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2026-07-14tracing: fprobe: Remove __packed from generic __fprobe_headerMarkus Schneider-Pargmann (The Capable Hub)
fp pointer and unsigned long have the same size on all relevant architectures that build Linux. Furthermore this struct is only used in architectures that do not set ARCH_DEFINE_ENCODE_FPROBE_HEADER which is set only for 64bit architectures (apart from LoongArch). Both fields are aligned on these architectures so the struct with __packed and without it are the same. Remove the __packed as it is unnecessary. [Masami: Removed Fixes tag because this is not fixing any problem.] Link: https://lore.kernel.org/all/20260428-topic-fprobe-packed-v7-1-v1-1-9abc9b866b4c@baylibre.com/ Signed-off-by: Markus Schneider-Pargmann (The Capable Hub) <msp@baylibre.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Add this_cpu_read() and this_cpu_ptr() dereference method to ↵Masami Hiramatsu (Google)
fetcharg When tracing the kernel local variables, sometimes we need to get the CPU local variables. To access it, current simple dereference is not enough. Thus, introduce a special this_cpu_read() dereference to access per-cpu variable for the current CPU (accessing other CPU variable may race with updates on other CPUs). Also this_cpu_ptr() is for accessing per-cpu pointer. Those are working as same as the kernel percpu macro. Link: https://lore.kernel.org/all/178271367680.1176915.4711734074448973989.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Add $current variable supportMasami Hiramatsu (Google)
Since we can use the BTF to cast value to a structure pointer type, it is useful to introduce "$current" special variable support to fetcharg. User can define a fetcharg to access current task_struct properties using BTF info. e.g. $current->cpus_ptr Link: https://lore.kernel.org/all/178271366709.1176915.15320906169981578568.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Support field specifier option for typecastMasami Hiramatsu (Google)
Add a field specifier option for the typecast. This works like container_of() macro. (STRUCT[,FIELD[.FIELD2...]])VAR This is equivalent to : container_of(VAR, struct STRUCT, FIELD[.FIELD2...]) For example: echo "f tick_nohz_handler next_tick=(tick_sched,sched_timer)timer->next_tick" >> dynamic_events This will trace tick_nohz_handler() with its tick_sched::next_tick which is converted from @timer by contianer_of(tick, struct tick_sched, sched_timer). So, if you enabkle both fprobes:tick_nohz_handler__entry and timer:hrtimer_expire_entry events, we will see something like: <idle>-0 [002] d.h1. 3778.087272: hrtimer_expire_entry: hrtimer=00000000d63db328 f unction=tick_nohz_handler now=3777450051040 <idle>-0 [002] d.h1. 3778.087281: tick_nohz_handler__entry: (tick_nohz_handler+0x4 /0x140) next_tick=3777450000000 Link: https://lore.kernel.org/all/178271365745.1176915.725923927180862257.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Type casting always involves nested callsMasami Hiramatsu (Google)
This allows type casting to various fetchargs without parentheses by recursively calling parse_probe_arg on the target when type casting is used. For example, this allows the following expressions: - (STRUCT)%REG->FIELD - (STRUCT)$stackN->FIELD - (STRUCT)@SYM->FIELD Note that @SYM+/-OFFSET with typecast needs parentheses like: - (STRUCT)(@SYM-8)->FIELD Link: https://lore.kernel.org/all/178271364804.1176915.17600229399446264813.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Support nested typecastMasami Hiramatsu (Google)
When we hit an open parenthesis right after typecast closing parenthesis, it means we have nested typecast. This allows us to typecast a generic data member in a structure to a pointer to another structure. For example, to cast a DATA_MEMBER of VAR structure to STRUCT pointer and get MEMBER value. (STRUCT)(VAR->DATA_MEMBER)->MEMBER Also, we can nest typecast. (STRUCT1)((STRUCT2)$ARG->FIELD2)->FIELD1 Currently the max nest level is limited to 3. This also allows user to use typecasting for registers or stacks on kprobe events. e.g. (STRUCT)(%ax)->MEMBER (STRUCT)($stack0)->MEMBER Link: https://lore.kernel.org/all/178271363855.1176915.16793301788257446529.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14tracing/probes: Support typecast for various probe eventsMasami Hiramatsu (Google)
Support BTF typecast feature on other probe events, but only if it is kernel function entry or return, and must use function parameter name or $retval. This means you can do: (STRUCT)PARAM->MEMBER Note: you can not use other variables like $stackN, %reg etc. That needs nesting support. To support other probe events, we just need to use last_struct type when we find a function parameter in parse_btf_arg(). This also updates <tracefs>/README file to show struct typecast. Link: https://lore.kernel.org/all/178271362928.1176915.12235759508786922490.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-13sched_ext: Add scx_bpf_sub_kill() to evict a child sub-schedulerTejun Heo
A cid-form scheduler can grant caps to and revoke them from its child sub-schedulers but has no way to tear one down. Add scx_bpf_sub_kill() to evict a direct child with a printf-style reason that reaches the child's scx_exit_info. No exit code is taken because the child is a separate scheduler whose exit-code semantics the parent cannot know. The child and its subtree are disabled through the usual async path under a new exit kind, SCX_EXIT_PARENT_KILL. The bstr formatting infrastructure in ext.c is exposed through internal.h with scx_ prefixes so the kfunc, which lives in sub.c, can format the reason. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Replay ecaps notifications suppressed by bypassTejun Heo
scx_process_sync_ecaps() consumes ecaps syncs while the sched is bypassing without delivering ops.sub_ecaps_updated(), leaving reported_ecaps stale. Nothing re-queued a sync when bypass lifted, so a cid whose caps never change again would never be notified. Attach-time initial grants hit this every time: they are consumed during the enable bypass window, so a sched never learned its initial effective caps through the callback. Re-queue a sync for every (sched, cpu) with an undelivered delta at the per-cpu bypass exit in scx_bypass(), next to the idle renotify catch-up. The next balance on the cpu then delivers the pending delta with proper dispatch context. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Route ops.update_idle() to sub-schedulers and re-notify owed schedsTejun Heo
__scx_update_idle() notified only the root scheduler. A sub-scheduler that holds a cid needs that cid's idle state to place and kick on it. Deliver ops.update_idle() to every scheduler that holds SCX_CAP_BASE on the transitioning cid. The root holds every cap, so a real transition always reaches it. Real transitions are not enough on their own. A cid that is already idle when a sub-sched gains baseline access produces no transition, so the new holder would never learn it is idle. The ecaps sync arms a re-notify on the gain, and the next idle pick delivers ops.update_idle() to just that sched, leaving holders that already track the cpu untouched. A matching loss of baseline access drops any pending re-notify. Bypass suppresses ops.update_idle() too, so a cpu that goes idle during a bypass window and stays idle yields no transition to re-deliver on un-bypass. Arm the same re-notify for every sched leaving bypass. The acute case is a child granted cids during its own ops.sub_attach(). The grant lands while the child is bypassed and the notify walk skips it, so on un-bypass it holds cids it never saw go idle. The root is owed the same and is armed through a separate per-rq flag, which keeps this working when sub-schedulers are compiled out. v2: Gate the idle catch-up in pick_task_idle() to avoid a double ops.update_idle(). (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Authorize remote-move inserts against the placing schedulerTejun Heo
scx_local_or_reject_dsq() authorizes a local-DSQ insert against the caps of the scheduler doing the insert. On the consume/dispatch paths that is the scheduler running balance_one(), passed down through scx_consume_dispatch_q() and move_local_task_to_local_dsq(), so the check is correct. The remote-move path loses it. move_remote_task_to_local_dsq() re-activates @p on the destination rq through enqueue_task_scx(), which reconstructs the scheduler from the task, i.e. @p's owner. When an ancestor places a descendant's task - e.g. draining a bypassed sub-scheduler - the owner is a sub-scheduler of the placer, so authorizing against the owner checks a narrower cap set and can spuriously reject a task the placer is entitled to run. Carry the placing scheduler across the activate_task() boundary the same way enq_flags already are, via a per-rq field set only for the duration of the re-activation, and have scx_local_or_reject_dsq() authorize against it. The placer's caps are a superset of the owner's, so this admits what the placer may run and keeps rejecting what it may not. v2: Document @sch in move_remote_task_to_local_dsq()'s kerneldoc. (Andrea) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Gate kicks on SCX_CAP_BASE and preemption on SCX_CAP_PREEMPTTejun Heo
A kick forces a scheduling event on the target cpu, and a preemption also evicts the running task. Gate both on caps. Any kick requires baseline access on the cid, and preempting a task the sub-sched does not own - whether by a SCX_ENQ_PREEMPT insert or a SCX_KICK_PREEMPT kick - requires the new SCX_CAP_PREEMPT. Gating either alone would leave a hole - the weakest cap authorizing preempting kicks, or plain kicks disturbing cpus the kicker has no access to. Preempting the sched's own subtree is always allowed, and the cap extends the right to any task on the cid. PREEMPT implies ENQ, and so ENQ_IMMED. A preempting insert tests the running task under the target rq lock and is rejected and reenqueued unless the victim is in the inserter's subtree or it holds PREEMPT. A migration-disabled task is admitted regardless, but with SCX_ENQ_PREEMPT stripped. Kicks are enforced on the delivery path, where the effective caps can be read coherently under the target rq's lock. A kick from a sub-sched lacking SCX_CAP_BASE on the cid is dropped, and a SCX_KICK_PREEMPT kick without PREEMPT for a task outside the kicker's subtree degrades to a plain reschedule. Unlike the enqueue caps, PREEMPT is checked only at the instant of the insert or kick, never as a standing property of a queued task. v2: Clear SCX_ENQ_PREEMPT on the offline and migration_pending force-admits. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add the SCX_CAP_ENQ capTejun Heo
Add SCX_CAP_ENQ, which gates inserting tasks onto a cid's local DSQ. Unlike IMMED enqueue, plain enqueues can pile up, so ENQ is the stronger cap and implies ENQ_IMMED. Losing ENQ also triggers the reenq scan. The scan tests each queued task and the running task against the cap each needs via scx_caps_for_task(), so an ENQ-only loss reenqueues plain tasks, evicting a running one, while IMMED tasks, which need only ENQ_IMMED, stay put. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Tie cpu occupancy to SCX_CAP_BASE through the task sliceTejun Heo
A task's slice grants it cpu occupancy - how long it holds its cpu. In a sub-scheduler hierarchy cpu access is delegated through revocable capabilities, so a task's occupancy must follow them. Only its own scheduler sets its slice, and extending the slice is allowed only while that scheduler holds baseline cpu access (SCX_CAP_BASE) on the cpu. Otherwise a scheduler could keep occupying a cpu it has been denied simply by handing out long slices. The cap check reads effective caps, which are coherent only under the task's rq lock, and the kernel decrements the slice under that lock as the task runs, so a running task's slice can be changed only there while a queued task's can be set directly. Make scx_bpf_task_set_slice() apply the slice under the rq lock. Synchronously when the caller already holds it, otherwise by stashing it in the new p->scx.slice_oob, tagged with the scheduler's id so a request that outlived a reassignment is dropped. Whether the caller holds @p's current rq lock is tested with p->scx.runnable_cpu. Revocation is enforced through the same grant. When a cpu's effective caps lose SCX_CAP_BASE, the cap-revoke reenq scan also checks the running task and zeroes its slice to evict it. The scan runs as a balance callback after the pick, so this catches both the task that was running when the revoke landed and a capless task the pick just promoted off the local DSQ. The paths that keep a task on its cpu - holding on to the last runnable task in balance, the ENQ_LAST reinsertion and the slice refill on pick - skip tasks lacking baseline access. A migration-disabled task is exempt, mirroring its capless admission on insert. v4: Test rq ownership with p->scx.runnable_cpu, closing a remote-wakeup TOCTOU. (sashiko AI) v3: Keep a pending out-of-band slice request across refill and preserve. (sashiko AI) v2: Only write slice directly when @p is queued on the held rq. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Track the cpu a task is runnable onTejun Heo
Add p->scx.runnable_cpu, the cpu @p is runnable on, or -1 when it is not. It is stamped as @p joins the runnable_list (set_task_runnable()) and cleared as it leaves (clr_task_runnable()), both under the rq lock. task_cpu() can't answer "is @p on this rq" reliably: a remote wakeup changes it under @p's pi_lock alone, without the source rq lock, so it can read as the locked rq while @p is really elsewhere. runnable_cpu changes only under the rq lock, so a caller holding an rq lock can compare against it to know whether that is @p's current rq. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Route task slice writes through set_task_slice()Tejun Heo
A later change makes set_task_slice() also drop a pending out-of-band slice request, so the BPF-triggered writes to p->scx.slice need to funnel through one place. Introduce set_task_slice() and route those writes through it. update_curr_scx() decrements curr->scx.slice directly for accounting and is left alone. No functional change - the helper only assigns p->scx.slice. v2: Reword the set_task_slice comment to "BPF-triggered writes". (Andrea) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Assign a unique id to each scheduler instanceTejun Heo
Neither a scx_sched pointer nor its cgroup id uniquely identifies a scheduler instance. A freed sched's memory can be reallocated, and a cgroup can detach one sched and attach another. Add a monotonic, never-reused u64 id. A later patch compares it to drop a slice request that outlived a change of a task's owning scheduler. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add the SCX_CAP_ENQ_IMMED capTejun Heo
Replace the __SCX_CAP_DUMMY placeholder with SCX_CAP_ENQ_IMMED, which gates inserting IMMED tasks onto a cid's local DSQ. An IMMED enqueue is guaranteed to either get its task running on the cpu at once or hand it back to the scheduler, so IMMED work can never pile up on the cpu's queue and a cpu can be shared across sub-scheds through IMMED access without any of them swamping it. That makes ENQ_IMMED the natural baseline, the minimal cap to make any use of a cpu. SCX_CAP_BASE aliases it so gates on basic cpu access can state the intention instead of naming ENQ_IMMED. Enforcement covers inserts and queued tasks. An insert without the cap is diverted to the reject DSQ, and queued tasks are reenqueued when the cap is lost. scx_bpf_sub_dispatch() skips a child that lacks the cap on the cpu, as its inserts would only be rejected. Vacating the running task on cap loss lands in a later patch. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add SCX_ENQ_IGNORE_CAPS for in-place restoreTejun Heo
A SAVE/RESTORE requeue re-inserts a running task in place and is immediately followed by set_next_task_scx(). It is not a real scheduling event: the task is already admitted to its cid and must return to the local DSQ unconditionally. scx_caps_for_enq() maps an enqueue to the cap its local-DSQ insert requires. Add SCX_ENQ_IGNORE_CAPS, set it on the RESTORE-in-place branch of enqueue_task_scx(), and have scx_caps_for_enq() require no caps for it, so the cid admission gate never diverts an in-place restore to the reject DSQ. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add reject DSQ for cap-rejected dispatchesTejun Heo
When a sub-scheduler dispatches a task to a CPU it lacks the required capability on, the task must be rejected rather than allowed to run. Add the machinery for that. Each rq gets a reject DSQ, a kernel-internal holding queue that is never run and that the BPF scheduler cannot reach. An insert that must be refused is diverted there instead of the local DSQ, and a deferred requeue then hands the parked tasks back to the BPF scheduler to re-decide. A cap revoke extends this to already-queued tasks. When the revoke reaches the cpu's effective caps, the cpu scans its local DSQ and reenqueues the tasks that no longer qualify. A migration-disabled task must run on its cpu, so a capless one is admitted anyway and counted in the new SCX_EV_SUB_FORCED_ADMIT event. This is preparation for the actual sub-sched cap enforcement. The divert is wired but inert here. v2: Admit offline-rq and migration_pending inserts to local, not reject. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Generalize local-DSQ handling to rq-owned DSQsTejun Heo
The local DSQ is synchronized by the containing rq lock rather than its own dsq->lock. A later patch adds a second such DSQ. In preparation, factor the "rq owns the lock" test into dsq_is_rq_owned() and rename local_dsq_post_enq() to rq_owned_post_enq(), taking @rq explicitly. No behavior change. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add sub_ecaps_updated() effective-cap change notifierTejun Heo
A sub-scheduler that gains or loses effective caps on a cpu may want to act on it right away - e.g. place or preempt on a newly usable cpu. The existing ops.sub_caps_updated() doesn't fit as it is delivered asynchronously to scheduling operations and can arrive before the per-cpu effective caps go live. Add ops.sub_ecaps_updated(cid, before, after), a cid-form callback fired from scx_process_sync_ecaps() when a sub-sched's effective caps on a cid change. It runs in dispatch context so the sched can insert, kick or preempt on the cid directly. @before is the caps as of the last delivery. Cpu hotplug rides the same machinery. Going down zeroes each sched's ecaps on the cpu's cid, with queued syncs discarded at consumption while the cpu is inactive. Coming back up queues a sync for every sched. reported_ecaps is kept across the down/up cycle, so the resync fires the callback only if ownership actually changed while the cpu was down. v2: Compute cid below the active-cpu guard; discard queued syncs on !cpu_active(). (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Maintain per-cpu effective cap copies for single-read checksTejun Heo
Checking a sched's caps on a cid would need to test several cap bits against caps[] to account for implied caps. Also, caps[] modifications aren't synchronized against scheduling operations on each cpu, which can lead to awkward race conditions. Collect them per cpu instead. caps[] under pshard->lock stays the target configuration. scx_sched_pcpu->ecaps is added, the transposed effective copy: the set of cap bits the sched holds on that cpu which can be accessed with a single read. It is stable under the rq lock. It can also be read locklessly with READ_ONCE(). Grant and revoke only mutate caps[]. They queue a sync request on the target cpu's rq->scx.ecaps_to_sync and kick it, and the cpu recomputes the queued scheds' ecaps from caps[] in balance_one() under its own rq lock. A dying sched runs the sync directly to retire its queued request before freeing. As held references can defer the freeing past the enclosing root scheduler's lifetime, root enable discards leftover sync requests before going live. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add coalescing sub_caps_updated() notifier for sub-schedulersTejun Heo
Wire up ops_cid.sub_caps_updated() to notify sub-scheds of cap changes. Three constraints shape the design: 1. Static memory. Deliveries use a fixed-size buffer, both for runtime efficiency and so notifications can't be lost under memory pressure. 2. High-frequency updates. Grant/revoke can mutate caps in bursts, and the notifier path must absorb that without amplifying it. 3. Recursive grant/revoke from the callback. A child receiving a notification can call grant/revoke on its own children, which can cascade recursively down its subtree. (1) and (2) lead to coalescing into a fixed payload. Each delivery carries a single (cmask, caps) pair covering every change since the previous one. Direction (set vs cleared) isn't encoded as it doesn't fit in the fixed-size summary. The callback queries scx_bpf_sub_caps() for current state. Only one delivery is in flight per shard. Further changes fold into the same buffer and ship as the next callback, so a shard's callbacks fire in order. (3) leads to deferred delivery. Events accumulate during grant/revoke and are delivered after the shard lock is released. v2: - Request a private stack for ops.sub_caps_updated(). (sashiko AI) - Build cmask_arena_out via scx_cmask_ref, not by re-reading its header. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add per-shard cap delegation for sub-schedulersTejun Heo
Caps are per-cid permissions parents delegate to direct children via scx_bpf_sub_grant() / scx_bpf_sub_revoke(). A child's cap set is always a subset of its parent's. Sub-scheds check their caps locally, and cross-sched communication is needed only when the delegation set itself changes. Caps will be used to implement sub-sched scheduling on the enqueue path. Picking a cid for a task at a leaf depends on which cids the leaf is allowed to use, and resolving that programmatically on every enqueue would mean a cross-sched round-trip call chain, possibly retrying if the request can't be granted as-is. The dispatch path is different - it runs as top-down recursion via scx_bpf_sub_dispatch(). Locking is per shard. cid space is split into shards, and each sub-sched has its own pshard->lock for each shard. Operations are broken up on shard boundaries. Different shards never contend. Shards are expected to be topology-aligned and likely to serve as the locality unit when cids are allocated to schedulers, so per-shard lock granularity scales naturally with the allocation pattern. This patch adds the framework with a single dummy cap. Real caps land in later patches. The enable path is reordered for pshards. scx_arena_pool_init() moves ahead of scx_link_sched() so the pshards are allocated before the sched becomes reachable - scx_alloc_pshards() skips allocation when the arena pool isn't initialized. - scx_bpf_sub_grant(): Per-cid all-or-nothing grant to direct child. - scx_bpf_sub_revoke(): Clear caps on @cmask across @child and its subtree. - scx_bpf_sub_caps(): Lockless snapshot of caps on a cid range. /sys/kernel/sched_ext/SCHED/caps shows the caps each scheduler currently holds. v4: Move the pshard[] full build/publish and the err_disable scx_error() recording to earlier patches. (sashiko AI) v3: Build pshard[] fully before publishing it, read it with READ_ONCE. (sashiko AI) v2: Validate ops before scx_link_sched() publishes the sub. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Stop resolving a disabled scheduler's programsTejun Heo
A scheduler's BPF programs can outlive it. A timer it armed or a tracing program it loaded can fire after ops.exit() has run, before the programs are unloaded, and scx_prog_sched() still resolves the program to its scheduler through ops->priv. Harmless while kfuncs touch only lifetime-stable state, but a hazard once a kfunc reads global state a newly loaded scheduler can change underneath it. Add scx_sched->dead, set right after ops.exit() and drained with synchronize_rcu(). It follows exit() rather than preceding it so exit()'s own kfunc calls still resolve to @sch. scx_prog_sched() returns NULL for a dead scheduler, so every kfunc's existing !sch bail rejects it at one choke point. v2: Check dead in the CONFIG_EXT_SUB_SCHED=n scx_prog_sched() too. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add scx_skip_subtree_pre()Tejun Heo
Factor the sibling/ancestor portion of scx_next_descendant_pre() out as scx_skip_subtree_pre(), a pre-order walk primitive that skips @pos's subtree, and call it from scx_next_descendant_pre(). Same locking rules as the existing primitive. Used in a follow-up to fast-skip subtrees that have nothing to do during a descendant walk. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: RCU-protect the sub-sched tree's children/sibling listsTejun Heo
Future kfuncs need to walk descendants without scx_sched_lock. Make the walker RCU-safe so that they can. A sub-sched's fields are initialized before it is linked, so a walk that observes a linked node also observes its setup. In-place changes after linking carry their own ordering. Switch the children/sibling list ops to RCU and expand the descendant walker to accept rcu_read_lock as a valid read-side context. Walkers that mutate keep scx_sched_lock. A sub-sched can be linked while an ancestor is bypassing, after the bypass walk that propagates the depth has passed its parent. Bypass state is a per-cpu flag plus a depth count and can't be established atomically at link time, so refuse to link under a bypassing ancestor. Take scx_bypass_lock across linking to check the parent's bypass state coherently. v3: Reject linking under a bypassing ancestor instead of inheriting bypass_depth. (sashiko AI) v2: Inherit bypass_depth before publishing @sch on the RCU sibling list. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Build the set_cmask scratch from trusted geometryTejun Heo
scx_call_op_set_cpumask() builds a per-cpu cmask in the set_cmask scratch, which lives in BPF-writable arena. A scheduler can corrupt the scratch's inline header (base, nr_cids, alloc_words) from another cpu, so sizing and indexing the write from it risks an out-of-bounds write. Drive the build from kernel-known geometry instead. scx_cmask_ref_init_kern() imposes base and nr_cids rather than reading them, and scx_cmask_ref_from_cpumask() fills the scratch from the ref. Neither reads the header back. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add scx_cmask_ref for validated arena cmask accessTejun Heo
kfuncs taking struct scx_cmask * from BPF arena memory have two problems. The pointer can be any value the BPF prog hands in, and the header (@base, @nr_cids, @alloc_words) can be mutated by the prog concurrently with kernel access. Add scx_cmask_ref, a validated handle. _init() normalizes the input pointer into the arena's kern_vm range via scx_arena_to_kaddr() and snapshots the header, rejecting a range outside the machine or a nr_cids whose words exceed the declared @alloc_words. Downstream sizing uses the snapshot, not the live header. _shard() reads slices while _or() and _copy() write back, all bounded by the snapshot. No callers yet. struct scx_cmask's bits[] carried __counted_by(alloc_words), so UBSAN_BOUNDS and FORTIFY_SOURCE bound accesses to the array. That bound is read from @alloc_words at the access. For an arena cmask @alloc_words is BPF-writable. A prog that sets it larger than the real allocation makes the check pass on a genuine overrun, so the annotation catches nothing, and it only runs under those debug configs. Drop it - _init() validates @alloc_words explicitly, and kernel-owned cmasks set it themselves. v2: Validate @alloc_words in _init(), drop __counted_by. (Andrea, sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add per-shard scx_sched storage scaffoldingTejun Heo
Add struct scx_pshard and sch->pshard[] indexed by shard_idx, each entry allocated on its shard's NUMA node from scx_shard_node[si]. The struct starts empty (one dummy field). Follow-up patches will grow it as shard-local state lands. Only cid-type schedulers with an arena pool get pshards. Allocation happens after ops.init_cids() returns so any scx_bpf_cid_override() it issues has finalized scx_nr_cid_shards and scx_shard_node[]. sch->nr_pshards records the array size for the async RCU free path, which may run after a later scheduler's scx_cid_init() has rewritten the global. v3: Build and publish pshard[] fully-formed here rather than a later patch. v2: Free the partially-allocated pshard array on alloc failure. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Defer scx_sched kobj sysfs add into the enable workfnsTejun Heo
Split kobject_init_and_add() in scx_alloc_and_add_sched(): only kobject_init() runs there. A new scx_sched_sysfs_add() helper does kobject_add() (and creates sub_kset when the scheduler implements ops.sub_attach), called by both enable workfns once @sch is linked and its sysfs-visible state is initialized. Prep so a future caps attribute can rely on @sch being fully built by the time it's sysfs-visible. Add early enough that a stall later in enable still leaves sysfs inspectable. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add shard boundaries to scx_bpf_cid_override()Tejun Heo
An overridden cid mapping invalidates the auto-generated shard layout, so the override call has to provide both. Extend scx_bpf_cid_override() with a shard_start[] array that lists the first cid of each shard (starting at 0, strictly increasing, last shard implicitly extends to num_possible_cpus()). A scheduler that wants only custom shards with the auto-generated cid mapping can read the current mapping and pass it back unchanged. Overridden shards can span NUMA nodes, so scx_shard_node[] is rebuilt by majority count: each shard is assigned to the node that owns the most cpus in it. v2: Snapshot the caller's cpu_to_cid/shard_start arrays before validating. (sashiko AI) Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add CID shardingTejun Heo
Sub-sched operations need a scalable locking / work domain smaller than the whole cid space. Carve the cid space into topology-respecting shards: each shard is a contiguous cid range that stays within one LLC, and LLCs larger than the per-shard cap (default 24 cids, configurable via ops.cid_shard_size) split into enough shards to fit. A hard cap of SCX_CID_SHARD_MAX_CPUS prevents pathological sizes under custom configurations. No-topo cids pack into their own shards so every cid has a shard assignment. Also build scx_cid_shard_ranges[] for O(1) shard-to-cid-range lookup and scx_shard_node[] so callers can size or place work by NUMA without walking cids. Auto-built shards inherit their LLC's node. No-topo shards carry NUMA_NO_NODE. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-13sched_ext: Add ops.init_cids() to finalize the cid layout before initTejun Heo
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>
2026-07-13sched_ext: Make the kick machinery per-schedTejun Heo
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>
2026-07-13sched_ext: Assert per-task ops run on the task's ownerTejun Heo
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>
2026-07-14dma-direct: Improve readability of the dma_direct_map_sg() for P2PDMA caseMarek Szyprowski
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>
2026-07-13Merge tag 'cgroup-for-7.2-rc3-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 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
2026-07-13Merge tag 'sched_ext-for-7.2-rc3-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext 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
2026-07-13dma-coherent: use KiB in DMA allocation logsVova Sharaienko
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
2026-07-13dma-coherent: fix spacing coding style issueVova Sharaienko
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
2026-07-13crash_dump: release keyring reference at the correct timeGuangshuo Li
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>
2026-07-12Merge tag 'trace-v7.2-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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
2026-07-12seccomp, treewide: Rename and convert __secure_computing() to return booleanJinjie Ruan
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
2026-07-12bpf: Mark tracing_multi trampolines as ftrace managedLeon Hwang
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>
2026-07-12bpf: Require a BPF cpumask for bpf_cpumask_populate()Nicholas Dudar
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>
2026-07-11Merge tag 'perf-urgent-2026-07-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2026-07-11Merge tag 'timers-urgent-2026-07-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2026-07-10Merge tag 'audit-pr-20260710' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit 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