When a top-level migrator is deactivated, either at CPU down hotplug time
or when a CPU is domain isolated, a new migrator is elected among the
available CPUs and woken up to take over the migration duty.
However that election must happen at the scope of a given hierarchy and not
globally, which the introduction of per-capacity hierarchies failed to
handle.
As a result a given hierarchy may end up without migrator to handle global
timers.
Fix it by making sure that the new migrator belongs to the same hierarchy
as the outgoing CPU.
Fixes: 098cbaad8e ("timers/migration: Split per-capacity hierarchies")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260519220926.63437-2-frederic@kernel.org
The dyntick-idle steal time is currently accounted when the tick restarts
but the stolen idle time is not subtracted from the idle time that was
already accounted. This is to avoid observing the idle time going backward
as the dyntick-idle cputime accessors can't reliably know in advance the
stolen idle time.
In order to maintain a forward progressing idle cputime while subtracting
idle steal time from it, keep track of the previously accounted idle stolen
time and substract it from _later_ idle cputime accounting.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-16-frederic@kernel.org
The dyntick-idle cputime accounting always assumes that interrupt time
accounting is enabled and consequently stops elapsing the idle time during
dyntick-idle interrupts.
This doesn't mix up well with disabled interrupt time accounting because
then idle interrupts become a cputime blind-spot. Also this feature is
disabled on most configurations and the overhead of pausing dyntick-idle
accounting while in idle interrupts could then be avoided.
Fix the situation with conditionally pausing dyntick-idle accounting during
idle interrupts only iff either native vtime (which does interrupt time
accounting) or generic interrupt time accounting are enabled.
Also make sure that the accumulated interrupt time is not accidentally
substracted from later accounting.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-15-frederic@kernel.org
The last reason why get_cpu_idle/iowait_time_us() may return -1 now is if
the config doesn't support nohz.
The ad-hoc replacement solution by cpufreq is to compute jiffies minus the
whole busy cputime. Although the intention should provide a coherent low
resolution estimation of the idle and iowait time, the implementation is
buggy because jiffies don't start at 0.
Just provide instead a real get_cpu_[idle|iowait]_time_us() offcase.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-14-frederic@kernel.org
Fetching the idle cputime is available through a variety of accessors all
over the place depending on the different accounting flavours and needs:
- idle vtime generic accounting can be accessed by kcpustat_field(),
kcpustat_cpu_fetch(), get_idle/iowait_time() and
get_cpu_idle/iowait_time_us()
- dynticks-idle accounting can only be accessed by get_idle/iowait_time()
or get_cpu_idle/iowait_time_us()
- CONFIG_NO_HZ_COMMON=n idle accounting can be accessed by kcpustat_field()
kcpustat_cpu_fetch(), or get_idle/iowait_time() but not by
get_cpu_idle/iowait_time_us()
Moreover get_idle/iowait_time() relies on get_cpu_idle/iowait_time_us()
with a non-sensical conversion to microseconds and back to nanoseconds on
the way.
Start consolidating the APIs with removing get_idle/iowait_time() and make
kcpustat_field() and kcpustat_cpu_fetch() work for all cases.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-13-frederic@kernel.org
There is no real point in switching to dyntick-idle cputime accounting mode
if the tick is not actually stopped. This just adds overhead, notably
fetching the GTOD, on each idle exit and each idle IRQ entry for no reason
during short idle trips.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-12-frederic@kernel.org
Although the dynticks-idle cputime accounting is necessarily tied to the
tick subsystem, the actual related accounting code has no business residing
there and should be part of the scheduler cputime code.
Move away the relevant pieces and state machine to where they belong.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-10-frederic@kernel.org
Even when nohz is not runtime enabled, the dynticks idle cputime accounting
can run and the common idle cputime accessors are still relevant.
Remove the nohz disabled special case accordingly.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-9-frederic@kernel.org
The non-vtime dynticks-idle cputime accounting is a big mess that
accumulates within two concurrent statistics, each having their own
shortcomings:
* The accounting for online CPUs which is based on the delta between
tick_nohz_start_idle() and tick_nohz_stop_idle().
Pros:
- Works when the tick is off
- Has nsecs granularity
Cons:
- Account idle steal time but doesn't substract it from idle
cputime.
- Assumes CONFIG_IRQ_TIME_ACCOUNTING by not accounting IRQs but
the IRQ time is simply ignored when
CONFIG_IRQ_TIME_ACCOUNTING=n
- The windows between 1) idle task scheduling and the first call
to tick_nohz_start_idle() and 2) idle task between the last
tick_nohz_stop_idle() and the rest of the idle time are
blindspots wrt. cputime accounting (though mostly insignificant
amount)
- Relies on private fields outside of kernel stats, with specific
accessors.
* The accounting for offline CPUs which is based on ticks and the
jiffies delta during which the tick was stopped.
Pros:
- Handles steal time correctly
- Handle CONFIG_IRQ_TIME_ACCOUNTING=y and
CONFIG_IRQ_TIME_ACCOUNTING=n correctly.
- Handles the whole idle task
- Accounts directly to kernel stats, without midlayer accumulator.
Cons:
- Doesn't elapse when the tick is off, which doesn't make it
suitable for online CPUs.
- Has TICK_NSEC granularity (jiffies)
- Needs to track the dyntick-idle ticks that were accounted and
substract them from the total jiffies time spent while the tick
was stopped. This is an ugly workaround.
Having two different accounting for a single context is not the only
problem: since those accountings are of different natures, it is
possible to observe the global idle time going backward after a CPU goes
offline.
Clean up the situation with introducing a hybrid approach that stays
coherent and works for both online and offline CPUs:
* Tick based or native vtime accounting operate before the idle loop
is entered and resume once the idle loop prepares to exit.
* When the idle loop starts, switch to dynticks-idle accounting as is
done currently, except that the statistics accumulate directly to the
relevant kernel stat fields.
* Private dyntick cputime accounting fields are removed.
* Works on both online and offline case.
Further improvement will include:
* Only switch to dynticks-idle cputime accounting when the tick actually
goes in dynticks mode.
* Handle CONFIG_IRQ_TIME_ACCOUNTING=n correctly such that the
dynticks-idle accounting still elapses while on IRQs.
* Correctly substract idle steal cputime from idle time
Reported-by: Xin Zhao <jackzxcui1989@163.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-8-frederic@kernel.org
Currently the tick subsystem stores the idle cputime accounting in private
fields, allowing cohabitation with architecture idle vtime accounting. The
former is fetched on online CPUs, the latter on offline CPUs.
For consolidation purposes, architecture vtime accounting will continue to
account the cputime but will make a break when the idle tick is
stopped. The dyntick cputime accounting will then be relayed by the tick
subsystem so that the idle cputime is still seen advancing coherently even
when the tick isn't there to flush the idle vtime.
Prepare for that and introduce three new APIs which will be used in
subsequent patches:
- vtime_dynticks_start() is deemed to be called when idle enters in
dyntick mode. The idle cputime that elapsed so far is accumulated
and accounted. Also idle time accounting is ignored.
- vtime_dynticks_stop() is deemed to be called when idle exits from
dyntick mode. The vtime entry clocks are fast-forward to current time
so that idle accounting restarts elapsing from now. Also idle time
accounting is resumed.
- vtime_reset() is deemed to be called from dynticks idle IRQ entry to
fast-forward the clock to current time so that the IRQ time is still
accounted by vtime while nohz cputime is paused.
Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid
accounting twice the idle cputime, along with nohz accounting.
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-7-frederic@kernel.org
Currently the tick subsystem stores the idle cputime accounting in
private fields, allowing cohabitation with architecture idle vtime
accounting. The former is fetched on online CPUs, the latter on offline
CPUs.
For consolidation purpose, architecture vtime accounting will continue
to account the cputime but will make a break when the idle tick is
stopped. The dyntick cputime accounting will then be relayed by the tick
subsystem so that the idle cputime is still seen advancing coherently
even when the tick isn't there to flush the idle vtime.
Prepare for that and introduce three new APIs which will be used in
subsequent patches:
- vtime_dynticks_start() is deemed to be called when idle enters in
dyntick mode. The idle cputime that elapsed so far is accumulated.
- vtime_dynticks_stop() is deemed to be called when idle exits from
dyntick mode. The vtime entry clocks are fast-forward to current time
so that idle accounting restarts elapsing from now.
- vtime_reset() is deemed to be called from dynticks idle IRQ entry to
fast-forward the clock to current time so that the IRQ time is still
accounted by vtime while nohz cputime is paused.
Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid
accounting twice the idle cputime, along with nohz accounting.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-6-frederic@kernel.org
Currently whether generic vtime is running or not, the idle cputime is
fetched from the nohz accounting.
However generic vtime already does its own idle cputime accounting. Only
the kernel stat accessors are not plugged to support it.
Read the idle generic vtime cputime when it's running, this will allow to
later more clearly split nohz and vtime cputime accounting.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-5-frederic@kernel.org
The first parameter to kcpustat_field() is a pointer to the cpu kcpustat to
be fetched from. This parameter is error prone because a copy to a kcpustat
could be passed by accident instead of the original one. Also the kcpustat
structure can already be retrieved with the help of the mandatory CPU
argument.
Remove the needless parameter.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-4-frederic@kernel.org
Offline handling happens from within the inner idle loop, after the
beginning of dyntick cputime accounting, nohz idle load balancing and
TIF_NEED_RESCHED polling.
This is not necessary and even buggy because:
* There is no dyntick handling to do. And calling tick_nohz_idle_enter()
messes up with the struct tick_sched reset that was performed on
tick_sched_timer_dying().
* There is no nohz idle balancing to do.
* Polling on TIF_RESCHED is irrelevant at this stage, there are no more
tasks allowed to run.
* No need to check if need_resched() before offline handling since
stop_machine is done and all per-cpu kthread should be done with
their job.
Therefore move the offline handling at the beginning of the idle loop.
This will also ease the idle cputime unification later by not elapsing
idle time while offline through the call to:
tick_nohz_idle_enter() -> tick_nohz_start_idle()
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-3-frederic@kernel.org
When the nohz idle time is fetched, the current clock timestamp is taken
outside the seqcount, which can result in a race as reported by Sashiko:
get_cpu_sleep_time_us() tick_nohz_start_idle()
----------------------- ---------------------
now = ktime_get()
write_seqcount_begin(idle_sleeptime_seq);
idle_entrytime = ktime_get()
tick_sched_flag_set(ts, TS_FLAG_IDLE_ACTIVE);
write_seqcount_end(&ts->idle_sleeptime_seq);
read_seqcount_begin(idle_sleeptime_seq)
delta = now - idle_entrytime);
//!! But now < idle_entrytime
idle = *sleeptime + delta;
read_seqcount_retry(&ts->idle_sleeptime_seq, seq)
Here the read side fetches the timestamp before the write side and its
update. As a result the time delta computed on the read side is negative
(ktime_t is signed) and breaks the cputime monotonicity guarantee.
This could possibly be fixed with reading the current clock timestamp
inside the seqcount but the reader overhead might then increase. Also
simply checking that the current timestamp is above the idle entry time
is enough to prevent any issue of the like.
Fixes: 620a30fa0b ("timers/nohz: Protect idle/iowait sleep time under seqcount")
Reported-by: Sashiko
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260508131647.43868-2-frederic@kernel.org
The receive-side GARP attribute parser computes dlen with reversed
operands:
dlen = sizeof(*ga) - ga->len;
ga->len is the on-wire attribute length and includes the GARP attribute
header. For normal attributes with data, ga->len is larger than
sizeof(*ga), so the subtraction underflows in unsigned arithmetic.
The resulting value is later passed to garp_attr_lookup(), whose length
argument is u8. After truncation, the parsed data length usually no
longer matches the length stored for locally registered attributes, so
received Join/Leave events are ignored. This breaks the GARP receive path
for common attributes, such as GVRP VLAN registration attributes.
Compute the data length as the attribute length minus the header length.
Fixes: eca9ebac65 ("net: Add GARP applicant-only participant")
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260527083200.42861-1-zhaoyz24@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The validation check uses '>' instead of '>=' when comparing tv_usec
against USEC_PER_SEC, allowing the value 1000000 through. After
conversion to nanoseconds (*= 1000), this produces tv_nsec ==
NSEC_PER_SEC, violating the timespec invariant that tv_nsec must be
less than NSEC_PER_SEC.
Use '>=' to reject tv_usec values that are not in the valid range of
0 to 999999.
Fixes: 5e0fb1b57b ("y2038: time: avoid timespec usage in settimeofday()")
Signed-off-by: Naveen Kumar Chaudhary <naveen.osdev@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/4rikk44zew3s6577dugmx4jyblz7o5c57niuap6ct3td5yfm6w@gh7pcumg7qor
The stub for arch_inlined_clockevent_set_next_coupled() has 'u64 u64
cycles' in its parameter list. Since u64 is a typedef, the compiler
parses the second 'u64' as the parameter name, making 'cycles' an
unused token. Remove the duplicate so the parameter is correctly named.
Fixes: 89f951a1e8 ("clockevents: Provide support for clocksource coupled comparators")
Signed-off-by: Naveen Kumar Chaudhary <naveen.osdev@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/7tostpvxzdn6tobmyow63a5rweatls5kux3scqp2vzhe7mv6uq@ecr746b4hyhf
Switch over the ACPI button driver to devres-based resource management
by making the following changes:
* Use devm_kzalloc() for allocating button object memory.
* Use devm_input_allocate_device() for allocating the input class
device object.
* Turn acpi_lid_remove_fs() into a devm cleanup action added
by devm_acpi_lid_add_fs() which is a new wrapper around
acpi_lid_add_fs().
* Add devm_acpi_button_init_wakeup() for initializing the wakeup source
and make it add a custom devm action that will automatically remove
the wakeup source registered by it.
* Turn acpi_button_remove_event_handler() into a devm cleanup action
added by devm_acpi_button_add_event_handler() which is a new wrapper
around acpi_button_add_event_handler().
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2283436.Mh6RI2rZIc@rafael.j.wysocki
[ rjw: Rebased and removed unnecessary input device parent assignment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To facilitate subsequent changes, move the code installing and
removing button event handlers into two separate functions called
acpi_button_add_event_handler() and acpi_button_remove_event_handler(),
respectively, and rearrange it to reduce code duplication.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2714170.Lt9SDvczpP@rafael.j.wysocki
Instead of storing strings that never change later under
acpi_device_class(device) and using them for generating netlink
messages, use pointers to string literals with the same content.
This also allows the clearing of the acpi_device_class(device)
area during driver removal and in the probe rollback path to be
dropped.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2070791.usQuhbGJ8B@rafael.j.wysocki
The procfs interface is only used with lid devices which only becomes
clear after looking into the function bodies of acpi_button_add_fs()
and acpi_button_remove_fs(). Moreover, the only error code returned
by the former of these functions is -ENODEV, so the ret local variable
in it is redundant, and the return type of the latter one can be changed
to void.
Accordingly, rename these functions to acpi_button_add_fs() and
acpi_button_remove_fs(), respectively, move the button->type checks
against ACPI_BUTTON_TYPE_LID from them to their callers, and make
code simplifications as per the above.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/1869050.VLH7GnMWUR@rafael.j.wysocki
Two switch () statements in acpi_button_probe() operate on the same
value and the statements between them can be reordered with respect
to the second one, so merge them.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/3352815.5fSG56mABF@rafael.j.wysocki
Local char pointer called "name" in acpi_button_probe() is redundant
because its value can be assigned directly to input->name and the
latter can be used in the only other place where "name" is read, so
get rid of it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/3706239.iIbC2pHGDl@rafael.j.wysocki
Instead of manually comparing the primary ID of the device (retuned
by _HID) with each of the device IDs supported by the driver, use
acpi_match_acpi_device() (which includes the ACPI companion device
pointer check against NULL) and store the ACPI button type as
driver_data in button_device_ids[], which allows a multi-branch
conditional statement to be replaced with a switch () one. However,
to continue preventing successful probing of devices that only have
one of the supported device IDs in their _CID lists, compare the
matched device ID with the primary ID of the device and return an
error if they don't match.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/7960518.EvYhyI6sBW@rafael.j.wysocki
[ rjw: Fixed button memory leak on probe failure ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ntsync_schedule() takes the absolute timeout from userspace and hands it to
schedule_hrtimeout_range_clock() with HRTIMER_MODE_ABS. For the default
CLOCK_MONOTONIC path, it does not call timens_ktime_to_host() first.
A process inside a CLOCK_MONOTONIC time namespace computes the absolute
timeout in its own clock view. The kernel reads the same value against the
host clock. The two differ by the namespace offset. The timeout then fires
too early or too late.
Other users of absolute timeouts run the ktime through
timens_ktime_to_host() before starting the hrtimer. ntsync was added later
and missed that step.
/dev/ntsync is mode 0666. Any user inside a time namespace that can
open it is affected. The visible effect is wrong timeout behaviour
for Wine in a container that sets a CLOCK_MONOTONIC offset.
Reproducer: unshare --user --time, set the monotonic offset to -10s,
issue NTSYNC_IOC_WAIT_ANY with a 100 ms absolute MONOTONIC timeout.
The baseline run elapses about 100 ms. The run inside the namespace
elapses about 0 ms.
Apply timens_ktime_to_host() to the parsed timeout when the caller
did not set NTSYNC_WAIT_REALTIME. The helper does nothing in the
initial time namespace, so the fast path is unchanged.
Fixes: b4a7b5fe3f ("ntsync: Introduce NTSYNC_IOC_WAIT_ANY.")
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://patch.msgid.link/20260528063311.3300393-3-maoyixie.tju@gmail.com
timens_ktime_to_host() in compares the current time namespace against
init_time_ns for the fast path. It calls do_timens_ktime_to_host() for the
offset case. Both symbols are needed at link time by any caller of the
inline.
All current callers are builtin, but ntsync can be built as module, which
prevents it from using it.
Export both with EXPORT_SYMBOL_GPL.
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260528063311.3300393-2-maoyixie.tju@gmail.com
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Merge tag 'nf-26-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter/IPVS fixes for net
The following patchset contains Netfilter/IPVS fixes for net:
1) Fix splat with PREEMPT_RCU because smp_processor_id() in nfqueue,
from Fernando Fernandez Mancera.
2) Fix possible use of pointer to old IPVS scheduler after RCU grace
period when editing service, from Julian Anastasov.
3) Fix possible forever RCU walk over rt->fib6_siblings in nft_fib6,
if rt is unlinked mid-iteration, apparently same issue happens in
the fib6 core. From Jiayuan Chen.
4) Add mutex to guard refcount in synproxy infrastructure, since
concurrent hook {un}registration can happen.
From Fernando Fernandez Mancera.
5) Bail out if IRC conntrack helper fails to parse a command, do not
try parsing using other command handlers, from Florian Westphal.
This fixes a possible out-of-bound read.
6) Possible use-after-free in nft_tunnel by releasing template dst
after all references has been dropped, from Tristan Madani.
7) Ignore conntrack template in nft_ct, from Jiayuan Chen.
8) Missing skb_ensure_writable() in ebt_snat, Yiming Qian.
9) Remove multi-register byteorder support, this allows for kernel
stack info leak, from Florian Westphal.
* tag 'nf-26-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_byteorder: remove multi-register support
netfilter: bridge: make ebt_snat ARP rewrite writable
netfilter: nft_ct: bail out on template ct in get eval
netfilter: nft_tunnel: fix use-after-free on object destroy
netfilter: conntrack_irc: fix possible out-of-bounds read
netfilter: synproxy: add mutex to guard hook reference counting
netfilter: nft_fib_ipv6: bail out of sibling walk if rt got unlinked
ipvs: clear the svc scheduler ptr early on edit
netfilter: xt_NFQUEUE: prefer raw_smp_processor_id
====================
Link: https://patch.msgid.link/20260601115923.433946-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().
Let's wrap mod_timer() and refcount_set() with
preempt_disable_nested() and preempt_enable_nested().
Note that inet_ehash_insert() holds the normal spin_lock()
(mutex in PREEMPT_RT), so it must be called outside of
preempt_disable_nested(), but this is fine.
The lookup path just ignores 0 sk_refcnt entries in ehash
and tries to create another reqsk, but this will fail at
inet_ehash_insert().
[0]:
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: e4 7d d1 0a 67 48 0f b9 3a eb 4a e8 38 3d 23 fd 48 8d 3d e1 7d d1 0a 67 48 0f b9 3a eb 37 e8 25 3d 23 fd 48 8d 3d de 7d d1 0a <67> 48 0f b9 3a eb 24 e8 12 3d 23 fd 48 8d 3d db 7d d1 0a 67 48 0f
RSP: 0000:ffffc90000157948 EFLAGS: 00010246
RAX: ffffffff84a1301b RBX: 0000000000000003 RCX: ffff88801ca98000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8f72ae00
RBP: ffffffff99ae3b01 R08: ffff88801ca98000 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880425ef568
R13: ffff8880425ef4f8 R14: ffff8880425ef578 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126386000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b46710e9c CR3: 000000000dbb6000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
reqsk_put include/net/request_sock.h:136 [inline]
__inet_csk_reqsk_queue_drop+0x3ce/0x440 net/ipv4/inet_connection_sock.c:1007
reqsk_timer_handler+0x651/0xdf0 net/ipv4/inet_connection_sock.c:1137
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0x67/0x170 kernel/time/timer.c:2403
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Fixes: d2d6422f8b ("x86: Allow to enable PREEMPT_RT.")
Reported-by: syzbot+e809069bc15f26300526@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a1a7bcf.0a9e871e.332604.000b.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260601182101.3183993-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
UDP TX skb->destructor() is sock_wfree(), and UDP holds lock_sock()
only for UDP_CORK / MSG_MORE sendmsg().
Otherwise, sk->sk_write_space() may be read locklessly while SOCKMAP
rewrites sk->sk_write_space().
Let's use WRITE_ONCE() and READ_ONCE() for sk->sk_write_space().
Note that the write side is annotated by commit 2ef2b20cf4
("net: annotate data-races around sk->sk_{data_ready,write_space}").
Fixes: 7b98cd42b0 ("bpf: sockmap: Add UDP support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://patch.msgid.link/20260529193941.3897256-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
napi_complete_done may call gro_flush_normal (though not currently, as GRO
is unsupported at the moment), which may result in packet TX. This will
eventually result in calling pcnet32_start_xmit - resulting in a deadlock
while trying to re-acquire the already locked spin lock.
It is safe to split the spinlock block into two, because the hardware
registers are still protected from concurrent access, and the two blocks
perform unrelated operations that don't need to happen atomically.
Fixes: 5b2ec6f2be ("pcnet32: use napi_complete_done()")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Oscar Maes <oscmaes92@gmail.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260528140320.5556-1-oscmaes92@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Following the previous set of fixes, this addresses another significant
number of small issues found in firmware drivers (tee, optee, qcomtee,
qcom ice, exynos acpm) drivers through various tools. This is about
error handling, resource leaks, concurrency and a use-after-free bug.
The fixes for the Qualcomm ICE driver also introduce interface changes
in the UFS and MMC drivers using it.
Outside of firmware drivers, there are a few fixes across the tree:
- Minor driver code mistakes in the Atmel EBI memory controller,
the i.MX soc ID driver and socfpga boot logic
- A defconfig change to avoid a boot time regression on multiple
qualcomm boards
- Device tree fixes for qualcomm, at91 and gemini, addressing
mostly minor configuration mistakes
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Merge tag 'soc-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull SoC fixes from Arnd Bergmann:
"Following the previous set of fixes, this addresses another
significant number of small issues found in firmware drivers (tee,
optee, qcomtee, qcom ice, exynos acpm) drivers through various tools.
This is about error handling, resource leaks, concurrency and a
use-after-free bug.
The fixes for the Qualcomm ICE driver also introduce interface changes
in the UFS and MMC drivers using it.
Outside of firmware drivers, there are a few fixes across the tree:
- Minor driver code mistakes in the Atmel EBI memory controller, the
i.MX soc ID driver and socfpga boot logic
- A defconfig change to avoid a boot time regression on multiple
qualcomm boards
- Device tree fixes for qualcomm, at91 and gemini, addressing mostly
minor configuration mistakes"
* tag 'soc-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (28 commits)
firmware: samsung: acpm: Fix infinite loop on sequence number exhaustion
firmware: samsung: acpm: Fix missing LKMM barriers in sequence allocator
firmware: samsung: acpm: Fix false timeouts and Use-After-Free in polling
ARM: dts: gemini: Fix partition offsets
ARM: socfpga: Fix OF node refcount leak in SMP setup
soc: qcom: ice: Fix the error code when 'qcom,ice' property is not found
arm64: dts: qcom: eliza: Add power-domain and iface clk for ice node
arm64: dts: qcom: milos: Add power-domain and iface clk for ice node
tee: qcomtee: add missing va_end in early return qcomtee_object_user_init()
tee: fix params_from_user() error path in tee_ioctl_supp_recv
tee: shm: fix shm leak in register_shm_helper()
tee: fix tee_ioctl_object_invoke_arg padding
arm64: defconfig: Enable PCI M.2 power sequencing driver
scsi: ufs: ufs-qcom: Remove NULL check from devm_of_qcom_ice_get()
mmc: sdhci-msm: Remove NULL check from devm_of_qcom_ice_get()
soc: qcom: ice: Return proper error codes from devm_of_qcom_ice_get() instead of NULL
soc: qcom: ice: Return -ENODEV if the ICE platform device is not found
soc: qcom: ice: Fix race between qcom_ice_probe() and of_qcom_ice_get()
ARM: dts: microchip: sam9x7: fix GMAC clock configuration
firmware: samsung: acpm: Fix mailbox channel leak on probe error
...
Validate the SQ ring size against the device's max LLQ size. This
ensures that when using 128-byte WQEs, userspace cannot exceed the queue
limits.
On create QP, userspace provides the SQ ring size (depth x WQE size)
which is validated against the max LLQ size.
Fixes: 40909f664d ("RDMA/efa: Add EFA verbs implementation")
Link: https://patch.msgid.link/r/20260526081536.1203553-1-ynachum@amazon.com
Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
When CONFIG_UBSAN_ALIGNMENT is enabled, the stack usage of nocb_gp_wait()
grows above typical warning limits:
In file included from kernel/rcu/tree.c:4930:
kernel/rcu/tree_nocb.h: In function 'rcu_nocb_gp_kthread':
kernel/rcu/tree_nocb.h:866:1: error: the frame size of 1968 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
Apparently, the problem is passing rcu_data from a 'void *' pointer,
which gcc assumes may be misaligned. When the function is not inlined
into rcu_nocb_gp_kthread(), that is no longer visible to gcc.
Add a 'noinline_for_stack' annotation that leads to skipping a lot of
the alignment sanitizer checks and keeps the stack usage 60% lower here.
Reviewed-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
EPP 0 is the only supported value in the performance policy.
commit 798c47593c ("cpufreq/amd-pstate: Add support for platform profile
class") changed this while adding platform profile support to the
dynamic EPP feature, but this actually wasn't necessary since platform
profile writes disable manual EPP writes.
Restore allowing writing EPP of 0 when in performance mode.
Reviewed-by: Marco Scardovi <scardracs@disroot.org>
Tested-by: Marco Scardovi <scardracs@disroot.org>
Reported-by: Stuart Meckle <stuartmeckle@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473
Closes: https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/work_items/190
Fixes: 798c47593c ("cpufreq/amd-pstate: Add support for platform profile class")
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Migration entries do not need to be removed.
The swap subsystem has been (and still is being) heavily reworked. The
current implementation of ptep_zap_softleaf_entry() has been slowly
modified and is now wrong, since it unconditionally calls
swap_put_entries_direct() for both swap and migration entries.
Remove ptep_zap_softleaf_entry() altogether, merge the path for proper
swap entries directly in the only caller, and ignore migration entries.
Fixes: 200197908d ("KVM: s390: Refactor and split some gmap helpers")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260602142356.169458-11-imbrenda@linux.ibm.com>
If kvm_s390_new_mmu_cache() fails, kvm_s390_faultin_gfn() returns
without releasing the faulted page.
Fix this by moving the allocation of the memory cache outside of the
loop. There is no reason to check at every iteration.
Opportunistically fix a comment.
Fixes: e907ae5301 ("KVM: s390: Add helper functions for fault handling")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260602142356.169458-10-imbrenda@linux.ibm.com>
With KVM_S390_VM_MEM_LIMIT_SIZE, userspace can set the highest address
allowed for the VM. Creating a memslot that lies over the maximum
address does not make sense and is only a potential source of bugs.
Prevent creation of memslots over the maximum address, and prevent the
maximum address from being reduced below the end of existing memslots.
Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260602142356.169458-9-imbrenda@linux.ibm.com>
BPF programs should have no need in looking into struct io_ring_ctx, if
anything, most of such cases would be anti patterns like looking up ring
indices directly via the context.
Replace it with a new empty structure, which is just an alias to struct
io_ring_ctx. It'll create a new BTF type and fail verification if a BPF
program tries to access it (beyond the first byte). It'll also give more
flexibility for the future, and otherwise it can be made aligned with
io_ring_ctx as before with struct groups if ever needed or extended in a
different way.
Fixes: d0e437b76b ("io_uring/bpf-ops: implement loop_step with BPF struct_ops")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/5f6ca3649e9e0bae8667db4357e28dd00cd07901.1780394491.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use min() to replace the open-coded implementations and to simplify
riscix_partition() and linux_partition().
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20260602160757.973736-3-thorsten.blum@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
address post-7.1 issues or aren't considered suitable for backporting.
There's a 3 patch series "userfaultfd: verify VMA state across UFFDIO_COPY
retry" from Mike Rapoport which fixes a few uffd things. The rest are
singletons - please see the individual changelogs for details.
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Merge tag 'mm-hotfixes-stable-2026-06-01-20-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM fixes from Andrew Morton:
"13 hotfixes. All are for MM. 10 are cc:stable and the remaining 3
address post-7.1 issues or aren't considered suitable for backporting.
There's a three-patch series "userfaultfd: verify VMA state across
UFFDIO_COPY retry" from Mike Rapoport which fixes a few uffd things.
The rest are singletons - please see the individual changelogs for
details"
* tag 'mm-hotfixes-stable-2026-06-01-20-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
userfaultfd: remove redundant check in vm_uffd_ops()
userfaultfd: refuse to __mfill_atomic_pte() for unsupported VMAs
userfaultfd: verify VMA state across UFFDIO_COPY retry
mm/huge_memory: update file PMD counter before folio_put()
mm/huge_memory: update file PUD counter before folio_put()
mm/hugetlb_vmemmap: fix incorrect vmemmap restore in rollback
mm/damon/ops-common: call folio_test_lru() after folio_get()
mm/cma: fix reserved page leak on activation failure
mm/memory-failure: fix hugetlb_lock AA deadlock in get_huge_page_for_hwpoison
mm/hugetlb: restore reservation on error in hugetlb folio copy paths
mm/cma_debug: fix invalid accesses for inactive CMA areas
memcg: use round-robin victim selection in refill_stock
mm/hugetlb: avoid false positive lockdep assertion
The linear aliases of the kernel text and rodata are also mapped
read-only in the linear map. Given that the contents of these regions
are mostly identical to the version in the loadable image, mapping them
read-only and leaving their contents visible is a reasonable hardening
measure.
Data and bss, however, are now also mapped read-only but the contents of
these regions are more likely to contain data that we'd rather not leak.
So let's unmap these entirely in the linear map when the kernel is
running normally.
When going into hibernation or waking up from it, these regions need to
be mapped, so map the region initially, and toggle the valid bit so
map/unmap the region as needed.
Doing so is required because pages covering the kernel image are marked
as PageReserved, and therefore disregarded for snapshotting by the
hibernate logic unless they are mapped.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
On systems where the bootloader adheres to the original arm64 boot
protocol, the placement of the kernel in the physical address space is
highly predictable, and this makes the placement of its linear alias in
the kernel virtual address space equally predictable, given the lack of
randomization of the linear map.
The linear aliases of the kernel text and rodata regions are already
mapped read-only, but the kernel data and bss are mapped read-write in
this region. This is not needed, so map them read-only as well.
Note that the statically allocated kernel page tables do need to be
modifiable via the linear map, so leave these mapped read-write.
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
The empty zero page is used to back any kernel or user space mapping
that is supposed to remain cleared, and so the page itself is never
supposed to be modified.
So mark it as const, which moves it into .rodata rather than .bss: on
most architectures, this ensures that both the kernel's mapping of it
and any aliases that are accessible via the kernel direct (linear) map
are mapped read-only, and cannot be used (inadvertently or maliciously)
to corrupt the contents of the zero page.
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Feng Tang <feng.tang@linux.alibaba.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
SuperH performs cache maintenance on the zero page during boot,
presumably because before commit
6215d9f447 ("arch, mm: consolidate empty_zero_page")
the zero page did double duty as a boot params region, and was cleared
separately, as it was not part of BSS. The memset() in question was
dropped by that commit, but the __flush_wback_region() call remained.
As empty_zero_page[] has been moved to BSS, it can be treated as any
other BSS memory, and so the cache flush can be dropped.
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
The only remaining use of map_patch_area() is mapping the zero page, and
immediately unmapping it again so that the intermediate page table
levels are all guaranteed to be populated.
The use of the zero page here is completely arbitrary, and not harmful
per se, but currently, it creates a writable mapping, and does so in a
manner that requires that the empty_zero_page[] symbol is not
const-qualified.
Given that this is about to change, and that map_patch_area() now never
maps anything other than the zero page, let's simplify the code and
- remove the helpers and call [un]map_kernel_page() directly
- take the PA of empty_zero_page directly
- create a read-only temporary mapping.
This allows empty_zero_page[] to be repainted as const u8[] in a
subsequent patch, without making substantial changes to this code
patching logic.
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://lore.kernel.org/all/20260520085423.485402-1-ardb@kernel.org/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Now that the linear region mapping routines respect existing table
mappings and contiguous block and page mappings, it is no longer needed
to fiddle with the memblock tables to set and clear the NOMAP attribute
in order to omit text and rodata when creating the linear map.
Instead, map the kernel text and rodata alias first with the desired
initial attributes and granularity, so that the loop iterating over the
memblocks will not remap it in a manner that prevents it from being
remapped with updated attributes later.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
