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2024-08-03watchdog/perf: properly initialize the turbo mode timestamp and rearm counterThomas Gleixner
commit f944ffcbc2e1c759764850261670586ddf3bdabb upstream. For systems on which the performance counter can expire early due to turbo modes the watchdog handler has a safety net in place which validates that since the last watchdog event there has at least 4/5th of the watchdog period elapsed. This works reliably only after the first watchdog event because the per CPU variable which holds the timestamp of the last event is never initialized. So a first spurious event will validate against a timestamp of 0 which results in a delta which is likely to be way over the 4/5 threshold of the period. As this might happen before the first watchdog hrtimer event increments the watchdog counter, this can lead to false positives. Fix this by initializing the timestamp before enabling the hardware event. Reset the rearm counter as well, as that might be non zero after the watchdog was disabled and reenabled. Link: https://lkml.kernel.org/r/87frsfu15a.ffs@tglx Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with turbo modes") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03perf: Fix event leak upon exec and file releaseFrederic Weisbecker
commit 3a5465418f5fd970e86a86c7f4075be262682840 upstream. The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> <NMI> perf_event_overflow() event->pending_sigtrap = ... irq_work_queue(&event->pending_irq) <======= </NMI> perf_event_task_sched_out() event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) task_work_add(&event->pending_task) finish_lock_switch() =======> <IRQ> perf_pending_irq() //do nothing, rely on pending task work <======= </IRQ> begin_new_exec() perf_event_exit_task() perf_event_exit_event() // If is child event free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // event is leaked Similar scenarios can also happen with perf_event_remove_on_exec() or simply against concurrent perf_event_release(). Fix this with synchonizing against the possibly remaining pending task work while freeing the event, just like is done with remaining pending IRQ work. This means that the pending task callback neither need nor should hold a reference to the event, preventing it from ever beeing freed. Fixes: 517e6a301f34 ("perf: Fix perf_pending_task() UaF") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240621091601.18227-5-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03perf: Fix event leak upon exitFrederic Weisbecker
commit 2fd5ad3f310de22836cdacae919dd99d758a1f1b upstream. When a task is scheduled out, pending sigtrap deliveries are deferred to the target task upon resume to userspace via task_work. However failures while adding an event's callback to the task_work engine are ignored. And since the last call for events exit happen after task work is eventually closed, there is a small window during which pending sigtrap can be queued though ignored, leaking the event refcount addition such as in the following scenario: TASK A ----- do_exit() exit_task_work(tsk); <IRQ> perf_event_overflow() event->pending_sigtrap = pending_id; irq_work_queue(&event->pending_irq); </IRQ> =========> PREEMPTION: TASK A -> TASK B event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) // FAILS: task work has exited task_work_add(&event->pending_task) [...] <IRQ WORK> perf_pending_irq() // early return: event->oncpu = -1 </IRQ WORK> [...] =========> TASK B -> TASK A perf_event_exit_task(tsk) perf_event_exit_event() free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // leak event due to unexpected refcount == 2 As a result the event is never released while the task exits. Fix this with appropriate task_work_add()'s error handling. Fixes: 517e6a301f34 ("perf: Fix perf_pending_task() UaF") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240621091601.18227-4-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03trace/pid_list: Change gfp flags in pid_list_fill_irq()levi.yun
commit 7dc836187f7c6f70a82b4521503e9f9f96194581 upstream. pid_list_fill_irq() runs via irq_work. When CONFIG_PREEMPT_RT is disabled, it would run in irq_context. so it shouldn't sleep while memory allocation. Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in irq_work. This change wouldn't impact functionality in practice because the worst-size is 2K. Cc: stable@goodmis.org Fixes: 8d6e90983ade2 ("tracing: Create a sparse bitmask for pid filtering") Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@arm.com Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: levi.yun <yeoreum.yun@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03task_work: Introduce task_work_cancel() againFrederic Weisbecker
commit f409530e4db9dd11b88cb7703c97c8f326ff6566 upstream. Re-introduce task_work_cancel(), this time to cancel an actual callback and not *any* callback pointing to a given function. This is going to be needed for perf events event freeing. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03task_work: s/task_work_cancel()/task_work_cancel_func()/Frederic Weisbecker
commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream. A proper task_work_cancel() API that actually cancels a callback and not *any* callback pointing to a given function is going to be needed for perf events event freeing. Do the appropriate rename to prepare for that. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03sched/fair: Use all little CPUs for CPU-bound workloadsPierre Gondois
commit 3af7524b14198f5159a86692d57a9f28ec9375ce upstream. Running N CPU-bound tasks on an N CPUs platform: - with asymmetric CPU capacity - not being a DynamIq system (i.e. having a PKG level sched domain without the SD_SHARE_PKG_RESOURCES flag set) .. might result in a task placement where two tasks run on a big CPU and none on a little CPU. This placement could be more optimal by using all CPUs. Testing platform: Juno-r2: - 2 big CPUs (1-2), maximum capacity of 1024 - 4 little CPUs (0,3-5), maximum capacity of 383 Testing workload ([1]): Spawn 6 CPU-bound tasks. During the first 100ms (step 1), each tasks is affine to a CPU, except for: - one little CPU which is left idle. - one big CPU which has 2 tasks affine. After the 100ms (step 2), remove the cpumask affinity. Behavior before the patch: During step 2, the load balancer running from the idle CPU tags sched domains as: - little CPUs: 'group_has_spare'. Cf. group_has_capacity() and group_is_overloaded(), 3 CPU-bound tasks run on a 4 CPUs sched-domain, and the idle CPU provides enough spare capacity regarding the imbalance_pct - big CPUs: 'group_overloaded'. Indeed, 3 tasks run on a 2 CPUs sched-domain, so the following path is used: group_is_overloaded() \-if (sgs->sum_nr_running <= sgs->group_weight) return true; The following path which would change the migration type to 'migrate_task' is not taken: calculate_imbalance() \-if (env->idle != CPU_NOT_IDLE && env->imbalance == 0) as the local group has some spare capacity, so the imbalance is not 0. The migration type requested is 'migrate_util' and the busiest runqueue is the big CPU's runqueue having 2 tasks (each having a utilization of 512). The idle little CPU cannot pull one of these task as its capacity is too small for the task. The following path is used: detach_tasks() \-case migrate_util: \-if (util > env->imbalance) goto next; After the patch: As the number of failed balancing attempts grows (with 'nr_balance_failed'), progressively make it easier to migrate a big task to the idling little CPU. A similar mechanism is used for the 'migrate_load' migration type. Improvement: Running the testing workload [1] with the step 2 representing a ~10s load for a big CPU: Before patch: ~19.3s After patch: ~18s (-6.7%) Similar issue reported at: https://lore.kernel.org/lkml/20230716014125.139577-1-qyousef@layalina.io/ Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Qais Yousef <qyousef@layalina.io> Link: https://lore.kernel.org/r/20231206090043.634697-1-pierre.gondois@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE ↵Tejun Heo
tasks commit d329605287020c3d1c3b0dadc63d8208e7251382 upstream. When a task's weight is being changed, set_load_weight() is called with @update_load set. As weight changes aren't trivial for the fair class, set_load_weight() calls fair.c::reweight_task() for fair class tasks. However, set_load_weight() first tests task_has_idle_policy() on entry and skips calling reweight_task() for SCHED_IDLE tasks. This is buggy as SCHED_IDLE tasks are just fair tasks with a very low weight and they would incorrectly skip load, vlag and position updates. Fix it by updating reweight_task() to take struct load_weight as idle weight can't be expressed with prio and making set_load_weight() call reweight_task() for SCHED_IDLE tasks too when @update_load is set. Fixes: 9059393e4ec1 ("sched/fair: Use reweight_entity() for set_user_nice()") Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org # v4.15+ Link: http://lkml.kernel.org/r/20240624102331.GI31592@noisy.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03kernel: rerun task_work while freezing in get_signal()Pavel Begunkov
commit 943ad0b62e3c21f324c4884caa6cb4a871bca05c upstream. io_uring can asynchronously add a task_work while the task is getting freezed. TIF_NOTIFY_SIGNAL will prevent the task from sleeping in do_freezer_trap(), and since the get_signal()'s relock loop doesn't retry task_work, the task will spin there not being able to sleep until the freezing is cancelled / the task is killed / etc. Run task_works in the freezer path. Keep the patch small and simple so it can be easily back ported, but we might need to do some cleaning after and look if there are other places with similar problems. Cc: stable@vger.kernel.org Link: https://github.com/systemd/systemd/issues/33626 Fixes: 12db8b690010c ("entry: Add support for TIF_NOTIFY_SIGNAL") Reported-by: Julian Orth <ju.orth@gmail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/89ed3a52933370deaaf61a0a620a6ac91f1e754d.1720634146.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03tick/broadcast: Make takeover of broadcast hrtimer reliableYu Liao
commit f7d43dd206e7e18c182f200e67a8db8c209907fa upstream. Running the LTP hotplug stress test on a aarch64 machine results in rcu_sched stall warnings when the broadcast hrtimer was owned by the un-plugged CPU. The issue is the following: CPU1 (owns the broadcast hrtimer) CPU2 tick_broadcast_enter() // shutdown local timer device broadcast_shutdown_local() ... tick_broadcast_exit() clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT) // timer device is not programmed cpumask_set_cpu(cpu, tick_broadcast_force_mask) initiates offlining of CPU1 take_cpu_down() /* * CPU1 shuts down and does not * send broadcast IPI anymore */ takedown_cpu() hotplug_cpu__broadcast_tick_pull() // move broadcast hrtimer to this CPU clockevents_program_event() bc_set_next() hrtimer_start() /* * timer device is not programmed * because only the first expiring * timer will trigger clockevent * device reprogramming */ What happens is that CPU2 exits broadcast mode with force bit set, then the local timer device is not reprogrammed and CPU2 expects to receive the expired event by the broadcast IPI. But this does not happen because CPU1 is offlined by CPU2. CPU switches the clockevent device to ONESHOT state, but does not reprogram the device. The subsequent reprogramming of the hrtimer broadcast device does not program the clockevent device of CPU2 either because the pending expiry time is already in the past and the CPU expects the event to be delivered. As a consequence all CPUs which wait for a broadcast event to be delivered are stuck forever. Fix this issue by reprogramming the local timer device if the broadcast force bit of the CPU is set so that the broadcast hrtimer is delivered. [ tglx: Massage comment and change log. Add Fixes tag ] Fixes: 989dcb645ca7 ("tick: Handle broadcast wakeup of multiple cpus") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240711124843.64167-1-liaoyu15@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.oAlan Maguire
[ Upstream commit 2454075f8e2915cebbe52a1195631bc7efe2b7e1 ] As reported by Mirsad [1] we still see format warnings in kernel/bpf/btf.o at W=1 warning level: CC kernel/bpf/btf.o ./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’: ./kernel/bpf/btf.c:7553:21: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7553 | sseq.showfn = btf_seq_show; | ^ ./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’: ./kernel/bpf/btf.c:7604:31: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7604 | ssnprintf.show.showfn = btf_snprintf_show; | ^ Combined with CONFIG_WERROR=y these can halt the build. The fix (annotating the structure field with __printf()) suggested by Mirsad resolves these. Apologies I missed this last time. No other W=1 warnings were observed in kernel/bpf after this fix. [1] https://lore.kernel.org/bpf/92c9d047-f058-400c-9c7d-81d4dc1ef71b@gmail.com/ Fixes: b3470da314fd ("bpf: annotate BTF show functions with __printf") Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com> Suggested-by: Mirsad Todorovac <mtodorovac69@gmail.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240712092859.1390960-1-alan.maguire@oracle.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03bpf: annotate BTF show functions with __printfAlan Maguire
[ Upstream commit b3470da314fd8018ee237e382000c4154a942420 ] -Werror=suggest-attribute=format warns about two functions in kernel/bpf/btf.c [1]; add __printf() annotations to silence these warnings since for CONFIG_WERROR=y they will trigger build failures. [1] https://lore.kernel.org/bpf/a8b20c72-6631-4404-9e1f-0410642d7d20@gmail.com/ Fixes: 31d0bc81637d ("bpf: Move to generic BTF show support, apply it to seq files/strings") Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Tested-by: Mirsad Todorovac <mtodorovac69@yahoo.com> Link: https://lore.kernel.org/r/20240711182321.963667-1-alan.maguire@oracle.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03locking/rwsem: Add __always_inline annotation to __down_write_common() and ↵John Stultz
inlined callers [ Upstream commit e81859fe64ad42dccefe134d1696e0635f78d763 ] Apparently despite it being marked inline, the compiler may not inline __down_write_common() which makes it difficult to identify the cause of lock contention, as the wchan of the blocked function will always be listed as __down_write_common(). So add __always_inline annotation to the common function (as well as the inlined helper callers) to force it to be inlined so a more useful blocking function will be listed (via wchan). This mirrors commit 92cc5d00a431 ("locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers") which did the same for __down_read_common. I sort of worry that I'm playing wack-a-mole here, and talking with compiler people, they tell me inline means nothing, which makes me want to cry a little. So I'm wondering if we need to replace all the inlines with __always_inline, or remove them because either we mean something by it, or not. Fixes: c995e638ccbb ("locking/rwsem: Fold __down_{read,write}*()") Reported-by: Tim Murray <timmurray@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lkml.kernel.org/r/20240709060831.495366-1-jstultz@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03perf: Fix default aux_watermark calculationAdrian Hunter
[ Upstream commit 43deb76b19663a96ec2189d8f4eb9a9dc2d7623f ] The default aux_watermark is half the AUX area buffer size. In general, on a 64-bit architecture, the AUX area buffer size could be a bigger than fits in a 32-bit type, but the calculation does not allow for that possibility. However the aux_watermark value is recorded in a u32, so should not be more than U32_MAX either. Fix by doing the calculation in a correctly sized type, and limiting the result to U32_MAX. Fixes: d68e6799a5c8 ("perf: Cap allocation order at aux_watermark") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03perf: Prevent passing zero nr_pages to rb_alloc_aux()Adrian Hunter
[ Upstream commit dbc48c8f41c208082cfa95e973560134489e3309 ] nr_pages is unsigned long but gets passed to rb_alloc_aux() as an int, and is stored as an int. Only power-of-2 values are accepted, so if nr_pages is a 64_bit value, it will be passed to rb_alloc_aux() as zero. That is not ideal because: 1. the value is incorrect 2. rb_alloc_aux() is at risk of misbehaving, although it manages to return -ENOMEM in that case, it is a result of passing zero to get_order() even though the get_order() result is documented to be undefined in that case. Fix by simply validating the maximum supported value in the first place. Use -ENOMEM error code for consistency with the current error code that is returned in that case. Fixes: 45bfb2e50471 ("perf: Add AUX area to ring buffer for raw data streams") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240624201101.60186-6-adrian.hunter@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03perf: Fix perf_aux_size() for greater-than 32-bit sizeAdrian Hunter
[ Upstream commit 3df94a5b1078dfe2b0c03f027d018800faf44c82 ] perf_buffer->aux_nr_pages uses a 32-bit type, so a cast is needed to calculate a 64-bit size. Fixes: 45bfb2e50471 ("perf: Add AUX area to ring buffer for raw data streams") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240624201101.60186-5-adrian.hunter@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03jump_label: Fix concurrency issues in static_key_slow_dec()Thomas Gleixner
[ Upstream commit 83ab38ef0a0b2407d43af9575bb32333fdd74fb2 ] The commit which tried to fix the concurrency issues of concurrent static_key_slow_inc() failed to fix the equivalent issues vs. static_key_slow_dec(): CPU0 CPU1 static_key_slow_dec() static_key_slow_try_dec() key->enabled == 1 val = atomic_fetch_add_unless(&key->enabled, -1, 1); if (val == 1) return false; jump_label_lock(); if (atomic_dec_and_test(&key->enabled)) { --> key->enabled == 0 __jump_label_update() static_key_slow_dec() static_key_slow_try_dec() key->enabled == 0 val = atomic_fetch_add_unless(&key->enabled, -1, 1); --> key->enabled == -1 <- FAIL There is another bug in that code, when there is a concurrent static_key_slow_inc() which enables the key as that sets key->enabled to -1 so on the other CPU val = atomic_fetch_add_unless(&key->enabled, -1, 1); will succeed and decrement to -2, which is invalid. Cure all of this by replacing the atomic_fetch_add_unless() with a atomic_try_cmpxchg() loop similar to static_key_fast_inc_not_disabled(). [peterz: add WARN_ON_ONCE for the -1 race] Fixes: 4c5ea0a9cd02 ("locking/static_key: Fix concurrent static_key_slow_inc()") Reported-by: Yue Sun <samsun1006219@gmail.com> Reported-by: Xingwei Lee <xrivendell7@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20240610124406.422897838@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03jump_label: Prevent key->enabled int overflowDmitry Safonov
[ Upstream commit eb8c507296f6038d46010396d91b42a05c3b64d9 ] 1. With CONFIG_JUMP_LABEL=n static_key_slow_inc() doesn't have any protection against key->enabled refcounter overflow. 2. With CONFIG_JUMP_LABEL=y static_key_slow_inc_cpuslocked() still may turn the refcounter negative as (v + 1) may overflow. key->enabled is indeed a ref-counter as it's documented in multiple places: top comment in jump_label.h, Documentation/staging/static-keys.rst, etc. As -1 is reserved for static key that's in process of being enabled, functions would break with negative key->enabled refcount: - for CONFIG_JUMP_LABEL=n negative return of static_key_count() breaks static_key_false(), static_key_true() - the ref counter may become 0 from negative side by too many static_key_slow_inc() calls and lead to use-after-free issues. These flaws result in that some users have to introduce an additional mutex and prevent the reference counter from overflowing themselves, see bpf_enable_runtime_stats() checking the counter against INT_MAX / 2. Prevent the reference counter overflow by checking if (v + 1) > 0. Change functions API to return whether the increment was successful. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 83ab38ef0a0b ("jump_label: Fix concurrency issues in static_key_slow_dec()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03jump_label: Use atomic_try_cmpxchg() in static_key_slow_inc_cpuslocked()Uros Bizjak
[ Upstream commit d0c006402e7941558e5283ae434e2847c7999378 ] Use atomic_try_cmpxchg() instead of atomic_cmpxchg (*ptr, old, new) == old in static_key_slow_inc_cpuslocked(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, atomic_try_cmpxchg() implicitly assigns old *ptr value to "old" when cmpxchg fails, enabling further code simplifications. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221019140850.3395-1-ubizjak@gmail.com Stable-dep-of: 83ab38ef0a0b ("jump_label: Fix concurrency issues in static_key_slow_dec()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03cgroup/cpuset: Prevent UAF in proc_cpuset_show()Chen Ridong
[ Upstream commit 1be59c97c83ccd67a519d8a49486b3a8a73ca28a ] An UAF can happen when /proc/cpuset is read as reported in [1]. This can be reproduced by the following methods: 1.add an mdelay(1000) before acquiring the cgroup_lock In the cgroup_path_ns function. 2.$cat /proc/<pid>/cpuset repeatly. 3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/ $umount /sys/fs/cgroup/cpuset/ repeatly. The race that cause this bug can be shown as below: (umount) | (cat /proc/<pid>/cpuset) css_release | proc_cpuset_show css_release_work_fn | css = task_get_css(tsk, cpuset_cgrp_id); css_free_rwork_fn | cgroup_path_ns(css->cgroup, ...); cgroup_destroy_root | mutex_lock(&cgroup_mutex); rebind_subsystems | cgroup_free_root | | // cgrp was freed, UAF | cgroup_path_ns_locked(cgrp,..); When the cpuset is initialized, the root node top_cpuset.css.cgrp will point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will allocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated &cgroup_root.cgrp. When the umount operation is executed, top_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp. The problem is that when rebinding to cgrp_dfl_root, there are cases where the cgroup_root allocated by setting up the root for cgroup v1 is cached. This could lead to a Use-After-Free (UAF) if it is subsequently freed. The descendant cgroups of cgroup v1 can only be freed after the css is released. However, the css of the root will never be released, yet the cgroup_root should be freed when it is unmounted. This means that obtaining a reference to the css of the root does not guarantee that css.cgrp->root will not be freed. Fix this problem by using rcu_read_lock in proc_cpuset_show(). As cgroup_root is kfree_rcu after commit d23b5c577715 ("cgroup: Make operations on the cgroup root_list RCU safe"), css->cgroup won't be freed during the critical section. To call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to replace task_get_css with task_css. [1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd Fixes: a79a908fd2b0 ("cgroup: introduce cgroup namespaces") Signed-off-by: Chen Ridong <chenridong@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()Kees Cook
[ Upstream commit ff6d413b0b59466e5acf2e42f294b1842ae130a1 ] One of the last remaining users of strlcpy() in the kernel is kernfs_path_from_node_locked(), which passes back the problematic "length we _would_ have copied" return value to indicate truncation. Convert the chain of all callers to use the negative return value (some of which already doing this explicitly). All callers were already also checking for negative return values, so the risk to missed checks looks very low. In this analysis, it was found that cgroup1_release_agent() actually didn't handle the "too large" condition, so this is technically also a bug fix. :) Here's the chain of callers, and resolution identifying each one as now handling the correct return value: kernfs_path_from_node_locked() kernfs_path_from_node() pr_cont_kernfs_path() returns void kernfs_path() sysfs_warn_dup() return value ignored cgroup_path() blkg_path() bfq_bic_update_cgroup() return value ignored TRACE_IOCG_PATH() return value ignored TRACE_CGROUP_PATH() return value ignored perf_event_cgroup() return value ignored task_group_path() return value ignored damon_sysfs_memcg_path_eq() return value ignored get_mm_memcg_path() return value ignored lru_gen_seq_show() return value ignored cgroup_path_from_kernfs_id() return value ignored cgroup_show_path() already converted "too large" error to negative value cgroup_path_ns_locked() cgroup_path_ns() bpf_iter_cgroup_show_fdinfo() return value ignored cgroup1_release_agent() wasn't checking "too large" error proc_cgroup_show() already converted "too large" to negative value Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: <cgroups@vger.kernel.org> Co-developed-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Link: https://lore.kernel.org/r/20231116192127.1558276-3-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20231212211741.164376-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 1be59c97c83c ("cgroup/cpuset: Prevent UAF in proc_cpuset_show()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03rcu/tasks: Fix stale task snaphot for Tasks TraceFrederic Weisbecker
[ Upstream commit 399ced9594dfab51b782798efe60a2376cd5b724 ] When RCU-TASKS-TRACE pre-gp takes a snapshot of the current task running on all online CPUs, no explicit ordering synchronizes properly with a context switch. This lack of ordering can permit the new task to miss pre-grace-period update-side accesses. The following diagram, courtesy of Paul, shows the possible bad scenario: CPU 0 CPU 1 ----- ----- // Pre-GP update side access WRITE_ONCE(*X, 1); smp_mb(); r0 = rq->curr; RCU_INIT_POINTER(rq->curr, TASK_B) spin_unlock(rq) rcu_read_lock_trace() r1 = X; /* ignore TASK_B */ Either r0==TASK_B or r1==1 is needed but neither is guaranteed. One possible solution to solve this is to wait for an RCU grace period at the beginning of the RCU-tasks-trace grace period before taking the current tasks snaphot. However this would introduce large additional latencies to RCU-tasks-trace grace periods. Another solution is to lock the target runqueue while taking the current task snapshot. This ensures that the update side sees the latest context switch and subsequent context switches will see the pre-grace-period update side accesses. This commit therefore adds runqueue locking to cpu_curr_snapshot(). Fixes: e386b6725798 ("rcu-tasks: Eliminate RCU Tasks Trace IPIs to online CPUs") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpathJohn Stultz
commit ddae0ca2a8fe12d0e24ab10ba759c3fbd755ada8 upstream. It was reported that in moving to 6.1, a larger then 10% regression was seen in the performance of clock_gettime(CLOCK_THREAD_CPUTIME_ID,...). Using a simple reproducer, I found: 5.10: 100000000 calls in 24345994193 ns => 243.460 ns per call 100000000 calls in 24288172050 ns => 242.882 ns per call 100000000 calls in 24289135225 ns => 242.891 ns per call 6.1: 100000000 calls in 28248646742 ns => 282.486 ns per call 100000000 calls in 28227055067 ns => 282.271 ns per call 100000000 calls in 28177471287 ns => 281.775 ns per call The cause of this was finally narrowed down to the addition of psi_account_irqtime() in update_rq_clock_task(), in commit 52b1364ba0b1 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure"). In my initial attempt to resolve this, I leaned towards moving all accounting work out of the clock_gettime() call path, but it wasn't very pretty, so it will have to wait for a later deeper rework. Instead, Peter shared this approach: Rework psi_account_irqtime() to use its own psi_irq_time base for accounting, and move it out of the hotpath, calling it instead from sched_tick() and __schedule(). In testing this, we found the importance of ensuring psi_account_irqtime() is run under the rq_lock, which Johannes Weiner helpfully explained, so also add some lockdep annotations to make that requirement clear. With this change the performance is back in-line with 5.10: 6.1+fix: 100000000 calls in 24297324597 ns => 242.973 ns per call 100000000 calls in 24318869234 ns => 243.189 ns per call 100000000 calls in 24291564588 ns => 242.916 ns per call Reported-by: Jimmy Shiu <jimmyshiu@google.com> Originally-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Qais Yousef <qyousef@layalina.io> Link: https://lore.kernel.org/r/20240618215909.4099720-1-jstultz@google.com Fixes: 52b1364ba0b1 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure") [jstultz: Fixed up minor collisions w/ 6.1-stable] Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18bpf: Allow reads from uninit stackEduard Zingerman
commit 6715df8d5d24655b9fd368e904028112b54c7de1 upstream. This commits updates the following functions to allow reads from uninitialized stack locations when env->allow_uninit_stack option is enabled: - check_stack_read_fixed_off() - check_stack_range_initialized(), called from: - check_stack_read_var_off() - check_helper_mem_access() Such change allows to relax logic in stacksafe() to treat STACK_MISC and STACK_INVALID in a same way and make the following stack slot configurations equivalent: | Cached state | Current state | | stack slot | stack slot | |------------------+------------------| | STACK_INVALID or | STACK_INVALID or | | STACK_MISC | STACK_SPILL or | | | STACK_MISC or | | | STACK_ZERO or | | | STACK_DYNPTR | This leads to significant verification speed gains (see below). The idea was suggested by Andrii Nakryiko [1] and initial patch was created by Alexei Starovoitov [2]. Currently the env->allow_uninit_stack is allowed for programs loaded by users with CAP_PERFMON or CAP_SYS_ADMIN capabilities. A number of test cases from verifier/*.c were expecting uninitialized stack access to be an error. These test cases were updated to execute in unprivileged mode (thus preserving the tests). The test progs/test_global_func10.c expected "invalid indirect read from stack" error message because of the access to uninitialized memory region. This error is no longer possible in privileged mode. The test is updated to provoke an error "invalid indirect access to stack" because of access to invalid stack address (such error is not verified by progs/test_global_func*.c series of tests). The following tests had to be removed because these can't be made unprivileged: - verifier/sock.c: - "sk_storage_get(map, skb->sk, &stack_value, 1): partially init stack_value" BPF_PROG_TYPE_SCHED_CLS programs are not executed in unprivileged mode. - verifier/var_off.c: - "indirect variable-offset stack access, max_off+size > max_initialized" - "indirect variable-offset stack access, uninitialized" These tests verify that access to uninitialized stack values is detected when stack offset is not a constant. However, variable stack access is prohibited in unprivileged mode, thus these tests are no longer valid. * * * Here is veristat log comparing this patch with current master on a set of selftest binaries listed in tools/testing/selftests/bpf/veristat.cfg and cilium BPF binaries (see [3]): $ ./veristat -e file,prog,states -C -f 'states_pct<-30' master.log current.log File Program States (A) States (B) States (DIFF) -------------------------- -------------------------- ---------- ---------- ---------------- bpf_host.o tail_handle_ipv6_from_host 349 244 -105 (-30.09%) bpf_host.o tail_handle_nat_fwd_ipv4 1320 895 -425 (-32.20%) bpf_lxc.o tail_handle_nat_fwd_ipv4 1320 895 -425 (-32.20%) bpf_sock.o cil_sock4_connect 70 48 -22 (-31.43%) bpf_sock.o cil_sock4_sendmsg 68 46 -22 (-32.35%) bpf_xdp.o tail_handle_nat_fwd_ipv4 1554 803 -751 (-48.33%) bpf_xdp.o tail_lb_ipv4 6457 2473 -3984 (-61.70%) bpf_xdp.o tail_lb_ipv6 7249 3908 -3341 (-46.09%) pyperf600_bpf_loop.bpf.o on_event 287 145 -142 (-49.48%) strobemeta.bpf.o on_event 15915 4772 -11143 (-70.02%) strobemeta_nounroll2.bpf.o on_event 17087 3820 -13267 (-77.64%) xdp_synproxy_kern.bpf.o syncookie_tc 21271 6635 -14636 (-68.81%) xdp_synproxy_kern.bpf.o syncookie_xdp 23122 6024 -17098 (-73.95%) -------------------------- -------------------------- ---------- ---------- ---------------- Note: I limited selection by states_pct<-30%. Inspection of differences in pyperf600_bpf_loop behavior shows that the following patch for the test removes almost all differences: - a/tools/testing/selftests/bpf/progs/pyperf.h + b/tools/testing/selftests/bpf/progs/pyperf.h @ -266,8 +266,8 @ int __on_event(struct bpf_raw_tracepoint_args *ctx) } if (event->pthread_match || !pidData->use_tls) { - void* frame_ptr; - FrameData frame; + void* frame_ptr = 0; + FrameData frame = {}; Symbol sym = {}; int cur_cpu = bpf_get_smp_processor_id(); W/o this patch the difference comes from the following pattern (for different variables): static bool get_frame_data(... FrameData *frame ...) { ... bpf_probe_read_user(&frame->f_code, ...); if (!frame->f_code) return false; ... bpf_probe_read_user(&frame->co_name, ...); if (frame->co_name) ...; } int __on_event(struct bpf_raw_tracepoint_args *ctx) { FrameData frame; ... get_frame_data(... &frame ...) // indirectly via a bpf_loop & callback ... } SEC("raw_tracepoint/kfree_skb") int on_event(struct bpf_raw_tracepoint_args* ctx) { ... ret |= __on_event(ctx); ret |= __on_event(ctx); ... } With regards to value `frame->co_name` the following is important: - Because of the conditional `if (!frame->f_code)` each call to __on_event() produces two states, one with `frame->co_name` marked as STACK_MISC, another with it as is (and marked STACK_INVALID on a first call). - The call to bpf_probe_read_user() does not mark stack slots corresponding to `&frame->co_name` as REG_LIVE_WRITTEN but it marks these slots as BPF_MISC, this happens because of the following loop in the check_helper_call(): for (i = 0; i < meta.access_size; i++) { err = check_mem_access(env, insn_idx, meta.regno, i, BPF_B, BPF_WRITE, -1, false); if (err) return err; } Note the size of the write, it is a one byte write for each byte touched by a helper. The BPF_B write does not lead to write marks for the target stack slot. - Which means that w/o this patch when second __on_event() call is verified `if (frame->co_name)` will propagate read marks first to a stack slot with STACK_MISC marks and second to a stack slot with STACK_INVALID marks and these states would be considered different. [1] https://lore.kernel.org/bpf/CAEf4BzY3e+ZuC6HUa8dCiUovQRg2SzEk7M-dSkqNZyn=xEmnPA@mail.gmail.com/ [2] https://lore.kernel.org/bpf/CAADnVQKs2i1iuZ5SUGuJtxWVfGYR9kDgYKhq3rNV+kBLQCu7rA@mail.gmail.com/ [3] git@github.com:anakryiko/cilium.git Suggested-by: Andrii Nakryiko <andrii@kernel.org> Co-developed-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230219200427.606541-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18Revert "sched/fair: Make sure to try to detach at least one movable task"Josh Don
commit 2feab2492deb2f14f9675dd6388e9e2bf669c27a upstream. This reverts commit b0defa7ae03ecf91b8bfd10ede430cff12fcbd06. b0defa7ae03ec changed the load balancing logic to ignore env.max_loop if all tasks examined to that point were pinned. The goal of the patch was to make it more likely to be able to detach a task buried in a long list of pinned tasks. However, this has the unfortunate side effect of creating an O(n) iteration in detach_tasks(), as we now must fully iterate every task on a cpu if all or most are pinned. Since this load balance code is done with rq lock held, and often in softirq context, it is very easy to trigger hard lockups. We observed such hard lockups with a user who affined O(10k) threads to a single cpu. When I discussed this with Vincent he initially suggested that we keep the limit on the number of tasks to detach, but increase the number of tasks we can search. However, after some back and forth on the mailing list, he recommended we instead revert the original patch, as it seems likely no one was actually getting hit by the original issue. Fixes: b0defa7ae03e ("sched/fair: Make sure to try to detach at least one movable task") Signed-off-by: Josh Don <joshdon@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240620214450.316280-1-joshdon@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18bpf: fix order of args in call to bpf_map_kvcallocMohammad Shehar Yaar Tausif
[ Upstream commit af253aef183a31ce62d2e39fc520b0ebfb562bb9 ] The original function call passed size of smap->bucket before the number of buckets which raises the error 'calloc-transposed-args' on compilation. Vlastimil Babka added: The order of parameters can be traced back all the way to 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage") accross several refactorings, and that's why the commit is used as a Fixes: tag. In v6.10-rc1, a different commit 2c321f3f70bc ("mm: change inlined allocation helpers to account at the call site") however exposed the order of args in a way that gcc-14 has enough visibility to start warning about it, because (in !CONFIG_MEMCG case) bpf_map_kvcalloc is then a macro alias for kvcalloc instead of a static inline wrapper. To sum up the warning happens when the following conditions are all met: - gcc-14 is used (didn't see it with gcc-13) - commit 2c321f3f70bc is present - CONFIG_MEMCG is not enabled in .config - CONFIG_WERROR turns this from a compiler warning to error Fixes: 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage") Reviewed-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Mohammad Shehar Yaar Tausif <sheharyaar48@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/r/20240710100521.15061-2-vbabka@suse.cz Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18bpf: Remove __bpf_local_storage_map_allocMartin KaFai Lau
[ Upstream commit 62827d612ae525695799b3635a087cb49c55e977 ] bpf_local_storage_map_alloc() is the only caller of __bpf_local_storage_map_alloc(). The remaining logic in bpf_local_storage_map_alloc() is only a one liner setting the smap->cache_idx. Remove __bpf_local_storage_map_alloc() to simplify code. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: af253aef183a ("bpf: fix order of args in call to bpf_map_kvcalloc") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18bpf: use bpf_map_kvcalloc in bpf_local_storageYafang Shao
[ Upstream commit ddef81b5fd1da4d7c3cc8785d2043b73b72f38ef ] Introduce new helper bpf_map_kvcalloc() for the memory allocation in bpf_local_storage(). Then the allocation will charge the memory from the map instead of from current, though currently they are the same thing as it is only used in map creation path now. By charging map's memory into the memcg from the map, it will be more clear. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-3-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: af253aef183a ("bpf: fix order of args in call to bpf_map_kvcalloc") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18bpf: Reduce smap->elem_sizeMartin KaFai Lau
[ Upstream commit 552d42a356ebf78df9d2f4b73e077d2459966fac ] 'struct bpf_local_storage_elem' has an unused 56 byte padding at the end due to struct's cache-line alignment requirement. This padding space is overlapped by storage value contents, so if we use sizeof() to calculate the total size, we overinflate it by 56 bytes. Use offsetof() instead to calculate more exact memory use. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221221013036.3427431-1-martin.lau@linux.dev Stable-dep-of: af253aef183a ("bpf: fix order of args in call to bpf_map_kvcalloc") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18bpf: Refactor some inode/task/sk storage functions for reuseYonghong Song
[ Upstream commit c83597fa5dc6b322e9bdf929e5f4136a3f4aa4db ] Refactor codes so that inode/task/sk storage implementation can maximally share the same code. I also added some comments in new function bpf_local_storage_unlink_nolock() to make codes easy to understand. There is no functionality change. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221026042845.672944-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: af253aef183a ("bpf: fix order of args in call to bpf_map_kvcalloc") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11dma-mapping: benchmark: avoid needless copy_to_user if benchmark failsFedor Pchelkin
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ] If do_map_benchmark() has failed, there is nothing useful to copy back to userspace. Suggested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11ima: Avoid blocking in RCU read-side critical sectionGUO Zihua
commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua <guozihua@huawei.com> Acked-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-11mm: optimize the redundant loop of mm_update_owner_next()Jinliang Zheng
commit cf3f9a593dab87a032d2b6a6fb205e7f3de4f0a1 upstream. When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or /proc or ptrace or page migration (get_task_mm()), it is impossible to find an appropriate task_struct in the loop whose mm_struct is the same as the target mm_struct. If the above race condition is combined with the stress-ng-zombie and stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in write_lock_irq() for tasklist_lock. Recognize this situation in advance and exit early. Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tycho Andersen <tandersen@netflix.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-11locking/mutex: Introduce devm_mutex_init()George Stark
[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ] Using of devm API leads to a certain order of releasing resources. So all dependent resources which are not devm-wrapped should be deleted with respect to devm-release order. Mutex is one of such objects that often is bound to other resources and has no own devm wrapping. Since mutex_destroy() actually does nothing in non-debug builds frequently calling mutex_destroy() is just ignored which is safe for now but wrong formally and can lead to a problem if mutex_destroy() will be extended so introduce devm_mutex_init(). Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: George Stark <gnstark@salutedevices.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Marek Behún <kabel@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05syscalls: fix compat_sys_io_pgetevents_time64 usageArnd Bergmann
commit d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream. Using sys_io_pgetevents() as the entry point for compat mode tasks works almost correctly, but misses the sign extension for the min_nr and nr arguments. This was addressed on parisc by switching to compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc: io_pgetevents_time64() needs compat syscall in 32-bit compat mode"), as well as by using more sophisticated system call wrappers on x86 and s390. However, arm64, mips, powerpc, sparc and riscv still have the same bug. Change all of them over to use compat_sys_io_pgetevents_time64() like parisc already does. This was clearly the intention when the function was originally added, but it got hooked up incorrectly in the tables. Cc: stable@vger.kernel.org Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures") Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05cpu/hotplug: Fix dynstate assignment in __cpuhp_setup_state_cpuslocked()Yuntao Wang
commit 932d8476399f622aa0767a4a0a9e78e5341dc0e1 upstream. Commit 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage") added a dynamic range for the prepare states, but did not handle the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked(). This causes the corresponding startup callback not to be invoked when calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN parameter, even though it should be. Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or another, have not triggered this bug. Fixes: 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage") Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter modeMartin KaFai Lau
[ Upstream commit e8742081db7d01f980c6161ae1e8a1dbc1e30979 ] syzbot reported uninit memory usages during map_{lookup,delete}_elem. ========== BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 ____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline] bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237 ========== The reproducer should be in the interpreter mode. The C reproducer is trying to run the following bpf prog: 0: (18) r0 = 0x0 2: (18) r1 = map[id:49] 4: (b7) r8 = 16777216 5: (7b) *(u64 *)(r10 -8) = r8 6: (bf) r2 = r10 7: (07) r2 += -229 ^^^^^^^^^^ 8: (b7) r3 = 8 9: (b7) r4 = 0 10: (85) call dev_map_lookup_elem#1543472 11: (95) exit It is due to the "void *key" (r2) passed to the helper. bpf allows uninit stack memory access for bpf prog with the right privileges. This patch uses kmsan_unpoison_memory() to mark the stack as initialized. This should address different syzbot reports on the uninit "void *key" argument during map_{lookup,delete}_elem. Reported-by: syzbot+603bcd9b0bf1d94dbb9b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000f9ce6d061494e694@google.com/ Reported-by: syzbot+eb02dc7f03dce0ef39f3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000a5c69c06147c2238@google.com/ Reported-by: syzbot+b4e65ca24fd4d0c734c3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000ac56fb06143b6cfa@google.com/ Reported-by: syzbot+d2b113dc9fea5e1d2848@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/0000000000000d69b206142d1ff7@google.com/ Reported-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/0000000000006f876b061478e878@google.com/ Tested-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com Suggested-by: Yonghong Song <yonghong.song@linux.dev> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240328185801.1843078-1-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05bpf: Take return from set_memory_ro() into account with bpf_prog_lock_ro()Christophe Leroy
[ Upstream commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 ] set_memory_ro() can fail, leaving memory unprotected. Check its return and take it into account as an error. Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: linux-hardening@vger.kernel.org <linux-hardening@vger.kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Message-ID: <286def78955e04382b227cb3e4b6ba272a7442e3.1709850515.git.christophe.leroy@csgroup.eu> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05bpf: Fix overrunning reservations in ringbufDaniel Borkmann
[ Upstream commit cfa1a2329a691ffd991fcf7248a57d752e712881 ] The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data reserved by all producers. Each time a record is reserved, the producer that "owns" the record will successfully advance producer counter. In user space each time a record is read, the consumer of the data advanced the consumer counter once it finished processing. Both counters are stored in separate pages so that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect that simplifies and thus speeds up the implementation of both producers and consumers is how the data area is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the first chunk and as a result, the BPF program is now able to edit first chunk's header. For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit slower on some benchmarks, it is still not significantly enough to matter. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Reported-by: Muhammad Ramdhan <ramdhan@starlabs.sg> Co-developed-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Co-developed-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27kheaders: explicitly define file modes for archived headersMatthias Maennich
[ Upstream commit 3bd27a847a3a4827a948387cc8f0dbc9fa5931d5 ] Build environments might be running with different umask settings resulting in indeterministic file modes for the files contained in kheaders.tar.xz. The file itself is served with 444, i.e. world readable. Archive the files explicitly with 744,a+X to improve reproducibility across build environments. --mode=0444 is not suitable as directories need to be executable. Also, 444 makes it hard to delete all the readonly files after extraction. Cc: stable@vger.kernel.org Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27Revert "kheaders: substituting --sort in archive creation"Masahiro Yamada
[ Upstream commit 49c386ebbb43394ff4773ce24f726f6afc4c30c8 ] This reverts commit 700dea5a0bea9f64eba89fae7cb2540326fdfdc1. The reason for that commit was --sort=ORDER introduced in tar 1.28 (2014). More than 3 years have passed since then. Requiring GNU tar 1.28 should be fine now because we require GCC 5.1 (2015). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Stable-dep-of: 3bd27a847a3a ("kheaders: explicitly define file modes for archived headers") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_testJeff Johnson
[ Upstream commit 23748e3e0fbfe471eff5ce439921629f6a427828 ] Fix the 'make W=1' warning: WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: f96e8577da10 ("lib: Add module for testing preemptoff/irqsoff latency tracers") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27kcov: don't lose track of remote references during softirqsAleksandr Nogikh
commit 01c8f9806bde438ca1c8cbbc439f0a14a6694f6c upstream. In kcov_remote_start()/kcov_remote_stop(), we swap the previous KCOV metadata of the current task into a per-CPU variable. However, the kcov_mode_enabled(mode) check is not sufficient in the case of remote KCOV coverage: current->kcov_mode always remains KCOV_MODE_DISABLED for remote KCOV objects. If the original task that has invoked the KCOV_REMOTE_ENABLE ioctl happens to get interrupted and kcov_remote_start() is called, it ultimately leads to kcov_remote_stop() NOT restoring the original KCOV reference. So when the task exits, all registered remote KCOV handles remain active forever. The most uncomfortable effect (at least for syzkaller) is that the bug prevents the reuse of the same /sys/kernel/debug/kcov descriptor. If we obtain it in the parent process and then e.g. drop some capabilities and continuously fork to execute individual programs, at some point current->kcov of the forked process is lost, kcov_task_exit() takes no action, and all KCOV_REMOTE_ENABLE ioctls calls from subsequent forks fail. And, yes, the efficiency is also affected if we keep on losing remote kcov objects. a) kcov_remote_map keeps on growing forever. b) (If I'm not mistaken), we're also not freeing the memory referenced by kcov->area. Fix it by introducing a special kcov_mode that is assigned to the task that owns a KCOV remote object. It makes kcov_mode_enabled() return true and yet does not trigger coverage collection in __sanitizer_cov_trace_pc() and write_comp_data(). [nogikh@google.com: replace WRITE_ONCE() with an ordinary assignment] Link: https://lkml.kernel.org/r/20240614171221.2837584-1-nogikh@google.com Link: https://lkml.kernel.org/r/20240611133229.527822-1-nogikh@google.com Fixes: 5ff3b30ab57d ("kcov: collect coverage from interrupts") Signed-off-by: Aleksandr Nogikh <nogikh@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marco Elver <elver@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-27gcov: add support for GCC 14Peter Oberparleiter
commit c1558bc57b8e5b4da5d821537cd30e2e660861d8 upstream. Using gcov on kernels compiled with GCC 14 results in truncated 16-byte long .gcda files with no usable data. To fix this, update GCOV_COUNTERS to match the value defined by GCC 14. Tested with GCC versions 14.1.0 and 13.2.0. Link: https://lkml.kernel.org/r/20240610092743.1609845-1-oberpar@linux.ibm.com Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reported-by: Allison Henderson <allison.henderson@oracle.com> Reported-by: Chuck Lever III <chuck.lever@oracle.com> Tested-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-27tracing: Build event generation tests only as modulesMasami Hiramatsu (Google)
[ Upstream commit 3572bd5689b0812b161b40279e39ca5b66d73e88 ] The kprobes and synth event generation test modules add events and lock (get a reference) those event file reference in module init function, and unlock and delete it in module exit function. This is because those are designed for playing as modules. If we make those modules as built-in, those events are left locked in the kernel, and never be removed. This causes kprobe event self-test failure as below. [ 97.349708] ------------[ cut here ]------------ [ 97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.357106] Modules linked in: [ 97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14 [ 97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90 [ 97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286 [ 97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000 [ 97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68 [ 97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000 [ 97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000 [ 97.381536] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 97.383813] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0 [ 97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 97.391196] Call Trace: [ 97.391967] <TASK> [ 97.392647] ? __warn+0xcc/0x180 [ 97.393640] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.395181] ? report_bug+0xbd/0x150 [ 97.396234] ? handle_bug+0x3e/0x60 [ 97.397311] ? exc_invalid_op+0x1a/0x50 [ 97.398434] ? asm_exc_invalid_op+0x1a/0x20 [ 97.399652] ? trace_kprobe_is_busy+0x20/0x20 [ 97.400904] ? tracing_reset_all_online_cpus+0x15/0x90 [ 97.402304] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.403773] ? init_kprobe_trace+0x50/0x50 [ 97.404972] do_one_initcall+0x112/0x240 [ 97.406113] do_initcall_level+0x95/0xb0 [ 97.407286] ? kernel_init+0x1a/0x1a0 [ 97.408401] do_initcalls+0x3f/0x70 [ 97.409452] kernel_init_freeable+0x16f/0x1e0 [ 97.410662] ? rest_init+0x1f0/0x1f0 [ 97.411738] kernel_init+0x1a/0x1a0 [ 97.412788] ret_from_fork+0x39/0x50 [ 97.413817] ? rest_init+0x1f0/0x1f0 [ 97.414844] ret_from_fork_asm+0x11/0x20 [ 97.416285] </TASK> [ 97.417134] irq event stamp: 13437323 [ 97.418376] hardirqs last enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150 [ 97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150 [ 97.423838] softirqs last enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0 [ 97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0 [ 97.428850] ---[ end trace 0000000000000000 ]--- And also, since we can not cleanup dynamic_event file, ftracetest are failed too. To avoid these issues, build these tests only as modules. Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/ Fixes: 9fe41efaca08 ("tracing: Add synth event generation test module") Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27rcutorture: Fix invalid context warning when enable srcu barrier testingZqiang
[ Upstream commit 668c0406d887467d53f8fe79261dda1d22d5b671 ] When the torture_type is set srcu or srcud and cb_barrier is non-zero, running the rcutorture test will trigger the following warning: [ 163.910989][ C1] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 163.910994][ C1] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 [ 163.910999][ C1] preempt_count: 10001, expected: 0 [ 163.911002][ C1] RCU nest depth: 0, expected: 0 [ 163.911005][ C1] INFO: lockdep is turned off. [ 163.911007][ C1] irq event stamp: 30964 [ 163.911010][ C1] hardirqs last enabled at (30963): [<ffffffffabc7df52>] do_idle+0x362/0x500 [ 163.911018][ C1] hardirqs last disabled at (30964): [<ffffffffae616eff>] sysvec_call_function_single+0xf/0xd0 [ 163.911025][ C1] softirqs last enabled at (0): [<ffffffffabb6475f>] copy_process+0x16ff/0x6580 [ 163.911033][ C1] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 163.911038][ C1] Preemption disabled at: [ 163.911039][ C1] [<ffffffffacf1964b>] stack_depot_save_flags+0x24b/0x6c0 [ 163.911063][ C1] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 6.8.0-rc4-rt4-yocto-preempt-rt+ #3 1e39aa9a737dd024a3275c4f835a872f673a7d3a [ 163.911071][ C1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [ 163.911075][ C1] Call Trace: [ 163.911078][ C1] <IRQ> [ 163.911080][ C1] dump_stack_lvl+0x88/0xd0 [ 163.911089][ C1] dump_stack+0x10/0x20 [ 163.911095][ C1] __might_resched+0x36f/0x530 [ 163.911105][ C1] rt_spin_lock+0x82/0x1c0 [ 163.911112][ C1] spin_lock_irqsave_ssp_contention+0xb8/0x100 [ 163.911121][ C1] srcu_gp_start_if_needed+0x782/0xf00 [ 163.911128][ C1] ? _raw_spin_unlock_irqrestore+0x46/0x70 [ 163.911136][ C1] ? debug_object_active_state+0x336/0x470 [ 163.911148][ C1] ? __pfx_srcu_gp_start_if_needed+0x10/0x10 [ 163.911156][ C1] ? __pfx_lock_release+0x10/0x10 [ 163.911165][ C1] ? __pfx_rcu_torture_barrier_cbf+0x10/0x10 [ 163.911188][ C1] __call_srcu+0x9f/0xe0 [ 163.911196][ C1] call_srcu+0x13/0x20 [ 163.911201][ C1] srcu_torture_call+0x1b/0x30 [ 163.911224][ C1] rcu_torture_barrier1cb+0x4a/0x60 [ 163.911247][ C1] __flush_smp_call_function_queue+0x267/0xca0 [ 163.911256][ C1] ? __pfx_rcu_torture_barrier1cb+0x10/0x10 [ 163.911281][ C1] generic_smp_call_function_single_interrupt+0x13/0x20 [ 163.911288][ C1] __sysvec_call_function_single+0x7d/0x280 [ 163.911295][ C1] sysvec_call_function_single+0x93/0xd0 [ 163.911302][ C1] </IRQ> [ 163.911304][ C1] <TASK> [ 163.911308][ C1] asm_sysvec_call_function_single+0x1b/0x20 [ 163.911313][ C1] RIP: 0010:default_idle+0x17/0x20 [ 163.911326][ C1] RSP: 0018:ffff888001997dc8 EFLAGS: 00000246 [ 163.911333][ C1] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffffae618b51 [ 163.911337][ C1] RDX: 0000000000000000 RSI: ffffffffaea80920 RDI: ffffffffaec2de80 [ 163.911342][ C1] RBP: ffff888001997dc8 R08: 0000000000000001 R09: ffffed100d740cad [ 163.911346][ C1] R10: ffffed100d740cac R11: ffff88806ba06563 R12: 0000000000000001 [ 163.911350][ C1] R13: ffffffffafe460c0 R14: ffffffffafe460c0 R15: 0000000000000000 [ 163.911358][ C1] ? ct_kernel_exit.constprop.3+0x121/0x160 [ 163.911369][ C1] ? lockdep_hardirqs_on+0xc4/0x150 [ 163.911376][ C1] arch_cpu_idle+0x9/0x10 [ 163.911383][ C1] default_idle_call+0x7a/0xb0 [ 163.911390][ C1] do_idle+0x362/0x500 [ 163.911398][ C1] ? __pfx_do_idle+0x10/0x10 [ 163.911404][ C1] ? complete_with_flags+0x8b/0xb0 [ 163.911416][ C1] cpu_startup_entry+0x58/0x70 [ 163.911423][ C1] start_secondary+0x221/0x280 [ 163.911430][ C1] ? __pfx_start_secondary+0x10/0x10 [ 163.911440][ C1] secondary_startup_64_no_verify+0x17f/0x18b [ 163.911455][ C1] </TASK> This commit therefore use smp_call_on_cpu() instead of smp_call_function_single(), make rcu_torture_barrier1cb() invoked happens on task-context. Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27rcutorture: Make stall-tasks directly exit when rcutorture tests endZqiang
[ Upstream commit 431315a563015f259b28e34c5842f6166439e969 ] When the rcutorture tests start to exit, the rcu_torture_cleanup() is invoked to stop kthreads and release resources, if the stall-task kthreads exist, cpu-stall has started and the rcutorture.stall_cpu is set to a larger value, the rcu_torture_cleanup() will be blocked for a long time and the hung-task may occur, this commit therefore add kthread_should_stop() to the loop of cpu-stall operation, when rcutorture tests ends, no need to wait for cpu-stall to end, exit directly. Use the following command to test: insmod rcutorture.ko torture_type=srcu fwd_progress=0 stat_interval=4 stall_cpu_block=1 stall_cpu=200 stall_cpu_holdoff=10 read_exit_burst=0 object_debug=1 rmmod rcutorture [15361.918610] INFO: task rmmod:878 blocked for more than 122 seconds. [15361.918613] Tainted: G W 6.8.0-rc2-yoctodev-standard+ #25 [15361.918615] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [15361.918616] task:rmmod state:D stack:0 pid:878 tgid:878 ppid:773 flags:0x00004002 [15361.918621] Call Trace: [15361.918623] <TASK> [15361.918626] __schedule+0xc0d/0x28f0 [15361.918631] ? __pfx___schedule+0x10/0x10 [15361.918635] ? rcu_is_watching+0x19/0xb0 [15361.918638] ? schedule+0x1f6/0x290 [15361.918642] ? __pfx_lock_release+0x10/0x10 [15361.918645] ? schedule+0xc9/0x290 [15361.918648] ? schedule+0xc9/0x290 [15361.918653] ? trace_preempt_off+0x54/0x100 [15361.918657] ? schedule+0xc9/0x290 [15361.918661] schedule+0xd0/0x290 [15361.918665] schedule_timeout+0x56d/0x7d0 [15361.918669] ? debug_smp_processor_id+0x1b/0x30 [15361.918672] ? rcu_is_watching+0x19/0xb0 [15361.918676] ? __pfx_schedule_timeout+0x10/0x10 [15361.918679] ? debug_smp_processor_id+0x1b/0x30 [15361.918683] ? rcu_is_watching+0x19/0xb0 [15361.918686] ? wait_for_completion+0x179/0x4c0 [15361.918690] ? __pfx_lock_release+0x10/0x10 [15361.918693] ? __kasan_check_write+0x18/0x20 [15361.918696] ? wait_for_completion+0x9d/0x4c0 [15361.918700] ? _raw_spin_unlock_irq+0x36/0x50 [15361.918703] ? wait_for_completion+0x179/0x4c0 [15361.918707] ? _raw_spin_unlock_irq+0x36/0x50 [15361.918710] ? wait_for_completion+0x179/0x4c0 [15361.918714] ? trace_preempt_on+0x54/0x100 [15361.918718] ? wait_for_completion+0x179/0x4c0 [15361.918723] wait_for_completion+0x181/0x4c0 [15361.918728] ? __pfx_wait_for_completion+0x10/0x10 [15361.918738] kthread_stop+0x152/0x470 [15361.918742] _torture_stop_kthread+0x44/0xc0 [torture 7af7f9cbba28271a10503b653f9e05d518fbc8c3] [15361.918752] rcu_torture_cleanup+0x2ac/0xe90 [rcutorture f2cb1f556ee7956270927183c4c2c7749a336529] [15361.918766] ? __pfx_rcu_torture_cleanup+0x10/0x10 [rcutorture f2cb1f556ee7956270927183c4c2c7749a336529] [15361.918777] ? __kasan_check_write+0x18/0x20 [15361.918781] ? __mutex_unlock_slowpath+0x17c/0x670 [15361.918789] ? __might_fault+0xcd/0x180 [15361.918793] ? find_module_all+0x104/0x1d0 [15361.918799] __x64_sys_delete_module+0x2a4/0x3f0 [15361.918803] ? __pfx___x64_sys_delete_module+0x10/0x10 [15361.918807] ? syscall_exit_to_user_mode+0x149/0x280 Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27rcutorture: Fix rcu_torture_one_read() pipe_count overflow commentPaul E. McKenney
[ Upstream commit 8b9b443fa860276822b25057cb3ff3b28734dec0 ] The "pipe_count > RCU_TORTURE_PIPE_LEN" check has a comment saying "Should not happen, but...". This is only true when testing an RCU whose grace periods are always long enough. This commit therefore fixes this comment. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Closes: https://lore.kernel.org/lkml/CAHk-=wi7rJ-eGq+xaxVfzFEgbL9tdf6Kc8Z89rCpfcQOKm74Tw@mail.gmail.com/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27padata: Disable BH when taking works lock on MT pathHerbert Xu
[ Upstream commit 58329c4312031603bb1786b44265c26d5065fe72 ] As the old padata code can execute in softirq context, disable softirqs for the new padata_do_mutithreaded code too as otherwise lockdep will get antsy. Reported-by: syzbot+0cb5bb0f4bf9e79db3b3@syzkaller.appspotmail.com Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDINGOleg Nesterov
[ Upstream commit 7fea700e04bd3f424c2d836e98425782f97b494e ] kernel_wait4() doesn't sleep and returns -EINTR if there is no eligible child and signal_pending() is true. That is why zap_pid_ns_processes() clears TIF_SIGPENDING but this is not enough, it should also clear TIF_NOTIFY_SIGNAL to make signal_pending() return false and avoid a busy-wait loop. Link: https://lkml.kernel.org/r/20240608120616.GB7947@redhat.com Fixes: 12db8b690010 ("entry: Add support for TIF_NOTIFY_SIGNAL") Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Rachel Menge <rachelmenge@linux.microsoft.com> Closes: https://lore.kernel.org/all/1386cd49-36d0-4a5c-85e9-bc42056a5a38@linux.microsoft.com/ Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Tested-by: Wei Fu <fuweid89@gmail.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Cc: Allen Pais <apais@linux.microsoft.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joel Granados <j.granados@samsung.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mike Christie <michael.christie@oracle.com> Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Zqiang <qiang.zhang1211@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>