To enable more complex parameterized testing scenarios, the
generate_params() function needs additional context beyond just
the previously generated parameter. This patch modifies the
generate_params() function signature to include an extra
`struct kunit *test` argument, giving test users access to the
parameterized test context when generating parameters.
The `struct kunit *test` argument was added as the first parameter
to the function signature as it aligns with the convention of other
KUnit functions that accept `struct kunit *test` first. This also
mirrors the "this" or "self" reference found in object-oriented
programming languages.
This patch also modifies xe_pci_live_device_gen_param() in xe_pci.c
and nthreads_gen_params() in kcsan_test.c to reflect this signature
change.
Link: https://lore.kernel.org/r/20250826091341.1427123-4-davidgow@google.com
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Marie Zhussupova <marievic@google.com>
[Catch some additional gen_params signatures in drm/xe/tests --David]
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
On CPU offline the kernel stalled with below call trace:
INFO: task kworker/0:1:11 blocked for more than 120 seconds.
cpuhp hold the cpu hotplug lock endless and stalled vmstat_shepherd.
This is because we count nr_running twice on cpuhp enqueuing and failed
the wait condition of cpuhp:
enqueue_task_fair() // pick cpuhp from idle, rq->nr_running = 0
dl_server_start()
[...]
add_nr_running() // rq->nr_running = 1
add_nr_running() // rq->nr_running = 2
[switch to cpuhp, waiting on balance_hotplug_wait()]
rcuwait_wait_event(rq->nr_running == 1 && ...) // failed, rq->nr_running=2
schedule() // wait again
It doesn't make sense to count the dl_server towards runnable tasks,
since it runs other tasks.
Fixes: 63ba8422f8 ("sched/deadline: Introduce deadline servers")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250627035420.37712-1-yangyicong@huawei.com
[Symptom]
The fair server mechanism, which is intended to prevent fair starvation
when higher-priority tasks monopolize the CPU.
Specifically, RT tasks on the runqueue may not be scheduled as expected.
[Analysis]
The log "sched: DL replenish lagged too much" triggered.
By memory dump of dl_server:
curr = 0xFFFFFF80D6A0AC00 (
dl_server = 0xFFFFFF83CD5B1470(
dl_runtime = 0x02FAF080,
dl_deadline = 0x3B9ACA00,
dl_period = 0x3B9ACA00,
dl_bw = 0xCCCC,
dl_density = 0xCCCC,
runtime = 0x02FAF080,
deadline = 0x0000082031EB0E80,
flags = 0x0,
dl_throttled = 0x0,
dl_yielded = 0x0,
dl_non_contending = 0x0,
dl_overrun = 0x0,
dl_server = 0x1,
dl_server_active = 0x1,
dl_defer = 0x1,
dl_defer_armed = 0x0,
dl_defer_running = 0x1,
dl_timer = (
node = (
expires = 0x000008199756E700),
_softexpires = 0x000008199756E700,
function = 0xFFFFFFDB9AF44D30 = dl_task_timer,
base = 0xFFFFFF83CD5A12C0,
state = 0x0,
is_rel = 0x0,
is_soft = 0x0,
clock_update_flags = 0x4,
clock = 0x000008204A496900,
- The timer expiration time (rq->curr->dl_server->dl_timer->expires)
is already in the past, indicating the timer has expired.
- The timer state (rq->curr->dl_server->dl_timer->state) is 0.
[Suspected Root Cause]
The relevant code flow in the throttle path of
update_curr_dl_se() as follows:
dequeue_dl_entity(dl_se, 0); // the DL entity is dequeued
if (unlikely(is_dl_boosted(dl_se) || !start_dl_timer(dl_se))) {
if (dl_server(dl_se)) // timer registration fails
enqueue_dl_entity(dl_se, ENQUEUE_REPLENISH);//enqueue immediately
...
}
The failure of `start_dl_timer` is caused by attempting to register a
timer with an expiration time that is already in the past. When this
situation persists, the code repeatedly re-enqueues the DL entity
without properly replenishing or restarting the timer, resulting in RT
task may not be scheduled as expected.
[Proposed Solution]:
Instead of immediately re-enqueuing the DL entity on timer registration
failure, this change ensures the DL entity is properly replenished and
the timer is restarted, preventing RT potential starvation.
Fixes: 63ba8422f8 ("sched/deadline: Introduce deadline servers")
Signed-off-by: kuyo chang <kuyo.chang@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Closes: https://lore.kernel.org/CAMuHMdXn4z1pioTtBGMfQM0jsLviqS2jwysaWXpoLxWYoGa82w@mail.gmail.com
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Tested-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://lkml.kernel.org/r/20250615131129.954975-1-kuyo.chang@mediatek.com
Commit cccb45d7c4 ("sched/deadline: Less agressive dl_server
handling") reduced dl-server overhead by delaying disabling servers only
after there are no fair task around for a whole period, which means that
deadline entities are not dequeued right away on a server stop event.
However, the delay opens up a window in which a request for changing
server parameters can break per-runqueue running_bw tracking, as
reported by Yuri.
Close the problematic window by unconditionally calling dl_server_stop()
before applying the new parameters (ensuring deadline entities go
through an actual dequeue).
Fixes: cccb45d7c4 ("sched/deadline: Less agressive dl_server handling")
Reported-by: Yuri Andriaccio <yurand2000@gmail.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20250721-upstream-fix-dlserver-lessaggressive-b4-v1-1-4ebc10c87e40@redhat.com
To determine if a task is a kernel thread or not, it is more reliable to
use (current->flags & (PF_KTHREAD|PF_USER_WORKERi)) than to rely on
current->mm being NULL. That is because some kernel tasks (io_uring
helpers) may have a mm field.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250820180428.592367294@kernel.org
cpuset: add helpers for cpus_read_lock and cpuset_mutex locks.
Replace repetitive locking patterns with new helpers:
- cpuset_full_lock()
- cpuset_full_unlock()
This makes the code cleaner and ensures consistent lock ordering.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, free_cpumasks() can free both tmpmasks and cpumasks of a cpuset
(cs). However, these two operations are not logically coupled. To improve
code clarity:
1. Move cpumask freeing to free_cpuset()
2. Rename free_cpumasks() to free_tmpmasks()
This change enforces the single responsibility principle.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The list_for_each_rcu() relies on the rcu_dereference() API which is not
provided by the list.h. At the same time list.h is a low-level basic header
that must not have dependencies like RCU, besides the fact of the potential
circular dependencies in some cases. With all that said, move RCU related
API to the rculist.h where it belongs.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Reviewed-by: "Paul E. McKenney" <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.upadhyay@kernel.org>
Signed-off-by: "Paul E. McKenney" <paulmck@kernel.org>
Pull perf fix from Borislav Petkov:
- Fix a case where the events throttling logic operates on inactive
events
* tag 'perf_urgent_for_v6.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Avoid undefined behavior from stopping/starting inactive events
Pull modules fix from Daniel Gomez:
"This includes a fix part of the KSPP (Kernel Self Protection Project)
to replace the deprecated and unsafe strcpy() calls in the kernel
parameter string handler and sysfs parameters for built-in modules.
Single commit, no functional changes"
* tag 'modules-6.17-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
params: Replace deprecated strcpy() with strscpy() and memcpy()
devm_request_threaded_irq() and devm_request_any_context_irq() currently
don't print any error message when interrupt registration fails.
This forces each driver to implement redundant error logging - over 2,000
lines of error messages exist across drivers. Additionally, when
upper-layer functions propagate these errors without logging, critical
debugging information is lost.
Add devm_request_result() helper to unify error reporting via dev_err_probe(),
Use it in devm_request_threaded_irq() and devm_request_any_context_irq()
printing device name, IRQ number, handler functions, and error code on failure
automatically.
Co-developed-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Pan Chuang <panchuang@vivo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250805092922.135500-2-panchuang@vivo.com
As the MSI controller on SG2044 uses PLIC as the underlying interrupt
controller, it needs to call irq_enable() and irq_disable() to
startup/shutdown interrupts. Otherwise, the MSI interrupt can not be
startup correctly and will not respond any incoming interrupt.
Introduce irq_chip_startup_parent() and irq_chip_shutdown_parent() to allow
the interrupt controller to call the irq_startup()/irq_shutdown() callbacks
of the parent interrupt chip.
In case the irq_startup()/irq_shutdown() callbacks are not implemented for
the parent interrupt chip, this will fallback to irq_chip_enable_parent()
or irq_chip_disable_parent().
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen Wang <unicorn_wang@outlook.com> # Pioneerbox
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Link: https://lore.kernel.org/all/20250813232835.43458-2-inochiama@gmail.com
Link: https://lore.kernel.org/lkml/20250722224513.22125-1-inochiama@gmail.com/
Pull tracing fixes from Steven Rostedt:
- Fix rtla and latency tooling pkg-config errors
If libtraceevent and libtracefs is installed, but their corresponding
'.pc' files are not installed, it reports that the libraries are
missing and confuses the developer. Instead, report that the
pkg-config files are missing and should be installed.
- Fix overflow bug of the parser in trace_get_user()
trace_get_user() uses the parsing functions to parse the user space
strings. If the parser fails due to incorrect processing, it doesn't
terminate the buffer with a nul byte. Add a "failed" flag to the
parser that gets set when parsing fails and is used to know if the
buffer is fine to use or not.
- Remove a semicolon that was at an end of a comment line
- Fix register_ftrace_graph() to unregister the pm notifier on error
The register_ftrace_graph() registers a pm notifier but there's an
error path that can exit the function without unregistering it. Since
the function returns an error, it will never be unregistered.
- Allocate and copy ftrace hash for reader of ftrace filter files
When the set_ftrace_filter or set_ftrace_notrace files are open for
read, an iterator is created and sets its hash pointer to the
associated hash that represents filtering or notrace filtering to it.
The issue is that the hash it points to can change while the
iteration is happening. All the locking used to access the tracer's
hashes are released which means those hashes can change or even be
freed. Using the hash pointed to by the iterator can cause UAF bugs
or similar.
Have the read of these files allocate and copy the corresponding
hashes and use that as that will keep them the same while the
iterator is open. This also simplifies the code as opening it for
write already does an allocate and copy, and now that the read is
doing the same, there's no need to check which way it was opened on
the release of the file, and the iterator hash can always be freed.
- Fix function graph to copy args into temp storage
The output of the function graph tracer shows both the entry and the
exit of a function. When the exit is right after the entry, it
combines the two events into one with the output of "function();",
instead of showing:
function() {
}
In order to do this, the iterator descriptor that reads the events
includes storage that saves the entry event while it peaks at the
next event in the ring buffer. The peek can free the entry event so
the iterator must store the information to use it after the peek.
With the addition of function graph tracer recording the args, where
the args are a dynamic array in the entry event, the temp storage
does not save them. This causes the args to be corrupted or even
cause a read of unsafe memory.
Add space to save the args in the temp storage of the iterator.
- Fix race between ftrace_dump and reading trace_pipe
ftrace_dump() is used when a crash occurs where the ftrace buffer
will be printed to the console. But it can also be triggered by
sysrq-z. If a sysrq-z is triggered while a task is reading trace_pipe
it can cause a race in the ftrace_dump() where it checks if the
buffer has content, then it checks if the next event is available,
and then prints the output (regardless if the next event was
available or not). Reading trace_pipe at the same time can cause it
to not be available, and this triggers a WARN_ON in the print. Move
the printing into the check if the next event exists or not
* tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Also allocate and copy hash for reading of filter files
ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
fgraph: Copy args in intermediate storage with entry
trace/fgraph: Fix the warning caused by missing unregister notifier
ring-buffer: Remove redundant semicolons
tracing: Limit access to parser->buffer when trace_get_user failed
rtla: Check pkg-config install
tools/latency-collector: Check pkg-config install
When calling ftrace_dump_one() concurrently with reading trace_pipe,
a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race
condition.
The issue occurs because:
CPU0 (ftrace_dump) CPU1 (reader)
echo z > /proc/sysrq-trigger
!trace_empty(&iter)
trace_iterator_reset(&iter) <- len = size = 0
cat /sys/kernel/tracing/trace_pipe
trace_find_next_entry_inc(&iter)
__find_next_entry
ring_buffer_empty_cpu <- all empty
return NULL
trace_printk_seq(&iter.seq)
WARN_ON_ONCE(s->seq.len >= s->seq.size)
In the context between trace_empty() and trace_find_next_entry_inc()
during ftrace_dump, the ring buffer data was consumed by other readers.
This caused trace_find_next_entry_inc to return NULL, failing to populate
`iter.seq`. At this point, due to the prior trace_iterator_reset, both
`iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal,
the WARN_ON_ONCE condition is triggered.
Move the trace_printk_seq() into the if block that checks to make sure the
return value of trace_find_next_entry_inc() is non-NULL in
ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before
subsequent operations.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@elte.hu>
Link: https://lore.kernel.org/20250822033343.3000289-1-wutengda@huaweicloud.com
Fixes: d769041f86 ("ring_buffer: implement new locking")
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The output of the function graph tracer has two ways to display its
entries. One way for leaf functions with no events recorded within them,
and the other is for functions with events recorded inside it. As function
graph has an entry and exit event, to simplify the output of leaf
functions it combines the two, where as non leaf functions are separate:
2) | invoke_rcu_core() {
2) | raise_softirq() {
2) 0.391 us | __raise_softirq_irqoff();
2) 1.191 us | }
2) 2.086 us | }
The __raise_softirq_irqoff() function above is really two events that were
merged into one. Otherwise it would have looked like:
2) | invoke_rcu_core() {
2) | raise_softirq() {
2) | __raise_softirq_irqoff() {
2) 0.391 us | }
2) 1.191 us | }
2) 2.086 us | }
In order to do this merge, the reading of the trace output file needs to
look at the next event before printing. But since the pointer to the event
is on the ring buffer, it needs to save the entry event before it looks at
the next event as the next event goes out of focus as soon as a new event
is read from the ring buffer. After it reads the next event, it will print
the entry event with either the '{' (non leaf) or ';' and timestamps (leaf).
The iterator used to read the trace file has storage for this event. The
problem happens when the function graph tracer has arguments attached to
the entry event as the entry now has a variable length "args" field. This
field only gets set when funcargs option is used. But the args are not
recorded in this temp data and garbage could be printed. The entry field
is copied via:
data->ent = *curr;
Where "curr" is the entry field. But this method only saves the non
variable length fields from the structure.
Add a helper structure to the iterator data that adds the max args size to
the data storage in the iterator. Then simply copy the entire entry into
this storage (with size protection).
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250820195522.51d4a268@gandalf.local.home
Reported-by: Sasha Levin <sashal@kernel.org>
Tested-by: Sasha Levin <sashal@kernel.org>
Closes: https://lore.kernel.org/all/aJaxRVKverIjF4a6@lappy/
Fixes: ff5c9c576e ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There isn't yet a clear way to identify a set of "lost" time that
everyone (or at least a wider group of users) cares about. However,
users can perform some delay accounting by iterating over components of
interest. This patch allows cgroup v2 freezing time to be one of those
components.
Track the cumulative time that each v2 cgroup spends freezing and expose
it to userland via a new local stat file in cgroupfs. Thank you to
Michal, who provided the ASCII art in the updated documentation.
To access this value:
$ mkdir /sys/fs/cgroup/test
$ cat /sys/fs/cgroup/test/cgroup.stat.local
freeze_time_total 0
Ensure consistent freeze time reads with freeze_seq, a per-cgroup
sequence counter. Writes are serialized using the css_set_lock.
Signed-off-by: Tiffany Yang <ynaffit@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
A hung task can occur during [1] LTP cgroup testing when repeatedly
mounting/unmounting perf_event and net_prio controllers with
systemd.unified_cgroup_hierarchy=1. The hang manifests in
cgroup_lock_and_drain_offline() during root destruction.
Related case:
cgroup_fj_function_perf_event cgroup_fj_function.sh perf_event
cgroup_fj_function_net_prio cgroup_fj_function.sh net_prio
Call Trace:
cgroup_lock_and_drain_offline+0x14c/0x1e8
cgroup_destroy_root+0x3c/0x2c0
css_free_rwork_fn+0x248/0x338
process_one_work+0x16c/0x3b8
worker_thread+0x22c/0x3b0
kthread+0xec/0x100
ret_from_fork+0x10/0x20
Root Cause:
CPU0 CPU1
mount perf_event umount net_prio
cgroup1_get_tree cgroup_kill_sb
rebind_subsystems // root destruction enqueues
// cgroup_destroy_wq
// kill all perf_event css
// one perf_event css A is dying
// css A offline enqueues cgroup_destroy_wq
// root destruction will be executed first
css_free_rwork_fn
cgroup_destroy_root
cgroup_lock_and_drain_offline
// some perf descendants are dying
// cgroup_destroy_wq max_active = 1
// waiting for css A to die
Problem scenario:
1. CPU0 mounts perf_event (rebind_subsystems)
2. CPU1 unmounts net_prio (cgroup_kill_sb), queuing root destruction work
3. A dying perf_event CSS gets queued for offline after root destruction
4. Root destruction waits for offline completion, but offline work is
blocked behind root destruction in cgroup_destroy_wq (max_active=1)
Solution:
Split cgroup_destroy_wq into three dedicated workqueues:
cgroup_offline_wq – Handles CSS offline operations
cgroup_release_wq – Manages resource release
cgroup_free_wq – Performs final memory deallocation
This separation eliminates blocking in the CSS free path while waiting for
offline operations to complete.
[1] https://github.com/linux-test-project/ltp/blob/master/runtest/controllers
Fixes: 334c3679ec ("cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends")
Reported-by: Gao Yingjie <gaoyingjie@uniontech.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Suggested-by: Teju Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
In the following toy program (reg states minimized for readability), R0
and R1 always have different values at instruction 6. This is obvious
when reading the program but cannot be guessed from ranges alone as
they overlap (R0 in [0; 0xc0000000], R1 in [1024; 0xc0000400]).
0: call bpf_get_prandom_u32#7 ; R0_w=scalar()
1: w0 = w0 ; R0_w=scalar(var_off=(0x0; 0xffffffff))
2: r0 >>= 30 ; R0_w=scalar(var_off=(0x0; 0x3))
3: r0 <<= 30 ; R0_w=scalar(var_off=(0x0; 0xc0000000))
4: r1 = r0 ; R1_w=scalar(var_off=(0x0; 0xc0000000))
5: r1 += 1024 ; R1_w=scalar(var_off=(0x400; 0xc0000000))
6: if r1 != r0 goto pc+1
Looking at tnums however, we can deduce that R1 is always different from
R0 because their tnums don't agree on known bits. This patch uses this
logic to improve is_scalar_branch_taken in case of BPF_JEQ and BPF_JNE.
This change has a tiny impact on complexity, which was measured with
the Cilium complexity CI test. That test covers 72 programs with
various build and load time configurations for a total of 970 test
cases. For 80% of test cases, the patch has no impact. On the other
test cases, the patch decreases complexity by only 0.08% on average. In
the best case, the verifier needs to walk 3% less instructions and, in
the worst case, 1.5% more. Overall, the patch has a small positive
impact, especially for our largest programs.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/be3ee70b6e489c49881cb1646114b1d861b5c334.1755694147.git.paul.chaignon@gmail.com
Use kcalloc() in main_func() to gain built-in overflow protection, making
memory allocation safer when calculating allocation size compared to
explicit multiplication.
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Use kcalloc() in rcu_torture_writer() to gain built-in overflow protection,
making memory allocation safer when calculating allocation size compared to
explicit multiplication.
Change sizeof(ulo[0]) and sizeof(rgo[0]) to sizeof(*ulo) and sizeof(*rgo),
as this is more consistent with coding conventions.
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Pull misc fixes from Andrew Morton:
"20 hotfixes. 10 are cc:stable and the remainder address post-6.16
issues or aren't considered necessary for -stable kernels. 17 of these
fixes are for MM.
As usual, singletons all over the place, apart from a three-patch
series of KHO followup work from Pasha which is actually also a bunch
of singletons"
* tag 'mm-hotfixes-stable-2025-08-21-18-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/mremap: fix WARN with uffd that has remap events disabled
mm/damon/sysfs-schemes: put damos dests dir after removing its files
mm/migrate: fix NULL movable_ops if CONFIG_ZSMALLOC=m
mm/damon/core: fix damos_commit_filter not changing allow
mm/memory-failure: fix infinite UCE for VM_PFNMAP pfn
MAINTAINERS: mark MGLRU as maintained
mm: rust: add page.rs to MEMORY MANAGEMENT - RUST
iov_iter: iterate_folioq: fix handling of offset >= folio size
selftests/damon: fix selftests by installing drgn related script
.mailmap: add entry for Easwar Hariharan
selftests/mm: add test for invalid multi VMA operations
mm/mremap: catch invalid multi VMA moves earlier
mm/mremap: allow multi-VMA move when filesystem uses thp_get_unmapped_area
mm/damon/core: fix commit_ops_filters by using correct nth function
tools/testing: add linux/args.h header and fix radix, VMA tests
mm/debug_vm_pgtable: clear page table entries at destroy_args()
squashfs: fix memory leak in squashfs_fill_super
kho: warn if KHO is disabled due to an error
kho: mm: don't allow deferred struct page with KHO
kho: init new_physxa->phys_bits to fix lockdep
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf02 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable@vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-08-21
We've added 9 non-merge commits during the last 3 day(s) which contain
a total of 13 files changed, 1027 insertions(+), 27 deletions(-).
The main changes are:
1) Added bpf dynptr support for accessing the metadata of a skb,
from Jakub Sitnicki.
The patches are merged from a stable branch bpf-next/skb-meta-dynptr.
The same patches have also been merged into bpf-next/master.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
selftests/bpf: Cover metadata access from a modified skb clone
selftests/bpf: Cover read/write to skb metadata at an offset
selftests/bpf: Cover write access to skb metadata via dynptr
selftests/bpf: Cover read access to skb metadata via dynptr
selftests/bpf: Parametrize test_xdp_context_tuntap
selftests/bpf: Pass just bpf_map to xdp_context_test helper
selftests/bpf: Cover verifier checks for skb_meta dynptr type
bpf: Enable read/write access to skb metadata through a dynptr
bpf: Add dynptr type for skb metadata
====================
Link: https://patch.msgid.link/20250821191827.2099022-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull cgroup fixes from Tejun Heo:
- Fix NULL de-ref in css_rstat_exit() which could happen after
allocation failure
- Fix a cpuset partition handling bug and a couple other misc issues
- Doc spelling fix
* tag 'cgroup-for-6.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
docs: cgroup: fixed spelling mistakes in documentation
cgroup: avoid null de-ref in css_rstat_exit()
cgroup/cpuset: Remove the unnecessary css_get/put() in cpuset_partition_write()
cgroup/cpuset: Fix a partition error with CPU hotplug
cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key
Pull sched_ext fixes from Tejun Heo:
- Fix a subtle bug during SCX enabling where a dead task skips init
but doesn't skip sched class switch leading to invalid task state
transition warning
- Cosmetic fix in selftests
* tag 'sched_ext-for-6.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
selftests/sched_ext: Remove duplicate sched.h header
sched/ext: Fix invalid task state transitions on class switch
Adding uprobe as another exception to the seccomp filter alongside
with the uretprobe syscall.
Same as the uretprobe the uprobe syscall is installed by kernel as
replacement for the breakpoint exception and is limited to x86_64
arch and isn't expected to ever be supported in i386.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250720112133.244369-21-jolsa@kernel.org
Putting together all the previously added pieces to support optimized
uprobes on top of 5-byte nop instruction.
The current uprobe execution goes through following:
- installs breakpoint instruction over original instruction
- exception handler hit and calls related uprobe consumers
- and either simulates original instruction or does out of line single step
execution of it
- returns to user space
The optimized uprobe path does following:
- checks the original instruction is 5-byte nop (plus other checks)
- adds (or uses existing) user space trampoline with uprobe syscall
- overwrites original instruction (5-byte nop) with call to user space
trampoline
- the user space trampoline executes uprobe syscall that calls related uprobe
consumers
- trampoline returns back to next instruction
This approach won't speed up all uprobes as it's limited to using nop5 as
original instruction, but we plan to use nop5 as USDT probe instruction
(which currently uses single byte nop) and speed up the USDT probes.
The arch_uprobe_optimize triggers the uprobe optimization and is called after
first uprobe hit. I originally had it called on uprobe installation but then
it clashed with elf loader, because the user space trampoline was added in a
place where loader might need to put elf segments, so I decided to do it after
first uprobe hit when loading is done.
The uprobe is un-optimized in arch specific set_orig_insn call.
The instruction overwrite is x86 arch specific and needs to go through 3 updates:
(on top of nop5 instruction)
- write int3 into 1st byte
- write last 4 bytes of the call instruction
- update the call instruction opcode
And cleanup goes though similar reverse stages:
- overwrite call opcode with breakpoint (int3)
- write last 4 bytes of the nop5 instruction
- write the nop5 first instruction byte
We do not unmap and release uprobe trampoline when it's no longer needed,
because there's no easy way to make sure none of the threads is still
inside the trampoline. But we do not waste memory, because there's just
single page for all the uprobe trampoline mappings.
We do waste frame on page mapping for every 4GB by keeping the uprobe
trampoline page mapped, but that seems ok.
We take the benefit from the fact that set_swbp and set_orig_insn are
called under mmap_write_lock(mm), so we can use the current instruction
as the state the uprobe is in - nop5/breakpoint/call trampoline -
and decide the needed action (optimize/un-optimize) based on that.
Attaching the speed up from benchs/run_bench_uprobes.sh script:
current:
usermode-count : 152.604 ± 0.044M/s
syscall-count : 13.359 ± 0.042M/s
--> uprobe-nop : 3.229 ± 0.002M/s
uprobe-push : 3.086 ± 0.004M/s
uprobe-ret : 1.114 ± 0.004M/s
uprobe-nop5 : 1.121 ± 0.005M/s
uretprobe-nop : 2.145 ± 0.002M/s
uretprobe-push : 2.070 ± 0.001M/s
uretprobe-ret : 0.931 ± 0.001M/s
uretprobe-nop5 : 0.957 ± 0.001M/s
after the change:
usermode-count : 152.448 ± 0.244M/s
syscall-count : 14.321 ± 0.059M/s
uprobe-nop : 3.148 ± 0.007M/s
uprobe-push : 2.976 ± 0.004M/s
uprobe-ret : 1.068 ± 0.003M/s
--> uprobe-nop5 : 7.038 ± 0.007M/s
uretprobe-nop : 2.109 ± 0.004M/s
uretprobe-push : 2.035 ± 0.001M/s
uretprobe-ret : 0.908 ± 0.001M/s
uretprobe-nop5 : 3.377 ± 0.009M/s
I see bit more speed up on Intel (above) compared to AMD. The big nop5
speed up is partly due to emulating nop5 and partly due to optimization.
The key speed up we do this for is the USDT switch from nop to nop5:
uprobe-nop : 3.148 ± 0.007M/s
uprobe-nop5 : 7.038 ± 0.007M/s
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250720112133.244369-11-jolsa@kernel.org
Adding new uprobe syscall that calls uprobe handlers for given
'breakpoint' address.
The idea is that the 'breakpoint' address calls the user space
trampoline which executes the uprobe syscall.
The syscall handler reads the return address of the initial call
to retrieve the original 'breakpoint' address. With this address
we find the related uprobe object and call its consumers.
Adding the arch_uprobe_trampoline_mapping function that provides
uprobe trampoline mapping. This mapping is backed with one global
page initialized at __init time and shared by the all the mapping
instances.
We do not allow to execute uprobe syscall if the caller is not
from uprobe trampoline mapping.
The uprobe syscall ensures the consumer (bpf program) sees registers
values in the state before the trampoline was called.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250720112133.244369-10-jolsa@kernel.org
Adding support to add special mapping for user space trampoline with
following functions:
uprobe_trampoline_get - find or add uprobe_trampoline
uprobe_trampoline_put - remove or destroy uprobe_trampoline
The user space trampoline is exported as arch specific user space special
mapping through tramp_mapping, which is initialized in following changes
with new uprobe syscall.
The uprobe trampoline needs to be callable/reachable from the probed address,
so while searching for available address we use is_reachable_by_call function
to decide if the uprobe trampoline is callable from the probe address.
All uprobe_trampoline objects are stored in uprobes_state object and are
cleaned up when the process mm_struct goes down. Adding new arch hooks
for that, because this change is x86_64 specific.
Locking is provided by callers in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250720112133.244369-9-jolsa@kernel.org
