History log of /linux/kernel/trace/Kconfig (Results 1 – 25 of 1716)
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# c17ee635 23-Feb-2026 Maxime Ripard <mripard@kernel.org>

Merge drm/drm-fixes into drm-misc-fixes

7.0-rc1 was just released, let's merge it to kick the new release cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


Revision tags: v7.0-rc1
# 3c6e577d 14-Feb-2026 Linus Torvalds <torvalds@linux-foundation.org>

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 f

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()
...

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# f17b474e 10-Feb-2026 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

- Support associating BPF program with struct_ops (Amery Hung)

-

Merge tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

- Support associating BPF program with struct_ops (Amery Hung)

- Switch BPF local storage to rqspinlock and remove recursion detection
counters which were causing false positives (Amery Hung)

- Fix live registers marking for indirect jumps (Anton Protopopov)

- Introduce execution context detection BPF helpers (Changwoo Min)

- Improve verifier precision for 32bit sign extension pattern
(Cupertino Miranda)

- Optimize BTF type lookup by sorting vmlinux BTF and doing binary
search (Donglin Peng)

- Allow states pruning for misc/invalid slots in iterator loops (Eduard
Zingerman)

- In preparation for ASAN support in BPF arenas teach libbpf to move
global BPF variables to the end of the region and enable arena kfuncs
while holding locks (Emil Tsalapatis)

- Introduce support for implicit arguments in kfuncs and migrate a
number of them to new API. This is a prerequisite for cgroup
sub-schedulers in sched-ext (Ihor Solodrai)

- Fix incorrect copied_seq calculation in sockmap (Jiayuan Chen)

- Fix ORC stack unwind from kprobe_multi (Jiri Olsa)

- Speed up fentry attach by using single ftrace direct ops in BPF
trampolines (Jiri Olsa)

- Require frozen map for calculating map hash (KP Singh)

- Fix lock entry creation in TAS fallback in rqspinlock (Kumar
Kartikeya Dwivedi)

- Allow user space to select cpu in lookup/update operations on per-cpu
array and hash maps (Leon Hwang)

- Make kfuncs return trusted pointers by default (Matt Bobrowski)

- Introduce "fsession" support where single BPF program is executed
upon entry and exit from traced kernel function (Menglong Dong)

- Allow bpf_timer and bpf_wq use in all programs types (Mykyta
Yatsenko, Andrii Nakryiko, Kumar Kartikeya Dwivedi, Alexei
Starovoitov)

- Make KF_TRUSTED_ARGS the default for all kfuncs and clean up their
definition across the tree (Puranjay Mohan)

- Allow BPF arena calls from non-sleepable context (Puranjay Mohan)

- Improve register id comparison logic in the verifier and extend
linked registers with negative offsets (Puranjay Mohan)

- In preparation for BPF-OOM introduce kfuncs to access memcg events
(Roman Gushchin)

- Use CFI compatible destructor kfunc type (Sami Tolvanen)

- Add bitwise tracking for BPF_END in the verifier (Tianci Cao)

- Add range tracking for BPF_DIV and BPF_MOD in the verifier (Yazhou
Tang)

- Make BPF selftests work with 64k page size (Yonghong Song)

* tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (268 commits)
selftests/bpf: Fix outdated test on storage->smap
selftests/bpf: Choose another percpu variable in bpf for btf_dump test
selftests/bpf: Remove test_task_storage_map_stress_lookup
selftests/bpf: Update task_local_storage/task_storage_nodeadlock test
selftests/bpf: Update task_local_storage/recursion test
selftests/bpf: Update sk_storage_omem_uncharge test
bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy}
bpf: Support lockless unlink when freeing map or local storage
bpf: Prepare for bpf_selem_unlink_nofail()
bpf: Remove unused percpu counter from bpf_local_storage_map_free
bpf: Remove cgroup local storage percpu counter
bpf: Remove task local storage percpu counter
bpf: Change local_storage->lock and b->lock to rqspinlock
bpf: Convert bpf_selem_unlink to failable
bpf: Convert bpf_selem_link_map to failable
bpf: Convert bpf_selem_unlink_map to failable
bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage
selftests/xsk: fix number of Tx frags in invalid packet
selftests/xsk: properly handle batch ending in the middle of a packet
bpf: Prevent reentrance into call_rcu_tasks_trace()
...

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# ec496f77 09-Feb-2026 Jiri Kosina <jkosina@suse.com>

Merge branch 'for-6.20/sony' into for-linus

- Support for Rock band 4 PS4 and PS5 guitars (Rosalie Wanders)


Revision tags: v6.19
# c4f1fe47 08-Feb-2026 Steven Rostedt <rostedt@goodmis.org>

tracing: Better separate SNAPSHOT and MAX_TRACE options

The latency tracers (scheduler, irqsoff, etc) were created when tracing
was first added. These tracers required a "snapshot" buffer that was t

tracing: Better separate SNAPSHOT and MAX_TRACE options

The latency tracers (scheduler, irqsoff, etc) were created when tracing
was first added. These tracers required a "snapshot" buffer that was the
same size as the ring buffer being written to. When a new max latency was
hit, the main ring buffer would swap with the snapshot buffer so that the
trace leading up to the latency would be saved in the snapshot buffer (The
snapshot buffer is never written to directly and the data within it can be
viewed without fear of being overwritten).

Later, a new feature was added to allow snapshots to be taken by user
space or even event triggers. This created a "snapshot" file that allowed
users to trigger a snapshot from user space to save the current trace.

The config for this new feature (CONFIG_TRACER_SNAPSHOT) would select the
latency tracer config (CONFIG_TRACER_MAX_LATENCY) as it would need all the
functionality from it as it already existed. But this was incorrect. As
the snapshot feature is really what the latency tracers need and not the
other way around.

Have CONFIG_TRACER_MAX_TRACE select CONFIG_TRACER_SNAPSHOT where the
tracers that needs the max latency buffer selects the TRACE_MAX_TRACE
which will then select TRACER_SNAPSHOT.

Also, go through trace.c and trace.h and make the code that only needs the
TRACER_MAX_TRACE protected by that and the code that always requires the
snapshot to be protected by TRACER_SNAPSHOT.

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>
Link: https://patch.msgid.link/20260208183856.767870992@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...


Revision tags: v6.19-rc8
# ba225407 28-Jan-2026 Andrii Nakryiko <andrii@kernel.org>

Merge branch 'ftrace-bpf-use-single-direct-ops-for-bpf-trampolines'

Jiri Olsa says:

====================
ftrace,bpf: Use single direct ops for bpf trampolines

hi,
while poking the multi-tracing in

Merge branch 'ftrace-bpf-use-single-direct-ops-for-bpf-trampolines'

Jiri Olsa says:

====================
ftrace,bpf: Use single direct ops for bpf trampolines

hi,
while poking the multi-tracing interface I ended up with just one ftrace_ops
object to attach all trampolines.

This change allows to use less direct API calls during the attachment changes
in the future code, so in effect speeding up the attachment.

In current code we get a speed up from using just a single ftrace_ops object.

- with current code:

Performance counter stats for 'bpftrace -e fentry:vmlinux:ksys_* {} -c true':

6,364,157,902 cycles:k
828,728,902 cycles:u
1,064,803,824 instructions:u # 1.28 insn per cycle
23,797,500,067 instructions:k # 3.74 insn per cycle

4.416004987 seconds time elapsed

0.164121000 seconds user
1.289550000 seconds sys

- with the fix:

Performance counter stats for 'bpftrace -e fentry:vmlinux:ksys_* {} -c true':

6,535,857,905 cycles:k
810,809,429 cycles:u
1,064,594,027 instructions:u # 1.31 insn per cycle
23,962,552,894 instructions:k # 3.67 insn per cycle

1.666961239 seconds time elapsed

0.157412000 seconds user
1.283396000 seconds sys

The speedup seems to be related to the fact that with single ftrace_ops object
we don't call ftrace_shutdown anymore (we use ftrace_update_ops instead) and
we skip the synchronize rcu calls (each ~100ms) at the end of that function.

rfc: https://lore.kernel.org/bpf/20250729102813.1531457-1-jolsa@kernel.org/
v1: https://lore.kernel.org/bpf/20250923215147.1571952-1-jolsa@kernel.org/
v2: https://lore.kernel.org/bpf/20251113123750.2507435-1-jolsa@kernel.org/
v3: https://lore.kernel.org/bpf/20251120212402.466524-1-jolsa@kernel.org/
v4: https://lore.kernel.org/bpf/20251203082402.78816-1-jolsa@kernel.org/
v5: https://lore.kernel.org/bpf/20251215211402.353056-10-jolsa@kernel.org/

v6 changes:
- rename add_hash_entry_direct to add_ftrace_hash_entry_direct [Steven]
- factor hash_add/hash_sub [Steven]
- add kerneldoc header for update_ftrace_direct_* functions [Steven]
- few assorted smaller fixes [Steven]
- added missing direct_ops wrappers for !CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
case [Steven]

v5 changes:
- do not export ftrace_hash object [Steven]
- fix update_ftrace_direct_add new_filter_hash leak [ci]

v4 changes:
- rebased on top of bpf-next/master (with jmp attach changes)
added patch 1 to deal with that
- added extra checks for update_ftrace_direct_del/mod to address
the ci bot review

v3 changes:
- rebased on top of bpf-next/master
- fixed update_ftrace_direct_del cleanup path
- added missing inline to update_ftrace_direct_* stubs

v2 changes:
- rebased on top fo bpf-next/master plus Song's livepatch fixes [1]
- renamed the API functions [2] [Steven]
- do not export the new api [Steven]
- kept the original direct interface:

I'm not sure if we want to melt both *_ftrace_direct and the new interface
into single one. It's bit different in semantic (hence the name change as
Steven suggested [2]) and I don't think the changes are not that big so
we could easily keep both APIs.

v1 changes:
- make the change x86 specific, after discussing with Mark options for
arm64 [Mark]

thanks,
jirka

[1] https://lore.kernel.org/bpf/20251027175023.1521602-1-song@kernel.org/
[2] https://lore.kernel.org/bpf/20250924050415.4aefcb91@batman.local.home/
---
====================

Link: https://patch.msgid.link/20251230145010.103439-1-jolsa@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

show more ...


Revision tags: v6.19-rc7, v6.19-rc6, v6.19-rc5, v6.19-rc4
# 424f6a36 30-Dec-2025 Jiri Olsa <jolsa@kernel.org>

bpf,x86: Use single ftrace_ops for direct calls

Using single ftrace_ops for direct calls update instead of allocating
ftrace_ops object for each trampoline.

With single ftrace_ops object we can use

bpf,x86: Use single ftrace_ops for direct calls

Using single ftrace_ops for direct calls update instead of allocating
ftrace_ops object for each trampoline.

With single ftrace_ops object we can use update_ftrace_direct_* api
that allows multiple ip sites updates on single ftrace_ops object.

Adding HAVE_SINGLE_FTRACE_DIRECT_OPS config option to be enabled on
each arch that supports this.

At the moment we can enable this only on x86 arch, because arm relies
on ftrace_ops object representing just single trampoline image (stored
in ftrace_ops::direct_call). Archs that do not support this will continue
to use *_ftrace_direct api.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20251230145010.103439-10-jolsa@kernel.org

show more ...


# cc4adab1 20-Jan-2026 Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Merge tag 'v6.19-rc1' into msm-next

Merge Linux 6.19-rc1 in order to catch up with other changes (e.g. UBWC
config database defining UBWC_6).

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.q

Merge tag 'v6.19-rc1' into msm-next

Merge Linux 6.19-rc1 in order to catch up with other changes (e.g. UBWC
config database defining UBWC_6).

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

show more ...


Revision tags: v6.19-rc3, v6.19-rc2
# 5add3c3c 19-Dec-2025 Thomas Hellström <thomas.hellstrom@linux.intel.com>

Merge drm/drm-next into drm-xe-next

Backmerging to bring in 6.19-rc1. An important upstream bugfix and
to help unblock PTL CI.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


# ec439c38 17-Dec-2025 Alexei Starovoitov <ast@kernel.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after 6.19-rc1

Cross-merge BPF and other fixes after downstream PR.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>


# b8304863 15-Dec-2025 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-next

Sync-up some display code needed for Async flips refactor.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>


# 7f790dd2 15-Dec-2025 Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-misc-next

Let's kickstart the v6.20 (7.0?) release cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


# 24f171c7 21-Dec-2025 Takashi Iwai <tiwai@suse.de>

Merge tag 'asoc-fix-v6.19-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v6.19

We've been quite busy with fixes since the merge window, though

Merge tag 'asoc-fix-v6.19-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v6.19

We've been quite busy with fixes since the merge window, though not in
any particularly exciting ways - the standout thing is the fix for _SX
controls which were broken by a change to how we do clamping, otherwise
it's all fairly run of the mill fixes and quirks.

show more ...


# 84318277 15-Dec-2025 Maarten Lankhorst <dev@lankhorst.se>

Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes

Pull in rc1 to include all changes since the merge window closed,
and grab all fixes and changes from drm/drm-next.

Signed-off-by: M

Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes

Pull in rc1 to include all changes since the merge window closed,
and grab all fixes and changes from drm/drm-next.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

show more ...


Revision tags: v6.19-rc1
# 69c5079b 05-Dec-2025 Linus Torvalds <torvalds@linux-foundation.org>

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 w

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
...

show more ...


Revision tags: v6.18, v6.18-rc7
# f93a7d0c 21-Nov-2025 Steven Rostedt <rostedt@goodmis.org>

ftrace: Allow tracing of some of the tracing code

There is times when tracing the tracing infrastructure can be useful for
debugging the tracing code. Currently all files in the tracing directory
ar

ftrace: Allow tracing of some of the tracing code

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 <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251120181514.736f2d5f@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...


Revision tags: v6.18-rc6, v6.18-rc5, v6.18-rc4
# 299ea67e 29-Oct-2025 Steven Rostedt <rostedt@goodmis.org>

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

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>

show more ...


# 015e7b0b 04-Dec-2025 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

- Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to

Merge tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

- Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to
test_progs runner (Alexis Lothoré)

- Convert selftests/bpf/test_xsk to test_progs runner (Bastien
Curutchet)

- Replace bpf memory allocator with kmalloc_nolock() in
bpf_local_storage (Amery Hung), and in bpf streams and range tree
(Puranjay Mohan)

- Introduce support for indirect jumps in BPF verifier and x86 JIT
(Anton Protopopov) and arm64 JIT (Puranjay Mohan)

- Remove runqslower bpf tool (Hoyeon Lee)

- Fix corner cases in the verifier to close several syzbot reports
(Eduard Zingerman, KaFai Wan)

- Several improvements in deadlock detection in rqspinlock (Kumar
Kartikeya Dwivedi)

- Implement "jmp" mode for BPF trampoline and corresponding
DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance
from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong)

- Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul
Chaignon)

- Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel
Borkmann)

- Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko)

- Optimize bpf_map_update_elem() for map-in-map types (Ritesh
Oedayrajsingh Varma)

- Introduce overwrite mode for BPF ring buffer (Xu Kuohai)

* tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits)
bpf: optimize bpf_map_update_elem() for map-in-map types
bpf: make kprobe_multi_link_prog_run always_inline
selftests/bpf: do not hardcode target rate in test_tc_edt BPF program
selftests/bpf: remove test_tc_edt.sh
selftests/bpf: integrate test_tc_edt into test_progs
selftests/bpf: rename test_tc_edt.bpf.c section to expose program type
selftests/bpf: Add success stats to rqspinlock stress test
rqspinlock: Precede non-head waiter queueing with AA check
rqspinlock: Disable spinning for trylock fallback
rqspinlock: Use trylock fallback when per-CPU rqnode is busy
rqspinlock: Perform AA checks immediately
rqspinlock: Enclose lock/unlock within lock entry acquisitions
bpf: Remove runqslower tool
selftests/bpf: Remove usage of lsm/file_alloc_security in selftest
bpf: Disable file_alloc_security hook
bpf: check for insn arrays in check_ptr_alignment
bpf: force BPF_F_RDONLY_PROG on insn array creation
bpf: Fix exclusive map memory leak
selftests/bpf: Make CS length configurable for rqspinlock stress test
selftests/bpf: Add lock wait time stats to rqspinlock stress test
...

show more ...


# acf87264 24-Nov-2025 Alexei Starovoitov <ast@kernel.org>

Merge branch 'bpf-trampoline-support-jmp-mode'

Menglong Dong says:

====================
bpf trampoline support "jmp" mode

For now, the bpf trampoline is called by the "call" instruction. However,

Merge branch 'bpf-trampoline-support-jmp-mode'

Menglong Dong says:

====================
bpf trampoline support "jmp" mode

For now, the bpf trampoline is called by the "call" instruction. However,
it break the RSB and introduce extra overhead in x86_64 arch.

For example, we hook the function "foo" with fexit, the call and return
logic will be like this:
call foo -> call trampoline -> call foo-body ->
return foo-body -> return foo

As we can see above, there are 3 call, but 2 return, which break the RSB
balance. We can pseudo a "return" here, but it's not the best choice,
as it will still cause once RSB miss:
call foo -> call trampoline -> call foo-body ->
return foo-body -> return dummy -> return foo

The "return dummy" doesn't pair the "call trampoline", which can also
cause the RSB miss.

Therefore, we introduce the "jmp" mode for bpf trampoline, as advised by
Alexei in [1]. And the logic will become this:
call foo -> jmp trampoline -> call foo-body ->
return foo-body -> return foo

As we can see above, the RSB is totally balanced after this series.

In this series, we introduce the FTRACE_OPS_FL_JMP for ftrace to make it
use the "jmp" instruction instead of "call".

And we also do some adjustment to bpf_arch_text_poke() to allow us specify
the old and new poke_type.

For the BPF_TRAMP_F_SHARE_IPMODIFY case, we will fallback to the "call"
mode, as it need to get the function address from the stack, which is not
supported in "jmp" mode.

Before this series, we have the following performance with the bpf
benchmark:

$ cd tools/testing/selftests/bpf
$ ./benchs/run_bench_trigger.sh
usermode-count : 890.171 ± 1.522M/s
kernel-count : 409.184 ± 0.330M/s
syscall-count : 26.792 ± 0.010M/s
fentry : 171.242 ± 0.322M/s
fexit : 80.544 ± 0.045M/s
fmodret : 78.301 ± 0.065M/s
rawtp : 192.906 ± 0.900M/s
tp : 81.883 ± 0.209M/s
kprobe : 52.029 ± 0.113M/s
kprobe-multi : 62.237 ± 0.060M/s
kprobe-multi-all: 4.761 ± 0.014M/s
kretprobe : 23.779 ± 0.046M/s
kretprobe-multi: 29.134 ± 0.012M/s
kretprobe-multi-all: 3.822 ± 0.003M/

And after this series, we have the following performance:

usermode-count : 890.443 ± 0.307M/s
kernel-count : 416.139 ± 0.055M/s
syscall-count : 31.037 ± 0.813M/s
fentry : 169.549 ± 0.519M/s
fexit : 136.540 ± 0.518M/s
fmodret : 159.248 ± 0.188M/s
rawtp : 194.475 ± 0.144M/s
tp : 84.505 ± 0.041M/s
kprobe : 59.951 ± 0.071M/s
kprobe-multi : 63.153 ± 0.177M/s
kprobe-multi-all: 4.699 ± 0.012M/s
kretprobe : 23.740 ± 0.015M/s
kretprobe-multi: 29.301 ± 0.022M/s
kretprobe-multi-all: 3.869 ± 0.005M/s

As we can see above, the performance of fexit increase from 80.544M/s to
136.540M/s, and the "fmodret" increase from 78.301M/s to 159.248M/s.

Link: https://lore.kernel.org/bpf/20251117034906.32036-1-dongml2@chinatelecom.cn/
Changes since v2:
* reject if the addr is already "jmp" in register_ftrace_direct() and
__modify_ftrace_direct() in the 1st patch.
* fix compile error in powerpc in the 5th patch.
* changes in the 6th patch:
- fix the compile error by wrapping the write to tr->fops->flags with
CONFIG_DYNAMIC_FTRACE_WITH_JMP
- reset BPF_TRAMP_F_SKIP_FRAME when the second try of modify_fentry in
bpf_trampoline_update()

Link: https://lore.kernel.org/bpf/20251114092450.172024-1-dongml2@chinatelecom.cn/
Changes since v1:
* change the bool parameter that we add to save_args() to "u32 flags"
* rename bpf_trampoline_need_jmp() to bpf_trampoline_use_jmp()
* add new function parameter to bpf_arch_text_poke instead of introduce
bpf_arch_text_poke_type()
* rename bpf_text_poke to bpf_trampoline_update_fentry
* remove the BPF_TRAMP_F_JMPED and check the current mode with the origin
flags instead.

Link: https://lore.kernel.org/bpf/CAADnVQLX54sVi1oaHrkSiLqjJaJdm3TQjoVrgU-LZimK6iDcSA@mail.gmail.com/[1]
====================

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/20251118123639.688444-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...


# 25e4e356 18-Nov-2025 Menglong Dong <menglong8.dong@gmail.com>

ftrace: Introduce FTRACE_OPS_FL_JMP

For now, the "nop" will be replaced with a "call" instruction when a
function is hooked by the ftrace. However, sometimes the "call" can break
the RSB and introdu

ftrace: Introduce FTRACE_OPS_FL_JMP

For now, the "nop" will be replaced with a "call" instruction when a
function is hooked by the ftrace. However, sometimes the "call" can break
the RSB and introduce extra overhead. Therefore, introduce the flag
FTRACE_OPS_FL_JMP, which indicate that the ftrace_ops should be called
with a "jmp" instead of "call". For now, it is only used by the direct
call case.

When a direct ftrace_ops is marked with FTRACE_OPS_FL_JMP, the last bit of
the ops->direct_call will be set to 1. Therefore, we can tell if we should
use "jmp" for the callback in ftrace_call_replace().

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20251118123639.688444-2-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...


# cb9f145f 01-Nov-2025 Rob Clark <robin.clark@oss.qualcomm.com>

Merge remote-tracking branch 'drm/drm-next' into msm-next-robclark

Back-merge drm-next to get caught up.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>


Revision tags: v6.18-rc3, v6.18-rc2, v6.18-rc1, v6.17, v6.17-rc7
# f088104d 16-Sep-2025 Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Merge drm/drm-next into drm-intel-gt-next

Backmerge in order to get the commit:

048832a3f400 ("drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter")

To drm-intel-gt-next as there are f

Merge drm/drm-next into drm-intel-gt-next

Backmerge in order to get the commit:

048832a3f400 ("drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter")

To drm-intel-gt-next as there are followup fixes to be applied.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...


Revision tags: v6.17-rc6, v6.17-rc5, v6.17-rc4, v6.17-rc3, v6.17-rc2, v6.17-rc1
# a53d0cf7 05-Aug-2025 Ingo Molnar <mingo@kernel.org>

Merge commit 'linus' into core/bugs, to resolve conflicts

Resolve conflicts with this commit that was developed in parallel
during the merge window:

8c8efa93db68 ("x86/bug: Add ARCH_WARN_ASM macro

Merge commit 'linus' into core/bugs, to resolve conflicts

Resolve conflicts with this commit that was developed in parallel
during the merge window:

8c8efa93db68 ("x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust")

Conflicts:
arch/riscv/include/asm/bug.h
arch/x86/include/asm/bug.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...


# 8b87f67b 08-Oct-2025 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 6.18 merge window.


# 4b051897 21-Aug-2025 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v6.17-rc2' into HEAD

Sync up with mainline to bring in changes to include/linux/sprintf.h


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