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[ Upstream commit 494b332064c0ce2f7392fa92632bc50191c1b517 ]
Fix eprobe event to unregister event call and release eprobe when it fails
to add dynamic event correctly.
Link: https://lore.kernel.org/all/173289886698.73724.1959899350183686006.stgit@devnote2/
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e932c4ab38f072ce5894b2851fea8bc5754bb8e5 ]
Scheduler raises a SCHED_SOFTIRQ to trigger a load balancing event on
from the IPI handler on the idle CPU. If the SMP function is invoked
from an idle CPU via flush_smp_call_function_queue() then the HARD-IRQ
flag is not set and raise_softirq_irqoff() needlessly wakes ksoftirqd
because soft interrupts are handled before ksoftirqd get on the CPU.
Adding a trace_printk() in nohz_csd_func() at the spot of raising
SCHED_SOFTIRQ and enabling trace events for sched_switch, sched_wakeup,
and softirq_entry (for SCHED_SOFTIRQ vector alone) helps observing the
current behavior:
<idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ from nohz_csd_func
<idle>-0 [000] dN.4.: sched_wakeup: comm=ksoftirqd/0 pid=16 prio=120 target_cpu=000
<idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED]
<idle>-0 [000] .Ns1.: softirq_exit: vec=7 [action=SCHED]
<idle>-0 [000] d..2.: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=ksoftirqd/0 next_pid=16 next_prio=120
ksoftirqd/0-16 [000] d..2.: sched_switch: prev_comm=ksoftirqd/0 prev_pid=16 prev_prio=120 prev_state=S ==> next_comm=swapper/0 next_pid=0 next_prio=120
...
Use __raise_softirq_irqoff() to raise the softirq. The SMP function call
is always invoked on the requested CPU in an interrupt handler. It is
guaranteed that soft interrupts are handled at the end.
Following are the observations with the changes when enabling the same
set of events:
<idle>-0 [000] dN.1.: nohz_csd_func: Raising SCHED_SOFTIRQ for nohz_idle_balance
<idle>-0 [000] dN.1.: softirq_raise: vec=7 [action=SCHED]
<idle>-0 [000] .Ns1.: softirq_entry: vec=7 [action=SCHED]
No unnecessary ksoftirqd wakeups are seen from idle task's context to
service the softirq.
Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
Closes: https://lore.kernel.org/lkml/fcf823f-195e-6c9a-eac3-25f870cb35ac@inria.fr/ [1]
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20241119054432.6405-5-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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busy
[ Upstream commit ff47a0acfcce309cf9e175149c75614491953c8f ]
Commit b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
optimizes IPIs to idle CPUs in TIF_POLLING_NRFLAG mode by setting the
TIF_NEED_RESCHED flag in idle task's thread info and relying on
flush_smp_call_function_queue() in idle exit path to run the
call-function. A softirq raised by the call-function is handled shortly
after in do_softirq_post_smp_call_flush() but the TIF_NEED_RESCHED flag
remains set and is only cleared later when schedule_idle() calls
__schedule().
need_resched() check in _nohz_idle_balance() exists to bail out of load
balancing if another task has woken up on the CPU currently in-charge of
idle load balancing which is being processed in SCHED_SOFTIRQ context.
Since the optimization mentioned above overloads the interpretation of
TIF_NEED_RESCHED, check for idle_cpu() before going with the existing
need_resched() check which can catch a genuine task wakeup on an idle
CPU processing SCHED_SOFTIRQ from do_softirq_post_smp_call_flush(), as
well as the case where ksoftirqd needs to be preempted as a result of
new task wakeup or slice expiry.
In case of PREEMPT_RT or threadirqs, although the idle load balancing
may be inhibited in some cases on the ilb CPU, the fact that ksoftirqd
is the only fair task going back to sleep will trigger a newidle balance
on the CPU which will alleviate some imbalance if it exists if idle
balance fails to do so.
Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241119054432.6405-4-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit efd984c481abb516fab8bafb25bf41fd9397a43c ]
A following patch will trigger NOHZ idle balances as a means to update
nohz.next_balance. Vincent noted that blocked load updates can have
non-negligible overhead, which should be avoided if the intent is to only
update nohz.next_balance.
Add a new NOHZ balance kick flag, NOHZ_NEXT_KICK. Gate NOHZ blocked load
update by the presence of NOHZ_STATS_KICK - currently all NOHZ balance
kicks will have the NOHZ_STATS_KICK flag set, so no change in behaviour is
expected.
Suggested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210823111700.2842997-2-valentin.schneider@arm.com
Stable-dep-of: ff47a0acfcce ("sched/fair: Check idle_cpu() before need_resched() to detect ilb CPU turning busy")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ea9cffc0a154124821531991d5afdd7e8b20d7aa ]
The need_resched() check currently in nohz_csd_func() can be tracked
to have been added in scheduler_ipi() back in 2011 via commit
ca38062e57e9 ("sched: Use resched IPI to kick off the nohz idle balance")
Since then, it has travelled quite a bit but it seems like an idle_cpu()
check currently is sufficient to detect the need to bail out from an
idle load balancing. To justify this removal, consider all the following
case where an idle load balancing could race with a task wakeup:
o Since commit f3dd3f674555b ("sched: Remove the limitation of WF_ON_CPU
on wakelist if wakee cpu is idle") a target perceived to be idle
(target_rq->nr_running == 0) will return true for
ttwu_queue_cond(target) which will offload the task wakeup to the idle
target via an IPI.
In all such cases target_rq->ttwu_pending will be set to 1 before
queuing the wake function.
If an idle load balance races here, following scenarios are possible:
- The CPU is not in TIF_POLLING_NRFLAG mode in which case an actual
IPI is sent to the CPU to wake it out of idle. If the
nohz_csd_func() queues before sched_ttwu_pending(), the idle load
balance will bail out since idle_cpu(target) returns 0 since
target_rq->ttwu_pending is 1. If the nohz_csd_func() is queued after
sched_ttwu_pending() it should see rq->nr_running to be non-zero and
bail out of idle load balancing.
- The CPU is in TIF_POLLING_NRFLAG mode and instead of an actual IPI,
the sender will simply set TIF_NEED_RESCHED for the target to put it
out of idle and flush_smp_call_function_queue() in do_idle() will
execute the call function. Depending on the ordering of the queuing
of nohz_csd_func() and sched_ttwu_pending(), the idle_cpu() check in
nohz_csd_func() should either see target_rq->ttwu_pending = 1 or
target_rq->nr_running to be non-zero if there is a genuine task
wakeup racing with the idle load balance kick.
o The waker CPU perceives the target CPU to be busy
(targer_rq->nr_running != 0) but the CPU is in fact going idle and due
to a series of unfortunate events, the system reaches a case where the
waker CPU decides to perform the wakeup by itself in ttwu_queue() on
the target CPU but target is concurrently selected for idle load
balance (XXX: Can this happen? I'm not sure, but we'll consider the
mother of all coincidences to estimate the worst case scenario).
ttwu_do_activate() calls enqueue_task() which would increment
"rq->nr_running" post which it calls wakeup_preempt() which is
responsible for setting TIF_NEED_RESCHED (via a resched IPI or by
setting TIF_NEED_RESCHED on a TIF_POLLING_NRFLAG idle CPU) The key
thing to note in this case is that rq->nr_running is already non-zero
in case of a wakeup before TIF_NEED_RESCHED is set which would
lead to idle_cpu() check returning false.
In all cases, it seems that need_resched() check is unnecessary when
checking for idle_cpu() first since an impending wakeup racing with idle
load balancer will either set the "rq->ttwu_pending" or indicate a newly
woken task via "rq->nr_running".
Chasing the reason why this check might have existed in the first place,
I came across Peter's suggestion on the fist iteration of Suresh's
patch from 2011 [1] where the condition to raise the SCHED_SOFTIRQ was:
sched_ttwu_do_pending(list);
if (unlikely((rq->idle == current) &&
rq->nohz_balance_kick &&
!need_resched()))
raise_softirq_irqoff(SCHED_SOFTIRQ);
Since the condition to raise the SCHED_SOFIRQ was preceded by
sched_ttwu_do_pending() (which is equivalent of sched_ttwu_pending()) in
the current upstream kernel, the need_resched() check was necessary to
catch a newly queued task. Peter suggested modifying it to:
if (idle_cpu() && rq->nohz_balance_kick && !need_resched())
raise_softirq_irqoff(SCHED_SOFTIRQ);
where idle_cpu() seems to have replaced "rq->idle == current" check.
Even back then, the idle_cpu() check would have been sufficient to catch
a new task being enqueued. Since commit b2a02fc43a1f ("smp: Optimize
send_call_function_single_ipi()") overloads the interpretation of
TIF_NEED_RESCHED for TIF_POLLING_NRFLAG idling, remove the
need_resched() check in nohz_csd_func() to raise SCHED_SOFTIRQ based
on Peter's suggestion.
Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241119054432.6405-3-kprateek.nayak@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit eb887c4567d1b0e7684c026fe7df44afa96589e6 ]
Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
to use optimized implementation and ease register pressure around
the primitive for targets that implement optimized variant.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241007085651.48544-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 7543c3e3b9b88212fcd0aaf5cab5588797bdc7de ]
radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock
otherwise, there's a possible deadlock scenario when
dma debug API is called holding rq_lock():
CPU0 CPU1 CPU2
dma_free_attrs()
check_unmap() add_dma_entry() __schedule() //out
(A) rq_lock()
get_hash_bucket()
(A) dma_entry_hash
check_sync()
(A) radix_lock() (W) dma_entry_hash
dma_entry_free()
(W) radix_lock()
// CPU2's one
(W) rq_lock()
CPU1 situation can happen when it extending radix tree and
it tries to wake up kswapd via wake_all_kswapd().
CPU2 situation can happen while perf_event_task_sched_out()
(i.e. dma sync operation is called while deleting perf_event using
etm and etr tmc which are Arm Coresight hwtracing driver backends).
To remove this possible situation, call dma_entry_free() after
put_hash_bucket() in check_unmap().
Reported-by: Denis Nikitin <denik@chromium.org>
Closes: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/2WMS7BBSF5OZYB63VT44U5YWLFP5HL6U/#RWM6MLQX5ANBTEQ2PRM7OXCBGCE6NPWU
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 59458fa4ddb47e7891c61b4a928d13d5f5b00aa0 ]
Ran Xiaokai reports that with a KCSAN-enabled PREEMPT_RT kernel, we can see
splats like:
| BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
| preempt_count: 10002, expected: 0
| RCU nest depth: 0, expected: 0
| no locks held by swapper/1/0.
| irq event stamp: 156674
| hardirqs last enabled at (156673): [<ffffffff81130bd9>] do_idle+0x1f9/0x240
| hardirqs last disabled at (156674): [<ffffffff82254f84>] sysvec_apic_timer_interrupt+0x14/0xc0
| softirqs last enabled at (0): [<ffffffff81099f47>] copy_process+0xfc7/0x4b60
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| Preemption disabled at:
| [<ffffffff814a3e2a>] paint_ptr+0x2a/0x90
| CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0+ #3
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
| Call Trace:
| <IRQ>
| dump_stack_lvl+0x7e/0xc0
| dump_stack+0x1d/0x30
| __might_resched+0x1a2/0x270
| rt_spin_lock+0x68/0x170
| kcsan_skip_report_debugfs+0x43/0xe0
| print_report+0xb5/0x590
| kcsan_report_known_origin+0x1b1/0x1d0
| kcsan_setup_watchpoint+0x348/0x650
| __tsan_unaligned_write1+0x16d/0x1d0
| hrtimer_interrupt+0x3d6/0x430
| __sysvec_apic_timer_interrupt+0xe8/0x3a0
| sysvec_apic_timer_interrupt+0x97/0xc0
| </IRQ>
On a detected data race, KCSAN's reporting logic checks if it should
filter the report. That list is protected by the report_filterlist_lock
*non-raw* spinlock which may sleep on RT kernels.
Since KCSAN may report data races in any context, convert it to a
raw_spinlock.
This requires being careful about when to allocate memory for the filter
list itself which can be done via KCSAN's debugfs interface. Concurrent
modification of the filter list via debugfs should be rare: the chosen
strategy is to optimistically pre-allocate memory before the critical
section and discard if unused.
Link: https://lore.kernel.org/all/20240925143154.2322926-1-ranxiaokai627@163.com/
Reported-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Tested-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit ab244dd7cf4c291f82faacdc50b45cc0f55b674d upstream.
Jordy reported issue against XSKMAP which also applies to DEVMAP - the
index used for accessing map entry, due to being a signed integer,
causes the OOB writes. Fix is simple as changing the type from int to
u32, however, when compared to XSKMAP case, one more thing needs to be
addressed.
When map is released from system via dev_map_free(), we iterate through
all of the entries and an iterator variable is also an int, which
implies OOB accesses. Again, change it to be u32.
Example splat below:
[ 160.724676] BUG: unable to handle page fault for address: ffffc8fc2c001000
[ 160.731662] #PF: supervisor read access in kernel mode
[ 160.736876] #PF: error_code(0x0000) - not-present page
[ 160.742095] PGD 0 P4D 0
[ 160.744678] Oops: Oops: 0000 [#1] PREEMPT SMP
[ 160.749106] CPU: 1 UID: 0 PID: 520 Comm: kworker/u145:12 Not tainted 6.12.0-rc1+ #487
[ 160.757050] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
[ 160.767642] Workqueue: events_unbound bpf_map_free_deferred
[ 160.773308] RIP: 0010:dev_map_free+0x77/0x170
[ 160.777735] Code: 00 e8 fd 91 ed ff e8 b8 73 ed ff 41 83 7d 18 19 74 6e 41 8b 45 24 49 8b bd f8 00 00 00 31 db 85 c0 74 48 48 63 c3 48 8d 04 c7 <48> 8b 28 48 85 ed 74 30 48 8b 7d 18 48 85 ff 74 05 e8 b3 52 fa ff
[ 160.796777] RSP: 0018:ffffc9000ee1fe38 EFLAGS: 00010202
[ 160.802086] RAX: ffffc8fc2c001000 RBX: 0000000080000000 RCX: 0000000000000024
[ 160.809331] RDX: 0000000000000000 RSI: 0000000000000024 RDI: ffffc9002c001000
[ 160.816576] RBP: 0000000000000000 R08: 0000000000000023 R09: 0000000000000001
[ 160.823823] R10: 0000000000000001 R11: 00000000000ee6b2 R12: dead000000000122
[ 160.831066] R13: ffff88810c928e00 R14: ffff8881002df405 R15: 0000000000000000
[ 160.838310] FS: 0000000000000000(0000) GS:ffff8897e0c40000(0000) knlGS:0000000000000000
[ 160.846528] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 160.852357] CR2: ffffc8fc2c001000 CR3: 0000000005c32006 CR4: 00000000007726f0
[ 160.859604] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 160.866847] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 160.874092] PKRU: 55555554
[ 160.876847] Call Trace:
[ 160.879338] <TASK>
[ 160.881477] ? __die+0x20/0x60
[ 160.884586] ? page_fault_oops+0x15a/0x450
[ 160.888746] ? search_extable+0x22/0x30
[ 160.892647] ? search_bpf_extables+0x5f/0x80
[ 160.896988] ? exc_page_fault+0xa9/0x140
[ 160.900973] ? asm_exc_page_fault+0x22/0x30
[ 160.905232] ? dev_map_free+0x77/0x170
[ 160.909043] ? dev_map_free+0x58/0x170
[ 160.912857] bpf_map_free_deferred+0x51/0x90
[ 160.917196] process_one_work+0x142/0x370
[ 160.921272] worker_thread+0x29e/0x3b0
[ 160.925082] ? rescuer_thread+0x4b0/0x4b0
[ 160.929157] kthread+0xd4/0x110
[ 160.932355] ? kthread_park+0x80/0x80
[ 160.936079] ret_from_fork+0x2d/0x50
[ 160.943396] ? kthread_park+0x80/0x80
[ 160.950803] ret_from_fork_asm+0x11/0x20
[ 160.958482] </TASK>
Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references")
CC: stable@vger.kernel.org
Reported-by: Jordy Zomer <jordyzomer@google.com>
Suggested-by: Jordy Zomer <jordyzomer@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20241122121030.716788-3-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e63fbd5f6810ed756bbb8a1549c7d4132968baa9 upstream.
The cmp_entries_dup() function used as the comparator for sort()
violated the symmetry and transitivity properties required by the
sorting algorithm. Specifically, it returned 1 whenever memcmp() was
non-zero, which broke the following expectations:
* Symmetry: If x < y, then y > x.
* Transitivity: If x < y and y < z, then x < z.
These violations could lead to incorrect sorting and failure to
correctly identify duplicate elements.
Fix the issue by directly returning the result of memcmp(), which
adheres to the required comparison properties.
Cc: stable@vger.kernel.org
Fixes: 08d43a5fa063 ("tracing: Add lock-free tracing_map")
Link: https://lore.kernel.org/20241203202228.1274403-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 27abc7b3fa2e09bbe41e2924d328121546865eda ]
trie_get_next_key() uses node->prefixlen == key->prefixlen to identify
an exact match, However, it is incorrect because when the target key
doesn't fully match the found node (e.g., node->prefixlen != matchlen),
these two nodes may also have the same prefixlen. It will return
expected result when the passed key exist in the trie. However when a
recently-deleted key or nonexistent key is passed to
trie_get_next_key(), it may skip keys and return incorrect result.
Fix it by using node->prefixlen == matchlen to identify exact matches.
When the condition is true after the search, it also implies
node->prefixlen equals key->prefixlen, otherwise, the search would
return NULL instead.
Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map")
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241206110622.1161752-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit eae6a075e9537dd69891cf77ca5a88fa8a28b4a1 ]
Add the currently missing handling for the BPF_EXIST and BPF_NOEXIST
flags. These flags can be specified by users and are relevant since LPM
trie supports exact matches during update.
Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241206110622.1161752-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit afe5960dc208fe069ddaaeb0994d857b24ac19d1 ]
When a tracepoint event is created with attr.freq = 1,
'hwc->period_left' is not initialized correctly. As a result,
in the perf_swevent_overflow() function, when the first time the event occurs,
it calculates the event overflow and the perf_swevent_set_period() returns 3,
this leads to the event are recorded for three duplicate times.
Step to reproduce:
1. Enable the tracepoint event & starting tracing
$ echo 1 > /sys/kernel/tracing/events/module/module_free
$ echo 1 > /sys/kernel/tracing/tracing_on
2. Record with perf
$ perf record -a --strict-freq -F 1 -e "module:module_free"
3. Trigger module_free event.
$ modprobe -i sunrpc
$ modprobe -r sunrpc
Result:
- Trace pipe result:
$ cat trace_pipe
modprobe-174509 [003] ..... 6504.868896: module_free: sunrpc
- perf sample:
modprobe 174509 [003] 6504.868980: module:module_free: sunrpc
modprobe 174509 [003] 6504.868980: module:module_free: sunrpc
modprobe 174509 [003] 6504.868980: module:module_free: sunrpc
By setting period_left via perf_swevent_set_period() as other sw_event did,
This problem could be solved.
After patch:
- Trace pipe result:
$ cat trace_pipe
modprobe 1153096 [068] 613468.867774: module:module_free: xfs
- perf sample
modprobe 1153096 [068] 613468.867794: module:module_free: xfs
Link: https://lore.kernel.org/20240913021347.595330-1-yeoreum.yun@arm.com
Fixes: bd2b5b12849a ("perf_counter: More aggressive frequency adjustment")
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2190df6c91373fdec6db9fc07e427084f232f57e ]
Only cgroup v2 can be attached by bpf programs, so this patch introduces
that cgroup_bpf_inherit and cgroup_bpf_offline can only be called in
cgroup v2, and this can fix the memleak mentioned by commit 04f8ef5643bc
("cgroup: Fix memory leak caused by missing cgroup_bpf_offline"), which
has been reverted.
Fixes: 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Fixes: 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhesjlfdw@46zxhg5bdnr7/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit feb301c60970bd2a1310a53ce2d6e4375397a51b ]
This reverts commit 04f8ef5643bcd8bcde25dfdebef998aea480b2ba.
Only cgroup v2 can be attached by cgroup by BPF programs. Revert this
commit and cgroup_bpf_inherit and cgroup_bpf_offline won't be called in
cgroup v1. The memory leak issue will be fixed with next patch.
Fixes: 04f8ef5643bc ("cgroup: Fix memory leak caused by missing cgroup_bpf_offline")
Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhesjlfdw@46zxhg5bdnr7/
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d16317de9b412aa7bd3598c607112298e36b4352 ]
The read side of seqcount_latch consists of:
do {
seq = raw_read_seqcount_latch(&latch->seq);
...
} while (read_seqcount_latch_retry(&latch->seq, seq));
which is asymmetric in the raw_ department, and sure enough,
read_seqcount_latch_retry() includes (explicit) instrumentation where
raw_read_seqcount_latch() does not.
This inconsistency becomes a problem when trying to use it from
noinstr code. As such, fix it by renaming and re-implementing
raw_read_seqcount_latch_retry() without the instrumentation.
Specifically the instrumentation in question is kcsan_atomic_next(0)
in do___read_seqcount_retry(). Loosing this annotation is not a
problem because raw_read_seqcount_latch() does not pass through
kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.233598176@infradead.org
Stable-dep-of: 5c1806c41ce0 ("kcsan, seqlock: Support seqcount_latch_t")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 90be8d6c1f91e1e5121c219726524c91b52bfc20 ]
Provide a inline function which replaces the copy & pasta.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220415091921.072296632@linutronix.de
Stable-dep-of: 5c1806c41ce0 ("kcsan, seqlock: Support seqcount_latch_t")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 92b043fd995a63a57aae29ff85a39b6f30cd440c ]
The details about the handling of the "normal" values were moved
to the _msecs_to_jiffies() helpers in commit ca42aaf0c861 ("time:
Refactor msecs_to_jiffies"). However, the same commit still mentioned
__msecs_to_jiffies() in the added documentation.
Thus point to _msecs_to_jiffies() instead.
Fixes: ca42aaf0c861 ("time: Refactor msecs_to_jiffies")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241025110141.157205-2-ojeda@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 5c9a9ca44fda41c5e82f50efced5297a9c19760d upstream.
Any idle task corresponding to an offline CPU is in an RCU Tasks Trace
quiescent state. This commit causes rcu_tasks_trace_postscan() to ignore
idle tasks for offline CPUs, which it can do safely due to CPU-hotplug
operations being disabled.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: KP Singh <kpsingh@kernel.org>
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 45af52e7d3b8560f21d139b3759735eead8b1653 upstream.
When executing the following command:
# echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
The current mod command causes a null pointer dereference. While commit
0f17976568b3f ("ftrace: Fix regression with module command in stack_trace_filter")
has addressed part of the issue, it left a corner case unhandled, which still
results in a kernel crash.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241120052750.275463-1-guoweikang.kernel@gmail.com
Fixes: 04ec7bb642b77 ("tracing: Have the trace_array hold the list of registered func probes");
Signed-off-by: guoweikang <guoweikang.kernel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 434247637c66e1be2bc71a9987d4c3f0d8672387 ]
The kzmalloc call in bpf_check can fail when memory is very fragmented,
which in turn can lead to an OOM kill.
Use kvzmalloc to fall back to vmalloc when memory is too fragmented to
allocate an order 3 sized bpf verifier environment.
Admittedly this is not a very common case, and only happens on systems
where memory has already been squeezed close to the limit, but this does
not seem like much of a hot path, and it's a simple enough fix.
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/r/20241008170735.16766766@imladris.surriel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 432dc0654c612457285a5dcf9bb13968ac6f0804 upstream.
The inc_rlimit_get_ucounts() increments the specified rlimit counter and
then checks its limit. If the value exceeds the limit, the function
returns an error without decrementing the counter.
Link: https://lkml.kernel.org/r/20241101191940.3211128-1-roman.gushchin@linux.dev
Fixes: 15bc01effefe ("ucounts: Fix signal ucount refcounting")
Signed-off-by: Andrei Vagin <avagin@google.com>
Co-developed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Tested-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Alexey Gladkov <legion@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Andrei Vagin <avagin@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b5413156bad91dc2995a5c4eab1b05e56914638a ]
When cloning a new thread, its posix_cputimers are not inherited, and
are cleared by posix_cputimers_init(). However, this does not clear the
tick dependency it creates in tsk->tick_dep_mask, and the handler does
not reach the code to clear the dependency if there were no timers to
begin with.
Thus if a thread has a cputimer running before clone/fork, all
descendants will prevent nohz_full unless they create a cputimer of
their own.
Fix this by entirely clearing the tick_dep_mask in copy_process().
(There is currently no inherited state that needs a tick dependency)
Process-wide timers do not have this problem because fork does not copy
signal_struct as a baseline, it creates one from scratch.
Fixes: b78783000d5c ("posix-cpu-timers: Migrate to use new tick dependency mask model")
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/xm26o737bq8o.fsf@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 13400ac8fb80c57c2bfb12ebd35ee121ce9b4d21 ]
trie_get_next_key() allocates a node stack with size trie->max_prefixlen,
while it writes (trie->max_prefixlen + 1) nodes to the stack when it has
full paths from the root to leaves. For example, consider a trie with
max_prefixlen is 8, and the nodes with key 0x00/0, 0x00/1, 0x00/2, ...
0x00/8 inserted. Subsequent calls to trie_get_next_key with _key with
.prefixlen = 8 make 9 nodes be written on the node stack with size 8.
Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map")
Signed-off-by: Byeonguk Jeong <jungbu2855@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Tested-by: Hou Tao <houtao1@huawei.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/Zxx384ZfdlFYnz6J@localhost.localdomain
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3cc4e13bb1617f6a13e5e6882465984148743cf4 ]
cgroup.max.depth is the maximum allowed descent depth below the current
cgroup. If the actual descent depth is equal or larger, an attempt to
create a new child cgroup will fail. However due to the cgroup->max_depth
is of int type and having the default value INT_MAX, the condition
'level > cgroup->max_depth' will never be satisfied, and it will cause
an overflow of the level after it reaches to INT_MAX.
Fix it by starting the level from 0 and using '>=' instead.
It's worth mentioning that this issue is unlikely to occur in reality,
as it's impossible to have a depth of INT_MAX hierarchy, but should be
be avoided logically.
Fixes: 1a926e0bbab8 ("cgroup: implement hierarchy limits")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0ee288e69d033850bc87abe0f9cc3ada24763d7f ]
Peter reported that perf_event_detach_bpf_prog might skip to release
the bpf program for -ENOENT error from bpf_prog_array_copy.
This can't happen because bpf program is stored in perf event and is
detached and released only when perf event is freed.
Let's drop the -ENOENT check and make sure the bpf program is released
in any case.
Fixes: 170a7e3ea070 ("bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found")
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241023200352.3488610-1-jolsa@kernel.org
Closes: https://lore.kernel.org/lkml/20241022111638.GC16066@noisy.programming.kicks-ass.net/
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 6e62807c7fbb3c758d233018caf94dfea9c65dbd ]
If get_clock_desc() succeeds, it calls fget() for the clockid's fd,
and get the clk->rwsem read lock, so the error path should release
the lock to make the lock balance and fput the clockid's fd to make
the refcount balance and release the fd related resource.
However the below commit left the error path locked behind resulting in
unbalanced locking. Check timespec64_valid_strict() before
get_clock_desc() to fix it, because the "ts" is not changed
after that.
Fixes: d8794ac20a29 ("posix-clock: Fix missing timespec64 check in pc_clock_settime()")
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
[pabeni@redhat.com: fixed commit message typo]
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0b6e2e22cb23105fcb171ab92f0f7516c69c8471 ]
strlen() returns a string length excluding the null byte. If the string
length equals to the maximum buffer length, the buffer will have no
space for the NULL terminating character.
This commit checks this condition and returns failure for it.
Link: https://lore.kernel.org/all/20241007144724.920954-1-leo.yan@arm.com/
Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ca9984c5f0ab3690d98b13937b2485a978c8dd73 ]
rxq contains a pointer to the device from where
the redirect happened. Currently, the BPF program
that was executed after a redirect via BPF_MAP_TYPE_DEVMAP*
does not have it set.
This is particularly bad since accessing ingress_ifindex, e.g.
SEC("xdp")
int prog(struct xdp_md *pkt)
{
return bpf_redirect_map(&dev_redirect_map, 0, 0);
}
SEC("xdp/devmap")
int prog_after_redirect(struct xdp_md *pkt)
{
bpf_printk("ifindex %i", pkt->ingress_ifindex);
return XDP_PASS;
}
depends on access to rxq, so a NULL pointer gets dereferenced:
<1>[ 574.475170] BUG: kernel NULL pointer dereference, address: 0000000000000000
<1>[ 574.475188] #PF: supervisor read access in kernel mode
<1>[ 574.475194] #PF: error_code(0x0000) - not-present page
<6>[ 574.475199] PGD 0 P4D 0
<4>[ 574.475207] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
<4>[ 574.475217] CPU: 4 UID: 0 PID: 217 Comm: kworker/4:1 Not tainted 6.11.0-rc5-reduced-00859-g780801200300 #23
<4>[ 574.475226] Hardware name: Intel(R) Client Systems NUC13ANHi7/NUC13ANBi7, BIOS ANRPL357.0026.2023.0314.1458 03/14/2023
<4>[ 574.475231] Workqueue: mld mld_ifc_work
<4>[ 574.475247] RIP: 0010:bpf_prog_5e13354d9cf5018a_prog_after_redirect+0x17/0x3c
<4>[ 574.475257] Code: cc cc cc cc cc cc cc 80 00 00 00 cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 66 90 55 48 89 e5 f3 0f 1e fa 48 8b 57 20 <48> 8b 52 00 8b 92 e0 00 00 00 48 bf f8 a6 d5 c4 5d a0 ff ff be 0b
<4>[ 574.475263] RSP: 0018:ffffa62440280c98 EFLAGS: 00010206
<4>[ 574.475269] RAX: ffffa62440280cd8 RBX: 0000000000000001 RCX: 0000000000000000
<4>[ 574.475274] RDX: 0000000000000000 RSI: ffffa62440549048 RDI: ffffa62440280ce0
<4>[ 574.475278] RBP: ffffa62440280c98 R08: 0000000000000002 R09: 0000000000000001
<4>[ 574.475281] R10: ffffa05dc8b98000 R11: ffffa05f577fca40 R12: ffffa05dcab24000
<4>[ 574.475285] R13: ffffa62440280ce0 R14: ffffa62440549048 R15: ffffa62440549000
<4>[ 574.475289] FS: 0000000000000000(0000) GS:ffffa05f4f700000(0000) knlGS:0000000000000000
<4>[ 574.475294] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[ 574.475298] CR2: 0000000000000000 CR3: 000000025522e000 CR4: 0000000000f50ef0
<4>[ 574.475303] PKRU: 55555554
<4>[ 574.475306] Call Trace:
<4>[ 574.475313] <IRQ>
<4>[ 574.475318] ? __die+0x23/0x70
<4>[ 574.475329] ? page_fault_oops+0x180/0x4c0
<4>[ 574.475339] ? skb_pp_cow_data+0x34c/0x490
<4>[ 574.475346] ? kmem_cache_free+0x257/0x280
<4>[ 574.475357] ? exc_page_fault+0x67/0x150
<4>[ 574.475368] ? asm_exc_page_fault+0x26/0x30
<4>[ 574.475381] ? bpf_prog_5e13354d9cf5018a_prog_after_redirect+0x17/0x3c
<4>[ 574.475386] bq_xmit_all+0x158/0x420
<4>[ 574.475397] __dev_flush+0x30/0x90
<4>[ 574.475407] veth_poll+0x216/0x250 [veth]
<4>[ 574.475421] __napi_poll+0x28/0x1c0
<4>[ 574.475430] net_rx_action+0x32d/0x3a0
<4>[ 574.475441] handle_softirqs+0xcb/0x2c0
<4>[ 574.475451] do_softirq+0x40/0x60
<4>[ 574.475458] </IRQ>
<4>[ 574.475461] <TASK>
<4>[ 574.475464] __local_bh_enable_ip+0x66/0x70
<4>[ 574.475471] __dev_queue_xmit+0x268/0xe40
<4>[ 574.475480] ? selinux_ip_postroute+0x213/0x420
<4>[ 574.475491] ? alloc_skb_with_frags+0x4a/0x1d0
<4>[ 574.475502] ip6_finish_output2+0x2be/0x640
<4>[ 574.475512] ? nf_hook_slow+0x42/0xf0
<4>[ 574.475521] ip6_finish_output+0x194/0x300
<4>[ 574.475529] ? __pfx_ip6_finish_output+0x10/0x10
<4>[ 574.475538] mld_sendpack+0x17c/0x240
<4>[ 574.475548] mld_ifc_work+0x192/0x410
<4>[ 574.475557] process_one_work+0x15d/0x380
<4>[ 574.475566] worker_thread+0x29d/0x3a0
<4>[ 574.475573] ? __pfx_worker_thread+0x10/0x10
<4>[ 574.475580] ? __pfx_worker_thread+0x10/0x10
<4>[ 574.475587] kthread+0xcd/0x100
<4>[ 574.475597] ? __pfx_kthread+0x10/0x10
<4>[ 574.475606] ret_from_fork+0x31/0x50
<4>[ 574.475615] ? __pfx_kthread+0x10/0x10
<4>[ 574.475623] ret_from_fork_asm+0x1a/0x30
<4>[ 574.475635] </TASK>
<4>[ 574.475637] Modules linked in: veth br_netfilter bridge stp llc iwlmvm x86_pkg_temp_thermal iwlwifi efivarfs nvme nvme_core
<4>[ 574.475662] CR2: 0000000000000000
<4>[ 574.475668] ---[ end trace 0000000000000000 ]---
Therefore, provide it to the program by setting rxq properly.
Fixes: cb261b594b41 ("bpf: Run devmap xdp_prog on flush instead of bulk enqueue")
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Florian Kauer <florian.kauer@linutronix.de>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20240911-devel-koalo-fix-ingress-ifindex-v4-1-5c643ae10258@linutronix.de
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit d8794ac20a299b647ba9958f6d657051fc51a540 upstream.
As Andrew pointed out, it will make sense that the PTP core
checked timespec64 struct's tv_sec and tv_nsec range before calling
ptp->info->settime64().
As the man manual of clock_settime() said, if tp.tv_sec is negative or
tp.tv_nsec is outside the range [0..999,999,999], it should return EINVAL,
which include dynamic clocks which handles PTP clock, and the condition is
consistent with timespec64_valid(). As Thomas suggested, timespec64_valid()
only check the timespec is valid, but not ensure that the time is
in a valid range, so check it ahead using timespec64_valid_strict()
in pc_clock_settime() and return -EINVAL if not valid.
There are some drivers that use tp->tv_sec and tp->tv_nsec directly to
write registers without validity checks and assume that the higher layer
has checked it, which is dangerous and will benefit from this, such as
hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(),
and some drivers can remove the checks of itself.
Cc: stable@vger.kernel.org
Fixes: 0606f422b453 ("posix clocks: Introduce dynamic clocks")
Acked-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20241009072302.1754567-2-ruanjinjie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 214e01ad4ed7158cab66498810094fac5d09b218 upstream.
Calling into kthread unparking unconditionally is mostly harmless when
the kthread is already unparked. The wake up is then simply ignored
because the target is not in TASK_PARKED state.
However if the kthread is per CPU, the wake up is preceded by a call
to kthread_bind() which expects the task to be inactive and in
TASK_PARKED state, which obviously isn't the case if it is unparked.
As a result, calling kthread_stop() on an unparked per-cpu kthread
triggers such a warning:
WARNING: CPU: 0 PID: 11 at kernel/kthread.c:525 __kthread_bind_mask kernel/kthread.c:525
<TASK>
kthread_stop+0x17a/0x630 kernel/kthread.c:707
destroy_workqueue+0x136/0xc40 kernel/workqueue.c:5810
wg_destruct+0x1e2/0x2e0 drivers/net/wireguard/device.c:257
netdev_run_todo+0xe1a/0x1000 net/core/dev.c:10693
default_device_exit_batch+0xa14/0xa90 net/core/dev.c:11769
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:640
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Fix this with skipping unecessary unparking while stopping a kthread.
Link: https://lkml.kernel.org/r/20240913214634.12557-1-frederic@kernel.org
Fixes: 5c25b5ff89f0 ("workqueue: Tag bound workers with KTHREAD_IS_PER_CPU")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reported-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com
Tested-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit b4afe4183ec77f230851ea139d91e5cf2644c68b upstream.
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
$ dd if=data of=/dev/mem bs=$((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
Link: https://lkml.kernel.org/r/20240906030713.204292-2-ying.huang@intel.com
Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like normal RAM")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 1d244784be6b01162b732a5a7d637dfc024c3203 ]
Percpu map is often used, but the map value size limit often ignored,
like issue: https://github.com/iovisor/bcc/issues/2519. Actually,
percpu map value size is bound by PCPU_MIN_UNIT_SIZE, so we
can check the value size whether it exceeds PCPU_MIN_UNIT_SIZE first,
like percpu map of local_storage. Maybe the error message seems clearer
compared with "cannot allocate memory".
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240910144111.1464912-2-chen.dylane@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 0b18c852cc6fb8284ac0ab97e3e840974a6a8a64 ]
The saved_cmdlines have three arrays for mapping PIDs to COMMs:
- map_pid_to_cmdline[]
- map_cmdline_to_pid[]
- saved_cmdlines
The map_pid_to_cmdline[] is PID_MAX_DEFAULT in size and holds the index
into the other arrays. The map_cmdline_to_pid[] is a mapping back to the
full pid as it can be larger than PID_MAX_DEFAULT. And the
saved_cmdlines[] just holds the COMMs associated to the pids.
Currently the map_pid_to_cmdline[] and saved_cmdlines[] are allocated
together (in reality the saved_cmdlines is just in the memory of the
rounding of the allocation of the structure as it is always allocated in
powers of two). The map_cmdline_to_pid[] array is allocated separately.
Since the rounding to a power of two is rather large (it allows for 8000
elements in saved_cmdlines), also include the map_cmdline_to_pid[] array.
(This drops it to 6000 by default, which is still plenty for most use
cases). This saves even more memory as the map_cmdline_to_pid[] array
doesn't need to be allocated.
Link: https://lore.kernel.org/linux-trace-kernel/20240212174011.068211d9@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.182330529@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Fixes: 44dc5c41b5b1 ("tracing: Fix wasted memory in saved_cmdlines logic")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 5efd3e2aef91d2d812290dcb25b2058e6f3f532c ]
This reverts 60be76eeabb3d ("tracing: Add size check when printing
trace_marker output"). The only reason the precision check was added
was because of a bug that miscalculated the write size of the string into
the ring buffer and it truncated it removing the terminating nul byte. On
reading the trace it crashed the kernel. But this was due to the bug in
the code that happened during development and should never happen in
practice. If anything, the precision can hide bugs where the string in the
ring buffer isn't nul terminated and it will not be checked.
Link: https://lore.kernel.org/all/C7E7AF1A-D30F-4D18-B8E5-AF1EF58004F5@linux.ibm.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240227125706.04279ac2@gandalf.local.home
Link: https://lore.kernel.org/all/20240302111244.3a1674be@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240304174341.2a561d9f@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 60be76eeabb3d ("tracing: Add size check when printing trace_marker output")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 34820304cc2cd1804ee1f8f3504ec77813d29c8e upstream.
xol_add_vma() maps the uninitialized page allocated by __create_xol_area()
into userspace. On some architectures (x86) this memory is readable even
without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ,
although this doesn't really matter, debugger can read this memory anyway.
Link: https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/
Reported-by: Will Deacon <will@kernel.org>
Fixes: d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 678379e1d4f7443b170939525d3312cfc37bf86b upstream.
Cloning a descriptor table picks the size that would cover all currently
opened files. That's fine for clone() and unshare(), but for close_range()
there's an additional twist - we clone before we close, and it would be
a shame to have
close_range(3, ~0U, CLOSE_RANGE_UNSHARE)
leave us with a huge descriptor table when we are not going to keep
anything past stderr, just because some large file descriptor used to
be open before our call has taken it out.
Unfortunately, it had been dealt with in an inherently racy way -
sane_fdtable_size() gets a "don't copy anything past that" argument
(passed via unshare_fd() and dup_fd()), close_range() decides how much
should be trimmed and passes that to unshare_fd().
The problem is, a range that used to extend to the end of descriptor
table back when close_range() had looked at it might very well have stuff
grown after it by the time dup_fd() has allocated a new files_struct
and started to figure out the capacity of fdtable to be attached to that.
That leads to interesting pathological cases; at the very least it's a
QoI issue, since unshare(CLONE_FILES) is atomic in a sense that it takes
a snapshot of descriptor table one might have observed at some point.
Since CLOSE_RANGE_UNSHARE close_range() is supposed to be a combination
of unshare(CLONE_FILES) with plain close_range(), ending up with a
weird state that would never occur with unshare(2) is confusing, to put
it mildly.
It's not hard to get rid of - all it takes is passing both ends of the
range down to sane_fdtable_size(). There we are under ->files_lock,
so the race is trivially avoided.
So we do the following:
* switch close_files() from calling unshare_fd() to calling
dup_fd().
* undo the calling convention change done to unshare_fd() in
60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE"
* introduce struct fd_range, pass a pointer to that to dup_fd()
and sane_fdtable_size() instead of "trim everything past that point"
they are currently getting. NULL means "we are not going to be punching
any holes"; NR_OPEN_MAX is gone.
* make sane_fdtable_size() use find_last_bit() instead of
open-coding it; it's easier to follow that way.
* while we are at it, have dup_fd() report errors by returning
ERR_PTR(), no need to use a separate int *errorp argument.
Fixes: 60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE"
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 829e0c9f0855f26b3ae830d17b24aec103f7e915 upstream.
There is another found exception that the "timerlat/1" thread was
scheduled on CPU0, and lead to timer corruption finally:
```
ODEBUG: init active (active state 0) object: ffff888237c2e108 object type: hrtimer hint: timerlat_irq+0x0/0x220
WARNING: CPU: 0 PID: 426 at lib/debugobjects.c:518 debug_print_object+0x7d/0xb0
Modules linked in:
CPU: 0 UID: 0 PID: 426 Comm: timerlat/1 Not tainted 6.11.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:debug_print_object+0x7d/0xb0
...
Call Trace:
<TASK>
? __warn+0x7c/0x110
? debug_print_object+0x7d/0xb0
? report_bug+0xf1/0x1d0
? prb_read_valid+0x17/0x20
? handle_bug+0x3f/0x70
? exc_invalid_op+0x13/0x60
? asm_exc_invalid_op+0x16/0x20
? debug_print_object+0x7d/0xb0
? debug_print_object+0x7d/0xb0
? __pfx_timerlat_irq+0x10/0x10
__debug_object_init+0x110/0x150
hrtimer_init+0x1d/0x60
timerlat_main+0xab/0x2d0
? __pfx_timerlat_main+0x10/0x10
kthread+0xb7/0xe0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2d/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
```
After tracing the scheduling event, it was discovered that the migration
of the "timerlat/1" thread was performed during thread creation. Further
analysis confirmed that it is because the CPU online processing for
osnoise is implemented through workers, which is asynchronous with the
offline processing. When the worker was scheduled to create a thread, the
CPU may has already been removed from the cpu_online_mask during the offline
process, resulting in the inability to select the right CPU:
T1 | T2
[CPUHP_ONLINE] | cpu_device_down()
osnoise_hotplug_workfn() |
| cpus_write_lock()
| takedown_cpu(1)
| cpus_write_unlock()
[CPUHP_OFFLINE] |
cpus_read_lock() |
start_kthread(1) |
cpus_read_unlock() |
To fix this, skip online processing if the CPU is already offline.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-4-liwei391@huawei.com
Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2a13ca2e8abb12ee43ada8a107dadca83f140937 upstream.
The cpuhp online/offline processing race also exists in percpu-mode hwlat
tracer in theory, apply the fix too. That is:
T1 | T2
[CPUHP_ONLINE] | cpu_device_down()
hwlat_hotplug_workfn() |
| cpus_write_lock()
| takedown_cpu(1)
| cpus_write_unlock()
[CPUHP_OFFLINE] |
cpus_read_lock() |
start_kthread(1) |
cpus_read_unlock() |
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-5-liwei391@huawei.com
Fixes: ba998f7d9531 ("trace/hwlat: Support hotplug operations")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 62c0b1061593d7012292f781f11145b2d46f43ab upstream.
In perf_adjust_period, we will first calculate period, and then use
this period to calculate delta. However, when delta is less than 0,
there will be a deviation compared to when delta is greater than or
equal to 0. For example, when delta is in the range of [-14,-1], the
range of delta = delta + 7 is between [-7,6], so the final value of
delta/8 is 0. Therefore, the impact of -1 and -2 will be ignored.
This is unacceptable when the target period is very short, because
we will lose a lot of samples.
Here are some tests and analyzes:
before:
# perf record -e cs -F 1000 ./a.out
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.022 MB perf.data (518 samples) ]
# perf script
...
a.out 396 257.956048: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.957891: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.959730: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.961545: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.963355: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.965163: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.966973: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.968785: 23 cs: ffffffff81f4eeec schedul>
a.out 396 257.970593: 23 cs: ffffffff81f4eeec schedul>
...
after:
# perf record -e cs -F 1000 ./a.out
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.058 MB perf.data (1466 samples) ]
# perf script
...
a.out 395 59.338813: 11 cs: ffffffff81f4eeec schedul>
a.out 395 59.339707: 12 cs: ffffffff81f4eeec schedul>
a.out 395 59.340682: 13 cs: ffffffff81f4eeec schedul>
a.out 395 59.341751: 13 cs: ffffffff81f4eeec schedul>
a.out 395 59.342799: 12 cs: ffffffff81f4eeec schedul>
a.out 395 59.343765: 11 cs: ffffffff81f4eeec schedul>
a.out 395 59.344651: 11 cs: ffffffff81f4eeec schedul>
a.out 395 59.345539: 12 cs: ffffffff81f4eeec schedul>
a.out 395 59.346502: 13 cs: ffffffff81f4eeec schedul>
...
test.c
int main() {
for (int i = 0; i < 20000; i++)
usleep(10);
return 0;
}
# time ./a.out
real 0m1.583s
user 0m0.040s
sys 0m0.298s
The above results were tested on x86-64 qemu with KVM enabled using
test.c as test program. Ideally, we should have around 1500 samples,
but the previous algorithm had only about 500, whereas the modified
algorithm now has about 1400. Further more, the new version shows 1
sample per 0.001s, while the previous one is 1 sample per 0.002s.This
indicates that the new algorithm is more sensitive to small negative
values compared to old algorithm.
Fixes: bd2b5b12849a ("perf_counter: More aggressive frequency adjustment")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20240831074316.2106159-2-luogengkun@huaweicloud.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 11377947b5861fa59bf77c827e1dd7c081842cc9 ]
Currently, if the rcuscale module's async module parameter is specified
for RCU implementations that do not have async primitives such as RCU
Tasks Rude (which now lacks a call_rcu_tasks_rude() function), there
will be a series of splats due to calls to a NULL pointer. This commit
therefore warns of this situation, but switches to non-async testing.
Signed-off-by: "Paul E. McKenney" <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 7f8af7bac5380f2d95a63a6f19964e22437166e1 ]
These really can be handled gracefully without killing the machine.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit fe513c2ef0a172a58f158e2e70465c4317f0a9a2 ]
static_call_module_notify() triggers a WARN_ON(), when memory allocation
fails in __static_call_add_module().
That's not really justified, because the failure case must be correctly
handled by the well known call chain and the error code is passed
through to the initiating userspace application.
A memory allocation fail is not a fatal problem, but the WARN_ON() takes
the machine out when panic_on_warn is set.
Replace it with a pr_warn().
Fixes: 9183c3f9ed71 ("static_call: Add inline static call infrastructure")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/8734mf7pmb.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 4b30051c4864234ec57290c3d142db7c88f10d8a ]
Module insertion invokes static_call_add_module() to initialize the static
calls in a module. static_call_add_module() invokes __static_call_init(),
which allocates a struct static_call_mod to either encapsulate the built-in
static call sites of the associated key into it so further modules can be
added or to append the module to the module chain.
If that allocation fails the function returns with an error code and the
module core invokes static_call_del_module() to clean up eventually added
static_call_mod entries.
This works correctly, when all keys used by the module were converted over
to a module chain before the failure. If not then static_call_del_module()
causes a #GP as it blindly assumes that key::mods points to a valid struct
static_call_mod.
The problem is that key::mods is not a individual struct member of struct
static_call_key, it's part of a union to save space:
union {
/* bit 0: 0 = mods, 1 = sites */
unsigned long type;
struct static_call_mod *mods;
struct static_call_site *sites;
};
key::sites is a pointer to the list of built-in usage sites of the static
call. The type of the pointer is differentiated by bit 0. A mods pointer
has the bit clear, the sites pointer has the bit set.
As static_call_del_module() blidly assumes that the pointer is a valid
static_call_mod type, it fails to check for this failure case and
dereferences the pointer to the list of built-in call sites, which is
obviously bogus.
Cure it by checking whether the key has a sites or a mods pointer.
If it's a sites pointer then the key is not to be touched. As the sites are
walked in the same order as in __static_call_init() the site walk can be
terminated because all subsequent sites have not been touched by the init
code due to the error exit.
If it was converted before the allocation fail, then the inner loop which
searches for a module match will find nothing.
A fail in the second allocation in __static_call_init() is harmless and
does not require special treatment. The first allocation succeeded and
converted the key to a module chain. That first entry has mod::mod == NULL
and mod::next == NULL, so the inner loop of static_call_del_module() will
neither find a module match nor a module chain. The next site in the walk
was either already converted, but can't match the module, or it will exit
the outer loop because it has a static_call_site pointer and not a
static_call_mod pointer.
Fixes: 9183c3f9ed71 ("static_call: Add inline static call infrastructure")
Closes: https://lore.kernel.org/all/20230915082126.4187913-1-ruanjinjie@huawei.com
Reported-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/87zfon6b0s.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit a6f88ac32c6e63e69c595bfae220d8641704c9b7 upstream.
There is a deadlock scenario between lockdep and rcu when
rcu nocb feature is enabled, just as following call stack:
rcuop/x
-000|queued_spin_lock_slowpath(lock = 0xFFFFFF817F2A8A80, val = ?)
-001|queued_spin_lock(inline) // try to hold nocb_gp_lock
-001|do_raw_spin_lock(lock = 0xFFFFFF817F2A8A80)
-002|__raw_spin_lock_irqsave(inline)
-002|_raw_spin_lock_irqsave(lock = 0xFFFFFF817F2A8A80)
-003|wake_nocb_gp_defer(inline)
-003|__call_rcu_nocb_wake(rdp = 0xFFFFFF817F30B680)
-004|__call_rcu_common(inline)
-004|call_rcu(head = 0xFFFFFFC082EECC28, func = ?)
-005|call_rcu_zapped(inline)
-005|free_zapped_rcu(ch = ?)// hold graph lock
-006|rcu_do_batch(rdp = 0xFFFFFF817F245680)
-007|nocb_cb_wait(inline)
-007|rcu_nocb_cb_kthread(arg = 0xFFFFFF817F245680)
-008|kthread(_create = 0xFFFFFF80803122C0)
-009|ret_from_fork(asm)
rcuop/y
-000|queued_spin_lock_slowpath(lock = 0xFFFFFFC08291BBC8, val = 0)
-001|queued_spin_lock()
-001|lockdep_lock()
-001|graph_lock() // try to hold graph lock
-002|lookup_chain_cache_add()
-002|validate_chain()
-003|lock_acquire
-004|_raw_spin_lock_irqsave(lock = 0xFFFFFF817F211D80)
-005|lock_timer_base(inline)
-006|mod_timer(inline)
-006|wake_nocb_gp_defer(inline)// hold nocb_gp_lock
-006|__call_rcu_nocb_wake(rdp = 0xFFFFFF817F2A8680)
-007|__call_rcu_common(inline)
-007|call_rcu(head = 0xFFFFFFC0822E0B58, func = ?)
-008|call_rcu_hurry(inline)
-008|rcu_sync_call(inline)
-008|rcu_sync_func(rhp = 0xFFFFFFC0822E0B58)
-009|rcu_do_batch(rdp = 0xFFFFFF817F266680)
-010|nocb_cb_wait(inline)
-010|rcu_nocb_cb_kthread(arg = 0xFFFFFF817F266680)
-011|kthread(_create = 0xFFFFFF8080363740)
-012|ret_from_fork(asm)
rcuop/x and rcuop/y are rcu nocb threads with the same nocb gp thread.
This patch release the graph lock before lockdep call_rcu.
Fixes: a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use")
Cc: stable@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240620225436.3127927-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9a22b2812393d93d84358a760c347c21939029a6 upstream.
When submitting more than 2^32 padata objects to padata_do_serial, the
current sorting implementation incorrectly sorts padata objects with
overflowed seq_nr, causing them to be placed before existing objects in
the reorder list. This leads to a deadlock in the serialization process
as padata_find_next cannot match padata->seq_nr and pd->processed
because the padata instance with overflowed seq_nr will be selected
next.
To fix this, we use an unsigned integer wrap around to correctly sort
padata objects in scenarios with integer overflow.
Fixes: bfde23ce200e ("padata: unbind parallel jobs from specific CPUs")
Cc: <stable@vger.kernel.org>
Co-developed-by: Christian Gafert <christian.gafert@rohde-schwarz.com>
Signed-off-by: Christian Gafert <christian.gafert@rohde-schwarz.com>
Co-developed-by: Max Ferger <max.ferger@rohde-schwarz.com>
Signed-off-by: Max Ferger <max.ferger@rohde-schwarz.com>
Signed-off-by: Van Giang Nguyen <vangiang.nguyen@rohde-schwarz.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit cfe69c50b05510b24e26ccb427c7cc70beafd6c1 ]
The bpf_strtol() and bpf_strtoul() helpers are currently broken on 32bit:
The argument type ARG_PTR_TO_LONG is BPF-side "long", not kernel-side "long"
and therefore always considered fixed 64bit no matter if 64 or 32bit underlying
architecture.
This contract breaks in case of the two mentioned helpers since their BPF_CALL
definition for the helpers was added with {unsigned,}long *res. Meaning, the
transition from BPF-side "long" (BPF program) to kernel-side "long" (BPF helper)
breaks here.
Both helpers call __bpf_strtoll() with "long long" correctly, but later assigning
the result into 32-bit "*(long *)" on 32bit architectures. From a BPF program
point of view, this means upper bits will be seen as uninitialised.
Therefore, fix both BPF_CALL signatures to {s,u}64 types to fix this situation.
Now, changing also uapi/bpf.h helper documentation which generates bpf_helper_defs.h
for BPF programs is tricky: Changing signatures there to __{s,u}64 would trigger
compiler warnings (incompatible pointer types passing 'long *' to parameter of type
'__s64 *' (aka 'long long *')) for existing BPF programs.
Leaving the signatures as-is would be fine as from BPF program point of view it is
still BPF-side "long" and thus equivalent to __{s,u}64 on 64 or 32bit underlying
architectures.
Note that bpf_strtol() and bpf_strtoul() are the only helpers with this issue.
Fixes: d7a4cb9b6705 ("bpf: Introduce bpf_strtol and bpf_strtoul helpers")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/481fcec8-c12c-9abb-8ecb-76c71c009959@iogearbox.net
Link: https://lore.kernel.org/r/20240913191754.13290-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e16c7b07784f3fb03025939c4590b9a7c64970a7 ]
When analyzing a kernel waring message, Peter pointed out that there is a
race condition when the kworker is being frozen and falls into
try_to_freeze() with TASK_INTERRUPTIBLE, which could trigger a
might_sleep() warning in try_to_freeze(). Although the root cause is not
related to freeze()[1], it is still worthy to fix this issue ahead.
One possible race scenario:
CPU 0 CPU 1
----- -----
// kthread_worker_fn
set_current_state(TASK_INTERRUPTIBLE);
suspend_freeze_processes()
freeze_processes
static_branch_inc(&freezer_active);
freeze_kernel_threads
pm_nosig_freezing = true;
if (work) { //false
__set_current_state(TASK_RUNNING);
} else if (!freezing(current)) //false, been frozen
freezing():
if (static_branch_unlikely(&freezer_active))
if (pm_nosig_freezing)
return true;
schedule()
}
// state is still TASK_INTERRUPTIBLE
try_to_freeze()
might_sleep() <--- warning
Fix this by explicitly set the TASK_RUNNING before entering
try_to_freeze().
Link: https://lore.kernel.org/lkml/Zs2ZoAcUsZMX2B%2FI@chenyu5-mobl2/ [1]
Link: https://lkml.kernel.org/r/20240827112308.181081-1-yu.c.chen@intel.com
Fixes: b56c0d8937e6 ("kthread: implement kthread_worker")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: David Gow <davidgow@google.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mickaël Salaün <mic@digikod.net>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 24cc57d8faaa4060fd58adf810b858fcfb71a02f ]
In the case where we are forcing the ps.chunk_size to be at least 1,
we are ignoring the caller's alignment.
Move the forcing of ps.chunk_size to be at least 1 before rounding it
up to caller's alignment, so that caller's alignment is honored.
While at it, use max() to force the ps.chunk_size to be at least 1 to
improve readability.
Fixes: 6d45e1c948a8 ("padata: Fix possible divide-by-0 panic in padata_mt_helper()")
Signed-off-by: Kamlesh Gurudasani <kamlesh@ti.com>
Acked-by: Waiman Long <longman@redhat.com>
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>
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[ Upstream commit d23b5c577715892c87533b13923306acc6243f93 ]
At present, when we perform operations on the cgroup root_list, we must
hold the cgroup_mutex, which is a relatively heavyweight lock. In reality,
we can make operations on this list RCU-safe, eliminating the need to hold
the cgroup_mutex during traversal. Modifications to the list only occur in
the cgroup root setup and destroy paths, which should be infrequent in a
production environment. In contrast, traversal may occur frequently.
Therefore, making it RCU-safe would be beneficial.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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