rethook arm implementation"
netdevice: add missing dm_private kdoc
net: bridge: mst: prevent NULL deref in br_mst_info_size()
selftests: forwarding: Use same VRF for port and VLAN upper
...

rethook: Add a generic return hook

2022-03-18T03:16:29+00:00

Add a return hook framework which hooks the function return. Most of the
logic came from the kretprobe, but this is independent from kretprobe.

Note that this is expected to be used with other function entry hooking
feature, like ftrace, fprobe, adn kprobes. Eventually this will replace
the kretprobe (e.g. kprobe + rethook = kretprobe), but at this moment,
this is just an additional hook.

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (Google) 
Tested-by: Steven Rostedt (Google) 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/164735285066.1084943.9259661137330166643.stgit@devnote2

fprobe: Add ftrace based probe APIs

2022-03-18T03:16:15+00:00

The fprobe is a wrapper API for ftrace function tracer.
Unlike kprobes, this probes only supports the function entry, but this
can probe multiple functions by one fprobe. The usage is similar, user
will set their callback to fprobe::entry_handler and call
register_fprobe*() with probed functions.
There are 3 registration interfaces,

 - register_fprobe() takes filtering patterns of the functin names.
 - register_fprobe_ips() takes an array of ftrace-location addresses.
 - register_fprobe_syms() takes an array of function names.

The registered fprobes can be unregistered with unregister_fprobe().
e.g.

struct fprobe fp = { .entry_handler = user_handler };
const char *targets[] = { "func1", "func2", "func3"};
...

ret = register_fprobe_syms(&fp, targets, ARRAY_SIZE(targets));

...

unregister_fprobe(&fp);

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (Google) 
Tested-by: Steven Rostedt (Google) 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/164735283857.1084943.1154436951479395551.stgit@devnote2