[ Upstream commit f2655ac2c06a15558e51ed6529de280e1553c86e ]
The current "nretries > 1 || nretries >= max_retries" check in
cs_watchdog_read() will always evaluate to true, and thus pr_warn(), if
nretries is greater than 1. The intent is instead to never warn on the
first try, but otherwise warn if the successful retry was the last retry.
Therefore, change that "||" to "&&".
Fixes: db3a34e174 ("clocksource: Retry clock read if long delays detected")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240802154618.4149953-2-paulmck@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2ed08e4bc53298db3f87b528cd804cb0cce066a9 ]
On a 8-socket server the TSC is wrongly marked as 'unstable' and disabled
during boot time on about one out of 120 boot attempts:
clocksource: timekeeping watchdog on CPU227: wd-tsc-wd excessive read-back delay of 153560ns vs. limit of 125000ns,
wd-wd read-back delay only 11440ns, attempt 3, marking tsc unstable
tsc: Marking TSC unstable due to clocksource watchdog
TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
sched_clock: Marking unstable (119294969739, 159204297)<-(125446229205, -5992055152)
clocksource: Checking clocksource tsc synchronization from CPU 319 to CPUs 0,99,136,180,210,542,601,896.
clocksource: Switched to clocksource hpet
The reason is that for platform with a large number of CPUs, there are
sporadic big or huge read latencies while reading the watchog/clocksource
during boot or when system is under stress work load, and the frequency and
maximum value of the latency goes up with the number of online CPUs.
The cCurrent code already has logic to detect and filter such high latency
case by reading the watchdog twice and checking the two deltas. Due to the
randomness of the latency, there is a low probabilty that the first delta
(latency) is big, but the second delta is small and looks valid. The
watchdog code retries the readouts by default twice, which is not
necessarily sufficient for systems with a large number of CPUs.
There is a command line parameter 'max_cswd_read_retries' which allows to
increase the number of retries, but that's not user friendly as it needs to
be tweaked per system. As the number of required retries is proportional to
the number of online CPUs, this parameter can be calculated at runtime.
Scale and enlarge the number of retries according to the number of online
CPUs and remove the command line parameter completely.
[ tglx: Massaged change log and comments ]
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jin Wang <jin1.wang@intel.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240221060859.1027450-1-feng.tang@intel.com
Stable-dep-of: f2655ac2c06a ("clocksource: Fix brown-bag boolean thinko in cs_watchdog_read()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 87d571d6fb77ec342a985afa8744bb9bb75b3622 ]
Using syzkaller alongside the newly reintroduced signed integer overflow
sanitizer spits out this report:
UBSAN: signed-integer-overflow in ../kernel/time/ntp.c:461:16
9223372036854775807 + 500 cannot be represented in type 'long'
Call Trace:
handle_overflow+0x171/0x1b0
second_overflow+0x2d6/0x500
accumulate_nsecs_to_secs+0x60/0x160
timekeeping_advance+0x1fe/0x890
update_wall_time+0x10/0x30
time_maxerror is unconditionally incremented and the result is checked
against NTP_PHASE_LIMIT, but the increment itself can overflow, resulting
in wrap-around to negative space.
Before commit eea83d896e ("ntp: NTP4 user space bits update") the user
supplied value was sanity checked to be in the operating range. That change
removed the sanity check and relied on clamping in handle_overflow() which
does not work correctly when the user supplied value is in the overflow
zone of the '+ 500' operation.
The operation requires CAP_SYS_TIME and the side effect of the overflow is
NTP getting out of sync.
Miroslav confirmed that the input value should be clamped to the operating
range and the same applies to time_esterror. The latter is not used by the
kernel, but the value still should be in the operating range as it was
before the sanity check got removed.
Clamp them to the operating range.
[ tglx: Changed it to clamping and included time_esterror ]
Fixes: eea83d896e ("ntp: NTP4 user space bits update")
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: https://lore.kernel.org/all/20240517-b4-sio-ntp-usec-v2-1-d539180f2b79@google.com
Closes: https://github.com/KSPP/linux/issues/354
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6881e75237a84093d0986f56223db3724619f26e upstream.
The recent fix for making the take over of the broadcast timer more
reliable retrieves a per CPU pointer in preemptible context.
This went unnoticed as compilers hoist the access into the non-preemptible
region where the pointer is actually used. But of course it's valid that
the compiler keeps it at the place where the code puts it which rightfully
triggers:
BUG: using smp_processor_id() in preemptible [00000000] code:
caller is hotplug_cpu__broadcast_tick_pull+0x1c/0xc0
Move it to the actual usage site which is in a non-preemptible region.
Fixes: f7d43dd206e7 ("tick/broadcast: Make takeover of broadcast hrtimer reliable")
Reported-by: David Wang <00107082@163.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Yu Liao <liaoyu15@huawei.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/87ttg56ers.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2124d84db293ba164059077944e6b429ba530495 ]
The recursive aes-arm-bs module load situation reported by Russell King
is getting fixed in the crypto layer, but this in the meantime fixes the
"recursive load hangs forever" by just making the waiting for the first
module load be interruptible.
This should now match the old behavior before commit 9b9879fc03
("modules: catch concurrent module loads, treat them as idempotent"),
which used the different "wait for module to be ready" code in
module_patient_check_exists().
End result: a recursive module load will still block, but now a signal
will interrupt it and fail the second module load, at which point the
first module will successfully complete loading.
Fixes: 9b9879fc03 ("modules: catch concurrent module loads, treat them as idempotent")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cb5b81bc9a448f8db817566f60f92e2ea788ea0f ]
Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herbert Xu bisected it to commit 9b9879fc03 ("modules:
catch concurrent module loads, treat them as idempotent"), and noted:
"So what's happening here is that the first modprobe tries to load a
fallback CBC implementation, in doing so it triggers a load of the
exact same module due to module aliases.
IOW we're loading aes-arm-bs which provides cbc(aes). However, this
needs a fallback of cbc(aes) to operate, which is made out of the
generic cbc module + any implementation of aes, or ecb(aes). The
latter happens to also be provided by aes-arm-cb so that's why it
tries to load the same module again"
So loading the aes-arm-bs module ends up wanting to recursively load
itself, and the recursive load then ends up waiting for the original
module load to complete.
This is a regression, in that it used to be that we just tried to load
the module multiple times, and then as we went on to install it the
second time we would instead just error out because the module name
already existed.
That is actually also exactly what the original "catch concurrent loads"
patch did in commit 9828ed3f69 ("module: error out early on concurrent
load of the same module file"), but it turns out that it ends up being
racy, in that erroring out before the module has been fully initialized
will cause failures in dependent module loading.
See commit ac2263b588 (which was the revert of that "error out early")
commit for details about why erroring out before the module has been
initialized is actually fundamentally racy.
Now, for the actual recursive module load (as opposed to just
concurrently loading the same module twice), the race is not an issue.
At the same time it's hard for the kernel to see that this is recursion,
because the module load is always done from a usermode helper, so the
recursion is not some simple callchain within the kernel.
End result: this is not the real fix, but this at least adds a warning
for the situation (admittedly much too late for all the debugging pain
that Russell and Herbert went through) and if we can come to a
resolution on how to detect the recursion properly, this re-organizes
the code to make that easier.
Link: https://lore.kernel.org/all/ZrFHLqvFqhzykuYw@shell.armlinux.org.uk/
Reported-by: Russell King <linux@armlinux.org.uk>
Debugged-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 2124d84db293 ("module: make waiting for a concurrent module loader interruptible")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8c8acb8f26cbde665b233dd1b9bbcbb9b86822dc ]
Since str_has_prefix() takes the prefix as the 2nd argument and the string
as the first, is_cfi_preamble_symbol() always fails to check the prefix.
Fix the function parameter order so that it correctly check the prefix.
Link: https://lore.kernel.org/all/172260679559.362040.7360872132937227206.stgit@devnote2/
Fixes: de02f2ac5d ("kprobes: Prohibit probing on CFI preamble symbol")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 77baa5bafcbe1b2a15ef9c37232c21279c95481c upstream.
In extreme test scenarios:
the 14th field utime in /proc/xx/stat is greater than sum_exec_runtime,
utime = 18446744073709518790 ns, rtime = 135989749728000 ns
In cputime_adjust() process, stime is greater than rtime due to
mul_u64_u64_div_u64() precision problem.
before call mul_u64_u64_div_u64(),
stime = 175136586720000, rtime = 135989749728000, utime = 1416780000.
after call mul_u64_u64_div_u64(),
stime = 135989949653530
unsigned reversion occurs because rtime is less than stime.
utime = rtime - stime = 135989749728000 - 135989949653530
= -199925530
= (u64)18446744073709518790
Trigger condition:
1). User task run in kernel mode most of time
2). ARM64 architecture
3). TICK_CPU_ACCOUNTING=y
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set
Fix mul_u64_u64_div_u64() conversion precision by reset stime to rtime
Fixes: 3dc167ba57 ("sched/cputime: Improve cputime_adjust()")
Signed-off-by: Zheng Zucheng <zhengzucheng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20240726023235.217771-1-zhengzucheng@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b88f55389ad27f05ed84af9e1026aa64dbfabc9a upstream.
The kernel sleep profile is no longer working due to a recursive locking
bug introduced by commit 42a20f86dc ("sched: Add wrapper for get_wchan()
to keep task blocked")
Booting with the 'profile=sleep' kernel command line option added or
executing
# echo -n sleep > /sys/kernel/profiling
after boot causes the system to lock up.
Lockdep reports
kthreadd/3 is trying to acquire lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70
but task is already holding lock:
ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370
with the call trace being
lock_acquire+0xc8/0x2f0
get_wchan+0x32/0x70
__update_stats_enqueue_sleeper+0x151/0x430
enqueue_entity+0x4b0/0x520
enqueue_task_fair+0x92/0x6b0
ttwu_do_activate+0x73/0x140
try_to_wake_up+0x213/0x370
swake_up_locked+0x20/0x50
complete+0x2f/0x40
kthread+0xfb/0x180
However, since nobody noticed this regression for more than two years,
let's remove 'profile=sleep' support based on the assumption that nobody
needs this functionality.
Fixes: 42a20f86dc ("sched: Add wrapper for get_wchan() to keep task blocked")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 55d4669ef1b76823083caecfab12a8bd2ccdcf64 ]
When rcu_barrier() calls rcu_rdp_cpu_online() and observes a CPU off
rnp->qsmaskinitnext, it means that all accesses from the offline CPU
preceding the CPUHP_TEARDOWN_CPU are visible to RCU barrier, including
callbacks expiration and counter updates.
However interrupts can still fire after stop_machine() re-enables
interrupts and before rcutree_report_cpu_dead(). The related accesses
happening between CPUHP_TEARDOWN_CPU and rnp->qsmaskinitnext clearing
are _NOT_ guaranteed to be seen by rcu_barrier() without proper
ordering, especially when callbacks are invoked there to the end, making
rcutree_migrate_callback() bypass barrier_lock.
The following theoretical race example can make rcu_barrier() hang:
CPU 0 CPU 1
----- -----
//cpu_down()
smpboot_park_threads()
//ksoftirqd is parked now
<IRQ>
rcu_sched_clock_irq()
invoke_rcu_core()
do_softirq()
rcu_core()
rcu_do_batch()
// callback storm
// rcu_do_batch() returns
// before completing all
// of them
// do_softirq also returns early because of
// timeout. It defers to ksoftirqd but
// it's parked
</IRQ>
stop_machine()
take_cpu_down()
rcu_barrier()
spin_lock(barrier_lock)
// observes rcu_segcblist_n_cbs(&rdp->cblist) != 0
<IRQ>
do_softirq()
rcu_core()
rcu_do_batch()
//completes all pending callbacks
//smp_mb() implied _after_ callback number dec
</IRQ>
rcutree_report_cpu_dead()
rnp->qsmaskinitnext &= ~rdp->grpmask;
rcutree_migrate_callback()
// no callback, early return without locking
// barrier_lock
//observes !rcu_rdp_cpu_online(rdp)
rcu_barrier_entrain()
rcu_segcblist_entrain()
// Observe rcu_segcblist_n_cbs(rsclp) == 0
// because no barrier between reading
// rnp->qsmaskinitnext and rsclp->len
rcu_segcblist_add_len()
smp_mb__before_atomic()
// will now observe the 0 count and empty
// list, but too late, we enqueue regardless
WRITE_ONCE(rsclp->len, rsclp->len + v);
// ignored barrier callback
// rcu barrier stall...
This could be solved with a read memory barrier, enforcing the message
passing between rnp->qsmaskinitnext and rsclp->len, matching the full
memory barrier after rsclp->len addition in rcu_segcblist_add_len()
performed at the end of rcu_do_batch().
However the rcu_barrier() is complicated enough and probably doesn't
need too many more subtleties. CPU down is a slowpath and the
barrier_lock seldom contended. Solve the issue with unconditionally
locking the barrier_lock on rcutree_migrate_callbacks(). This makes sure
that either rcu_barrier() sees the empty queue or its entrained
callback will be migrated.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6040072f4774a575fa67b912efe7722874be337b ]
On powerpc systems, spinlock acquisition does not order prior stores
against later loads. This means that this statement:
rfcp->rfc_next = NULL;
Can be reordered to follow this statement:
WRITE_ONCE(*rfcpp, rfcp);
Which is then a data race with rcu_torture_fwd_prog_cr(), specifically,
this statement:
rfcpn = READ_ONCE(rfcp->rfc_next)
KCSAN located this data race, which represents a real failure on powerpc.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <kasan-dev@googlegroups.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 224fa3552029a3d14bec7acf72ded8171d551b88 ]
Per the example of:
!atomic_cmpxchg(&key->enabled, 0, 1)
the inverse was written as:
atomic_cmpxchg(&key->enabled, 1, 0)
except of course, that while !old is only true for old == 0, old is
true for everything except old == 0.
Fix it to read:
atomic_cmpxchg(&key->enabled, 1, 0) == 1
such that only the 1->0 transition returns true and goes on to disable
the keys.
Fixes: 83ab38ef0a0b ("jump_label: Fix concurrency issues in static_key_slow_dec()")
Reported-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lkml.kernel.org/r/20240731105557.GY33588@noisy.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0be9ae5486cd9e767138c13638820d240713f5f1 ]
Since commit 0108a4e9f3 ("bpf: ensure main program has an extable"),
prog->aux->func[0]->kallsyms is left as uninitialized. For BPF programs
with subprogs, the symbol for the main program is missing just as shown
in the output of perf script below:
ffffffff81284b69 qp_trie_lookup_elem+0xb9 ([kernel.kallsyms])
ffffffffc0011125 bpf_prog_a4a0eb0651e6af8b_lookup_qp_trie+0x5d (bpf...)
ffffffff8127bc2b bpf_for_each_array_elem+0x7b ([kernel.kallsyms])
ffffffffc00110a1 +0x25 ()
ffffffff8121a89a trace_call_bpf+0xca ([kernel.kallsyms])
Fix it by always using prog instead prog->aux->func[0] to emit ksymbol
event for the main program. After the fix, the output of perf script
will be correct:
ffffffff81284b96 qp_trie_lookup_elem+0xe6 ([kernel.kallsyms])
ffffffffc001382d bpf_prog_a4a0eb0651e6af8b_lookup_qp_trie+0x5d (bpf...)
ffffffff8127bc2b bpf_for_each_array_elem+0x7b ([kernel.kallsyms])
ffffffffc0013779 bpf_prog_245c55ab25cfcf40_qp_trie_lookup+0x25 (bpf...)
ffffffff8121a89a trace_call_bpf+0xca ([kernel.kallsyms])
Fixes: 0108a4e9f3 ("bpf: ensure main program has an extable")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Krister Johansen <kjlx@templeofstupid.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240714065533.1112616-1-houtao@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28e8b7406d3a1f5329a03aa25a43aa28e087cb20 ]
dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.
If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.
Fix by destroying the devres entry before freeing the DMA
allocation.
Tested:
kokonut //net/encryption
http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03
Fixes: 9ac7849e35 ("devres: device resource management")
Signed-off-by: Lance Richardson <rlance@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e2e821095949cde46256034975a90f88626a2a73 ]
The function kdb_position_cursor() takes in a "prompt" parameter but
never uses it. This doesn't _really_ matter since all current callers
of the function pass the same value and it's a global variable, but
it's a bit ugly. Let's clean it up.
Found by code inspection. This patch is expected to functionally be a
no-op.
Fixes: 09b35989421d ("kdb: Use format-strings rather than '\0' injection in kdb_read()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240528071144.1.I0feb49839c6b6f4f2c4bf34764f5e95de3f55a66@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 70867efacf4370b6c7cdfc7a5b11300e9ef7de64 ]
When -Wformat-security is not disabled, using a string pointer
as a format causes a warning:
kernel/debug/kdb/kdb_io.c: In function 'kdb_read':
kernel/debug/kdb/kdb_io.c:365:36: error: format not a string literal and no format arguments [-Werror=format-security]
365 | kdb_printf(kdb_prompt_str);
| ^~~~~~~~~~~~~~
kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr':
kernel/debug/kdb/kdb_io.c:456:20: error: format not a string literal and no format arguments [-Werror=format-security]
456 | kdb_printf(kdb_prompt_str);
| ^~~~~~~~~~~~~~
Use an explcit "%s" format instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 5d5314d679 ("kdb: core for kgdb back end (1 of 2)")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240528121154.3662553-1-arnd@kernel.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f944ffcbc2e1c759764850261670586ddf3bdabb upstream.
For systems on which the performance counter can expire early due to turbo
modes the watchdog handler has a safety net in place which validates that
since the last watchdog event there has at least 4/5th of the watchdog
period elapsed.
This works reliably only after the first watchdog event because the per
CPU variable which holds the timestamp of the last event is never
initialized.
So a first spurious event will validate against a timestamp of 0 which
results in a delta which is likely to be way over the 4/5 threshold of the
period. As this might happen before the first watchdog hrtimer event
increments the watchdog counter, this can lead to false positives.
Fix this by initializing the timestamp before enabling the hardware event.
Reset the rearm counter as well, as that might be non zero after the
watchdog was disabled and reenabled.
Link: https://lkml.kernel.org/r/87frsfu15a.ffs@tglx
Fixes: 7edaeb6841 ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3a5465418f5fd970e86a86c7f4075be262682840 upstream.
The perf pending task work is never waited upon the matching event
release. In the case of a child event, released via free_event()
directly, this can potentially result in a leaked event, such as in the
following scenario that doesn't even require a weak IRQ work
implementation to trigger:
schedule()
prepare_task_switch()
=======> <NMI>
perf_event_overflow()
event->pending_sigtrap = ...
irq_work_queue(&event->pending_irq)
<======= </NMI>
perf_event_task_sched_out()
event_sched_out()
event->pending_sigtrap = 0;
atomic_long_inc_not_zero(&event->refcount)
task_work_add(&event->pending_task)
finish_lock_switch()
=======> <IRQ>
perf_pending_irq()
//do nothing, rely on pending task work
<======= </IRQ>
begin_new_exec()
perf_event_exit_task()
perf_event_exit_event()
// If is child event
free_event()
WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1)
// event is leaked
Similar scenarios can also happen with perf_event_remove_on_exec() or
simply against concurrent perf_event_release().
Fix this with synchonizing against the possibly remaining pending task
work while freeing the event, just like is done with remaining pending
IRQ work. This means that the pending task callback neither need nor
should hold a reference to the event, preventing it from ever beeing
freed.
Fixes: 517e6a301f ("perf: Fix perf_pending_task() UaF")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-5-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2fd5ad3f310de22836cdacae919dd99d758a1f1b upstream.
When a task is scheduled out, pending sigtrap deliveries are deferred
to the target task upon resume to userspace via task_work.
However failures while adding an event's callback to the task_work
engine are ignored. And since the last call for events exit happen
after task work is eventually closed, there is a small window during
which pending sigtrap can be queued though ignored, leaking the event
refcount addition such as in the following scenario:
TASK A
-----
do_exit()
exit_task_work(tsk);
<IRQ>
perf_event_overflow()
event->pending_sigtrap = pending_id;
irq_work_queue(&event->pending_irq);
</IRQ>
=========> PREEMPTION: TASK A -> TASK B
event_sched_out()
event->pending_sigtrap = 0;
atomic_long_inc_not_zero(&event->refcount)
// FAILS: task work has exited
task_work_add(&event->pending_task)
[...]
<IRQ WORK>
perf_pending_irq()
// early return: event->oncpu = -1
</IRQ WORK>
[...]
=========> TASK B -> TASK A
perf_event_exit_task(tsk)
perf_event_exit_event()
free_event()
WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1)
// leak event due to unexpected refcount == 2
As a result the event is never released while the task exits.
Fix this with appropriate task_work_add()'s error handling.
Fixes: 517e6a301f ("perf: Fix perf_pending_task() UaF")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-4-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ce3e98184b625d2870991880bf9586ded7ea7f9 upstream.
fwnode_handle_get(fwnode) is called when a domain is created with fwnode
passed as a function parameter. fwnode_handle_put(domain->fwnode) is called
when the domain is destroyed but during the creation a path exists that
does not set domain->fwnode.
If this path is taken, the fwnode get will never be put.
To avoid the unbalanced get and put, set domain->fwnode unconditionally.
Fixes: d59f6617ee ("genirq: Allow fwnode to carry name information only")
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240614173232.1184015-4-herve.codina@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7dc836187f7c6f70a82b4521503e9f9f96194581 upstream.
pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.
Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.
This change wouldn't impact functionality in practice because the worst-size
is 2K.
Cc: stable@goodmis.org
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@arm.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f409530e4db9dd11b88cb7703c97c8f326ff6566 upstream.
Re-introduce task_work_cancel(), this time to cancel an actual callback
and not *any* callback pointing to a given function. This is going to be
needed for perf events event freeing.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream.
A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d329605287020c3d1c3b0dadc63d8208e7251382 upstream.
When a task's weight is being changed, set_load_weight() is called with
@update_load set. As weight changes aren't trivial for the fair class,
set_load_weight() calls fair.c::reweight_task() for fair class tasks.
However, set_load_weight() first tests task_has_idle_policy() on entry and
skips calling reweight_task() for SCHED_IDLE tasks. This is buggy as
SCHED_IDLE tasks are just fair tasks with a very low weight and they would
incorrectly skip load, vlag and position updates.
Fix it by updating reweight_task() to take struct load_weight as idle weight
can't be expressed with prio and making set_load_weight() call
reweight_task() for SCHED_IDLE tasks too when @update_load is set.
Fixes: 9059393e4e ("sched/fair: Use reweight_entity() for set_user_nice()")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # v4.15+
Link: http://lkml.kernel.org/r/20240624102331.GI31592@noisy.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 943ad0b62e3c21f324c4884caa6cb4a871bca05c upstream.
io_uring can asynchronously add a task_work while the task is getting
freezed. TIF_NOTIFY_SIGNAL will prevent the task from sleeping in
do_freezer_trap(), and since the get_signal()'s relock loop doesn't
retry task_work, the task will spin there not being able to sleep
until the freezing is cancelled / the task is killed / etc.
Run task_works in the freezer path. Keep the patch small and simple
so it can be easily back ported, but we might need to do some cleaning
after and look if there are other places with similar problems.
Cc: stable@vger.kernel.org
Link: https://github.com/systemd/systemd/issues/33626
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Reported-by: Julian Orth <ju.orth@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89ed3a52933370deaaf61a0a620a6ac91f1e754d.1720634146.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f7d43dd206e7e18c182f200e67a8db8c209907fa upstream.
Running the LTP hotplug stress test on a aarch64 machine results in
rcu_sched stall warnings when the broadcast hrtimer was owned by the
un-plugged CPU. The issue is the following:
CPU1 (owns the broadcast hrtimer) CPU2
tick_broadcast_enter()
// shutdown local timer device
broadcast_shutdown_local()
...
tick_broadcast_exit()
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT)
// timer device is not programmed
cpumask_set_cpu(cpu, tick_broadcast_force_mask)
initiates offlining of CPU1
take_cpu_down()
/*
* CPU1 shuts down and does not
* send broadcast IPI anymore
*/
takedown_cpu()
hotplug_cpu__broadcast_tick_pull()
// move broadcast hrtimer to this CPU
clockevents_program_event()
bc_set_next()
hrtimer_start()
/*
* timer device is not programmed
* because only the first expiring
* timer will trigger clockevent
* device reprogramming
*/
What happens is that CPU2 exits broadcast mode with force bit set, then the
local timer device is not reprogrammed and CPU2 expects to receive the
expired event by the broadcast IPI. But this does not happen because CPU1
is offlined by CPU2. CPU switches the clockevent device to ONESHOT state,
but does not reprogram the device.
The subsequent reprogramming of the hrtimer broadcast device does not
program the clockevent device of CPU2 either because the pending expiry
time is already in the past and the CPU expects the event to be delivered.
As a consequence all CPUs which wait for a broadcast event to be delivered
are stuck forever.
Fix this issue by reprogramming the local timer device if the broadcast
force bit of the CPU is set so that the broadcast hrtimer is delivered.
[ tglx: Massage comment and change log. Add Fixes tag ]
Fixes: 989dcb645c ("tick: Handle broadcast wakeup of multiple cpus")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240711124843.64167-1-liaoyu15@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2454075f8e2915cebbe52a1195631bc7efe2b7e1 ]
As reported by Mirsad [1] we still see format warnings in kernel/bpf/btf.o
at W=1 warning level:
CC kernel/bpf/btf.o
./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’:
./kernel/bpf/btf.c:7553:21: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format]
7553 | sseq.showfn = btf_seq_show;
| ^
./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’:
./kernel/bpf/btf.c:7604:31: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format]
7604 | ssnprintf.show.showfn = btf_snprintf_show;
| ^
Combined with CONFIG_WERROR=y these can halt the build.
The fix (annotating the structure field with __printf())
suggested by Mirsad resolves these. Apologies I missed this last time.
No other W=1 warnings were observed in kernel/bpf after this fix.
[1] https://lore.kernel.org/bpf/92c9d047-f058-400c-9c7d-81d4dc1ef71b@gmail.com/
Fixes: b3470da314fd ("bpf: annotate BTF show functions with __printf")
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Suggested-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240712092859.1390960-1-alan.maguire@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b3470da314fd8018ee237e382000c4154a942420 ]
-Werror=suggest-attribute=format warns about two functions
in kernel/bpf/btf.c [1]; add __printf() annotations to silence
these warnings since for CONFIG_WERROR=y they will trigger
build failures.
[1] https://lore.kernel.org/bpf/a8b20c72-6631-4404-9e1f-0410642d7d20@gmail.com/
Fixes: 31d0bc8163 ("bpf: Move to generic BTF show support, apply it to seq files/strings")
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Mirsad Todorovac <mtodorovac69@yahoo.com>
Link: https://lore.kernel.org/r/20240711182321.963667-1-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e81859fe64ad42dccefe134d1696e0635f78d763 ]
Apparently despite it being marked inline, the compiler
may not inline __down_write_common() which makes it difficult
to identify the cause of lock contention, as the wchan of the
blocked function will always be listed as __down_write_common().
So add __always_inline annotation to the common function (as
well as the inlined helper callers) to force it to be inlined
so a more useful blocking function will be listed (via wchan).
This mirrors commit 92cc5d00a4 ("locking/rwsem: Add
__always_inline annotation to __down_read_common() and inlined
callers") which did the same for __down_read_common.
I sort of worry that I'm playing wack-a-mole here, and talking
with compiler people, they tell me inline means nothing, which
makes me want to cry a little. So I'm wondering if we need to
replace all the inlines with __always_inline, or remove them
because either we mean something by it, or not.
Fixes: c995e638cc ("locking/rwsem: Fold __down_{read,write}*()")
Reported-by: Tim Murray <timmurray@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20240709060831.495366-1-jstultz@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 43deb76b19663a96ec2189d8f4eb9a9dc2d7623f ]
The default aux_watermark is half the AUX area buffer size. In general,
on a 64-bit architecture, the AUX area buffer size could be a bigger than
fits in a 32-bit type, but the calculation does not allow for that
possibility.
However the aux_watermark value is recorded in a u32, so should not be
more than U32_MAX either.
Fix by doing the calculation in a correctly sized type, and limiting the
result to U32_MAX.
Fixes: d68e6799a5 ("perf: Cap allocation order at aux_watermark")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dbc48c8f41c208082cfa95e973560134489e3309 ]
nr_pages is unsigned long but gets passed to rb_alloc_aux() as an int,
and is stored as an int.
Only power-of-2 values are accepted, so if nr_pages is a 64_bit value, it
will be passed to rb_alloc_aux() as zero.
That is not ideal because:
1. the value is incorrect
2. rb_alloc_aux() is at risk of misbehaving, although it manages to
return -ENOMEM in that case, it is a result of passing zero to get_order()
even though the get_order() result is documented to be undefined in that
case.
Fix by simply validating the maximum supported value in the first place.
Use -ENOMEM error code for consistency with the current error code that
is returned in that case.
Fixes: 45bfb2e504 ("perf: Add AUX area to ring buffer for raw data streams")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-6-adrian.hunter@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3df94a5b1078dfe2b0c03f027d018800faf44c82 ]
perf_buffer->aux_nr_pages uses a 32-bit type, so a cast is needed to
calculate a 64-bit size.
Fixes: 45bfb2e504 ("perf: Add AUX area to ring buffer for raw data streams")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-5-adrian.hunter@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 83ab38ef0a0b2407d43af9575bb32333fdd74fb2 ]
The commit which tried to fix the concurrency issues of concurrent
static_key_slow_inc() failed to fix the equivalent issues
vs. static_key_slow_dec():
CPU0 CPU1
static_key_slow_dec()
static_key_slow_try_dec()
key->enabled == 1
val = atomic_fetch_add_unless(&key->enabled, -1, 1);
if (val == 1)
return false;
jump_label_lock();
if (atomic_dec_and_test(&key->enabled)) {
--> key->enabled == 0
__jump_label_update()
static_key_slow_dec()
static_key_slow_try_dec()
key->enabled == 0
val = atomic_fetch_add_unless(&key->enabled, -1, 1);
--> key->enabled == -1 <- FAIL
There is another bug in that code, when there is a concurrent
static_key_slow_inc() which enables the key as that sets key->enabled to -1
so on the other CPU
val = atomic_fetch_add_unless(&key->enabled, -1, 1);
will succeed and decrement to -2, which is invalid.
Cure all of this by replacing the atomic_fetch_add_unless() with a
atomic_try_cmpxchg() loop similar to static_key_fast_inc_not_disabled().
[peterz: add WARN_ON_ONCE for the -1 race]
Fixes: 4c5ea0a9cd ("locking/static_key: Fix concurrent static_key_slow_inc()")
Reported-by: Yue Sun <samsun1006219@gmail.com>
Reported-by: Xingwei Lee <xrivendell7@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20240610124406.422897838@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1be59c97c83ccd67a519d8a49486b3a8a73ca28a ]
An UAF can happen when /proc/cpuset is read as reported in [1].
This can be reproduced by the following methods:
1.add an mdelay(1000) before acquiring the cgroup_lock In the
cgroup_path_ns function.
2.$cat /proc/<pid>/cpuset repeatly.
3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/
$umount /sys/fs/cgroup/cpuset/ repeatly.
The race that cause this bug can be shown as below:
(umount) | (cat /proc/<pid>/cpuset)
css_release | proc_cpuset_show
css_release_work_fn | css = task_get_css(tsk, cpuset_cgrp_id);
css_free_rwork_fn | cgroup_path_ns(css->cgroup, ...);
cgroup_destroy_root | mutex_lock(&cgroup_mutex);
rebind_subsystems |
cgroup_free_root |
| // cgrp was freed, UAF
| cgroup_path_ns_locked(cgrp,..);
When the cpuset is initialized, the root node top_cpuset.css.cgrp
will point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will
allocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated
&cgroup_root.cgrp. When the umount operation is executed,
top_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp.
The problem is that when rebinding to cgrp_dfl_root, there are cases
where the cgroup_root allocated by setting up the root for cgroup v1
is cached. This could lead to a Use-After-Free (UAF) if it is
subsequently freed. The descendant cgroups of cgroup v1 can only be
freed after the css is released. However, the css of the root will never
be released, yet the cgroup_root should be freed when it is unmounted.
This means that obtaining a reference to the css of the root does
not guarantee that css.cgrp->root will not be freed.
Fix this problem by using rcu_read_lock in proc_cpuset_show().
As cgroup_root is kfree_rcu after commit d23b5c577715
("cgroup: Make operations on the cgroup root_list RCU safe"),
css->cgroup won't be freed during the critical section.
To call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to
replace task_get_css with task_css.
[1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd
Fixes: a79a908fd2 ("cgroup: introduce cgroup namespaces")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ff6d413b0b59466e5acf2e42f294b1842ae130a1 ]
One of the last remaining users of strlcpy() in the kernel is
kernfs_path_from_node_locked(), which passes back the problematic "length
we _would_ have copied" return value to indicate truncation. Convert the
chain of all callers to use the negative return value (some of which
already doing this explicitly). All callers were already also checking
for negative return values, so the risk to missed checks looks very low.
In this analysis, it was found that cgroup1_release_agent() actually
didn't handle the "too large" condition, so this is technically also a
bug fix. :)
Here's the chain of callers, and resolution identifying each one as now
handling the correct return value:
kernfs_path_from_node_locked()
kernfs_path_from_node()
pr_cont_kernfs_path()
returns void
kernfs_path()
sysfs_warn_dup()
return value ignored
cgroup_path()
blkg_path()
bfq_bic_update_cgroup()
return value ignored
TRACE_IOCG_PATH()
return value ignored
TRACE_CGROUP_PATH()
return value ignored
perf_event_cgroup()
return value ignored
task_group_path()
return value ignored
damon_sysfs_memcg_path_eq()
return value ignored
get_mm_memcg_path()
return value ignored
lru_gen_seq_show()
return value ignored
cgroup_path_from_kernfs_id()
return value ignored
cgroup_show_path()
already converted "too large" error to negative value
cgroup_path_ns_locked()
cgroup_path_ns()
bpf_iter_cgroup_show_fdinfo()
return value ignored
cgroup1_release_agent()
wasn't checking "too large" error
proc_cgroup_show()
already converted "too large" to negative value
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <cgroups@vger.kernel.org>
Co-developed-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Link: https://lore.kernel.org/r/20231116192127.1558276-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231212211741.164376-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 1be59c97c83c ("cgroup/cpuset: Prevent UAF in proc_cpuset_show()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 399ced9594dfab51b782798efe60a2376cd5b724 ]
When RCU-TASKS-TRACE pre-gp takes a snapshot of the current task running
on all online CPUs, no explicit ordering synchronizes properly with a
context switch. This lack of ordering can permit the new task to miss
pre-grace-period update-side accesses. The following diagram, courtesy
of Paul, shows the possible bad scenario:
CPU 0 CPU 1
----- -----
// Pre-GP update side access
WRITE_ONCE(*X, 1);
smp_mb();
r0 = rq->curr;
RCU_INIT_POINTER(rq->curr, TASK_B)
spin_unlock(rq)
rcu_read_lock_trace()
r1 = X;
/* ignore TASK_B */
Either r0==TASK_B or r1==1 is needed but neither is guaranteed.
One possible solution to solve this is to wait for an RCU grace period
at the beginning of the RCU-tasks-trace grace period before taking the
current tasks snaphot. However this would introduce large additional
latencies to RCU-tasks-trace grace periods.
Another solution is to lock the target runqueue while taking the current
task snapshot. This ensures that the update side sees the latest context
switch and subsequent context switches will see the pre-grace-period
update side accesses.
This commit therefore adds runqueue locking to cpu_curr_snapshot().
Fixes: e386b67257 ("rcu-tasks: Eliminate RCU Tasks Trace IPIs to online CPUs")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ddae0ca2a8fe12d0e24ab10ba759c3fbd755ada8 upstream.
It was reported that in moving to 6.1, a larger then 10%
regression was seen in the performance of
clock_gettime(CLOCK_THREAD_CPUTIME_ID,...).
Using a simple reproducer, I found:
5.10:
100000000 calls in 24345994193 ns => 243.460 ns per call
100000000 calls in 24288172050 ns => 242.882 ns per call
100000000 calls in 24289135225 ns => 242.891 ns per call
6.1:
100000000 calls in 28248646742 ns => 282.486 ns per call
100000000 calls in 28227055067 ns => 282.271 ns per call
100000000 calls in 28177471287 ns => 281.775 ns per call
The cause of this was finally narrowed down to the addition of
psi_account_irqtime() in update_rq_clock_task(), in commit
52b1364ba0 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ
pressure").
In my initial attempt to resolve this, I leaned towards moving
all accounting work out of the clock_gettime() call path, but it
wasn't very pretty, so it will have to wait for a later deeper
rework. Instead, Peter shared this approach:
Rework psi_account_irqtime() to use its own psi_irq_time base
for accounting, and move it out of the hotpath, calling it
instead from sched_tick() and __schedule().
In testing this, we found the importance of ensuring
psi_account_irqtime() is run under the rq_lock, which Johannes
Weiner helpfully explained, so also add some lockdep annotations
to make that requirement clear.
With this change the performance is back in-line with 5.10:
6.1+fix:
100000000 calls in 24297324597 ns => 242.973 ns per call
100000000 calls in 24318869234 ns => 243.189 ns per call
100000000 calls in 24291564588 ns => 242.916 ns per call
Reported-by: Jimmy Shiu <jimmyshiu@google.com>
Originally-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Link: https://lore.kernel.org/r/20240618215909.4099720-1-jstultz@google.com
Fixes: 52b1364ba0 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure")
[jstultz: Fixed up minor collisions w/ 6.6-stable]
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2feab2492deb2f14f9675dd6388e9e2bf669c27a upstream.
This reverts commit b0defa7ae0.
b0defa7ae0 changed the load balancing logic to ignore env.max_loop if
all tasks examined to that point were pinned. The goal of the patch was
to make it more likely to be able to detach a task buried in a long list
of pinned tasks. However, this has the unfortunate side effect of
creating an O(n) iteration in detach_tasks(), as we now must fully
iterate every task on a cpu if all or most are pinned. Since this load
balance code is done with rq lock held, and often in softirq context, it
is very easy to trigger hard lockups. We observed such hard lockups with
a user who affined O(10k) threads to a single cpu.
When I discussed this with Vincent he initially suggested that we keep
the limit on the number of tasks to detach, but increase the number of
tasks we can search. However, after some back and forth on the mailing
list, he recommended we instead revert the original patch, as it seems
likely no one was actually getting hit by the original issue.
Fixes: b0defa7ae0 ("sched/fair: Make sure to try to detach at least one movable task")
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240620214450.316280-1-joshdon@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d4523831f07a267a943f0dde844bf8ead7495f13 ]
Given a schedule:
timer1 cb timer2 cb
bpf_timer_cancel(timer2); bpf_timer_cancel(timer1);
Both bpf_timer_cancel calls would wait for the other callback to finish
executing, introducing a lockup.
Add an atomic_t count named 'cancelling' in bpf_hrtimer. This keeps
track of all in-flight cancellation requests for a given BPF timer.
Whenever cancelling a BPF timer, we must check if we have outstanding
cancellation requests, and if so, we must fail the operation with an
error (-EDEADLK) since cancellation is synchronous and waits for the
callback to finish executing. This implies that we can enter a deadlock
situation involving two or more timer callbacks executing in parallel
and attempting to cancel one another.
Note that we avoid incrementing the cancelling counter for the target
timer (the one being cancelled) if bpf_timer_cancel is not invoked from
a callback, to avoid spurious errors. The whole point of detecting
cur->cancelling and returning -EDEADLK is to not enter a busy wait loop
(which may or may not lead to a lockup). This does not apply in case the
caller is in a non-callback context, the other side can continue to
cancel as it sees fit without running into errors.
Background on prior attempts:
Earlier versions of this patch used a bool 'cancelling' bit and used the
following pattern under timer->lock to publish cancellation status.
lock(t->lock);
t->cancelling = true;
mb();
if (cur->cancelling)
return -EDEADLK;
unlock(t->lock);
hrtimer_cancel(t->timer);
t->cancelling = false;
The store outside the critical section could overwrite a parallel
requests t->cancelling assignment to true, to ensure the parallely
executing callback observes its cancellation status.
It would be necessary to clear this cancelling bit once hrtimer_cancel
is done, but lack of serialization introduced races. Another option was
explored where bpf_timer_start would clear the bit when (re)starting the
timer under timer->lock. This would ensure serialized access to the
cancelling bit, but may allow it to be cleared before in-flight
hrtimer_cancel has finished executing, such that lockups can occur
again.
Thus, we choose an atomic counter to keep track of all outstanding
cancellation requests and use it to prevent lockups in case callbacks
attempt to cancel each other while executing in parallel.
Reported-by: Dohyun Kim <dohyunkim@google.com>
Reported-by: Neel Natu <neelnatu@google.com>
Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709185440.1104957-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 56b4a177ae6322173360a93ea828ad18570a5a14 ]
No code change except for the new flags argument being stored in the
local data struct.
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-2-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: d4523831f07a ("bpf: Fail bpf_timer_cancel when callback is being cancelled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be2749beff62e0d63cf97fe63cabc79a68443139 ]
To be able to add workqueues and reuse most of the timer code, we need
to make bpf_hrtimer more generic.
There is no code change except that the new struct gets a new u64 flags
attribute. We are still below 2 cache lines, so this shouldn't impact
the current running codes.
The ordering is also changed. Everything related to async callback
is now on top of bpf_hrtimer.
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-1-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: d4523831f07a ("bpf: Fail bpf_timer_cancel when callback is being cancelled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit af253aef183a31ce62d2e39fc520b0ebfb562bb9 ]
The original function call passed size of smap->bucket before the number of
buckets which raises the error 'calloc-transposed-args' on compilation.
Vlastimil Babka added:
The order of parameters can be traced back all the way to 6ac99e8f23
("bpf: Introduce bpf sk local storage") accross several refactorings,
and that's why the commit is used as a Fixes: tag.
In v6.10-rc1, a different commit 2c321f3f70bc ("mm: change inlined
allocation helpers to account at the call site") however exposed the
order of args in a way that gcc-14 has enough visibility to start
warning about it, because (in !CONFIG_MEMCG case) bpf_map_kvcalloc is
then a macro alias for kvcalloc instead of a static inline wrapper.
To sum up the warning happens when the following conditions are all met:
- gcc-14 is used (didn't see it with gcc-13)
- commit 2c321f3f70bc is present
- CONFIG_MEMCG is not enabled in .config
- CONFIG_WERROR turns this from a compiler warning to error
Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Mohammad Shehar Yaar Tausif <sheharyaar48@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20240710100521.15061-2-vbabka@suse.cz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ]
If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.
Suggested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit cf3f9a593dab87a032d2b6a6fb205e7f3de4f0a1 upstream.
When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.
If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.
Recognize this situation in advance and exit early.
Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ef8eb5125722c241fd60d7b0c872d5c2e5dd4ca upstream.
After the rework of "Parallel CPU bringup", the cmdline "nosmp" and
"maxcpus=0" parameters are not working anymore. These parameters set
setup_max_cpus to zero and that's handed to bringup_nonboot_cpus().
The code there does a decrement before checking for zero, which brings it
into the negative space and brings up all CPUs.
Add a zero check at the beginning of the function to prevent this.
[ tglx: Massaged change log ]
Fixes: 18415f33e2 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Fixes: 06c6796e03 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit db5247d9bf5c6ade9fd70b4e4897441e0269b233 ]
Instead of lingering until the device is closed, this has us handle
SIGKILL by:
1. marking the worker as killed so we no longer try to use it with
new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.
Suggested-by: Edward Adam Davis <eadavis@qq.com>
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: <tencent_546DA49414E876EEBECF2C78D26D242EE50A@qq.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20240316004707.45557-9-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ]
Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init().
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit fdd411af81 which is
commit 7d2cc63eca0c993c99d18893214abf8f85d566d8 upstream.
It is part of a series that is reported to both break the arm64 builds
and instantly crashes the powerpc systems at the first load of a bpf
program. So revert it for now until it can come back in a safe way.
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Reported-by: Vitaly Chikunov <vt@altlinux.org>
Reported-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/5A29E00D83AB84E3+20240706031101.637601-1-wangyuli@uniontech.com
Link: https://lore.kernel.org/r/cf736c5e37489e7dc7ffd67b9de2ab47@matoro.tk
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Song Liu <song@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kees Cook <keescook@chromium.org>
Cc: Puranjay Mohan <puranjay12@gmail.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com> # s390x
Cc: Tiezhu Yang <yangtiezhu@loongson.cn> # LoongArch
Cc: Johan Almbladh <johan.almbladh@anyfinetworks.com> # MIPS Part
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream.
Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.
This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc8 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.
Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.
Cc: stable@vger.kernel.org
Fixes: 48166e6ea4 ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 932d8476399f622aa0767a4a0a9e78e5341dc0e1 upstream.
Commit 4205e4786d ("cpu/hotplug: Provide dynamic range for prepare
stage") added a dynamic range for the prepare states, but did not handle
the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().
This causes the corresponding startup callback not to be invoked when
calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN
parameter, even though it should be.
Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or
another, have not triggered this bug.
Fixes: 4205e4786d ("cpu/hotplug: Provide dynamic range for prepare stage")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit cfa1a2329a691ffd991fcf7248a57d752e712881 ]
The BPF ring buffer internally is implemented as a power-of-2 sized circular
buffer, with two logical and ever-increasing counters: consumer_pos is the
consumer counter to show which logical position the consumer consumed the
data, and producer_pos which is the producer counter denoting the amount of
data reserved by all producers.
Each time a record is reserved, the producer that "owns" the record will
successfully advance producer counter. In user space each time a record is
read, the consumer of the data advanced the consumer counter once it finished
processing. Both counters are stored in separate pages so that from user
space, the producer counter is read-only and the consumer counter is read-write.
One aspect that simplifies and thus speeds up the implementation of both
producers and consumers is how the data area is mapped twice contiguously
back-to-back in the virtual memory, allowing to not take any special measures
for samples that have to wrap around at the end of the circular buffer data
area, because the next page after the last data page would be first data page
again, and thus the sample will still appear completely contiguous in virtual
memory.
Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for
book-keeping the length and offset, and is inaccessible to the BPF program.
Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ`
for the BPF program to use. Bing-Jhong and Muhammad reported that it is however
possible to make a second allocated memory chunk overlapping with the first
chunk and as a result, the BPF program is now able to edit first chunk's
header.
For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size
of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to
bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in
[0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets
allocate a chunk B with size 0x3000. This will succeed because consumer_pos
was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask`
check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able
to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned
earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data
pages. This means that chunk B at [0x4000,0x4008] is chunk A's header.
bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then
locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk
B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong
page and could cause a crash.
Fix it by calculating the oldest pending_pos and check whether the range
from the oldest outstanding record to the newest would span beyond the ring
buffer size. If that is the case, then reject the request. We've tested with
the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh)
before/after the fix and while it seems a bit slower on some benchmarks, it
is still not significantly enough to matter.
Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Reported-by: Muhammad Ramdhan <ramdhan@starlabs.sg>
Co-developed-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 44b7f7151dfc2e0947f39ed4b9bc4b0c2ccd46fc ]
In coerce_subreg_to_size_sx(), for the case where upper
sign extension bits are the same for smax32 and smin32
values, we missed to setup properly. This is especially
problematic if both smax32 and smin32's sign extension
bits are 1.
The following is a simple example illustrating the inconsistent
verifier states due to missed var_off:
0: (85) call bpf_get_prandom_u32#7 ; R0_w=scalar()
1: (bf) r3 = r0 ; R0_w=scalar(id=1) R3_w=scalar(id=1)
2: (57) r3 &= 15 ; R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=15,var_off=(0x0; 0xf))
3: (47) r3 |= 128 ; R3_w=scalar(smin=umin=smin32=umin32=128,smax=umax=smax32=umax32=143,var_off=(0x80; 0xf))
4: (bc) w7 = (s8)w3
REG INVARIANTS VIOLATION (alu): range bounds violation u64=[0xffffff80, 0x8f] s64=[0xffffff80, 0x8f]
u32=[0xffffff80, 0x8f] s32=[0x80, 0xffffff8f] var_off=(0x80, 0xf)
The var_off=(0x80, 0xf) is not correct, and the correct one should
be var_off=(0xffffff80; 0xf) since from insn 3, we know that at
insn 4, the sign extension bits will be 1. This patch fixed this
issue by setting var_off properly.
Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240615174632.3995278-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 380d5f89a4815ff88461a45de2fb6f28533df708 ]
Zac reported a verification failure and Alexei reproduced the issue
with a simple reproducer ([1]). The verification failure is due to missed
setting for var_off.
The following is the reproducer in [1]:
0: R1=ctx() R10=fp0
0: (71) r3 = *(u8 *)(r10 -387) ;
R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R10=fp0
1: (bc) w7 = (s8)w3 ;
R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f))
2: (36) if w7 >= 0x2533823b goto pc-3
mark_precise: frame0: last_idx 2 first_idx 0 subseq_idx -1
mark_precise: frame0: regs=r7 stack= before 1: (bc) w7 = (s8)w3
mark_precise: frame0: regs=r3 stack= before 0: (71) r3 = *(u8 *)(r10 -387)
2: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f))
3: (b4) w0 = 0 ; R0_w=0
4: (95) exit
Note that after insn 1, the var_off for R7 is (0x0; 0x7f). This is not correct
since upper 24 bits of w7 could be 0 or 1. So correct var_off should be
(0x0; 0xffffffff). Missing var_off setting in set_sext32_default_val() caused later
incorrect analysis in zext_32_to_64(dst_reg) and reg_bounds_sync(dst_reg).
To fix the issue, set var_off correctly in set_sext32_default_val(). The correct
reg state after insn 1 becomes:
1: (bc) w7 = (s8)w3 ;
R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
R7_w=scalar(smin=0,smax=umax=0xffffffff,smin32=-128,smax32=127,var_off=(0x0; 0xffffffff))
and at insn 2, the verifier correctly determines either branch is possible.
[1] https://lore.kernel.org/bpf/CAADnVQLPU0Shz7dWV4bn2BgtGdxN3uFHPeobGBA72tpg5Xoykw@mail.gmail.com/
Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240615174626.3994813-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4b377b4868ef17b040065bd468668c707d2477a5 upstream.
Commit 1a7d0890dd4a ("kprobe/ftrace: bail out if ftrace was killed")
introduced a bad K&R function definition, which we haven't accepted in a
long long time.
Gcc seems to let it slide, but clang notices with the appropriate error:
kernel/kprobes.c:1140:24: error: a function declaration without a prototype is deprecated in all >
1140 | void kprobe_ftrace_kill()
| ^
| void
but this commit was apparently never in linux-next before it was sent
upstream, so it didn't get the appropriate build test coverage.
Fixes: 1a7d0890dd4a kprobe/ftrace: bail out if ftrace was killed
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 01c8f9806bde438ca1c8cbbc439f0a14a6694f6c upstream.
In kcov_remote_start()/kcov_remote_stop(), we swap the previous KCOV
metadata of the current task into a per-CPU variable. However, the
kcov_mode_enabled(mode) check is not sufficient in the case of remote KCOV
coverage: current->kcov_mode always remains KCOV_MODE_DISABLED for remote
KCOV objects.
If the original task that has invoked the KCOV_REMOTE_ENABLE ioctl happens
to get interrupted and kcov_remote_start() is called, it ultimately leads
to kcov_remote_stop() NOT restoring the original KCOV reference. So when
the task exits, all registered remote KCOV handles remain active forever.
The most uncomfortable effect (at least for syzkaller) is that the bug
prevents the reuse of the same /sys/kernel/debug/kcov descriptor. If
we obtain it in the parent process and then e.g. drop some
capabilities and continuously fork to execute individual programs, at
some point current->kcov of the forked process is lost,
kcov_task_exit() takes no action, and all KCOV_REMOTE_ENABLE ioctls
calls from subsequent forks fail.
And, yes, the efficiency is also affected if we keep on losing remote
kcov objects.
a) kcov_remote_map keeps on growing forever.
b) (If I'm not mistaken), we're also not freeing the memory referenced
by kcov->area.
Fix it by introducing a special kcov_mode that is assigned to the task
that owns a KCOV remote object. It makes kcov_mode_enabled() return true
and yet does not trigger coverage collection in __sanitizer_cov_trace_pc()
and write_comp_data().
[nogikh@google.com: replace WRITE_ONCE() with an ordinary assignment]
Link: https://lkml.kernel.org/r/20240614171221.2837584-1-nogikh@google.com
Link: https://lkml.kernel.org/r/20240611133229.527822-1-nogikh@google.com
Fixes: 5ff3b30ab5 ("kcov: collect coverage from interrupts")
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c1558bc57b8e5b4da5d821537cd30e2e660861d8 upstream.
Using gcov on kernels compiled with GCC 14 results in truncated 16-byte
long .gcda files with no usable data. To fix this, update GCOV_COUNTERS
to match the value defined by GCC 14.
Tested with GCC versions 14.1.0 and 13.2.0.
Link: https://lkml.kernel.org/r/20240610092743.1609845-1-oberpar@linux.ibm.com
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reported-by: Allison Henderson <allison.henderson@oracle.com>
Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]
If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.
This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:
[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer
sudo perf probe --add commit_creds
sudo perf trace -e probe:commit_creds
# In another terminal
make
sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug
# Back to perf terminal
# ctrl-c
sudo perf probe --del commit_creds
After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.
Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
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>
[ Upstream commit 8b9b443fa860276822b25057cb3ff3b28734dec0 ]
The "pipe_count > RCU_TORTURE_PIPE_LEN" check has a comment saying "Should
not happen, but...". This is only true when testing an RCU whose grace
periods are always long enough. This commit therefore fixes this comment.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Closes: https://lore.kernel.org/lkml/CAHk-=wi7rJ-eGq+xaxVfzFEgbL9tdf6Kc8Z89rCpfcQOKm74Tw@mail.gmail.com/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58329c4312031603bb1786b44265c26d5065fe72 ]
As the old padata code can execute in softirq context, disable
softirqs for the new padata_do_mutithreaded code too as otherwise
lockdep will get antsy.
Reported-by: syzbot+0cb5bb0f4bf9e79db3b3@syzkaller.appspotmail.com
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7fea700e04bd3f424c2d836e98425782f97b494e ]
kernel_wait4() doesn't sleep and returns -EINTR if there is no
eligible child and signal_pending() is true.
That is why zap_pid_ns_processes() clears TIF_SIGPENDING but this is not
enough, it should also clear TIF_NOTIFY_SIGNAL to make signal_pending()
return false and avoid a busy-wait loop.
Link: https://lkml.kernel.org/r/20240608120616.GB7947@redhat.com
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Rachel Menge <rachelmenge@linux.microsoft.com>
Closes: https://lore.kernel.org/all/1386cd49-36d0-4a5c-85e9-bc42056a5a38@linux.microsoft.com/
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Wei Fu <fuweid89@gmail.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit cec11fa2eb which is commit
35e351780fa9d8240dd6f7e4f245f9ea37e96c19 upstream.
The backport is incomplete and causes xfstests failures. The consequences
of the incomplete backport seem worse than the original issue, so pick
the lesser evil and revert until a full backport is ready.
Link: https://lore.kernel.org/stable/20240604004751.3883227-1-leah.rumancik@gmail.com/
Reported-by: Leah Rumancik <leah.rumancik@gmail.com>
Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 07c54cc5988f19c9642fd463c2dbdac7fc52f777 upstream.
After the recent commit 5097cbcb38e6 ("sched/isolation: Prevent boot crash
when the boot CPU is nohz_full") the kernel no longer crashes, but there is
another problem.
In this case tick_setup_device() calls tick_take_do_timer_from_boot() to
update tick_do_timer_cpu and this triggers the WARN_ON_ONCE(irqs_disabled)
in smp_call_function_single().
Kill tick_take_do_timer_from_boot() and just use WRITE_ONCE(), the new
comment explains why this is safe (thanks Thomas!).
Fixes: 08ae95f4fd ("nohz_full: Allow the boot CPU to be nohz_full")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240528122019.GA28794@redhat.com
Link: https://lore.kernel.org/all/20240522151742.GA10400@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit af133562d5aff41fcdbe51f1a504ae04788b5fc0 upstream.
Allow a buffer pre-padding of up to alloc_align_mask, even if it requires
allocating additional IO TLB slots.
If the allocation alignment is bigger than IO_TLB_SIZE and min_align_mask
covers any non-zero bits in the original address between IO_TLB_SIZE and
alloc_align_mask, these bits are not preserved in the swiotlb buffer
address.
To fix this case, increase the allocation size and use a larger offset
within the allocated buffer. As a result, extra padding slots may be
allocated before the mapping start address.
Leave orig_addr in these padding slots initialized to INVALID_PHYS_ADDR.
These slots do not correspond to any CPU buffer, so attempts to sync the
data should be ignored.
The padding slots should be automatically released when the buffer is
unmapped. However, swiotlb_tbl_unmap_single() takes only the address of the
DMA buffer slot, not the first padding slot. Save the number of padding
slots in struct io_tlb_slot and use it to adjust the slot index in
swiotlb_release_slots(), so all allocated slots are properly freed.
Cc: stable@vger.kernel.org # v6.6+
Fixes: 2fd4fa5d3fb5 ("swiotlb: Fix alignment checks when both allocation and DMA masks are present")
Link: https://lore.kernel.org/linux-iommu/20240311210507.217daf8b@meshulam.tesarici.cz/
Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 14cebf689a78e8a1c041138af221ef6eac6bc7da upstream.
For swiotlb allocations >= PAGE_SIZE, the slab search historically
adjusted the stride to avoid checking unaligned slots. This had the
side-effect of aligning large mapping requests to PAGE_SIZE, but that
was broken by 0eee5ae102 ("swiotlb: fix slot alignment checks").
Since this alignment could be relied upon drivers, reinstate PAGE_SIZE
alignment for swiotlb mappings >= PAGE_SIZE.
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 823353b7cf0ea9dfb09f5181d5fb2825d727200b upstream.
When allocating pages from a restricted DMA pool in swiotlb_alloc(),
the buffer address is blindly converted to a 'struct page *' that is
returned to the caller. In the unlikely event of an allocation bug,
page-unaligned addresses are not detected and slots can silently be
double-allocated.
Add a simple check of the buffer alignment in swiotlb_alloc() to make
debugging a little easier if something has gone wonky.
Cc: stable@vger.kernel.org # v6.6+
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3bd27a847a3a4827a948387cc8f0dbc9fa5931d5 upstream.
Build environments might be running with different umask settings
resulting in indeterministic file modes for the files contained in
kheaders.tar.xz. The file itself is served with 444, i.e. world
readable. Archive the files explicitly with 744,a+X to improve
reproducibility across build environments.
--mode=0444 is not suitable as directories need to be executable. Also,
444 makes it hard to delete all the readonly files after extraction.
Cc: stable@vger.kernel.org
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 74751ef5c1912ebd3e65c3b65f45587e05ce5d36 upstream.
In our production environment, we found many hung tasks which are
blocked for more than 18 hours. Their call traces are like this:
[346278.191038] __schedule+0x2d8/0x890
[346278.191046] schedule+0x4e/0xb0
[346278.191049] perf_event_free_task+0x220/0x270
[346278.191056] ? init_wait_var_entry+0x50/0x50
[346278.191060] copy_process+0x663/0x18d0
[346278.191068] kernel_clone+0x9d/0x3d0
[346278.191072] __do_sys_clone+0x5d/0x80
[346278.191076] __x64_sys_clone+0x25/0x30
[346278.191079] do_syscall_64+0x5c/0xc0
[346278.191083] ? syscall_exit_to_user_mode+0x27/0x50
[346278.191086] ? do_syscall_64+0x69/0xc0
[346278.191088] ? irqentry_exit_to_user_mode+0x9/0x20
[346278.191092] ? irqentry_exit+0x19/0x30
[346278.191095] ? exc_page_fault+0x89/0x160
[346278.191097] ? asm_exc_page_fault+0x8/0x30
[346278.191102] entry_SYSCALL_64_after_hwframe+0x44/0xae
The task was waiting for the refcount become to 1, but from the vmcore,
we found the refcount has already been 1. It seems that the task didn't
get woken up by perf_event_release_kernel() and got stuck forever. The
below scenario may cause the problem.
Thread A Thread B
... ...
perf_event_free_task perf_event_release_kernel
...
acquire event->child_mutex
...
get_ctx
... release event->child_mutex
acquire ctx->mutex
...
perf_free_event (acquire/release event->child_mutex)
...
release ctx->mutex
wait_var_event
acquire ctx->mutex
acquire event->child_mutex
# move existing events to free_list
release event->child_mutex
release ctx->mutex
put_ctx
... ...
In this case, all events of the ctx have been freed, so we couldn't
find the ctx in free_list and Thread A will miss the wakeup. It's thus
necessary to add a wakeup after dropping the reference.
Fixes: 1cf8dfe8a6 ("perf/core: Fix race between close() and fork()")
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20240513103948.33570-1-haifeng.xu@shopee.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 46ba0e49b64232adac35a2bc892f1710c5b0fb7f ]
Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.
Fix the check in uprobe_prog_run() to perform the same task->mm check.
While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.
Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.
We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.
Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade4 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2884dc7d08d98a89d8d65121524bb7533183a63a ]
After commit 1a80dbcb2dba, bpf_link can be freed by
link->ops->dealloc_deferred, but the code still tests and uses
link->ops->dealloc afterward, which leads to a use-after-free as
reported by syzbot. Actually, one of them should be sufficient, so
just call one of them instead of both. Also add a WARN_ON() in case
of any problematic implementation.
Fixes: 1a80dbcb2dba ("bpf: support deferring bpf_link dealloc to after RCU grace period")
Reported-by: syzbot+1989ee16d94720836244@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240602182703.207276-1-xiyou.wangcong@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit af66bfd3c8538ed21cf72af18426fc4a408665cf ]
When removing the inner map from the outer map, the inner map will be
freed after one RCU grace period and one RCU tasks trace grace
period, so it is certain that the bpf program, which may access the
inner map, has exited before the inner map is freed.
However there is no need to wait for one RCU tasks trace grace period if
the outer map is only accessed by non-sleepable program. So adding
sleepable_refcnt in bpf_map and increasing sleepable_refcnt when adding
the outer map into env->used_maps for sleepable program. Although the
max number of bpf program is INT_MAX - 1, the number of bpf programs
which are being loaded may be greater than INT_MAX, so using atomic64_t
instead of atomic_t for sleepable_refcnt. When removing the inner map
from the outer map, using sleepable_refcnt to decide whether or not a
RCU tasks trace grace period is needed before freeing the inner map.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 2884dc7d08d9 ("bpf: Fix a potential use-after-free in bpf_link_free()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4930b7f53a298533bc31d7540b6ea8b79a000331 ]
We will need to return ref_ctr_offsets values through link_info
interface in following change, so we need to keep them around.
Storing ref_ctr_offsets values directly into bpf_uprobe array.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20231125193130.834322-3-jolsa@kernel.org
Stable-dep-of: 2884dc7d08d9 ("bpf: Fix a potential use-after-free in bpf_link_free()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b84a8aba806261d2f759ccedf4a2a6a80a5e55ba upstream.
irq_find_at_or_after() dereferences the interrupt descriptor which is
returned by mt_find() while neither holding sparse_irq_lock nor RCU read
lock, which means the descriptor can be freed between mt_find() and the
dereference:
CPU0 CPU1
desc = mt_find()
delayed_free_desc(desc)
irq_desc_get_irq(desc)
The use-after-free is reported by KASAN:
Call trace:
irq_get_next_irq+0x58/0x84
show_stat+0x638/0x824
seq_read_iter+0x158/0x4ec
proc_reg_read_iter+0x94/0x12c
vfs_read+0x1e0/0x2c8
Freed by task 4471:
slab_free_freelist_hook+0x174/0x1e0
__kmem_cache_free+0xa4/0x1dc
kfree+0x64/0x128
irq_kobj_release+0x28/0x3c
kobject_put+0xcc/0x1e0
delayed_free_desc+0x14/0x2c
rcu_do_batch+0x214/0x720
Guard the access with a RCU read lock section.
Fixes: 721255b982 ("genirq: Use a maple tree for interrupt descriptor management")
Signed-off-by: dicken.ding <dicken.ding@mediatek.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240524091739.31611-1-dicken.ding@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c9b51ddb66b1d96e4d364c088da0f1dfb004c574 upstream.
Currently when the current line should be removed from the display
kdb_read() uses memset() to fill a temporary buffer with spaces.
The problem is not that this could be trivially implemented using a
format string rather than open coding it. The real problem is that
it is possible, on systems with a long kdb_prompt_str, to write past
the end of the tmpbuffer.
Happily, as mentioned above, this can be trivially implemented using a
format string. Make it so!
Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-5-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6244917f377bf64719551b58592a02a0336a7439 upstream.
The code that handles case 14 (down) and case 16 (up) has been copy and
pasted despite being byte-for-byte identical. Combine them.
Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-4-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db2f9c7dc29114f531df4a425d0867d01e1f1e28 upstream.
Currently, if the cursor position is not at the end of the command buffer
and the user uses the Tab-complete functions, then the console does not
leave the cursor in the correct position.
For example consider the following buffer with the cursor positioned
at the ^:
md kdb_pro 10
^
Pressing tab should result in:
md kdb_prompt_str 10
^
However this does not happen. Instead the cursor is placed at the end
(after then 10) and further cursor movement redraws incorrectly. The
same problem exists when we double-Tab but in a different part of the
code.
Fix this by sending a carriage return and then redisplaying the text to
the left of the cursor.
Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-3-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 09b35989421dfd5573f0b4683c7700a7483c71f9 upstream.
Currently when kdb_read() needs to reposition the cursor it uses copy and
paste code that works by injecting an '\0' at the cursor position before
delivering a carriage-return and reprinting the line (which stops at the
'\0').
Tidy up the code by hoisting the copy and paste code into an appropriately
named function. Additionally let's replace the '\0' injection with a
proper field width parameter so that the string will be abridged during
formatting instead.
Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Tested-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-2-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9730744bf3af04cda23799029342aa3cddbc454 upstream.
Currently, when the user attempts symbol completion with the Tab key, kdb
will use strncpy() to insert the completed symbol into the command buffer.
Unfortunately it passes the size of the source buffer rather than the
destination to strncpy() with predictably horrible results. Most obviously
if the command buffer is already full but cp, the cursor position, is in
the middle of the buffer, then we will write past the end of the supplied
buffer.
Fix this by replacing the dubious strncpy() calls with memmove()/memcpy()
calls plus explicit boundary checks to make sure we have enough space
before we start moving characters around.
Reported-by: Justin Stitt <justinstitt@google.com>
Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/
Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-1-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 upstream.
The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of
interrupt affinity reconfiguration via procfs. Instead, the change is
deferred until the next instance of the interrupt being triggered on the
original CPU.
When the interrupt next triggers on the original CPU, the new affinity is
enforced within __irq_move_irq(). A vector is allocated from the new CPU,
but the old vector on the original CPU remains and is not immediately
reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming
process is delayed until the next trigger of the interrupt on the new CPU.
Upon the subsequent triggering of the interrupt on the new CPU,
irq_complete_move() adds a task to the old CPU's vector_cleanup list if it
remains online. Subsequently, the timer on the old CPU iterates over its
vector_cleanup list, reclaiming old vectors.
However, a rare scenario arises if the old CPU is outgoing before the
interrupt triggers again on the new CPU.
In that case irq_force_complete_move() is not invoked on the outgoing CPU
to reclaim the old apicd->prev_vector because the interrupt isn't currently
affine to the outgoing CPU, and irq_needs_fixup() returns false. Even
though __vector_schedule_cleanup() is later called on the new CPU, it
doesn't reclaim apicd->prev_vector; instead, it simply resets both
apicd->move_in_progress and apicd->prev_vector to 0.
As a result, the vector remains unreclaimed in vector_matrix, leading to a
CPU vector leak.
To address this issue, move the invocation of irq_force_complete_move()
before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the
interrupt is currently or used to be affine to the outgoing CPU.
Additionally, reclaim the vector in __vector_schedule_cleanup() as well,
following a warning message, although theoretically it should never see
apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU.
Fixes: f0383c24b4 ("genirq/cpuhotplug: Add support for cleaning up move in progress")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6e58e0173507e506a5627741358bc770f220e356 ]
Commit 13e1df0928 ("kheaders: explicitly validate existence of cpio
command") added an explicit check for `cpio` using `type`.
However, `type` in `dash` (which is used in some popular distributions
and base images as the shell script runner) prints the missing message
to standard output, and thus no error is printed:
$ bash -c 'type missing >/dev/null'
bash: line 1: type: missing: not found
$ dash -c 'type missing >/dev/null'
$
For instance, this issue may be seen by loongarch builders, given its
defconfig enables CONFIG_IKHEADERS since commit 9cc1df421f00 ("LoongArch:
Update Loongson-3 default config file").
Therefore, use `command -v` instead to have consistent behavior, and
take the chance to provide a more explicit error.
Fixes: 13e1df0928 ("kheaders: explicitly validate existence of cpio command")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 98e948fb60d41447fd8d2d0c3b8637fc6b6dc26d ]
We have seen an influx of syzkaller reports where a BPF program attached to
a tracepoint triggers a locking rule violation by performing a map_delete
on a sockmap/sockhash.
We don't intend to support this artificial use scenario. Extend the
existing verifier allowed-program-type check for updating sockmap/sockhash
to also cover deleting from a map.
From now on only BPF programs which were previously allowed to update
sockmap/sockhash can delete from these map types.
Fixes: ff9105993240 ("bpf, sockmap: Prevent lock inversion deadlock in map delete elem")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com
Acked-by: John Fastabend <john.fastabend@gmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=ec941d6e24f633a59172
Link: https://lore.kernel.org/bpf/20240527-sockmap-verify-deletes-v1-1-944b372f2101@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e64746e74f717961250a155e14c156616fcd981f ]
cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark()
resulting in the following sanitizer report:
UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28
index -1 is out of range for type 'cpumask [64][1]'
CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117)
ubsan_epilogue (lib/ubsan.c:232)
__ubsan_handle_out_of_bounds (lib/ubsan.c:429)
cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline]
do_map_benchmark (kernel/dma/map_benchmark.c:104)
map_benchmark_ioctl (kernel/dma/map_benchmark.c:246)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Use cpumask_of_node() in place when binding a kernel thread to a cpuset
of a particular node.
Note that the provided node id is checked inside map_benchmark_ioctl().
It's just a NUMA_NO_NODE case which is not handled properly later.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1ff05e723f7ca30644b8ec3fb093f16312e408ad ]
While validating node ids in map_benchmark_ioctl(), node_possible() may
be provided with invalid argument outside of [0,MAX_NUMNODES-1] range
leading to:
BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971
CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117)
kasan_report (mm/kasan/report.c:603)
kasan_check_range (mm/kasan/generic.c:189)
variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline]
arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline]
_test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline]
node_state (include/linux/nodemask.h:423) [inline]
map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Compare node ids with sane bounds first. NUMA_NO_NODE is considered a
special valid case meaning that benchmarking kthreads won't be bound to a
cpuset of a given node.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bb9025f4432f8c158322cf2c04c2b492f23eb511 ]
kthread creation failure is invalidly handled inside do_map_benchmark().
The put_task_struct() calls on the error path are supposed to balance the
get_task_struct() calls which only happen after all the kthreads are
successfully created. Rollback using kthread_stop() for already created
kthreads in case of such failure.
In normal situation call kthread_stop_put() to gracefully stop kthreads
and put their task refcounts. This should be done for all started
kthreads.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6309727ef27162deabd5c095c11af24970fba5a2 ]
Add a kthread_stop_put() helper that stops a thread and puts its task
struct. Use it to replace the various instances of kthread_stop()
followed by put_task_struct().
Remove the kthread_stop_put() macro in usbip that is similar but doesn't
return the result of kthread_stop().
[agruenba@redhat.com: fix kerneldoc comment]
Link: https://lkml.kernel.org/r/20230911111730.2565537-1-agruenba@redhat.com
[akpm@linux-foundation.org: document kthread_stop_put()'s argument]
Link: https://lkml.kernel.org/r/20230907234048.2499820-1-agruenba@redhat.com
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: bb9025f4432f ("dma-mapping: benchmark: fix up kthread-related error handling")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e569eb34970281438e2b48a3ef11c87459fcfbcb ]
btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.
Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/
Fixes: c440adfbe3 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1e8b7b3dbb3103d577a586ca72bc329f7b67120b ]
The patch updates the function documentation comment for
rv_en(dis)able_monitor to adhere to the kernel-doc specification.
Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com
Fixes: 102227b970 ("rv: Add Runtime Verification (RV) interface")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b63db58e2fa5d6963db9c45df88e60060f0ff35f ]
Synthetic events create and destroy tracefs files when they are created
and removed. The tracing subsystem has its own file descriptor
representing the state of the events attached to the tracefs files.
There's a race between the eventfs files and this file descriptor of the
tracing system where the following can cause an issue:
With two scripts 'A' and 'B' doing:
Script 'A':
echo "hello int aaa" > /sys/kernel/tracing/synthetic_events
while :
do
echo 0 > /sys/kernel/tracing/events/synthetic/hello/enable
done
Script 'B':
echo > /sys/kernel/tracing/synthetic_events
Script 'A' creates a synthetic event "hello" and then just writes zero
into its enable file.
Script 'B' removes all synthetic events (including the newly created
"hello" event).
What happens is that the opening of the "enable" file has:
{
struct trace_event_file *file = inode->i_private;
int ret;
ret = tracing_check_open_get_tr(file->tr);
[..]
But deleting the events frees the "file" descriptor, and a "use after
free" happens with the dereference at "file->tr".
The file descriptor does have a reference counter, but there needs to be a
way to decrement it from the eventfs when the eventfs_inode is removed
that represents this file descriptor.
Add an optional "release" callback to the eventfs_entry array structure,
that gets called when the eventfs file is about to be removed. This allows
for the creating on the eventfs file to increment the tracing file
descriptor ref counter. When the eventfs file is deleted, it can call the
release function that will call the put function for the tracing file
descriptor.
This will protect the tracing file from being freed while a eventfs file
that references it is being opened.
Link: https://lore.kernel.org/linux-trace-kernel/20240426073410.17154-1-Tze-nan.Wu@mediatek.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240502090315.448cba46@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Tze-nan wu <Tze-nan.Wu@mediatek.com>
Tested-by: Tze-nan Wu (吳澤南) <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 49217ea147df7647cb89161b805c797487783fc0 ]
In the cgroup v2 CPU subsystem, assuming we have a
cgroup named 'test', and we set cpu.max and cpu.max.burst:
# echo 1000000 > /sys/fs/cgroup/test/cpu.max
# echo 1000000 > /sys/fs/cgroup/test/cpu.max.burst
then we check cpu.max and cpu.max.burst:
# cat /sys/fs/cgroup/test/cpu.max
1000000 100000
# cat /sys/fs/cgroup/test/cpu.max.burst
1000000
Next we set cpu.max again and check cpu.max and
cpu.max.burst:
# echo 2000000 > /sys/fs/cgroup/test/cpu.max
# cat /sys/fs/cgroup/test/cpu.max
2000000 100000
# cat /sys/fs/cgroup/test/cpu.max.burst
1000
... we find that the cpu.max.burst value changed unexpectedly.
In cpu_max_write(), the unit of the burst value returned
by tg_get_cfs_burst() is microseconds, while in cpu_max_write(),
the burst unit used for calculation should be nanoseconds,
which leads to the bug.
To fix it, get the burst value directly from tg->cfs_bandwidth.burst.
Fixes: f4183717b3 ("sched/fair: Introduce the burstable CFS controller")
Reported-by: Qixin Liao <liaoqixin@huawei.com>
Signed-off-by: Cheng Yu <serein.chengyu@huawei.com>
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240424132438.514720-1-serein.chengyu@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a1fd0b9d751f840df23ef0e75b691fc00cfd4743 ]
Change relax_domain_level checks so that it would be possible
to include or exclude all domains from newidle balancing.
This matches the behavior described in the documentation:
-1 no request. use system default or follow request of others.
0 no search.
1 search siblings (hyperthreads in a core).
"2" enables levels 0 and 1, level_max excludes the last (level_max)
level, and level_max+1 includes all levels.
Fixes: 1d3504fcf5 ("sched, cpuset: customize sched domains, core")
Signed-off-by: Vitalii Bursov <vitaly@bursov.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/bd6de28e80073c79466ec6401cdeae78f0d4423d.1714488502.git.vitaly@bursov.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bd125a084091396f3e796bb3dc009940d9771811 ]
When the ABI was updated to prevent same name w/different args, it
missed an important corner case when fields don't end with a space.
Typically, space is used for fields to help separate them, like
"u8 field1; u8 field2". If no spaces are used, like
"u8 field1;u8 field2", then the parsing works for the first time.
However, the match check fails on a subsequent register, leading to
confusion.
This is because the match check uses argv_split() and assumes that all
fields will be split upon the space. When spaces are used, we get back
{ "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }.
This causes a mismatch, and the user program gets back -EADDRINUSE.
Add a method to detect this case before calling argv_split(). If found
force a space after the field separator character ';'. This ensures all
cases work properly for matching.
With this fix, the following are all treated as matching:
u8 field1;u8 field2
u8 field1; u8 field2
u8 field1;\tu8 field2
u8 field1;\nu8 field2
Link: https://lore.kernel.org/linux-trace-kernel/20240423162338.292-2-beaub@linux.microsoft.com
Fixes: ba470eebc2 ("tracing/user_events: Prevent same name but different args event")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1e953de9e9b4ca77a9ce0fc17a0778eba3a4ca64 ]
The current code for finding and deleting events assumes that there will
never be cases when user_events are registered with the same name, but
different formats. Scenarios exist where programs want to use the same
name but have different formats. An example is multiple versions of a
program running side-by-side using the same event name, but with updated
formats in each version.
This change does not yet allow for multi-format events. If user_events
are registered with the same name but different arguments the programs
see the same return values as before. This change simply makes it
possible to easily accommodate for this.
Update find_user_event() to take in argument parameters and register
flags to accommodate future multi-format event scenarios. Have find
validate argument matching and return error pointers to cover when
an existing event has the same name but different format. Update
callers to handle error pointer logic.
Move delete_user_event() to use hash walking directly now that
find_user_event() has changed. Delete all events found that match the
register name, stop if an error occurs and report back to the user.
Update user_fields_match() to cover list_empty() scenarios now that
find_user_event() uses it directly. This makes the logic consistent
across several callsites.
Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-2-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable-dep-of: bd125a084091 ("tracing/user_events: Fix non-spaced field matching")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5dbd04eddb2c0841d1b3930e0a9944a2343c9cac ]
There are several scenarios that have come up where having a user_event
persist even if the process that registered it exits. The main one is
having a daemon create events on bootup that shouldn't get deleted if
the daemon has to exit or reload. Another is within OpenTelemetry
exporters, they wish to potentially check if a user_event exists on the
system to determine if exporting the data out should occur. The
user_event in this case must exist even in the absence of the owning
process running (such as the above daemon case).
Expose the previously internal flag USER_EVENT_REG_PERSIST to user
processes. Upon register or delete of events with this flag, ensure the
user is perfmon_capable to prevent random user processes with access to
tracefs from creating events that persist after exit.
Link: https://lkml.kernel.org/r/20230912180704.1284-2-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable-dep-of: bd125a084091 ("tracing/user_events: Fix non-spaced field matching")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d7a73e3f089204aee3393687e23fd45a22657b08 ]
Moving these stub functions to a .c file means we can kill a sched.h
dependency on printk.h.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Stable-dep-of: f9f67e5adc8d ("x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 543576ec15b17c0c93301ac8297333c7b6e84ac7 ]
bpf_prog_attach uses attach_type_to_prog_type to enforce proper
attach type for BPF_PROG_TYPE_CGROUP_SKB. link_create uses
bpf_prog_get and relies on bpf_prog_attach_check_attach_type
to properly verify prog_type <> attach_type association.
Add missing attach_type enforcement for the link_create case.
Otherwise, it's currently possible to attach cgroup_skb prog
types to other cgroup hooks.
Fixes: af6eea5743 ("bpf: Implement bpf_link-based cgroup BPF program attachment")
Link: https://lore.kernel.org/bpf/0000000000004792a90615a1dde0@google.com/
Reported-by: syzbot+838346b979830606c854@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240426231621.2716876-2-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0db63c0b86e981a1e97d2596d64ceceba1a5470e ]
The verifier assumes that 'sk' field in 'struct socket' is valid
and non-NULL when 'socket' pointer itself is trusted and non-NULL.
That may not be the case when socket was just created and
passed to LSM socket_accept hook.
Fix this verifier assumption and adjust tests.
Reported-by: Liam Wisehart <liamwisehart@meta.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 6fcd486b3a ("bpf: Refactor RCU enforcement in the verifier.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240427002544.68803-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1f2a74b41ea8b902687eb97c4e7e3f558801865b ]
r10 is a special register that is not under BPF program's control and is
always effectively precise. The rest of precision logic assumes that
only r0-r9 SCALAR registers are marked as precise, so prevent r10 from
being marked precise.
This can happen due to signed cast instruction allowing to do something
like `r0 = (s8)r10;`, which later, if r0 needs to be precise, would lead
to an attempt to mark r10 as precise.
Prevent this with an extra check during instruction backtracking.
Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Reported-by: syzbot+148110ee7cf72f39f33e@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404214536.3551295-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be3a51e68f2f1b17250ce40d8872c7645b7a2991 ]
root_domain::overutilized is only used for EAS(energy aware scheduler)
to decide whether to do load balance or not. It is not used if EAS
not possible.
Currently enqueue_task_fair and task_tick_fair accesses, sometime updates
this field. In update_sd_lb_stats it is updated often. This causes cache
contention due to true sharing and burns a lot of cycles. ::overload and
::overutilized are part of the same cacheline. Updating it often invalidates
the cacheline. That causes access to ::overload to slow down due to
false sharing. Hence add EAS check before accessing/updating this field.
EAS check is optimized at compile time or it is a static branch.
Hence it shouldn't cost much.
With the patch, both enqueue_task_fair and newidle_balance don't show
up as hot routines in perf profile.
6.8-rc4:
7.18% swapper [kernel.vmlinux] [k] enqueue_task_fair
6.78% s [kernel.vmlinux] [k] newidle_balance
+patch:
0.14% swapper [kernel.vmlinux] [k] enqueue_task_fair
0.00% swapper [kernel.vmlinux] [k] newidle_balance
While at it: trace_sched_overutilized_tp expect that second argument to
be bool. So do a int to bool conversion for that.
Fixes: 2802bf3cd9 ("sched/fair: Add over-utilization/tipping point indicator")
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240307085725.444486-2-sshegde@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3758f7d9917bd7ef0482c4184c0ad673b4c4e069 ]
The rcuc-starvation output from print_cpu_stall_info() might overflow the
buffer if there is a huge difference in jiffies difference. The situation
might seem improbable, but computers sometimes get very confused about
time, which can result in full-sized integers, and, in this case,
buffer overflow.
Also, the unsigned jiffies difference is printed using %ld, which is
normally for signed integers. This is intentional for debugging purposes,
but it is not obvious from the code.
This commit therefore changes sprintf() to snprintf() and adds a
clarifying comment about intention of %ld format.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 245a629825 ("rcu: Dump rcuc kthread status for CPUs not reporting quiescent state")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc5645fddb0ce28492b15520306d092730dffa48 ]
There is a possibility of buffer overflow in
show_rcu_tasks_trace_gp_kthread() if counters, passed
to sprintf() are huge. Counter numbers, needed for this
are unrealistically high, but buffer overflow is still
possible.
Use snprintf() with buffer size instead of sprintf().
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: edf3775f0a ("rcu-tasks: Add count for idle tasks on offline CPUs")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1dd1eff161bd55968d3d46bc36def62d71fb4785 ]
Currently, the condition "__this_cpu_read(ksoftirqd) == current" is used to
invoke rcu_softirq_qs() in ksoftirqd tasks context for non-RT kernels.
This works correctly as long as the context is actually task context but
this condition is wrong when:
- the current task is ksoftirqd
- the task is interrupted in a RCU read side critical section
- __do_softirq() is invoked on return from interrupt
Syzkaller triggered the following scenario:
-> finish_task_switch()
-> put_task_struct_rcu_user()
-> call_rcu(&task->rcu, delayed_put_task_struct)
-> __kasan_record_aux_stack()
-> pfn_valid()
-> rcu_read_lock_sched()
<interrupt>
__irq_exit_rcu()
-> __do_softirq)()
-> if (!IS_ENABLED(CONFIG_PREEMPT_RT) &&
__this_cpu_read(ksoftirqd) == current)
-> rcu_softirq_qs()
-> RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map))
The rcu quiescent state is reported in the rcu-read critical section, so
the lockdep warning is triggered.
Fix this by splitting out the inner working of __do_softirq() into a helper
function which takes an argument to distinguish between ksoftirqd task
context and interrupted context and invoke it from the relevant call sites
with the proper context information and use that for the conditional
invocation of rcu_softirq_qs().
Reported-by: syzbot+dce04ed6d1438ad69656@syzkaller.appspotmail.com
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240427102808.29356-1-qiang.zhang1211@gmail.com
Link: https://lore.kernel.org/lkml/8f281a10-b85a-4586-9586-5bbc12dc784f@paulmck-laptop/T/#mea8aba4abfcb97bbf499d169ce7f30c4cff1b0e3
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 257bf89d84121280904800acd25cc2c444c717ae ]
housekeeping_setup() checks cpumask_intersects(present, online) to ensure
that the kernel will have at least one housekeeping CPU after smp_init(),
but this doesn't work if the maxcpus= kernel parameter limits the number of
processors available after bootup.
For example, a kernel with "maxcpus=2 nohz_full=0-2" parameters crashes at
boot time on a virtual machine with 4 CPUs.
Change housekeeping_setup() to use cpumask_first_and() and check that the
returned CPU number is valid and less than setup_max_cpus.
Another corner case is "nohz_full=0" on a machine with a single CPU or with
the maxcpus=1 kernel argument. In this case non_housekeeping_mask is empty
and tick_nohz_full_setup() makes no sense. And indeed, the kernel hits the
WARN_ON(tick_nohz_full_running) in tick_sched_do_timer().
And how should the kernel interpret the "nohz_full=" parameter? It should
be silently ignored, but currently cpulist_parse() happily returns the
empty cpumask and this leads to the same problem.
Change housekeeping_setup() to check cpumask_empty(non_housekeeping_mask)
and do nothing in this case.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240413141746.GA10008@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ce0abef6a1d540acef85068e0e82bdf1fbeeb0e9 ]
Explicitly disallow enabling mitigations at runtime for kernels that were
built with CONFIG_CPU_MITIGATIONS=n, as some architectures may omit code
entirely if mitigations are disabled at compile time.
E.g. on x86, a large pile of Kconfigs are buried behind CPU_MITIGATIONS,
and trying to provide sane behavior for retroactively enabling mitigations
is extremely difficult, bordering on impossible. E.g. page table isolation
and call depth tracking require build-time support, BHI mitigations will
still be off without additional kernel parameters, etc.
[ bp: Touchups. ]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240420000556.2645001-3-seanjc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c2274b908db05529980ec056359fae916939fdaa upstream.
The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.
The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:
[ 190.271762] ------------[ cut here ]------------
[ 190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[ 190.271789] Modules linked in: [...]
[ 190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[ 190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G E 6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[ 190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[ 190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[ 190.272023] Code: [...]
[ 190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[ 190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[ 190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[ 190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[ 190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[ 190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[ 190.272053] FS: 00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[ 190.272057] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[ 190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 190.272077] Call Trace:
[ 190.272098] <TASK>
[ 190.272189] ring_buffer_resize+0x2ab/0x460
[ 190.272199] __tracing_resize_ring_buffer.part.0+0x23/0xa0
[ 190.272206] tracing_resize_ring_buffer+0x65/0x90
[ 190.272216] tracing_entries_write+0x74/0xc0
[ 190.272225] vfs_write+0xf5/0x420
[ 190.272248] ksys_write+0x67/0xe0
[ 190.272256] do_syscall_64+0x82/0x170
[ 190.272363] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 190.272373] RIP: 0033:0x7f1bd657d263
[ 190.272381] Code: [...]
[ 190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[ 190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[ 190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[ 190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[ 190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[ 190.272412] </TASK>
[ 190.272414] ---[ end trace 0000000000000000 ]---
Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab792705c
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.
The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():
ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
if (!ret)
goto spin;
for (unsigned i = 0; i < 1U << 26; i++) /* inserted delay loop */
__asm__ __volatile__ ("" : : : "memory");
rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;
.. and then run the following commands on the target system:
echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
while true; do
echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
done &
while true; do
for i in /sys/kernel/tracing/per_cpu/*; do
timeout 0.1 cat $i/trace_pipe; sleep 0.2
done
done
To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.
Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 659f451ff2 ("ring-buffer: Add integrity check at end of iter read")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
[ Fixed whitespace ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e60b613df8b6253def41215402f72986fee3fc8d upstream.
KASAN reports a bug:
BUG: KASAN: use-after-free in ftrace_location+0x90/0x120
Read of size 8 at addr ffff888141d40010 by task insmod/424
CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+
[...]
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
print_report+0xcf/0x610
kasan_report+0xb5/0xe0
ftrace_location+0x90/0x120
register_kprobe+0x14b/0xa40
kprobe_init+0x2d/0xff0 [kprobe_example]
do_one_initcall+0x8f/0x2d0
do_init_module+0x13a/0x3c0
load_module+0x3082/0x33d0
init_module_from_file+0xd2/0x130
__x64_sys_finit_module+0x306/0x440
do_syscall_64+0x68/0x140
entry_SYSCALL_64_after_hwframe+0x71/0x79
The root cause is that, in lookup_rec(), ftrace record of some address
is being searched in ftrace pages of some module, but those ftrace pages
at the same time is being freed in ftrace_release_mod() as the
corresponding module is being deleted:
CPU1 | CPU2
register_kprobes() { | delete_module() {
check_kprobe_address_safe() { |
arch_check_ftrace_location() { |
ftrace_location() { |
lookup_rec() // USE! | ftrace_release_mod() // Free!
To fix this issue:
1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();
2. Use ftrace_location_range() instead of lookup_rec() in
ftrace_location();
3. Call synchronize_rcu() before freeing any ftrace pages both in
ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().
Link: https://lore.kernel.org/linux-trace-kernel/20240509192859.1273558-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mathieu.desnoyers@efficios.com>
Fixes: ae6aa16fdc ("kprobes: introduce ftrace based optimization")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 57a01eafdcf78f6da34fad9ff075ed5dfdd9f420 upstream.
With cpu_possible_mask=0-63 and cpu_online_mask=0-7 the following
kernel oops was observed:
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 8 CPUs
Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000803
[..]
Call Trace:
arch_vcpu_is_preempted+0x12/0x80
select_idle_sibling+0x42/0x560
select_task_rq_fair+0x29a/0x3b0
try_to_wake_up+0x38e/0x6e0
kick_pool+0xa4/0x198
__queue_work.part.0+0x2bc/0x3a8
call_timer_fn+0x36/0x160
__run_timers+0x1e2/0x328
__run_timer_base+0x5a/0x88
run_timer_softirq+0x40/0x78
__do_softirq+0x118/0x388
irq_exit_rcu+0xc0/0xd8
do_ext_irq+0xae/0x168
ext_int_handler+0xbe/0xf0
psw_idle_exit+0x0/0xc
default_idle_call+0x3c/0x110
do_idle+0xd4/0x158
cpu_startup_entry+0x40/0x48
rest_init+0xc6/0xc8
start_kernel+0x3c4/0x5e0
startup_continue+0x3c/0x50
The crash is caused by calling arch_vcpu_is_preempted() for an offline
CPU. To avoid this, select the cpu with cpumask_any_and_distribute()
to mask __pod_cpumask with cpu_online_mask. In case no cpu is left in
the pool, skip the assignment.
tj: This doesn't fully fix the bug as CPUs can still go down between picking
the target CPU and the wake call. Fixing that likely requires adding
cpu_online() test to either the sched or s390 arch code. However, regardless
of how that is fixed, workqueue shouldn't be picking a CPU which isn't
online as that would result in unpredictable and worse behavior.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Fixes: 8639ecebc9 ("workqueue: Implement non-strict affinity scope for unbound workqueues")
Cc: stable@vger.kernel.org # v6.6+
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a8d89feba7e54e691ca7c4efc2a6264fa83f3687 ]
This patch adds a missing check to bloom filter creating, rejecting
values above KMALLOC_MAX_SIZE. This brings the bloom map in line with
many other map types.
The lack of this protection can cause kernel crashes for value sizes
that overflow int's. Such a crash was caught by syzkaller. The next
patch adds more guard-rails at a lower level.
Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240327024245.318299-2-andreimatei1@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 75961ffb5cb3e5196f19cae7683f35cc88b50800 ]
Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction
with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following
crash when initialising the restricted pools at boot-time:
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
| Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
| pc : rmem_swiotlb_device_init+0xfc/0x1ec
| lr : rmem_swiotlb_device_init+0xf0/0x1ec
| Call trace:
| rmem_swiotlb_device_init+0xfc/0x1ec
| of_reserved_mem_device_init_by_idx+0x18c/0x238
| of_dma_configure_id+0x31c/0x33c
| platform_dma_configure+0x34/0x80
faddr2line reveals that the crash is in the list validation code:
include/linux/list.h:83
include/linux/rculist.h:79
include/linux/rculist.h:106
kernel/dma/swiotlb.c:306
kernel/dma/swiotlb.c:1695
because add_mem_pool() is trying to list_add_rcu() to a NULL
'mem->pools'.
Fix the crash by initialising the 'mem->pools' list_head in
rmem_swiotlb_device_init() before calling add_mem_pool().
Reported-by: Nikita Ioffe <ioffe@google.com>
Tested-by: Nikita Ioffe <ioffe@google.com>
Fixes: 1aaa736815 ("swiotlb: allocate a new memory pool when existing pools are full")
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 37eacb9f6e89fb399a79e952bc9c78eb3e16290e ]
Long ago a map file descriptor in a pseudo ldimm64 instruction could
only be present as an immediate value insn[0].imm, and thus this value
was used in a verbose verifier message printed when the file descriptor
wasn't valid. Since addition of BPF_PSEUDO_MAP_IDX_VALUE/BPF_PSEUDO_MAP_IDX
the insn[0].imm field can also contain an index pointing to the file
descriptor in the attr.fd_array array. However, if the file descriptor
is invalid, the verifier still prints the verbose message containing
value of insn[0].imm. Patch the verifier message to always print the
actual file descriptor value.
Fixes: 387544bfa2 ("bpf: Introduce fd_idx")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240412141100.3562942-1-aspsk@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5af385f5f4cddf908f663974847a4083b2ff2c79 upstream.
bits_per() rounds up to the next power of two when passed a power of
two. This causes crashes on some machines and configurations.
Reported-by: Михаил Новоселов <m.novosyolov@rosalinux.ru>
Tested-by: Ильфат Гаптрахманов <i.gaptrakhmanov@rosalinux.ru>
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3347
Link: https://lore.kernel.org/all/1c978cf1-2934-4e66-e4b3-e81b04cb3571@rosalinux.ru/
Fixes: f2d5dcb48f7b (bounds: support non-power-of-two CONFIG_NR_CPUS)
Cc: <stable@vger.kernel.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1560d1f6eb6b398bddd80c16676776c0325fe5fe ]
It was possible to have pick_eevdf() return NULL, which then causes a
NULL-deref. This turned out to be due to entity_eligible() returning
falsely negative because of a s64 multiplcation overflow.
Specifically, reweight_eevdf() computes the vlag without considering
the limit placed upon vlag as update_entity_lag() does, and then the
scaling multiplication (remember that weight is 20bit fixed point) can
overflow. This then leads to the new vruntime being weird which then
causes the above entity_eligible() to go side-ways and claim nothing
is eligible.
Thus limit the range of vlag accordingly.
All this was quite rare, but fatal when it does happen.
Closes: https://lore.kernel.org/all/ZhuYyrh3mweP_Kd8@nz.home/
Closes: https://lore.kernel.org/all/CA+9S74ih+45M_2TPUY_mPPVDhNvyYfy1J1ftSix+KjiTVxg8nw@mail.gmail.com/
Closes: https://lore.kernel.org/lkml/202401301012.2ed95df0-oliver.sang@intel.com/
Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Reported-by: Sergei Trofimovich <slyich@gmail.com>
Reported-by: Igor Raits <igor@gooddata.com>
Reported-by: Breno Leitao <leitao@debian.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-and-tested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240422082238.5784-1-xuewen.yan@unisoc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit afae8002b4fd3560c8f5f1567f3c3202c30a70fa ]
reweight_eevdf() only keeps V unchanged inside itself. When se !=
cfs_rq->curr, it would be dequeued from rb tree first. So that V is
changed and the result is wrong. Pass the original V to reweight_eevdf()
to fix this issue.
Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
[peterz: flip if() condition for clarity]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Abel Wu <wuyun.abel@bytedance.com>
Link: https://lkml.kernel.org/r/20240306022133.81008-3-dtcccc@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 11b1b8bc2b98e21ddf47e08b56c21502c685b2c3 ]
reweight_eevdf() needs the latest V to do accurate calculation for new
ve and vd. So update V unconditionally when se is runnable.
Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Suggested-by: Abel Wu <wuyun.abel@bytedance.com>
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Abel Wu <wuyun.abel@bytedance.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Link: https://lore.kernel.org/r/20240306022133.81008-2-dtcccc@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d99e3140a4d33e26066183ff727d8f02f56bec64 upstream.
The current folio_test_hugetlb() can be fooled by a concurrent folio split
into returning true for a folio which has never belonged to hugetlbfs.
This can't happen if the caller holds a refcount on it, but we have a few
places (memory-failure, compaction, procfs) which do not and should not
take a speculative reference.
Since hugetlb pages do not use individual page mapcounts (they are always
fully mapped and use the entire_mapcount field to record the number of
mappings), the PageType field is available now that page_mapcount()
ignores the value in this field.
In compaction and with CONFIG_DEBUG_VM enabled, the current implementation
can result in an oops, as reported by Luis. This happens since 9c5ccf2db0
("mm: remove HUGETLB_PAGE_DTOR") effectively added some VM_BUG_ON() checks
in the PageHuge() testing path.
[willy@infradead.org: update vmcoreinfo]
Link: https://lkml.kernel.org/r/ZgGZUvsdhaT1Va-T@casper.infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-6-willy@infradead.org
Fixes: 9c5ccf2db0 ("mm: remove HUGETLB_PAGE_DTOR")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218227
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fe42754b94a42d08cf9501790afc25c4f6a5f631 upstream.
Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it
on for all architectures exception x86. A recent commit to turn
mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta
missed that "cpu_mitigations" is completely generic, whereas
SPECULATION_MITIGATIONS is x86-specific.
Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it
select CPU_MITIGATIONS, as having two configs for the same thing is
unnecessary and confusing. This will also allow x86 to use the knob to
manage mitigations that aren't strictly related to speculative
execution.
Use another Kconfig to communicate to common code that CPU_MITIGATIONS
is already defined instead of having x86's menu depend on the common
CPU_MITIGATIONS. This allows keeping a single point of contact for all
of x86's mitigations, and it's not clear that other architectures *want*
to allow disabling mitigations at compile-time.
Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 35e351780fa9d8240dd6f7e4f245f9ea37e96c19 upstream.
Thorvald reported a WARNING [1]. And the root cause is below race:
CPU 1 CPU 2
fork hugetlbfs_fallocate
dup_mmap hugetlbfs_punch_hole
i_mmap_lock_write(mapping);
vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree.
i_mmap_unlock_write(mapping);
hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem!
i_mmap_lock_write(mapping);
hugetlb_vmdelete_list
vma_interval_tree_foreach
hugetlb_vma_trylock_write -- Vma_lock is cleared.
tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem!
hugetlb_vma_unlock_write -- Vma_lock is assigned!!!
i_mmap_unlock_write(mapping);
hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside
i_mmap_rwsem lock while vma lock can be used in the same time. Fix this
by deferring linking file vma until vma is fully initialized. Those vmas
should be initialized first before they can be used.
Link: https://lkml.kernel.org/r/20240410091441.3539905-1-linmiaohe@huawei.com
Fixes: 8d9bfb2608 ("hugetlb: add vma based lock for pmd sharing")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reported-by: Thorvald Natvig <thorvald@google.com>
Closes: https://lore.kernel.org/linux-mm/20240129161735.6gmjsswx62o4pbja@revolver/T/ [1]
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fd37721803c6e73619108f76ad2e12a9aa5fafaf ]
NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.
NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.
[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: b6976f323a86 ("drm/ttm: stop pooling cached NUMA pages v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fe90f3967bdb3e13f133e5f44025e15f943a99c5 upstream.
Many architectures' switch_mm() (e.g. arm64) do not have an smp_mb()
which the core scheduler code has depended upon since commit:
commit 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
If switch_mm() doesn't call smp_mb(), sched_mm_cid_remote_clear() can
unset the actively used cid when it fails to observe active task after it
sets lazy_put.
There *is* a memory barrier between storing to rq->curr and _return to
userspace_ (as required by membarrier), but the rseq mm_cid has stricter
requirements: the barrier needs to be issued between store to rq->curr
and switch_mm_cid(), which happens earlier than:
- spin_unlock(),
- switch_to().
So it's fine when the architecture switch_mm() happens to have that
barrier already, but less so when the architecture only provides the
full barrier in switch_to() or spin_unlock().
It is a bug in the rseq switch_mm_cid() implementation. All architectures
that don't have memory barriers in switch_mm(), but rather have the full
barrier either in finish_lock_switch() or switch_to() have them too late
for the needs of switch_mm_cid().
Introduce a new smp_mb__after_switch_mm(), defined as smp_mb() in the
generic barrier.h header, and use it in switch_mm_cid() for scheduler
transitions where switch_mm() is expected to provide a memory barrier.
Architectures can override smp_mb__after_switch_mm() if their
switch_mm() implementation provides an implicit memory barrier.
Override it with a no-op on x86 which implicitly provide this memory
barrier by writing to CR3.
Fixes: 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
Reported-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> # for arm64
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> # for x86
Cc: <stable@vger.kernel.org> # 6.4.x
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240415152114.59122-2-mathieu.desnoyers@efficios.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f337a6a21e2fd67eadea471e93d05dd37baaa9be upstream.
Initialize cpu_mitigations to CPU_MITIGATIONS_OFF if the kernel is built
with CONFIG_SPECULATION_MITIGATIONS=n, as the help text quite clearly
states that disabling SPECULATION_MITIGATIONS is supposed to turn off all
mitigations by default.
│ If you say N, all mitigations will be disabled. You really
│ should know what you are doing to say so.
As is, the kernel still defaults to CPU_MITIGATIONS_AUTO, which results in
some mitigations being enabled in spite of SPECULATION_MITIGATIONS=n.
Fixes: f43b9876e8 ("x86/retbleed: Add fine grained Kconfig knobs")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Cc: stable@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240409175108.1512861-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 325f3fb551f8cd672dbbfc4cf58b14f9ee3fc9e8 upstream.
When unloading a module, its state is changing MODULE_STATE_LIVE ->
MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take
a time. `is_module_text_address()` and `__module_text_address()`
works with MODULE_STATE_LIVE and MODULE_STATE_GOING.
If we use `is_module_text_address()` and `__module_text_address()`
separately, there is a chance that the first one is succeeded but the
next one is failed because module->state becomes MODULE_STATE_UNFORMED
between those operations.
In `check_kprobe_address_safe()`, if the second `__module_text_address()`
is failed, that is ignored because it expected a kernel_text address.
But it may have failed simply because module->state has been changed
to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify
non-exist module text address (use-after-free).
To fix this problem, we should not use separated `is_module_text_address()`
and `__module_text_address()`, but use only `__module_text_address()`
once and do `try_module_get(module)` which is only available with
MODULE_STATE_LIVE.
Link: https://lore.kernel.org/all/20240410015802.265220-1-zhengyejian1@huawei.com/
Fixes: 28f6c37a29 ("kprobes: Forbid probing on trampoline and BPF code areas")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3c89a068bfd0698a5478f4cf39493595ef757d5e upstream.
s2idle works like a regular suspend with freezing processes and freezing
devices. All CPUs except the control CPU go into idle. Once this is
completed the control CPU kicks all other CPUs out of idle, so that they
reenter the idle loop and then enter s2idle state. The control CPU then
issues an swait() on the suspend state and therefore enters the idle loop
as well.
Due to being kicked out of idle, the other CPUs leave their NOHZ states,
which means the tick is active and the corresponding hrtimer is programmed
to the next jiffie.
On entering s2idle the CPUs shut down their local clockevent device to
prevent wakeups. The last CPU which enters s2idle shuts down its local
clockevent and freezes timekeeping.
On resume, one of the CPUs receives the wakeup interrupt, unfreezes
timekeeping and its local clockevent and starts the resume process. At that
point all other CPUs are still in s2idle with their clockevents switched
off. They only resume when they are kicked by another CPU or after resuming
devices and then receiving a device interrupt.
That means there is no guarantee that all CPUs will wakeup directly on
resume. As a consequence there is no guarantee that timers which are queued
on those CPUs and should expire directly after resume, are handled. Also
timer list timers which are remotely queued to one of those CPUs after
resume will not result in a reprogramming IPI as the tick is
active. Queueing a hrtimer will also not result in a reprogramming IPI
because the first hrtimer event is already in the past.
The recent introduction of the timer pull model (7ee988770326 ("timers:
Implement the hierarchical pull model")) amplifies this problem, if the
current migrator is one of the non woken up CPUs. When a non pinned timer
list timer is queued and the queuing CPU goes idle, it relies on the still
suspended migrator CPU to expire the timer which will happen by chance.
The problem exists since commit 8d89835b04 ("PM: suspend: Do not pause
cpuidle in the suspend-to-idle path"). There the cpuidle_pause() call which
in turn invoked a wakeup for all idle CPUs was moved to a later point in
the resume process. This might not be reached or reached very late because
it waits on a timer of a still suspended CPU.
Address this by kicking all CPUs out of idle after the control CPU returns
from swait() so that they resume their timers and restore consistent system
state.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218641
Fixes: 8d89835b04 ("PM: suspend: Do not pause cpuidle in the suspend-to-idle path")
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: 5.16+ <stable@kernel.org> # 5.16+
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ffe3986fece696cf65e0ef99e74c75f848be8e30 upstream.
The "buffer_percent" logic that is used by the ring buffer splice code to
only wake up the tasks when there's no data after the buffer is filled to
the percentage of the "buffer_percent" file is dependent on three
variables that determine the amount of data that is in the ring buffer:
1) pages_read - incremented whenever a new sub-buffer is consumed
2) pages_lost - incremented every time a writer overwrites a sub-buffer
3) pages_touched - incremented when a write goes to a new sub-buffer
The percentage is the calculation of:
(pages_touched - (pages_lost + pages_read)) / nr_pages
Basically, the amount of data is the total number of sub-bufs that have been
touched, minus the number of sub-bufs lost and sub-bufs consumed. This is
divided by the total count to give the buffer percentage. When the
percentage is greater than the value in the "buffer_percent" file, it
wakes up splice readers waiting for that amount.
It was observed that over time, the amount read from the splice was
constantly decreasing the longer the trace was running. That is, if one
asked for 60%, it would read over 60% when it first starts tracing, but
then it would be woken up at under 60% and would slowly decrease the
amount of data read after being woken up, where the amount becomes much
less than the buffer percent.
This was due to an accounting of the pages_touched incrementation. This
value is incremented whenever a writer transfers to a new sub-buffer. But
the place where it was incremented was incorrect. If a writer overflowed
the current sub-buffer it would go to the next one. If it gets preempted
by an interrupt at that time, and the interrupt performs a trace, it too
will end up going to the next sub-buffer. But only one should increment
the counter. Unfortunately, that was not the case.
Change the cmpxchg() that does the real switch of the tail-page into a
try_cmpxchg(), and on success, perform the increment of pages_touched. This
will only increment the counter once for when the writer moves to a new
sub-buffer, and not when there's a race and is incremented for when a
writer and its preempting writer both move to the same new sub-buffer.
Link: https://lore.kernel.org/linux-trace-kernel/20240409151309.0d0e5056@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f1e30cb6369251c03f63c564006f96a54197dcc4 ]
In function ring_buffer_iter_empty(), cpu_buffer->commit_page is read
while other threads may change it. It may cause the time_stamp that read
in the next line come from a different page. Use READ_ONCE() to avoid
having to reason about compiler optimizations now and in future.
Link: https://lore.kernel.org/linux-trace-kernel/tencent_DFF7D3561A0686B5E8FC079150A02505180A@qq.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b9fa16949d18e06bdf728a560f5c8af56d2bdcaf ]
On TDX it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
DMA could free decrypted/shared pages if dma_set_decrypted() fails. This
should be a rare case. Just leak the pages in this case instead of
freeing them.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d988d9a9b9d180bfd5c1d353b3b176cb90d6861b ]
If the kernel crashes in a context where printk() calls always
defer printing (such as in NMI or inside a printk_safe section)
then the final panic messages will be deferred to irq_work. But
if irq_work is not available, the messages will not get printed
unless explicitly flushed. The result is that the final
"end Kernel panic" banner does not get printed.
Add one final flush after the last printk() call to make sure
the final panic messages make it out as well.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0ab7cdd00491b532591ef065be706301de7e448f ]
Currently @suppress_panic_printk is checked along with
non-matching @panic_cpu and current CPU. This works
because @suppress_panic_printk is only set when
panic_in_progress() is true.
Rather than relying on the @suppress_panic_printk semantics,
use the concise helper function other_cpu_in_progress(). The
helper function exists to avoid open coding such tests.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-7-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce upstream.
BPF link for some program types is passed as a "context" which can be
used by those BPF programs to look up additional information. E.g., for
multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values.
Because of this runtime dependency, when bpf_link refcnt drops to zero
there could still be active BPF programs running accessing link data.
This patch adds generic support to defer bpf_link dealloc callback to
after RCU GP, if requested. This is done by exposing two different
deallocation callbacks, one synchronous and one deferred. If deferred
one is provided, bpf_link_free() will schedule dealloc_deferred()
callback to happen after RCU GP.
BPF is using two flavors of RCU: "classic" non-sleepable one and RCU
tasks trace one. The latter is used when sleepable BPF programs are
used. bpf_link_free() accommodates that by checking underlying BPF
program's sleepable flag, and goes either through normal RCU GP only for
non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP
(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF
program is sleepable.
We use this for multi-kprobe and multi-uprobe links, which dereference
link during program run. We also preventively switch raw_tp link to use
deferred dealloc callback, as upcoming changes in bpf-next tree expose
raw_tp link data (specifically, cookie value) to BPF program at runtime
as well.
Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com
Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com
Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9c856cabefb71d47b2eeb197f72c9c88e9b45b0 upstream.
There is no need to delay putting either path or task to deallocation
step. It can be done right after bpf_uprobe_unregister. Between release
and dealloc, there could be still some running BPF programs, but they
don't access either task or path, only data in link->uprobes, so it is
safe to do.
On the other hand, doing path_put() in dealloc callback makes this
dealloc sleepable because path_put() itself might sleep. Which is
problematic due to the need to call uprobe's dealloc through call_rcu(),
which is what is done in the next bug fix patch. So solve the problem by
releasing these resources early.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ecc6a2101840177e57c925c102d2d29f260d37c8 ]
This patch re-introduces protection against the size of access to stack
memory being negative; the access size can appear negative as a result
of overflowing its signed int representation. This should not actually
happen, as there are other protections along the way, but we should
protect against it anyway. One code path was missing such protections
(fixed in the previous patch in the series), causing out-of-bounds array
accesses in check_stack_range_initialized(). This patch causes the
verification of a program with such a non-sensical access size to fail.
This check used to exist in a more indirect way, but was inadvertendly
removed in a833a17aeac7.
Fixes: a833a17aeac7 ("bpf: Fix verification of indirect var-off stack access")
Reported-by: syzbot+33f4297b5f927648741a@syzkaller.appspotmail.com
Reported-by: syzbot+aafd0513053a1cbf52ef@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/CAADnVQLORV5PT0iTAhRER+iLBTkByCYNBYyvBSgjN1T31K+gOw@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Link: https://lore.kernel.org/r/20240327024245.318299-3-andreimatei1@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d5aad4c2ca057e760a92a9a7d65bd38d72963f27 upstream.
Patch series "ARM: prctl: Reject PR_SET_MDWE where not supported".
I noticed after a recent kernel update that my ARM926 system started
segfaulting on any execve() after calling prctl(PR_SET_MDWE). After some
investigation it appears that ARMv5 is incapable of providing the
appropriate protections for MDWE, since any readable memory is also
implicitly executable.
The prctl_set_mdwe() function already had some special-case logic added
disabling it on PARISC (commit 793838138c15, "prctl: Disable
prctl(PR_SET_MDWE) on parisc"); this patch series (1) generalizes that
check to use an arch_*() function, and (2) adds a corresponding override
for ARM to disable MDWE on pre-ARMv6 CPUs.
With the series applied, prctl(PR_SET_MDWE) is rejected on ARMv5 and
subsequent execve() calls (as well as mmap(PROT_READ|PROT_WRITE)) can
succeed instead of unconditionally failing; on ARMv6 the prctl works as it
did previously.
[0] https://lore.kernel.org/all/2023112456-linked-nape-bf19@gregkh/
This patch (of 2):
There exist systems other than PARISC where MDWE may not be feasible to
support; rather than cluttering up the generic code with additional
arch-specific logic let's add a generic function for checking MDWE support
and allow each arch to override it as needed.
Link: https://lkml.kernel.org/r/20240227013546.15769-4-zev@bewilderbeest.net
Link: https://lkml.kernel.org/r/20240227013546.15769-5-zev@bewilderbeest.net
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Acked-by: Helge Deller <deller@gmx.de> [parisc]
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Florent Revest <revest@chromium.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Sam James <sam@gentoo.org>
Cc: Stefan Roesch <shr@devkernel.io>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: <stable@vger.kernel.org> [6.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Paul E. McKenney