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A cid-form scheduler that calls scx_bpf_cid_override() to install a custom
cid layout can only do so from ops.init(). Enable-path setup that depends on
the cid layout thus has to run after ops.init(), and ops.init() itself can't
use anything derived from the final layout, which turned out to be too
restrictive.
Add an ops.init_cids() callback dedicated to finalizing the cid layout. It
runs before the rest of the enable-path setup, so the final layout is in
effect for everything that follows including ops.init(), which now runs
after the arena pool and cmask scratch allocations.
scx_bpf_cid_override() is restricted to ops.init_cids() at load time. It
sits in a kfunc set gated by SCX_KF_ALLOW_INIT_CIDS, a flag set only on the
init_cids op, so the verifier rejects a call from any other context. The
runtime root-only check is dropped as ops.init_cids() only runs during root
enable.
The qmap demo moves its override into a dedicated qmap_init_cids() and,
while at it, introduces an enum for the cid override modes instead of
hard-coded integers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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The kick machinery kept its targets in rq->scx shared by every sched on the
cpu. A preempt kick carried no record of which scheduler requested it.
A later patch needs preempt kicks scoped to the requesting scheduler so a
sub-scheduler can preempt only tasks in its own subtree. Move the kick masks
into the per-sched per-cpu scx_sched_pcpu and have scx_kick_cpu() link the
sched onto a per-cpu list (rq->scx.sched_pcpus_to_kick). The cpu's single
kick irq_work walks that list and kicks each sched's targets on its behalf,
so a kick stays attributed to its scheduler.
The SCX_KICK_WAIT sync set (cpus_to_sync, the kick_sync snapshot and the
balance-callback trigger) stays in rq->scx: the waiter is the cpu, not the
scheduler, and its only writers, the kick irq_work and the wait balance
callback, are cpu-local.
On disable, free_kick_syncs() flushes each cpu's pending kick irq_work
before clearing @ksyncs, so a late kick unlinks its to_kick_node instead of
early-returning on a NULL @ksyncs and leaving the node linked at free.
v3: Flush the kick irq_work in free_kick_syncs() before clearing @ksyncs. (sashiko AI)
v2: Warn once per sched on scx_bpf_kick_cpu() from NMI.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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A per-task op must be dispatched on the scheduler that owns the task.
SCX_CALL_OP_TASK() and its _RET twin take @sch explicitly, and a caller that
passes the wrong scheduler would silently run the op on it. Add a
WARN_ON_ONCE() that @sch matches the task's owner so such a mismatch is
caught rather than hidden.
Two sites legitimately target a scheduler other than the task's owner:
cgroup_move() runs on the root sched, and scx_sub_init_cancel_task() fires
exit_task() on a task not yet associated with @sch. Both switch to the inner
__SCX_CALL_OP_TASK(), which dispatches on the explicit @sch without the
assert.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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Improve readability of the sg_dma_len assignment in the P2PDMA cases by
removing duplicated code, which was a direct result of the d0d08f4bd7f6
("dma-direct: Fix missing sg_dma_len assignment in P2PDMA bus mappings")
fix. No functional change.
Suggested-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/all/20260604071856.GA245424@unreal/
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20260713083022.1110993-1-m.szyprowski@samsung.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
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Pull cgroup fixes from Tejun Heo:
- A cpuset that never set its memory nodes could divide by zero when a
task's mempolicy rebinds on CPU hotplug. Rebind against the effective
nodes, which are always populated
- Documentation fixes for memory.stat, io.stat, and the misc and v1
RDMA controllers
* tag 'cgroup-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Docs/admin-guide/cgroup-v2: note blkcg_debug_stats gates io.latency stats
Docs/admin-guide/cgroup-v1: document rdma.peak, rdma.events and rdma.events.local
Docs/admin-guide/cgroup-v2: drop stale misc interface file count
cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed
Docs/admin-guide/cgroup-v2: fix memory.stat doc details
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Pull sched_ext fixes from Tejun Heo:
- Lifecycle fixes for the new sub-scheduler support: two
use-after-frees and an enable-failure path that left a
half-initialized sub-scheduler linked.
- Two dispatch-path locking bugs: a spurious scheduler abort from a
migration race, and a lockdep splat from stale runqueue-lock
tracking.
- Callback and task-state fixes: stale scheduler-owned state on a task
leaving SCX, a weight callback running after disable, and a bogus
warning on core-scheduling forced idle.
- On nohz_full, finite-slice tasks could miss the tick that expires
their slice. Enable it when such a task is picked, with a selftest.
- Smaller fixes: userspace CPU-mask helpers, ratelimited deprecation
warnings, docs and a sparse annotation.
* tag 'sched_ext-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Skip ops.set_weight() for disabled tasks
tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()
sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched()
sched_ext: Record an error on errno-only sub-enable failure
selftests/sched_ext: Verify nohz_full tick behavior
sched_ext: Enable tick for finite slices on nohz_full
sched_ext: Preserve rq tracking across local DSQ dispatch
sched_ext: Documentation: Fix ops table header reference
sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()
sched_ext: Pin parent scx_sched across a child sub-scheduler's lifetime
sched_ext: Annotate ksyncs with __rcu in alloc/free_kick_syncs()
sched_ext: Check remote rq eligibility under task's rq lock
sched_ext: Reset dsq_vtime and slice when a task leaves SCX
sched_ext: Avoid flooding the log with deprecation warnings
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Update DMA reserved memory pool allocation log messages to display
sizes in KiB instead of MiB. Using MiB caused allocations less than
1 MiB to be logged as 0 MiB due to integer truncation. KiB provides
better precision for smaller memory regions specified in the Device Tree.
Signed-off-by: Vova Sharaienko <sharaienko@google.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260629223759.2637162-1-sharaienko@google.com
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Fixed spacing around * coding style issue
Signed-off-by: Vova Sharaienko <sharaienko@google.com>
[mszyprow: changed patch prefix]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260623000821.2269955-1-sharaienko@google.com
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restore_dm_crypt_keys_to_thread_keyring() gets a reference to the user
keyring before restoring the saved dm-crypt keys.
The same keyring reference is then passed to add_key_to_keyring() for each
saved key, but add_key_to_keyring() drops that reference on every call.
This is only balanced when exactly one key is restored. With multiple
keys, the keyring reference is dropped too many times and may trigger a
refcount underflow or use-after-free.
When more than five keys are restored, a refcount underflow/use-after-free
warning can be triggered.
The early error paths after lookup_user_key() also return without dropping
the keyring reference.
Keep ownership of the keyring reference in
restore_dm_crypt_keys_to_thread_keyring(), drop it once on all exit paths,
and make add_key_to_keyring() only use the reference without consuming it.
Fixes: 62f17d9df692 ("crash_dump: retrieve dm crypt keys in kdump kernel")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-and-tested-by: Coiby Xu <Coiby.Xu@gmail.com>
Acked-by: Baoquan He <baoquan.he@linux.dev>
Reviewed-by: Bradley Morgan <include@grrlz.net>
Link: https://patch.msgid.link/20260704112509.3717884-1-lgs201920130244@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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Pull tracing fixes from Steven Rostedt:
- Free field in error path of synthetic event parse
In __create_synth_event() the field was allocated but was not freed
in the error path
- Fix ring_buffer_event_length() on 8 byte aligned architectures
On architectures with CONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y, the
ring_buffer_event_length() may return the wrong size. This is because
archs with that config set will always use the "big event meta
header" as that is 8 bytes keeping the payload 8 bytes aligned, even
when a 4 byte header could hold the size of the event
But ring_buffer_event_length() doesn't take this into account and
only subtracts 4 bytes for the meta header in the length when it
should have subtracted 8 bytes
- Have osnoise wait for a full rcu synchronization on unregister
osnoise_unregister_instance() used to call synchronize_rcu() before
freeing its copy of the instance but was switched to kfree_rcu(). The
osniose tracer has code that traverses the instances that it uses,
and inst is just a pointer to that instance. By using kfree_rcu()
instead of synchronize_rcu(), the instance that the inst pointer is
pointing to can be freed while the osnoise code is still referencing
it
That is, a rmdir on an instance first unregisters the tracer. When
the unregister finishes, the rmdir expects that the tracer is
finished with the instance that it is using. By putting back the
synchronize_rcu() in osnoise_unregister_instance() the unregistering
of osnoise will now return when all the users of the instance have
finished
- Remove an unused setting of "ret" in tracing_set_tracer()
- Fix ring_buffer_read_page() copying events
The commit that changed ring_buffer_read_page() to show dropped
events from the buffer itself, split the "commit" variable between
the commit value (with flags) and "size" that holds the size of the
sub-buffer. A cut and paste error changed the test of the reading
from checking the size of the buffer to the size of the event causing
reads to only read one event at a time
- Make tracepoint_printk a static variable
When the tracing sysctl knobs were move from sysctl.c to trace.c, the
variable tracepoint_printk no longer needed to be global. Make it
static
- Fix some typos
- Fix NULL pointer dereference in func_set_flag()
The flags update of the function tracer first checks if the value of
the flag is the same and exits if they are, and then it checks if the
current tracer is the function tracer and exits if it isn't. The
problem is that these checks need to be in a reversed order, as if
the tracer isn't the function tracer, then the flag being checked may
not exist. Reverse the order of these checks
- Fix ufs core trace events to not dereference a pointer in TP_printk()
The TP_printk() part of the TRACE_EVENT() macro is called when the
user reads the "trace" file. This can be seconds, minutes, hours,
days, weeks, and even months after the data was recorded into the
ring buffer. Thus, saving a pointer to an object into the ring buffer
and then dereferencing it from TP_printk() can cause harm as the
object the pointer is pointing to may no longer exist
Fix all the trace events in ufs core to save the device name in the
ring buffer instead of dereferencing the device descriptor from
TP_printk()
- Prevent out-of-bound reads in glob matching of trace events
The filter logic of events allows simple glob logic to add wild cards
to filter on strings. But some events have fields that may not have a
terminating 'nul' character. This may cause the glob matching to go
beyond the string. Change the logic to always pass in the length of
the field that is being matched
- Add no-rcu-check version of trace_##event##_enabled()
The trace_##event##_enabled() usually wraps trace events to do extra
work that is only needed when the trace event is enabled. But this
can hide events that are placed in locations where RCU is not
watching, and can make lockdep not see these bugs when the event is
not enabled
The trace_##event##_enabled() was updated to always test to make sure
RCU is watching to catch locations that may call events without RCU
being active
This caused a false positive for the irq_disabled() and related
events. As that use trace_irq_disabled_enabled() to force RCU to be
watching when the event is enabled via the ct_irq_enter() function,
calls the event, and then calls ct_irq_exit() to put RCU back to its
original state
The trace_irq_disabled_enabled() should not trigger a warning when
RCU is not watching because the code within its block handles the
case properly. Make a __trace_##event##_enabled() version for this
event to use that doesn't check RCU is watching as it handles the
case when it isn't
- Fix use-after-free in user_event_mm_dup()
When the enabler is removed from the link list, it is freed
immediately. But it is protected via RCU and needs to be freed after
an RCU grace period. Use queue_rcu_work() so that the event_mutex can
also be taken as user_event_put() takes the mutex on the last
reference is released
- Free type string in error path of parse_synth_field()
There's an error path in parse_synth_field() where the allocated type
string is not freed
- Add selftest that tests deferred event teardown
- Fix leak in error path of trace_remote_alloc_buffer()
If page allocation fails, the desc->nr_cpus is not incremented for
the current CPU and the allocations done for it are not freed
- Fix allocation length in trace_remote_alloc_buffer()
The logic to calculate the struct_len was doing a double count and
setting the value too large. Calculate the size upfront to fix the
error and simplify the logic
- Fix sparse CPU masks in ring_buffer_desc()
If there are sparse CPUs (gaps in the numbering), the
ring_buffer_desc() will fail as it tests the CPU number against the
number of CPUs that are used
* tag 'trace-v7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Allow sparse CPU masks in ring_buffer_desc()
tracing/remotes: Fix struct_len in trace_remote_alloc_buffer()
tracing/remotes: Fix leak in trace_remote_alloc_buffer() error path
selftests/user_events: Wait for deferred event teardown after unregister
tracing/synthetic: Free type string on error path
tracing/user_events: Fix use-after-free in user_event_mm_dup()
tracing: Add a no-rcu-check version of trace_##event##_enabled()
tracing: Prevent out-of-bounds read in glob matching
ufs: core: tracing: Do not dereference pointers in TP_printk()
tracing: Fix NULL pointer dereference in func_set_flag()
samples: ftrace: Fix typos in benchmark comment
tracing: Make tracepoint_printk static as not exported
ring-buffer: Fix ring_buffer_read_page() copying only one event per page
tracing: Remove unused ret assignment in tracing_set_tracer()
tracing/osnoise: Call synchronize_rcu() when unregistering
ring-buffer: Fix event length with forced 8-byte alignment
tracing/synthetic: Free pending field on error path
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The return value of __secure_computing() currently uses 0 to indicate
that a system call should be allowed, and -1 to indicate that it should
be blocked/killed. This 0/-1 pattern is non-intuitive for a security
check function and makes the control flow at the call sites less readable.
Furthermore, any potential future changes to these return values would
require a high-risk, error-prone audit of all its users across different
architectures.
Sanitize this logic by converting the return type of __secure_computing()
to a proper boolean, where 'true' explicitly means 'allow' and 'false'
means 'fail/deny'.
Update all the two dozen or so call sites across the tree to align with
this new boolean semantic. No functional changes are intended, as the
callers still return -1 to the lower-level assembly entry code upon
seccomp denial.
Rename the function to __seccomp_permit_syscall() so that the purpose is
entirely clear.
[ tglx: Rename the function ]
Suggested-by: Thomas Gleixner <tglx@kernel.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://patch.msgid.link/20260707190254.230735780@kernel.org
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Since tracing_multi link does not set ftrace_managed, it would fail to
release the tracing_multi link when attaching tracing_multi link and
then attaching fentry link.
[ 3.714215] WARNING: kernel/bpf/trampoline.c:1727 at bpf_trampoline_multi_detach+0x20b/0x240, CPU#1: test_progs/97
...
[ 3.733170] bpf_tracing_multi_link_release+0x14/0x30
[ 3.733890] bpf_link_free+0x58/0x130
[ 3.734414] bpf_link_release+0x23/0x30
Fix it by setting 'ftrace_managed = true' in register_fentry_multi().
Fixes: aef4dfa790b2 ("bpf: Add bpf_trampoline_multi_attach/detach functions")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260711124822.29406-2-leon.hwang@linux.dev
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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bpf_cpumask_populate() writes to its destination with bitmap_copy(), but
the destination is typed as struct cpumask *. That allows the verifier to
accept borrowed cpumask pointers returned by read-only kfuncs, such as
scx_bpf_get_online_cpumask(), as a writable destination.
Make the destination a struct bpf_cpumask * so populate follows the same
ownership rule as the other mutating cpumask kfuncs. Query kfuncs continue
to accept const struct cpumask * inputs.
Fixes: 950ad93df2fc ("bpf: add kfunc for populating cpumask bits")
Signed-off-by: Nicholas Dudar <main.kalliope@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/bpf/20260709182800.2037938-2-main.kalliope@gmail.com
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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Pull perf events fixes from Ingo Molnar:
- Fix SVM #GP on AMD CPUs that LBR but not BRS (Sandipan Das)
- Fix UAF bug in the perf AUX code (Lee Jia Jie)
- Fix address leakage in the AMD LBR code (Sandipan Das)
- Fix address leakage in the AMD BRS code (Sandipan Das)
* tag 'perf-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/amd/brs: Fix kernel address leakage
perf/x86/amd/lbr: Fix kernel address leakage
perf/aux: Fix page UAF in map_range()
perf/x86/amd/core: Avoid enabling BRS from the SVM reload path
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Pull timer fix from Ingo Molnar:
- Fix a subtle posix-cpu-timers vs. exec() race, which
unearthed other races in the area (Thomas Gleixner)
* tag 'timers-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Prevent UAF caused by non-leader exec() race
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Pull audit fixes from Paul Moore:
"Two relatively small audit patches to fix potential data races with
the main audit backlog queue as well as possible integer overflows
when logging data as hex strings"
* tag 'audit-pr-20260710' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: fix potential integer overflow in audit_log_n_hex()
audit: Fix data races of skb_queue_len() readers on audit_queue
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No user currently relies on sparse CPU masks, but the descriptor logic already
supports them via linear fallback. Remove the arbitrary limitation.
Link: https://patch.msgid.link/20260709160017.1729517-4-vdonnefort@google.com
Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Pre-calculate desc->struct_len up-front in trace_remote_alloc_buffer()
with trace_buffer_desc_size() to fix double-counting.
While at it, use the accessor __first_ring_buffer_desc().
Link: https://patch.msgid.link/20260709160017.1729517-3-vdonnefort@google.com
Fixes: 96e43537af54 ("tracing: Introduce trace remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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If page allocation fails in trace_remote_alloc_buffer(), desc->nr_cpus
is not yet incremented for the current CPU. As a consequence, on error,
half-allocated rb_desc will not be freed in trace_remote_free_buffer().
Increment desc->nr_cpus as soon as the first allocation for the current
CPU has succeeded.
Link: https://patch.msgid.link/20260709160017.1729517-2-vdonnefort@google.com
Fixes: 96e43537af54 ("tracing: Introduce trace remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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When switching a task's sched_class away from sched_ext, we get the
following sequence of events in __sched_setscheduler():
sched_change_begin()
switched_from_scx()
scx_disable_task(p)
ops.disable(p)
__setscheduler_params()
set_load_weight()
reweight_task_scx(p)
ops.set_weight(p)
p->sched_class = next_class;
sched_change_end()
...
Notably, ops.set_weight() is called _after_ ops.disable().
This violates the expected semantics of the callbacks, the expectation
being that ops.disable() can only be followed by ops.exit_task() or
ops.enable().
Skipping the weight adjustment for disabled tasks should be harmless
since the weight will be recalculated in scx_enable_task() if the task
ever rejoins SCX.
Fixes: 637b0682821b ("sched: Fold sched_class::switch{ing,ed}_{to,from}() into the change pattern")
Cc: stable@vger.kernel.org # v6.19+
Signed-off-by: Kuba Piecuch <jpiecuch@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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sched_ext schedulers have state in BPF programs and kernel. scx_dump
provides kernel state and BPF program state on error, but this is static
in what it can provide.
Add a sched_ext_exit tracepoint in scx_claim_exit() so that BPF programs
can dynamically inspect scheduler specific state at the moment of exit.
Pass the exiting scx_sched so attached programs can read its state, and,
since exits propagate through a hierarchy of sub-schedulers, identify
which scheduler each event belongs to.
Signed-off-by: Pat Somaru <patso@likewhatevs.io>
Signed-off-by: Tejun Heo <tj@kernel.org>
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map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via
perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are
serialized by rb->aux_mutex, and mmap_mutex is per event.
Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race
rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:
CPU 0 CPU 1
===== =====
rb_alloc_aux() map_range()
[1]: allocate rb->aux_pages[0]
[2]: rb->aux_nr_pages++
[3]: perf_mmap_to_page()
returns rb->aux_pages[0]
[4]: map it as VM_PFNMAP
[5]: rb->aux_pgoff = 1
munmap the page
[6]: free rb->aux_pages[0]
Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a
mapping to a freed physical frame.
Fix this by taking rb->aux_mutex across the page walk in map_range().
Fixes: b709eb872e19 ("perf: map pages in advance")
Signed-off-by: Lee Jia Jie <jiajie.lee@starlabs.sg>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
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Now that nothing inflates tick_length beyond tick_length_base (the
adjtime path was converted to use time_offset in the previous commit),
the two fields are always equal.
Remove tick_length_base and keep tick_length as the single field.
Remove the per-second reset and the delta update in
ntp_update_frequency() since there is no separate base to track.
No functional change intended.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.6-1m
Link: https://patch.msgid.link/20260621220051.1030462-8-dwmw2@infradead.org
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time_offset (the exponential PLL phase slew) and time_adjust (the
linear adjtime() slew) can be asked to move the clock in opposite
directions. second_overflow() folds only their *net* into the per-tick
skew_delta, so the cancelling overlap would never be drained from
either tracker by the per-tick code — and if they cancel exactly,
skew_delta is zero and neither converges at all.
Arguably we could just let one of them entirely cancel out the other
immediately, but that would be a change in userspace-visible behaviour.
Instead, preserve the existing behaviour by calculating the "conflict"
portion between the opposing skew each second, and transferring that
amount directly from one tracker to the other.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-7-dwmw2@infradead.org
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The legacy adjtime() slew (ADJ_OFFSET_SINGLESHOT) was the last user of
tick_length != tick_length_base: it slewed the clock by inflating
tick_length directly, which delivered the correction imprecisely (e.g.
delivering only 4997.5µs when asked for a 5ms skew).
Deliver it accurately through the same per-tick mechanism that is now
used for time_offset, allowing it to contribute to skew_delta and thus
drive the delivery through ntp_error and mult selection.
To allow for accurate accounting, store the sub-microsecond part of
time_adjust is separately, while keeping time_adjust in microseconds
as that's the external API.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-6-dwmw2@infradead.org
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Currently, the phase offset of time_offset and time_adjust is delivered
by adjusting tick_length in second_overflow(), and immediately draining
time_offset/time_adjust by the amount that the tick_length adjustment is
*estimated* to cause. This is fairly approximate, in part because it is
not always correct to assume that precisely NTP_INTERVAL_FREQ ticks will
occur between one call to second_overflow() and the next. It could also
over and under-run in the final second of delivery.
Instead of inflating tick_length, transfer the intended skew directly
into ntp_error each tick to achieve the desired rate.
In second_overflow(), calculate skew_delta which is the per-tick slew
rate, in the same units as time_offset: (ns << NTP_SCALE_SHIFT) / HZ.
In logarithmic_accumulation(), drain up to 'skew_delta' time units from
time_offset into ntp_error to drive the overall effective rate. The new
ntp_drain_skew() function returns the amount which is actually 'claimed'
by time_offset (and in a future patch, time_adjust). Any overrun which
is delivered by the changed 'mult' (as described below) but not claimed
by ntp_drain_skew() will remain in ntp_error to be corrected away in
subsequent ticks.
Simply transferring the precise amount from time_offset to ntp_error
would be sufficent to make the time *eventually* converge, however the
skew delivered is limited by the choice of { mult, mult+1 } each tick
and thus the convergence would be extremely slow.
In theory we could inflate ntp_err_mult with the magnitude of ntp_error
in the general case — but that would cause overcorrection in a tickless
kernel. Instead, in timekeeping_adjust(), take skew_delta into account
when calculating 'mult', such that the available {mult, mult+1} choices
bracket the overall effective rate *including* the skew, to avoid the
delta just building up in ntp_error.
The effect is that the inflated 'mult' causes ntp_error to grow because
xtime_interval is (e.g.) longer than the true tick_length. But then the
same delta is removed again as it's drained from time_offset.
This gives behaviour equivalent to the old tick_length += delta approach
but with exact per-tick accounting of the time_offset actually imparted
to the clock, and no overrun.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-5-dwmw2@infradead.org
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cycle_interval is an integer number of counter cycles per NTP interval,
so the real time it represents differs from the nominal
NTP_INTERVAL_LENGTH by up to half a counter period. For coarse
clocksources this is significant: the 3.579545 MHz ACPI PM timer at
HZ=1000 rounds 3579.545 cycles up to 3580, making each tick 1.000127 ms
(+127 PPM).
Commit a386b5af8edd ("time: Compensate for rounding on odd-frequency
clocksources") introduced xtime_remainder to compensate for exactly
this, citing the same 127 PPM ACPI PM example. The compensation is
correct and necessary, but it was applied inside the timekeeping
accumulation in timekeeping.c: subtracted in the mult computation in
timekeeping_adjust() and folded into the ntp_error update in
logarithmic_accumulation(). That keeps the base rate correct and leaves
NTP its full symmetric +/-MAXFREQ range rather than +373/-627 PPM, but
the NTP code in ntp.c never sees it: tick_length is computed without the
correction, so ntp.c's notion of how long a tick is disagrees with the
rate timekeeping actually produces.
Make the offset an explicit part of the NTP tick_length instead. Add
ntp_data::cs_tick_adj, a fixed per-second addend that
ntp_update_frequency() includes alongside ntp_tick_adj and time_freq.
tk_setup_internals() computes it from the difference between the real
cycle_interval duration and the nominal interval, stores it in the
timekeeper, and hands it to NTP through a new argument to ntp_clear() --
which already recomputes the frequency and is invoked after every
clocksource (re)configuration. timekeeping_init() now uses TK_UPDATE_ALL
for this; clearing NTP there is otherwise redundant since ntp_init() has
just initialised it.
ntp.c now computes the true tick rate, giving a single source of truth.
Like ntp_tick_adj, cs_tick_adj stays internal to the kernel: userspace
still sees the nominal 1.000000 ms tick via adjtimex and is unaware of
the addends. timekeeping_adjust() and logarithmic_accumulation() use
ntp_tick / xtime_interval directly, and xtime_remainder is removed.
The base-rate arithmetic is unchanged: ntp_tick becomes
xtime_interval << ntp_error_shift, so the mult division yields the same
base mult and the ntp_error accumulation still nets to zero per tick.
Beyond the cleanup of treating all the tick_length contributions
(nominal interval, ntp_tick_adj, cs_tick_adj, time_freq) consistently
as addends in one place, it also prepares for feed-forward discipline:
a future timekeeping_set_reference() will set tick_length to track an
absolute external reference such as a vmclock, and that path needs
ntp.c to own a tick_length that already reflects the clocksource
quantisation, with no hidden correction applied elsewhere.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/20260621220051.1030462-4-dwmw2@infradead.org
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consume_remote_task() drops this_rq before unlinking a remote task from
its DSQ and locking src_rq. When called from ops.dispatch(),
scx_locked_rq() keeps pointing to this_rq across the lock dance. The
subsequent switch_rq_lock(src_rq, this_rq) cannot update the tracking
because its guard does not match, leaving the tracking stale while
src_rq is held.
Keep this_rq locked until the task has been unlinked and the DSQ lock
released, then use switch_rq_lock() to switch directly to src_rq. Use
the same helper to restore this_rq after losing the dequeue race. The
successful path already switches back through
move_remote_task_to_local_dsq(), so scx_locked_rq() now follows the
actually held rq throughout the consume path.
Suggested-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/all/455e701bca66bdecde530d225f4dba0a@kernel.org
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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scx_bpf_kick_cid() returned an error code, but the value conveys nothing
actionable and no caller consumes it. The kick is asynchronous, so a
successful return only means it was queued. An invalid @cid is already
reported through scx_error() by scx_cid_to_cpu(), and a missing scheduler
leaves nothing to kick.
Make scx_bpf_kick_cid() return void to match scx_bpf_kick_cpu(). The
cid-form kfuncs are not in practical use yet, so the ABI change is safe.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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Direct writes to p->scx.slice and p->scx.dsq_vtime bypass
scx_bpf_task_set_slice/dsq_vtime() and the authority checks they carry.
Those checks exist for sub-schedulers, which attach only through the
cid-form struct_ops, so the direct writes only need to be closed there.
Give sched_ext_ops_cid its own verifier ops that reject the two fields.
cid-form is a new interface with no legacy users, so there is no
compatibility to keep. The cpu-form keeps direct writes, and the deprecation
warning they carried is dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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scx_rq.extra_enq_flags carries scx-specific enqueue flags across the
activate_task() boundary during a cross-rq task move in
move_remote_task_to_local_dsq(). Rename it to remote_activate_enq_flags to
name that role, and fix the stale comment that referenced the old
move_task_to_local_dsq() name.
No functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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The cid-form ops overlay their cpu-form siblings at the same struct slot.
Ops whose signature matches the sibling are invoked through the cpu-form
call sites unchanged, but set_cmask() takes an arena cmask address rather
than a cpumask, so scx_call_op_set_cpumask() calls ops_cid.set_cmask()
directly and hand-rolled the kf_tasks[] and locked_rq bracket that
SCX_CALL_OP_TASK() provides. The hand-rolled bracket reset locked_rq to
NULL on exit instead of restoring the saved value, so a nested call would
clobber the outer op's locked-rq tracking.
Parameterize the dispatch macros by the ops-table member and add
SCX_CALL_CID_OP_TASK(), which routes through sch->ops_cid. Convert
scx_call_op_set_cpumask() to it and drop the hand-rolled bracket. The only
behavioral change is that locked_rq is now saved and restored like every
other op call site.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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The cmask ops can operate on BPF-arena cmasks which BPF programs may read
and write concurrently. The _RACY op variants existed to make such lockless
reads explicit but this turned out to be too restrictive. Mark the word
accesses in all the two-cmask ops with READ_ONCE/WRITE_ONCE instead and drop
the _RACY variants.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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Pull to receive:
db4e9defd2e8 ("sched_ext: Record an error on errno-only sub-enable failure")
49b3378a750c ("sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched()")
e6979d05c6a6 ("tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()")
for further sub-sched changes and to resolve the conflicts with the
sub-sched updates on for-7.3.
db4e9defd2e8 adds scx_error() to the sub-enable err_disable sink which
for-7.3 moved from ext.c into sub.c. Resolved by applying the fix to
scx_sub_enable_workfn() in sub.c.
49b3378a750c drops RCU_INIT_POINTER() from an scx_alloc_and_add_sched()
unwind label whose body changed with for-7.3's stall_cpus addition.
Resolved by dropping the line from the updated unwind.
Signed-off-by: Tejun Heo <tj@kernel.org>
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scx_alloc_and_add_sched() publishes @sch through ops->priv before allocating
the cgroup path. If that allocation fails, the unwind path clears ops->priv
and frees @sch immediately. scx_prog_sched() callers can dereference
ops->priv from RCU context the moment it is set, so freeing without a grace
period can use-after-free a concurrent kfunc caller.
Move the publication below the cgroup path allocation so that every failure
path after publication frees @sch through kobject_put(), whose release path
defers the freeing by a grace period.
Fixes: 105dcd005be2 ("sched_ext: Introduce scx_prog_sched()")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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scx_sub_enable_workfn() has several failure paths that only return an errno
(e.g. -ENOMEM from an allocation) and jump to err_disable without calling
scx_error(). scx_flush_disable_work() runs the disable, and thus ops.exit(),
only when an error has been recorded, so an errno-only failure leaves the
half-initialized sub-scheduler linked.
Record an error at the err_disable sink so every errno-only failure runs the
disable path.
Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
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The comment for scx_bpf_dsq_insert() references "@dsp_id" in the
description body, but the parameter is named "@dsq_id" in both the
parameter list and the function signature.
Signed-off-by: Liang Luo <luoliang@kylinos.cn>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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check_kfunc_args() detects a kfunc argument named rdonly_buf_size or
rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64,
and does not bound it. check_kfunc_call() later copies that value into
the returned register's mem_size field:
meta->r0_size = reg->var_off.value;
...
regs[BPF_REG_0].mem_size = meta.r0_size;
regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set
gets truncated instead of causing a load-time rejection, so the verifier
records a PTR_TO_MEM register with an approximately 4 GiB mem_size for
whatever allocation the kfunc returned. A later access check against
that register uses the truncated, wrong bound.
Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the
point meta->r0_size is set.
Fixes: eb1f7f71c126 ("bpf/verifier: allow kfunc to return an allocated mem")
Signed-off-by: Nicholas Dudar <main.kalliope@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260709155837.1879230-2-main.kalliope@gmail.com
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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When a spilled scalar is filled back with a sign-extending narrowing load
(BPF_MEMSX), check_stack_read_fixed_off() copies the spilled register
including its scalar id, but coerce_reg_to_size_sx() then sign-extends the
filled register's value. If the same slot is also filled with a plain
zero-extending load (BPF_MEM), both destination registers share the id yet
hold different values. A later 'if <zext-reg> == const' then refines the
sign-extended register through sync_linked_regs() to a value it does not
have at runtime (e.g. the verifier believes 0x80000000 while the register
is 0xffffffff80000000), which can be turned into an out-of-bounds access.
Drop the shared scalar id at the sign-extension site in check_mem_access()
when sign extension actually changes the value, mirroring the BPF_MOVSX
handling in check_alu_op() (no_sext = reg_umax < 2^(size*8-1)).
Fixes: 3cd5c890652b ("bpf: Let the verifier assign ids on stack fills")
Reported-by: STAR Labs SG <info@starlabs.sg>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
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When emitting a record via legacy printing, it is possible that a handover
to another legacy printing context occurs. When a context has performed a
handover, the console SRCU read lock is released and the pointer to the
console struct might now be invalid. Therefore, after calling
nbcon_legacy_emit_next_record() or console_emit_next_record(), it is
necessary to check if a handover occurred _before_ further @con usage.
Sashiko pointed out that console_flush_one_record() was not doing this.
In console_flush_one_record(), after emitting a record, move the further
usage of @con after the handover check.
Fixes: c158834b223f ("printk: nbcon: Use nbcon consoles in console_flush_all()")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/lkml/20260630170903.099D61F000E9@smtp.kernel.org
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/20260703141521.202813-1-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
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Commit 5816bf4273ed ("lsm,selinux: Add LSM blob support for BPF objects")
made the LSM hook wrappers for BPF object creation clean up the LSM
state internally upon denial, e.g. security_bpf_map_create() internally
calls security_bpf_map_free() when the bpf_map_create hook returns an
error. map_create() however still routes a denial to its free_map_sec
label, which invokes security_bpf_map_free() a second time, so the
bpf_map_free hook fires twice for a single denied map.
In-tree LSMs are unaffected in practice since the blob kfree() inside
security_bpf_map_free() is NULL-safe and idempotent and none of them
implement bpf_map_free, but a BPF LSM program attached to that hook
observes double invocations. Route the denial to free_map instead.
Fixes: 5816bf4273ed ("lsm,selinux: Add LSM blob support for BPF objects")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260709073422.379247-1-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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When an architecture (such as LoongArch, ARM64, and RISC-V) implements
bpf_jit_inlines_helper_call(), the verifier skips rewriting the helper
call offset (insn->imm) in bpf_do_misc_fixups(). This is because the
helper is expected to be inlined by the JIT compiler later. Therefore,
insn->imm remains as the raw helper enum ID.
However, if JIT is disabled at runtime (net.core.bpf_jit_enable=0) or
if JIT compilation fails dynamically (e.g., due to OOM), the program
falls back to the BPF interpreter.
When the interpreter executes (__bpf_call_base + insn->imm) with the
unpatched raw ID, it jumps into an invalid address space, triggering
an instruction alignment fault or a kernel panic.
Although these helpers have valid C implementations in the kernel, the
omission of offset rewriting makes runtime interpreter fallback fatal.
Fix this by setting 'prog->jit_required = 1' when helper call rewriting
is skipped for JIT inlining. This ensures that such programs are safely
rejected if JIT is not available, preventing the runtime kernel panic.
Fixes: 2ddec2c80b44 ("riscv, bpf: inline bpf_get_smp_processor_id()")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
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Introduce a 'jit_required' bitfield flag in struct bpf_prog to track
whether a BPF program strictly requires the JIT compiler to run. This
prevents a dangerous runtime fallback to the interpreter for features
that are only implemented in the JIT compiler.
Currently, bpf_prog_has_kfunc_call() is used only for kernel function
calls, replace the kfunc-specific helper with the new 'jit_required'
flag. This makes it easy to support other JIT-only BPF features, such
as inlined helpers.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: KaFai Wan <kafai.wan@linux.dev>
Suggested-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
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bpf_find_vma() reads task->mm and calls mmap_read_trylock(mm) without
holding a reference on the mm. On a foreign task, a concurrent exit_mm()
can free the mm_struct between the lockless read and the trylock,
resulting in a use-after-free. mm_struct is not SLAB_TYPESAFE_BY_RCU.
For the current task, task->mm is stable. For a foreign task, pin the mm
under task->alloc_lock and release it with mmput_async(), mirroring commit
d8e27d2d22b6 ("bpf: fix mm lifecycle in open-coded task_vma iterator").
Use spin_trylock() instead of get_task_mm() so BPF context does not block
on alloc_lock. Reject irqs-disabled contexts and !CONFIG_MMU on the
foreign-task path because dropping the mm reference is not safe there.
Race:
CPU0 (BPF program) CPU1 (exiting task)
============================ ==========================
bpf_find_vma(foreign_task):
mm = task->mm
exit_mm():
task->mm = NULL
mmput(mm) -> frees mm_struct
mmap_read_trylock(mm)
// UAF on mm
Fixes: 7c7e3d31e785 ("bpf: Introduce helper bpf_find_vma")
Signed-off-by: Sanghyun Park <sanghyun.park.cnu@gmail.com>
Reviewed-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20260708072106.199637-2-sanghyun.park.cnu@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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bpf_prog_calc_tag() copies the instructions into a plain vmalloc() scratch
buffer to blind the map fds before hashing. The buffer scales with the
program, up to ~8MB at the 1M instruction limit, and is allocated on every
program load, but unlike the rest of the load-time scratch memory it is
not charged to the loader's memcg. Use GFP_KERNEL_ACCOUNT to account it
like the other allocations scoped to the verification/load.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708211537.371874-5-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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The insn_aux_data array is allocated with a plain vzalloc(), while every
other allocation scoped to the verification - verifier states, explored
states, the cfg/scc arrays, liveness masks, jump history - is charged to
the loader's memcg via GFP_KERNEL_ACCOUNT.
At 136 bytes per instruction it is one of the largest verification-time
buffers, in the range of ~130MB for a program at the 1M instruction limit
(worst case), and it lives across the whole verification. The buffer is
also inconsistent with itself: when instruction patching grows it, the
vrealloc() in bpf_patch_insn_data() already passes GFP_KERNEL_ACCOUNT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708211537.371874-4-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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bpf_get_btf_vmlinux() serializes the lazy vmlinux BTF parse with
bpf_verifier_lock, the same mutex bpf_check() holds across the whole
verification of an unprivileged program (if enabled; it's disabled
by default). The latter can potentially stall the mutex holder for
a long time (e.g. via userfaultfd), and therefore block first-time
bpf_get_btf_vmlinux() caller from any context, including privileged
program loads.
Give the vmlinux BTF initialization a dedicated btf_vmlinux_lock so
it is independent of the unprivileged verification mutex. The parse
only needs mutual exclusion against itself.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708211537.371874-3-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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bpf_get_btf_vmlinux() lazily parses the vmlinux BTF under the
bpf_verifier_lock, but publishes the result through a plain store
and re-checks it through a plain lockless load. Nothing orders
the stores initializing the struct btf inside btf_parse_vmlinux()
against the store publishing the pointer: On a weakly ordered
arch, a concurrent first-time caller taking the lockless fast
path could in principle observe the pointer before the parsed
contents are visible. The mutex_unlock() does not help such a
reader given it only synchronizes with a later acquisition of the
same lock. Thus, publish the pointer with smp_store_release()
and read it on the fast path with smp_load_acquire().
Acquire semantics are needed rather than a dependency-ordered
READ_ONCE(): btf_parse_vmlinux() also populates globals outside
the returned object (e.g. bpf_ctx_convert.t). An address
dependency would only order accesses performed through the
pointer and not cover other globals.
Fixes: 8580ac9404f6 ("bpf: Process in-kernel BTF")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708211537.371874-2-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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set_next_task_scx() updates the tick dependency before __schedule()
updates rq->curr. When switching from a non-EXT task, such as idle, to
an EXT task with a finite slice, sched_update_tick_dependency() checks
the outgoing task and can allow the tick to remain stopped.
The dependency can also be lost without a slice-type transition. After a
finite-slice task leaves the CPU idle, the enqueue path can clear the
dependency against the idle rq->curr. SCX_RQ_CAN_STOP_TICK still records
a finite slice, so another finite task skips the transition block and
can run without the ticks needed to expire its slice.
The reverse mismatch can also happen when the last finite-slice EXT task
is dequeued: sub_nr_running() updates the dependency before rq->curr
changes, so the outgoing task state can keep the dependency set after
the CPU goes idle.
Fix this by unconditionally enabling the scheduler tick whenever a
finite-slice EXT task is selected on a nohz_full CPU. Moreover, when the
last runnable EXT task leaves, ignore the outgoing EXT slice state so
the generic scheduler can correctly re-evaluate and clear the tick
dependency.
Fixes: 22a920209ab6 ("sched_ext: Implement tickless support")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The function calculates new_len as len << 1 for hex encoding. This
has two overflow risks: the shift itself can overflow when len is
large, and the result can be truncated when assigned to new_len
(declared as int) from the size_t calculation.
Fix by using check_shl_overflow() to catch shift overflow and
changing new_len and loop counter i to size_t to prevent truncation.
Cc: stable@vger.kernel.org
Fixes: 168b7173959f ("AUDIT: Clean up logging of untrusted strings")
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Ricardo Robaina <rrobaina@redhat.com>
[PM: remove vertical whitspace noise]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Tejun Heo
Marek Szyprowski
Linus Torvalds
Vova Sharaienko
Guangshuo Li
Jinjie Ruan
Leon Hwang
Nicholas Dudar
Vincent Donnefort
Kuba Piecuch
Pat Somaru
Lee Jia Jie
David Woodhouse
Andrea Righi
Liang Luo
Daniel Borkmann
John Ogness
Tiezhu Yang
Sanghyun Park
Ricardo Robaina