| Age | Commit message (Collapse) | Author |
|---|
|
[ Upstream commit c94291914b200e10c72cef23c8e4c67eb4fdbcd9 ]
On SMP systems the CPU hotplug callbacks in the "starting" range are
invoked while the CPU is brought up and interrupts are still
disabled. Callbacks which are added later are invoked via the
hotplug-thread on the target CPU and interrupts are explicitly disabled.
In the UP case callbacks which are added later are invoked directly without
the thread indirection. This is in principle okay since there is just one
CPU but those callbacks are invoked with interrupt disabled code. That's
incorrect as those callbacks assume interrupt disabled context.
Disable interrupts before invoking the callbacks on UP if the state is
atomic and interrupts are expected to be disabled. The "save" part is
required because this is also invoked early in the boot process while
interrupts are disabled and must not be enabled prematurely.
Fixes: 06ddd17521bf1 ("sched/smp: Always define is_percpu_thread() and scheduler_ipi()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251127144723.ev9DuXXR@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit c418d8b4d7a43a86b82ee39cb52ece3034383530 ]
For events with inherit_stat enabled, a "read" event will be generated
to collect per task event counts on task exit.
The call chain is as follows:
do_exit
-> perf_event_exit_task
-> perf_event_exit_task_context
-> perf_event_exit_event
-> perf_remove_from_context
-> perf_child_detach
-> sync_child_event
-> perf_event_read_event
However, the child event context detaches the task too early in
perf_event_exit_task_context, which causes sync_child_event to never
generate the read event in this case, since child_event->ctx->task is
always set to TASK_TOMBSTONE. Fix that by moving context lock section
backward to ensure ctx->task is not set to TASK_TOMBSTONE before
generating the read event.
Because perf_event_free_task calls perf_event_exit_task_context with
exit = false to tear down all child events from the context, and the
task never lived, accessing the task PID can lead to a use-after-free.
To fix that, let sync_child_event read task from argument and move the
call to the only place it should be triggered to avoid the effect of
setting ctx->task to TASK_TOMESTONE, and add a task parameter to
perf_event_exit_event to trigger the sync_child_event properly when
needed.
This bug can be reproduced by running "perf record -s" and attaching to
any program that generates perf events in its child tasks. If we check
the result with "perf report -T", the last line of the report will leave
an empty table like "# PID TID", which is expected to contain the
per-task event counts by design.
Fixes: ef54c1a476ae ("perf: Rework perf_event_exit_event()")
Signed-off-by: Thaumy Cheng <thaumy.love@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-perf-users@vger.kernel.org
Link: https://patch.msgid.link/20251209041600.963586-1-thaumy.love@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 463d439becb81383f3a5a5d840800131f265a09c ]
atomic_pool_expand iteratively tries the allocation while decrementing
the page order. There is no need to issue a warning if an attempted
allocation fails.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone")
[mszyprow: fixed typo]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251202152810.142370-1-dave.kleikamp@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit c2ae8b0df2d1bb7a063f9e356e4e9a06cd4afe11 ]
Currently, if the sleep flag is set, psi_dequeue() doesn't
change any of the psi_flags.
This is because psi_task_switch() will clear TSK_ONCPU as well
as other potential flags (TSK_RUNNING), and the assumption is
that a voluntary sleep always consists of a task being dequeued
followed shortly there after with a psi_sched_switch() call.
Proxy Execution changes this expectation, as mutex-blocked tasks
that would normally sleep stay on the runqueue. But in the case
where the mutex-owning task goes to sleep, or the owner is on a
remote cpu, we will then deactivate the blocked task shortly
after.
In that situation, the mutex-blocked task will have had its
TSK_ONCPU cleared when it was switched off the cpu, but it will
stay TSK_RUNNING. Then if we later dequeue it (as currently done
if we hit a case find_proxy_task() can't yet handle, such as the
case of the owner being on another rq or a sleeping owner)
psi_dequeue() won't change any state (leaving it TSK_RUNNING),
as it incorrectly expects a psi_task_switch() call to
immediately follow.
Later on when the task get woken/re-enqueued, and psi_flags are
set for TSK_RUNNING, we hit an error as the task is already
TSK_RUNNING:
psi: inconsistent task state! task=188:kworker/28:0 cpu=28 psi_flags=4 clear=0 set=4
To resolve this, extend the logic in psi_dequeue() so that
if the sleep flag is set, we also check if psi_flags have
TSK_ONCPU set (meaning the psi_task_switch is imminent) before
we do the shortcut return.
If TSK_ONCPU is not set, that means we've already switched away,
and this psi_dequeue call needs to clear the flags.
Fixes: be41bde4c3a8 ("sched: Add an initial sketch of the find_proxy_task() function")
Reported-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Haiyue Wang <haiyuewa@163.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://patch.msgid.link/20251205012721.756394-1-jstultz@google.com
Closes: https://lore.kernel.org/lkml/20251117185550.365156-1-kprateek.nayak@amd.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
last task migrates out
[ Upstream commit ca125231dd29fc0678dd3622e9cdea80a51dffe4 ]
When a task is migrated out, there is a probability that the tg->load_avg
value will become abnormal. The reason is as follows:
1. Due to the 1ms update period limitation in update_tg_load_avg(), there
is a possibility that the reduced load_avg is not updated to tg->load_avg
when a task migrates out.
2. Even though __update_blocked_fair() traverses the leaf_cfs_rq_list and
calls update_tg_load_avg() for cfs_rqs that are not fully decayed, the key
function cfs_rq_is_decayed() does not check whether
cfs->tg_load_avg_contrib is null. Consequently, in some cases,
__update_blocked_fair() removes cfs_rqs whose avg.load_avg has not been
updated to tg->load_avg.
Add a check of cfs_rq->tg_load_avg_contrib in cfs_rq_is_decayed(),
which fixes the case (2.) mentioned above.
Fixes: 1528c661c24b ("sched/fair: Ratelimit update to tg->load_avg")
Signed-off-by: xupengbo <xupengbo@oppo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Aaron Lu <ziqianlu@bytedance.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Aaron Lu <ziqianlu@bytedance.com>
Link: https://patch.msgid.link/20250827022208.14487-1-xupengbo@oppo.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 81d5a6a438595e46be191d602e5c2d6d73992fdc ]
In addition to deferring to the trylock fallback in NMIs, only do so
when an rqspinlock waiter is queued on the current CPU. This is detected
by noticing a non-zero node index. This allows NMI waiters to join the
waiter queue if it isn't interrupting an existing rqspinlock waiter, and
increase the chances of fairly obtaining the lock, performing deadlock
detection as the head, and not being starved while attempting the
trylock.
The trylock path in particular is unlikely to succeed under contention,
as it relies on the lock word becoming 0, which indicates no contention.
This means that the most likely result for NMIs attempting a trylock is
a timeout under contention if they don't hit an AA or ABBA case.
The core problem being addressed through the fixed commit was removing
the dependency edge between an NMI queue waiter and the queue waiter it
is interrupting. Whenever a circular dependency forms, and with no way
to break it (as non-head waiters don't poll for deadlocks or timeouts),
we would enter into a deadlock. A trylock either breaks such an edge by
probing for deadlocks, and finally terminating the waiting loop using a
timeout.
By excluding queueing on CPUs where the node index is non-zero for NMIs,
this sort of dependency is broken. The CPU enters the trylock path for
those cases, and falls back to deadlock checks and timeouts. However, in
other case where it doesn't interrupt the CPU in the slow path while its
queued on the lock, it can join the queue as a normal waiter, and avoid
trylock associated starvation and subsequent timeouts.
There are a few remaining cases here that matter: the NMI can still
preempt the owner in its critical section, and if it queues as a
non-head waiter, it can end up impeding the progress of the owner. While
this won't deadlock, since the head waiter will eventually signal the
NMI waiter to either stop (due to a timeout), it can still lead to long
timeouts. These gaps will be addressed in subsequent commits.
Note that while the node count detection approach is less conservative
than simply deferring NMIs to trylock, it is going to return errors
where attempts to lock B in NMI happen while waiters for lock A are in a
lower context on the same CPU. However, this only occurs when the lower
context is queued in the slow path, and the NMI attempt can proceed
without failure in all other cases. To continue to prevent AA deadlocks
(or ABBA in a similar NMI interrupting lower context pattern), we'd need
a more fleshed out algorithm to unlink NMI waiters after they queue and
detect such cases. However, all that complexity isn't appealing yet to
reduce the failure rate in the small window inside the slow path.
It is important to note that reentrancy in the slow path can also happen
through trace_contention_{begin,end}, but in those cases, unlike an NMI,
the forward progress of the head waiter (or the predecessor in general)
is not being blocked.
Fixes: 0d80e7f951be ("rqspinlock: Choose trylock fallback for NMI waiters")
Reported-by: Ritesh Oedayrajsingh Varma <ritesh@superluminal.eu>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251128232802.1031906-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit beb7021a6003d9c6a463fffca0d6311efb8e0e66 ]
Ritesh reported that timeouts occurred frequently for rqspinlock despite
reentrancy on the same lock on the same CPU in [0]. This patch closes
one of the races leading to this behavior, and reduces the frequency of
timeouts.
We currently have a tiny window between the fast-path cmpxchg and the
grabbing of the lock entry where an NMI could land, attempt the same
lock that was just acquired, and end up timing out. This is not ideal.
Instead, move the lock entry acquisition from the fast path to before
the cmpxchg, and remove the grabbing of the lock entry in the slow path,
assuming it was already taken by the fast path. The TAS fallback is
invoked directly without being preceded by the typical fast path,
therefore we must continue to grab the deadlock detection entry in that
case.
Case on lock leading to missed AA:
cmpxchg lock A
<NMI>
... rqspinlock acquisition of A
... timeout
</NMI>
grab_held_lock_entry(A)
There is a similar case when unlocking the lock. If the NMI lands
between the WRITE_ONCE and smp_store_release, it is possible that we end
up in a situation where the NMI fails to diagnose the AA condition,
leading to a timeout.
Case on unlock leading to missed AA:
WRITE_ONCE(rqh->locks[rqh->cnt - 1], NULL)
<NMI>
... rqspinlock acquisition of A
... timeout
</NMI>
smp_store_release(A->locked, 0)
The patch changes the order on unlock to smp_store_release() succeeded
by WRITE_ONCE() of NULL. This avoids the missed AA detection described
above, but may lead to a false positive if the NMI lands between these
two statements, which is acceptable (and preferred over a timeout).
The original intention of the reverse order on unlock was to prevent the
following possible misdiagnosis of an ABBA scenario:
grab entry A
lock A
grab entry B
lock B
unlock B
smp_store_release(B->locked, 0)
grab entry B
lock B
grab entry A
lock A
! <detect ABBA>
WRITE_ONCE(rqh->locks[rqh->cnt - 1], NULL)
If the store release were is after the WRITE_ONCE, the other CPU would
not observe B in the table of the CPU unlocking the lock B. However,
since the threads are obviously participating in an ABBA deadlock, it
is no longer appealing to use the order above since it may lead to a
250 ms timeout due to missed AA detection.
[0]: https://lore.kernel.org/bpf/CAH6OuBTjG+N=+GGwcpOUbeDN563oz4iVcU3rbse68egp9wj9_A@mail.gmail.com
Fixes: 0d80e7f951be ("rqspinlock: Choose trylock fallback for NMI waiters")
Reported-by: Ritesh Oedayrajsingh Varma <ritesh@superluminal.eu>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251128232802.1031906-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 6fb3acdebf65a72df0a95f9fd2c901ff2bc9a3a2 ]
Commit 97523a4edb7b ("kernel/resource: remove first_lvl / siblings_only
logic") removed an optimization introduced by commit 756398750e11
("resource: avoid unnecessary lookups in find_next_iomem_res()"). That
was not called out in the message of the first commit explicitly so it's
not entirely clear whether removing the optimization happened
inadvertently or not.
As the original commit message of the optimization explains there is no
point considering the children of a subtree in find_next_iomem_res() if
the top level range does not match.
Reinstating the optimization results in performance improvements in
systems where /proc/iomem is ~5k lines long. Calling mmap() on /dev/mem
in such platforms takes 700-1500μs without the optimisation and 10-50μs
with the optimisation.
Note that even though commit 97523a4edb7b removed the 'sibling_only'
parameter from next_resource(), newer kernels have basically reinstated it
under the name 'skip_children'.
Link: https://lore.kernel.org/all/20251124165349.3377826-1-ilstam@amazon.com/T/#u
Fixes: 97523a4edb7b ("kernel/resource: remove first_lvl / siblings_only logic")
Signed-off-by: Ilias Stamatis <ilstam@amazon.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Huang, Ying" <huang.ying.caritas@gmail.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 688b745401ab16e2e1a3b504863f0a45fd345638 ]
When excl_prog_hash is 0 and excl_prog_hash_size is non-zero, the map also
needs to be freed. Otherwise, the map memory will not be reclaimed, just
like the memory leak problem reported by syzbot [1].
syzbot reported:
BUG: memory leak
backtrace (crc 7b9fb9b4):
map_create+0x322/0x11e0 kernel/bpf/syscall.c:1512
__sys_bpf+0x3556/0x3610 kernel/bpf/syscall.c:6131
Fixes: baefdbdf6812 ("bpf: Implement exclusive map creation")
Reported-by: syzbot+cf08c551fecea9fd1320@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cf08c551fecea9fd1320
Tested-by: syzbot+cf08c551fecea9fd1320@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/tencent_3F226F882CE56DCC94ACE90EED1ECCFC780A@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit e3245f8990431950d20631c72236d4e8cb2dcde8 ]
A successful ebpf tail call does not return to the caller, but to the
caller-of-the-caller, often just finishing the ebpf program altogether.
Any restrictions that the verifier needs to take into account - notably
the fact that the tail call might have modified packet pointers - are to
be checked on the caller-of-the-caller. Checking it on the caller made
the verifier refuse perfectly fine programs that would use the packet
pointers after a tail call, which is no problem as this code is only
executed if the tail call was unsuccessful, i.e. nothing happened.
This patch simulates the behavior of a tail call in the verifier. A
conditional jump to the code after the tail call is added for the case
of an unsucessful tail call, and a return to the caller is simulated for
a successful tail call.
For the successful case we assume that the tail call returns an int,
as tail calls are currently only allowed in functions that return and
int. We always assume that the tail call modified the packet pointers,
as we do not know what the tail call did.
For the unsuccessful case we know nothing happened, so we do not need to
add new constraints.
This approach also allows to check other problems that may occur with
tail calls, namely we are now able to check that precision is properly
propagated into subprograms using tail calls, as well as checking the
live slots in such a subprogram.
Fixes: 1a4607ffba35 ("bpf: consider that tail calls invalidate packet pointers")
Link: https://lore.kernel.org/bpf/20251029105828.1488347-1-martin.teichmann@xfel.eu/
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251119160355.1160932-2-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit b1bcaed1e39a9e0dfbe324a15d2ca4253deda316 ]
Currently, the check for whether a partition is populated does not
account for tasks in the cpuset of attaching. This is a corner case
that can leave a task stuck in a partition with no effective CPUs.
The race condition occurs as follows:
cpu0 cpu1
//cpuset A with cpu N
migrate task p to A
cpuset_can_attach
// with effective cpus
// check ok
// cpuset_mutex is not held // clear cpuset.cpus.exclusive
// making effective cpus empty
update_exclusive_cpumask
// tasks_nocpu_error check ok
// empty effective cpus, partition valid
cpuset_attach
...
// task p stays in A, with non-effective cpus.
To fix this issue, this patch introduces cs_is_populated, which considers
tasks in the attaching cpuset. This new helper is used in validate_change
and partition_is_populated.
Fixes: e2d59900d936 ("cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 7dc211c1159d991db609bdf4b0fb9033c04adcbc ]
Syzkaller triggers an invalid memory access issue following fault
injection in update_effective_progs. The issue can be described as
follows:
__cgroup_bpf_detach
update_effective_progs
compute_effective_progs
bpf_prog_array_alloc <-- fault inject
purge_effective_progs
/* change to dummy_bpf_prog */
array->items[index] = &dummy_bpf_prog.prog
---softirq start---
__do_softirq
...
__cgroup_bpf_run_filter_skb
__bpf_prog_run_save_cb
bpf_prog_run
stats = this_cpu_ptr(prog->stats)
/* invalid memory access */
flags = u64_stats_update_begin_irqsave(&stats->syncp)
---softirq end---
static_branch_dec(&cgroup_bpf_enabled_key[atype])
The reason is that fault injection caused update_effective_progs to fail
and then changed the original prog into dummy_bpf_prog.prog in
purge_effective_progs. Then a softirq came, and accessing the members of
dummy_bpf_prog.prog in the softirq triggers invalid mem access.
To fix it, skip updating stats when stats is NULL.
Fixes: 492ecee892c2 ("bpf: enable program stats")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/20251115102343.2200727-1-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit fea3f5e83c5cd80a76d97343023a2f2e6bd862bf ]
The error that returned by ftrace_set_filter_ip() in register_fentry() is
not handled properly. Just fix it.
Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20251110120705.1553694-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit c1da3df7191f1b4df9256bcd30d78f78201e1d17 ]
bpf_try_get_buffers() returns one of multiple per-CPU buffers based on a
per-CPU nesting counter. This mechanism expects that buffers are not
endlessly acquired before being returned. migrate_disable() ensures that a
task remains on the same CPU, but it does not prevent the task from being
preempted by another task on that CPU.
Without disabled preemption, a task may be preempted while holding a
buffer, allowing another task to run on same CPU and acquire an
additional buffer. Several such preemptions can cause the per-CPU
nest counter to exceed MAX_BPRINTF_NEST_LEVEL and trigger the warning in
bpf_try_get_buffers(). Adding preempt_disable()/preempt_enable() around
buffer acquisition and release prevents this task preemption and
preserves the intended bounded nesting behavior.
Reported-by: syzbot+b0cff308140f79a9c4cb@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68f6a4c8.050a0220.1be48.0011.GAE@google.com/
Fixes: 4223bf833c849 ("bpf: Remove preempt_disable in bpf_try_get_buffers")
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
Link: https://lore.kernel.org/r/20251114064922.11650-1-chandna.sahil@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 6af6e49a76c9af7d42eb923703e7648cb2bf401a ]
As [lru_,]percpu_hash maps support BPF_KPTR_{REF,PERCPU}, missing
calls to 'bpf_obj_free_fields()' in 'pcpu_copy_value()' could cause the
memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the
map gets freed.
Fix this by calling 'bpf_obj_free_fields()' after
'copy_map_value[,_long]()' in 'pcpu_copy_value()'.
Fixes: 65334e64a493 ("bpf: Support kptrs in percpu hashmap and percpu LRU hashmap")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20251105151407.12723-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit e52b43883d084a9af263c573f2a1bd1ca5088389 ]
With CONFIG_CPUMASK_OFFSTACK=y, the 'bind_writers' buffer is allocated via
alloc_cpumask_var() in param_set_cpumask(). But it is not freed, when
setting the module parameter multiple times by sysfs interface or removing
module.
Below kmemleak trace is seen for this issue:
unreferenced object 0xffff888100aabff8 (size 8):
comm "bash", pid 323, jiffies 4295059233
hex dump (first 8 bytes):
07 00 00 00 00 00 00 00 ........
backtrace (crc ac50919):
__kmalloc_node_noprof+0x2e5/0x420
alloc_cpumask_var_node+0x1f/0x30
param_set_cpumask+0x26/0xb0 [locktorture]
param_attr_store+0x93/0x100
module_attr_store+0x1b/0x30
kernfs_fop_write_iter+0x114/0x1b0
vfs_write+0x300/0x410
ksys_write+0x60/0xd0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
This issue can be reproduced by:
insmod locktorture.ko bind_writers=1
rmmod locktorture
or:
insmod locktorture.ko bind_writers=1
echo 2 > /sys/module/locktorture/parameters/bind_writers
Considering that setting the module parameter 'bind_writers' or
'bind_readers' by sysfs interface has no real effect, set the parameter
permissions to 0444. To fix the memory leak when removing module, free
'bind_writers' and 'bind_readers' memory in lock_torture_cleanup().
Fixes: 73e341242483 ("locktorture: Add readers_bind and writers_bind module parameters")
Suggested-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 5eb579dfd46b4949117ecb0f1ba2f12d3dc9a6f2 ]
When a CPU from a new node boots, the old root may happen to be
connected to the new root even if their node mismatch, as depicted in
the following scenario:
1) CPU 0 boots and creates the first group for node 0.
[GRP0:0]
node 0
|
CPU 0
2) CPU 1 from node 1 boots and creates a new top that corresponds to
node 1, but it also connects the old root from node 0 to the new root
from node 1 by mistake.
[GRP1:0]
node 1
/ \
/ \
[GRP0:0] [GRP0:1]
node 0 node 1
| |
CPU 0 CPU 1
3) This eventually leads to an imbalanced tree where some node 0 CPUs
migrate node 1 timers (and vice versa) way before reaching the
crossnode groups, resulting in more frequent remote memory accesses
than expected.
[GRP2:0]
NUMA_NO_NODE
/ \
[GRP1:0] [GRP1:1]
node 1 node 0
/ \ |
/ \ [...]
[GRP0:0] [GRP0:1]
node 0 node 1
| |
CPU 0... CPU 1...
A balanced tree should only contain groups having children that belong
to the same node:
[GRP2:0]
NUMA_NO_NODE
/ \
[GRP1:0] [GRP1:0]
node 0 node 1
/ \ / \
/ \ / \
[GRP0:0] [...] [...] [GRP0:1]
node 0 node 1
| |
CPU 0... CPU 1...
In order to fix this, the hierarchy must be unfolded up to the crossnode
level as soon as a node mismatch is detected. For example the stage 2
above should lead to this layout:
[GRP2:0]
NUMA_NO_NODE
/ \
[GRP1:0] [GRP1:1]
node 0 node 1
/ \
/ \
[GRP0:0] [GRP0:1]
node 0 node 1
| |
CPU 0 CPU 1
This means that not only GRP1:0 must be created but also GRP1:1 and
GRP2:0 in order to prepare a balanced tree for next CPUs to boot.
Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251024132536.39841-4-frederic@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit fa9620355d4192200f15cb3d97c6eb9c02442249 ]
Initializing the tmc's group, the group's number of children and the
group's parent can all be done without locking because:
1) Reading the group's parent and its group mask is done locklessly.
2) The connections prepared for a given CPU hierarchy are visible to the
target CPU once online, thanks to the CPU hotplug enforced memory
ordering.
3) In case of a newly created upper level, the new root and its
connections and initialization are made visible by the CPU which made
the connections. When that CPUs goes idle in the future, the new link
is published by tmigr_inactive_up() through the atomic RmW on
->migr_state.
4) If CPUs were still walking up the active hierarchy, they could observe
the new root earlier. In this case the ordering is enforced by an
early initialization of the group mask and by barriers that maintain
address dependency as explained in:
b729cc1ec21a ("timers/migration: Fix another race between hotplug and idle entry/exit")
de3ced72a792 ("timers/migration: Enforce group initialization visibility to tree walkers")
5) Timers are propagated by a chain of group locking from the bottom to
the top. And while doing so, the tree also propagates groups links
and initialization. Therefore remote expiration, which also relies
on group locking, will observe those links and initialization while
holding the root lock before walking the tree remotely and update
remote timers. This is especially important for migrators in the
active hierarchy that may observe the new root early.
Therefore the locking is unnecessary at initialization. If anything, it
just brings confusion. Remove it.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251024132536.39841-3-frederic@kernel.org
Stable-dep-of: 5eb579dfd46b ("timers/migration: Fix imbalanced NUMA trees")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 6c181b5667eea3e6564d334443536a5974190e15 ]
Both the "do while" and "while" loops in tmigr_setup_groups() eventually
mimic the behaviour of "for" loops.
Simplify accordingly.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251024132536.39841-2-frederic@kernel.org
Stable-dep-of: 5eb579dfd46b ("timers/migration: Fix imbalanced NUMA trees")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 768b1565d9d1e1eebf7567f477f7f46c05a98a4d ]
Otherwise we trip VFS_WARN_ON_ONC() in __ns_tree_add_raw().
Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-6-2e6f823ebdc0@kernel.org
Fixes: 7c6059398533 ("cgroup: support ns lookup")
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit ef1ea98c8fffe227e5319215d84a53fa2a4bcebc ]
__schedule()
// disable irqs
<NMI>
task_work_add(current, work, TWA_NMI_CURRENT);
</NMI>
// current = next;
// enable irqs
<IRQ>
task_work_set_notify_irq()
test_and_set_tsk_thread_flag(current,
TIF_NOTIFY_RESUME); // wrong task!
</IRQ>
// original task skips task work on its next return to user (or exit!)
Fixes: 466e4d801cd4 ("task_work: Add TWA_NMI_CURRENT as an additional notify mode.")
Reported-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/20250924080118.425949403@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 23f852daa4bab4d579110e034e4d513f7d490846 ]
Syzkaller reported a KASAN slab-out-of-bounds write in __bpf_get_stackid()
when copying stack trace data. The issue occurs when the perf trace
contains more stack entries than the stack map bucket can hold,
leading to an out-of-bounds write in the bucket's data array.
Fixes: ee2a098851bf ("bpf: Adjust BPF stack helper functions to accommodate skip > 0")
Reported-by: syzbot+c9b724fbb41cf2538b7b@syzkaller.appspotmail.com
Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20251025192941.1500-1-contact@arnaud-lcm.com
Closes: https://syzkaller.appspot.com/bug?extid=c9b724fbb41cf2538b7b
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit e17d62fedd10ae56e2426858bd0757da544dbc73 ]
Extract the duplicated maximum allowed depth computation for stack
traces stored in BPF stacks from bpf_get_stackid() and __bpf_get_stack()
into a dedicated stack_map_calculate_max_depth() helper function.
This unifies the logic for:
- The max depth computation
- Enforcing the sysctl_perf_event_max_stack limit
No functional changes for existing code paths.
Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20251025192858.31424-1-contact@arnaud-lcm.com
Stable-dep-of: 23f852daa4ba ("bpf: Fix stackmap overflow check in __bpf_get_stackid()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 79104becf42baeeb4a3f2b106f954b9fc7c10a3c ]
If a task yields, the scheduler may decide to pick it again. The task in
turn may decide to yield immediately or shortly after, leading to a tight
loop of yields.
If there's another runnable task as this point, the deadline will be
increased by the slice at each loop. This can cause the deadline to runaway
pretty quickly, and subsequent elevated run delays later on as the task
doesn't get picked again. The reason the scheduler can pick the same task
again and again despite its deadline increasing is because it may be the
only eligible task at that point.
Fix this by making the task forfeiting its remaining vruntime and pushing
the deadline one slice ahead. This implements yield behavior more
authentically.
We limit the forfeiting to eligible tasks. This is because core scheduling
prefers running ineligible tasks rather than force idling. As such, without
the condition, we can end up on a yield loop which makes the vruntime
increase rapidly, leading to anomalous run delays later down the line.
Fixes: 147f3efaa24182 ("sched/fair: Implement an EEVDF-like scheduling policy")
Signed-off-by: Fernand Sieber <sieberf@amazon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250401123622.584018-1-sieberf@amazon.com
Link: https://lore.kernel.org/r/20250911095113.203439-1-sieberf@amazon.com
Link: https://lore.kernel.org/r/20250916140228.452231-1-sieberf@amazon.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 5f8d41172931a92339c5cce81a3142065fa56e45 ]
Fix handling maps with no BTF and non-constant offsets for the bpf_wq.
This de-duplicates logic with other internal structs (task_work, timer),
keeps error reporting consistent, and makes future changes to the layout
handling centralized.
Fixes: d940c9b94d7e ("bpf: add support for KF_ARG_PTR_TO_WORKQUEUE")
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251010164606.147298-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 469d638d1520a9332cd0d034690e75e845610a51 ]
Fix the BPF verifier to correctly determine the sleepable context of
async callbacks based on the async primitive type rather than the arming
program's context.
The bug is in in_sleepable() which uses OR logic to check if the current
execution context is sleepable. When a sleepable program arms a timer
callback, the callback's state correctly has in_sleepable=false, but
in_sleepable() would still return true due to env->prog->sleepable being
true. This incorrectly allows sleepable helpers like
bpf_copy_from_user() inside timer callbacks when armed from sleepable
programs, even though timer callbacks always execute in non-sleepable
context.
Fix in_sleepable() to rely solely on env->cur_state->in_sleepable, and
initialize state->in_sleepable to env->prog->sleepable in
do_check_common() for the main program entry. This ensures the sleepable
context is properly tracked per verification state rather than being
overridden by the program's sleepability.
The env->cur_state NULL check in in_sleepable() was only needed for
do_misc_fixups() which runs after verification when env->cur_state is
set to NULL. Update do_misc_fixups() to use env->prog->sleepable
directly for the storage_get_function check, and remove the redundant
NULL check from in_sleepable().
Introduce is_async_cb_sleepable() helper to explicitly determine async
callback sleepability based on the primitive type:
- bpf_timer callbacks are never sleepable
- bpf_wq and bpf_task_work callbacks are always sleepable
Add verifier_bug() check to catch unhandled async callback types,
ensuring future additions cannot be silently mishandled. Move the
is_task_work_add_kfunc() forward declaration to the top alongside other
callback-related helpers. We update push_async_cb() to adjust to the new
changes.
At the same time, while simplifying in_sleepable(), we notice a problem
in do_misc_fixups. Fix storage_get helpers to use GFP_ATOMIC when called
from non-sleepable contexts within sleepable programs, such as bpf_timer
callbacks.
Currently, the check in do_misc_fixups assumes that env->prog->sleepable,
previously in_sleepable(env) which only resolved to this check before
last commit, holds across the program's execution, but that is not true.
Instead, the func_atomic bit must be set whenever we see the function
being called in an atomic context. Previously, this is being done when
the helper is invoked in atomic contexts in sleepable programs, we can
simply just set the value to true without doing an in_sleepable() check.
We must also do a standalone in_sleepable() check to handle cases where
the async callback itself is armed from a sleepable program, but is
itself non-sleepable (e.g., timer callback) and invokes such a helper,
thus needing the func_atomic bit to be true for the said call.
Adjust do_misc_fixups() to drop any checks regarding sleepable nature of
the program, and just depend on the func_atomic bit to decide which GFP
flag to pass.
Fixes: 81f1d7a583fa ("bpf: wq: add bpf_wq_set_callback_impl")
Fixes: b00fa38a9c1c ("bpf: Enable non-atomic allocations in local storage")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251007220349.3852807-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 56b4d162392dda2365fbc1f482184a24b489d07d ]
cleanup unused function args in check_deadlock* functions.
Fixes: 31158ad02ddb ("rqspinlock: Add deadlock detection and recovery")
Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251001172702.122838-1-sidchintamaneni@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit c14ecb555c3ee80eeb030a4e46d00e679537f03a upstream.
KCSAN reports:
BUG: KCSAN: data-race in do_raw_write_lock / do_raw_write_lock
write (marked) to 0xffff800009cf504c of 4 bytes by task 1102 on cpu 1:
do_raw_write_lock+0x120/0x204
_raw_write_lock_irq
do_exit
call_usermodehelper_exec_async
ret_from_fork
read to 0xffff800009cf504c of 4 bytes by task 1103 on cpu 0:
do_raw_write_lock+0x88/0x204
_raw_write_lock_irq
do_exit
call_usermodehelper_exec_async
ret_from_fork
value changed: 0xffffffff -> 0x00000001
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1103 Comm: kworker/u4:1 6.1.111
Commit 1a365e822372 ("locking/spinlock/debug: Fix various data races") has
adressed most of these races, but seems to be not consistent/not complete.
>From do_raw_write_lock() only debug_write_lock_after() part has been
converted to WRITE_ONCE(), but not debug_write_lock_before() part.
Do it now.
Fixes: 1a365e822372 ("locking/spinlock/debug: Fix various data races")
Reported-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Borislav Petkov:
- Have timekeeping aux clocks sysfs interface setup function return an
error code on failure instead of success
* tag 'timers_urgent_for_v6.18_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix error code in tk_aux_sysfs_init()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping fixes from Marek Szyprowski:
"Two last minute fixes for the recently modified DMA API infrastructure:
- proper handling of DMA_ATTR_MMIO in dma_iova_unlink() function (me)
- regression fix for the code refactoring related to P2PDMA (Pranjal
Shrivastava)"
* tag 'dma-mapping-6.18-2025-11-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
dma-direct: Fix missing sg_dma_len assignment in P2PDMA bus mappings
iommu/dma: add missing support for DMA_ATTR_MMIO for dma_iova_unlink()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer fix from Steven Rostedt:
- Do not allow mmapped ring buffer to be split
When the ring buffer VMA is split by a partial munmap or a MAP_FIXED,
the kernel calls vm_ops->close() on each portion. This causes the
ring_buffer_unmap() to be called multiple times. This causes
subsequent calls to return -ENODEV and triggers a warning.
There's no reason to allow user space to split up memory mapping of
the ring buffer. Have it return -EINVAL when that happens.
* tag 'trace-ringbuffer-v6.18-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs
|
|
Prior to commit a25e7962db0d7 ("PCI/P2PDMA: Refactor the p2pdma mapping
helpers"), P2P segments were mapped using the pci_p2pdma_map_segment()
helper. This helper was responsible for populating sg->dma_address,
marking the bus address, and also setting sg_dma_len(sg).
The refactor[1] removed this helper and moved the mapping logic directly
into the callers. While iommu_dma_map_sg() was correctly updated to set
the length in the new flow, it was missed in dma_direct_map_sg().
Thus, in dma_direct_map_sg(), the PCI_P2PDMA_MAP_BUS_ADDR case sets the
dma_address and marks the segment, but immediately executes 'continue',
which causes the loop to skip the standard assignment logic at the end:
sg_dma_len(sg) = sg->length;
As a result, when CONFIG_NEED_SG_DMA_LENGTH is enabled, the dma_length
field remains uninitialized (zero) for P2P bus address mappings. This
breaks upper-layer drivers (for e.g. RDMA/IB) that rely on sg_dma_len()
to determine the transfer size.
Fix this by explicitly setting the DMA length in the
PCI_P2PDMA_MAP_BUS_ADDR case before continuing to the next scatterlist
entry.
Fixes: a25e7962db0d7 ("PCI/P2PDMA: Refactor the p2pdma mapping helpers")
Reported-by: Jacob Moroni <jmoroni@google.com>
Signed-off-by: Pranjal Shrivastava <praan@google.com>
[1]
https://lore.kernel.org/all/ac14a0e94355bf898de65d023ccf8a2ad22a3ece.1746424934.git.leon@kernel.org/
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Shivaji Kant <shivajikant@google.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251126114112.3694469-1-praan@google.com
|
|
When a VMA is split (e.g., by partial munmap or MAP_FIXED), the kernel
calls vm_ops->close on each portion. For trace buffer mappings, this
results in ring_buffer_unmap() being called multiple times while
ring_buffer_map() was only called once.
This causes ring_buffer_unmap() to return -ENODEV on subsequent calls
because user_mapped is already 0, triggering a WARN_ON.
Trace buffer mappings cannot support partial mappings because the ring
buffer structure requires the complete buffer including the meta page.
Fix this by adding a may_split callback that returns -EINVAL to prevent
VMA splits entirely.
Cc: stable@vger.kernel.org
Fixes: cf9f0f7c4c5bb ("tracing: Allow user-space mapping of the ring-buffer")
Link: https://patch.msgid.link/20251119064019.25904-1-kartikey406@gmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a72c325b042aae6403c7
Tested-by: syzbot+a72c325b042aae6403c7@syzkaller.appspotmail.com
Reported-by: syzbot+a72c325b042aae6403c7@syzkaller.appspotmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
If kobject_create_and_add() fails on the first iteration, then the error
code is set to -ENOMEM which is correct. But if it fails in subsequent
iterations then "ret" is zero, which means success, but it should be
-ENOMEM.
Set the error code to -ENOMEM correctly.
Fixes: 7b5ab04f035f ("timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Malaya Kumar Rout <mrout@redhat.com>
Link: https://patch.msgid.link/aSW1R8q5zoY_DgQE@stanley.mountain
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
- Fix a race in timer->function clearing in timer_shutdown_sync()
- Fix a timekeeper sysfs-setup resource leak in error paths
- Fix the NOHZ report_idle_softirq() syslog rate-limiting
logic to have no side effects on the return value
* tag 'timers-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Fix NULL function pointer race in timer_shutdown_sync()
timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths
tick/sched: Fix bogus condition in report_idle_softirq()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Fix perf CPU-clock counters, and address a static checker warning"
* tag 'perf-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix 0 count issue of cpu-clock
perf/x86/intel/uncore: Remove superfluous check
|
|
There is a race condition between timer_shutdown_sync() and timer
expiration that can lead to hitting a WARN_ON in expire_timers().
The issue occurs when timer_shutdown_sync() clears the timer function
to NULL while the timer is still running on another CPU. The race
scenario looks like this:
CPU0 CPU1
<SOFTIRQ>
lock_timer_base()
expire_timers()
base->running_timer = timer;
unlock_timer_base()
[call_timer_fn enter]
mod_timer()
...
timer_shutdown_sync()
lock_timer_base()
// For now, will not detach the timer but only clear its function to NULL
if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer->function = NULL;
unlock_timer_base()
[call_timer_fn exit]
lock_timer_base()
base->running_timer = NULL;
unlock_timer_base()
...
// Now timer is pending while its function set to NULL.
// next timer trigger
<SOFTIRQ>
expire_timers()
WARN_ON_ONCE(!fn) // hit
...
lock_timer_base()
// Now timer will detach
if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer->function = NULL;
unlock_timer_base()
The problem is that timer_shutdown_sync() clears the timer function
regardless of whether the timer is currently running. This can leave a
pending timer with a NULL function pointer, which triggers the
WARN_ON_ONCE(!fn) check in expire_timers().
Fix this by only clearing the timer function when actually detaching the
timer. If the timer is running, leave the function pointer intact, which is
safe because the timer will be properly detached when it finishes running.
Fixes: 0cc04e80458a ("timers: Add shutdown mechanism to the internal functions")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251122093942.301559-1-zouyipeng@huawei.com
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fix from Tejun Heo:
"One low risk and obvious fix: scx_enable() was dereferencing an error
pointer on helper kthread creation failure. Fixed"
* tag 'sched_ext-for-6.18-rc6-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Fix scx_enable() crash on helper kthread creation failure
|
|
A crash was observed when the sched_ext selftests runner was
terminated with Ctrl+\ while test 15 was running:
NIP [c00000000028fa58] scx_enable.constprop.0+0x358/0x12b0
LR [c00000000028fa2c] scx_enable.constprop.0+0x32c/0x12b0
Call Trace:
scx_enable.constprop.0+0x32c/0x12b0 (unreliable)
bpf_struct_ops_link_create+0x18c/0x22c
__sys_bpf+0x23f8/0x3044
sys_bpf+0x2c/0x6c
system_call_exception+0x124/0x320
system_call_vectored_common+0x15c/0x2ec
kthread_run_worker() returns an ERR_PTR() on failure rather than NULL,
but the current code in scx_alloc_and_add_sched() only checks for a NULL
helper. Incase of failure on SIGQUIT, the error is not handled in
scx_alloc_and_add_sched() and scx_enable() ends up dereferencing an
error pointer.
Error handling is fixed in scx_alloc_and_add_sched() to propagate
PTR_ERR() into ret, so that scx_enable() jumps to the existing error
path, avoiding random dereference on failure.
Fixes: bff3b5aec1b7 ("sched_ext: Move disable machinery into scx_sched")
Cc: stable@vger.kernel.org # v6.16+
Reported-and-tested-by: Samir Mulani <samir@linux.ibm.com>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Vishal Chourasia <vishalc@linux.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
tk_aux_sysfs_init() returns immediately on error during the auxiliary clock
initialization loop without cleaning up previously allocated kobjects and
sysfs groups.
If kobject_create_and_add() or sysfs_create_group() fails during loop
iteration, the parent kobjects (tko and auxo) and any previously created
child kobjects are leaked.
Fix this by adding proper error handling with goto labels to ensure all
allocated resources are cleaned up on failure. kobject_put() on the
parent kobjects will handle cleanup of their children.
Fixes: 7b95663a3d96 ("timekeeping: Provide interface to control auxiliary clocks")
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251120150213.246777-1-mrout@redhat.com
|
|
Currently cpu-clock event always returns 0 count, e.g.,
perf stat -e cpu-clock -- sleep 1
Performance counter stats for 'sleep 1':
0 cpu-clock # 0.000 CPUs utilized
1.002308394 seconds time elapsed
The root cause is the commit 'bc4394e5e79c ("perf: Fix the throttle
error of some clock events")' adds PERF_EF_UPDATE flag check before
calling cpu_clock_event_update() to update the count, however the
PERF_EF_UPDATE flag is never set when the cpu-clock event is stopped in
counting mode (pmu->dev() -> cpu_clock_event_del() ->
cpu_clock_event_stop()). This leads to the cpu-clock event count is
never updated.
To fix this issue, force to set PERF_EF_UPDATE flag for cpu-clock event
just like what task-clock does.
Fixes: bc4394e5e79c ("perf: Fix the throttle error of some clock events")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20251112080526.3971392-1-dapeng1.mi@linux.intel.com
|
|
In commit 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") the
new function report_idle_softirq() was created by breaking code out of the
existing can_stop_idle_tick() for kernels v5.18 and newer.
In doing so, the code essentially went from this form:
if (A) {
static int ratelimit;
if (ratelimit < 10 && !C && A&D) {
pr_warn("NOHZ tick-stop error: ...");
ratelimit++;
}
return false;
}
to a new function:
static bool report_idle_softirq(void)
{
static int ratelimit;
if (likely(!A))
return false;
if (ratelimit < 10)
return false;
...
pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
pending);
ratelimit++;
return true;
}
commit a7e282c77785 ("tick/rcu: Fix bogus ratelimit condition") realized
ratelimit was essentially set to zero instead of ten, and hence *no*
softirq pending messages would ever be issued, but "fixed" it as:
- if (ratelimit < 10)
+ if (ratelimit >= 10)
return false;
However, this fix introduced another issue:
When ratelimit is greater than or equal 10, even if A is true, it will
directly return false. While ratelimit in the original code was only used
to control printing and will not affect the return value.
Restore the original logic and restrict ratelimit to control the printk and
not the return value.
Fixes: 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Fixes: a7e282c77785 ("tick/rcu: Fix bogus ratelimit condition")
Signed-off-by: Wen Yang <wen.yang@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251119174525.29470-1-wen.yang@linux.dev
|
|
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix unitialized variable in statmount_string()
- Fix hostfs mounting when passing host root during boot
- Fix dynamic lookup to fail on cell lookup failure
- Fix missing file type when reading bfs inodes from disk
- Enforce checking of sb_min_blocksize() calls and update all callers
accordingly
- Restore write access before closing files opened by open_exec() in
binfmt_misc
- Always freeze efivarfs during suspend/hibernate cycles
- Fix statmount()'s and listmount()'s grab_requested_mnt_ns() helper to
actually allow mount namespace file descriptor in addition to mount
namespace ids
- Fix tmpfs remount when noswap is specified
- Switch Landlock to iput_not_last() to remove false-positives from
might_sleep() annotations in iput()
- Remove dead node_to_mnt_ns() code
- Ensure that per-queue kobjects are successfully created
* tag 'vfs-6.18-rc7.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
landlock: fix splats from iput() after it started calling might_sleep()
fs: add iput_not_last()
shmem: fix tmpfs reconfiguration (remount) when noswap is set
fs/namespace: correctly handle errors returned by grab_requested_mnt_ns
power: always freeze efivarfs
binfmt_misc: restore write access before closing files opened by open_exec()
block: add __must_check attribute to sb_min_blocksize()
virtio-fs: fix incorrect check for fsvq->kobj
xfs: check the return value of sb_min_blocksize() in xfs_fs_fill_super
isofs: check the return value of sb_min_blocksize() in isofs_fill_super
exfat: check return value of sb_min_blocksize in exfat_read_boot_sector
vfat: fix missing sb_min_blocksize() return value checks
mnt: Remove dead code which might prevent from building
bfs: Reconstruct file type when loading from disk
afs: Fix dynamic lookup to fail on cell lookup failure
hostfs: Fix only passing host root in boot stage with new mount
fs: Fix uninitialized 'offp' in statmount_string()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
"Five fixes addressing PREEMPT_RT compatibility and locking issues.
Three commits fix potential deadlocks and sleeps in atomic contexts on
RT kernels by converting locks to raw spinlocks and ensuring IRQ work
runs in hard-irq context. The remaining two fix unsafe locking in the
debug dump path and a variable dereference typo"
* tag 'sched_ext-for-6.18-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Use IRQ_WORK_INIT_HARD() to initialize rq->scx.kick_cpus_irq_work
sched_ext: Fix possible deadlock in the deferred_irq_workfn()
sched/ext: convert scx_tasks_lock to raw spinlock
sched_ext: Fix unsafe locking in the scx_dump_state()
sched_ext: Fix use of uninitialized variable in scx_bpf_cpuperf_set()
|
|
For PREEMPT_RT kernels, the kick_cpus_irq_workfn() be invoked in
the per-cpu irq_work/* task context and there is no rcu-read critical
section to protect. this commit therefore use IRQ_WORK_INIT_HARD() to
initialize the per-cpu rq->scx.kick_cpus_irq_work in the
init_sched_ext_class().
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"7 hotfixes. 5 are cc:stable, 4 are against mm/
All are singletons - please see the respective changelogs for details"
* tag 'mm-hotfixes-stable-2025-11-16-10-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm, swap: fix potential UAF issue for VMA readahead
selftests/user_events: fix type cast for write_index packed member in perf_test
lib/test_kho: check if KHO is enabled
mm/huge_memory: fix folio split check for anon folios in swapcache
MAINTAINERS: update David Hildenbrand's email address
crash: fix crashkernel resource shrink
mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb
|
|
When crashkernel is configured with a high reservation, shrinking its
value below the low crashkernel reservation causes two issues:
1. Invalid crashkernel resource objects
2. Kernel crash if crashkernel shrinking is done twice
For example, with crashkernel=200M,high, the kernel reserves 200MB of high
memory and some default low memory (say 256MB). The reservation appears
as:
cat /proc/iomem | grep -i crash
af000000-beffffff : Crash kernel
433000000-43f7fffff : Crash kernel
If crashkernel is then shrunk to 50MB (echo 52428800 >
/sys/kernel/kexec_crash_size), /proc/iomem still shows 256MB reserved:
af000000-beffffff : Crash kernel
Instead, it should show 50MB:
af000000-b21fffff : Crash kernel
Further shrinking crashkernel to 40MB causes a kernel crash with the
following trace (x86):
BUG: kernel NULL pointer dereference, address: 0000000000000038
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
<snip...>
Call Trace: <TASK>
? __die_body.cold+0x19/0x27
? page_fault_oops+0x15a/0x2f0
? search_module_extables+0x19/0x60
? search_bpf_extables+0x5f/0x80
? exc_page_fault+0x7e/0x180
? asm_exc_page_fault+0x26/0x30
? __release_resource+0xd/0xb0
release_resource+0x26/0x40
__crash_shrink_memory+0xe5/0x110
crash_shrink_memory+0x12a/0x190
kexec_crash_size_store+0x41/0x80
kernfs_fop_write_iter+0x141/0x1f0
vfs_write+0x294/0x460
ksys_write+0x6d/0xf0
<snip...>
This happens because __crash_shrink_memory()/kernel/crash_core.c
incorrectly updates the crashk_res resource object even when
crashk_low_res should be updated.
Fix this by ensuring the correct crashkernel resource object is updated
when shrinking crashkernel memory.
Link: https://lkml.kernel.org/r/20251101193741.289252-1-sourabhjain@linux.ibm.com
Fixes: 16c6006af4d4 ("kexec: enable kexec_crash_size to support two crash kernel regions")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
"Fix a memory leak in the posix timer creation logic"
* tag 'timers-urgent-2025-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timers: Plug potential memory leak in do_timer_create()
|
|
Pull bpf fixes from Alexei Starovoitov:
- Fix interaction between livepatch and BPF fexit programs (Song Liu)
With Steven and Masami acks.
- Fix stack ORC unwind from BPF kprobe_multi (Jiri Olsa)
With Steven and Masami acks.
- Fix out of bounds access in widen_imprecise_scalars() in the verifier
(Eduard Zingerman)
- Fix conflicts between MPTCP and BPF sockmap (Jiayuan Chen)
- Fix net_sched storage collision with BPF data_meta/data_end (Eric
Dumazet)
- Add _impl suffix to BPF kfuncs with implicit args to avoid breaking
them in bpf-next when KF_IMPLICIT_ARGS is added (Mykyta Yatsenko)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: Test widen_imprecise_scalars() with different stack depth
bpf: account for current allocated stack depth in widen_imprecise_scalars()
bpf: Add bpf_prog_run_data_pointers()
selftests/bpf: Add mptcp test with sockmap
mptcp: Fix proto fallback detection with BPF
mptcp: Disallow MPTCP subflows from sockmap
selftests/bpf: Add stacktrace ips test for raw_tp
selftests/bpf: Add stacktrace ips test for kprobe_multi/kretprobe_multi
x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe
Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"
bpf: add _impl suffix for bpf_stream_vprintk() kfunc
bpf:add _impl suffix for bpf_task_work_schedule* kfuncs
selftests/bpf: Add tests for livepatch + bpf trampoline
ftrace: bpf: Fix IPMODIFY + DIRECT in modify_ftrace_direct()
ftrace: Fix BPF fexit with livepatch
|
|
The usage pattern for widen_imprecise_scalars() looks as follows:
prev_st = find_prev_entry(env, ...);
queued_st = push_stack(...);
widen_imprecise_scalars(env, prev_st, queued_st);
Where prev_st is an ancestor of the queued_st in the explored states
tree. This ancestor is not guaranteed to have same allocated stack
depth as queued_st. E.g. in the following case:
def main():
for i in 1..2:
foo(i) // same callsite, differnt param
def foo(i):
if i == 1:
use 128 bytes of stack
iterator based loop
Here, for a second 'foo' call prev_st->allocated_stack is 128,
while queued_st->allocated_stack is much smaller.
widen_imprecise_scalars() needs to take this into account and avoid
accessing bpf_verifier_state->frame[*]->stack out of bounds.
Fixes: 2793a8b015f7 ("bpf: exact states comparison for iterator convergence checks")
Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114025730.772723-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
