John Stultz [Thu, 20 Mar 2025 20:03:00 +0000 (13:03 -0700)]
timekeeping: Fix possible inconsistencies in _COARSE clockids
Lei Chen raised an issue with CLOCK_MONOTONIC_COARSE seeing time
inconsistencies.
Lei tracked down that this was being caused by the adjustment
tk->tkr_mono.xtime_nsec -= offset;
which is made to compensate for the unaccumulated cycles in offset when the
multiplicator is adjusted forward, so that the non-_COARSE clockids don't
see inconsistencies.
However, the _COARSE clockid getter functions use the adjusted xtime_nsec
value directly and do not compensate the negative offset via the
clocksource delta multiplied with the new multiplicator. In that case the
caller can observe time going backwards in consecutive calls.
By design, this negative adjustment should be fine, because the logic run
from timekeeping_adjust() is done after it accumulated approximately
multiplicator * interval_cycles
into xtime_nsec. The accumulated value is always larger then the
mult_adj * offset
value, which is subtracted from xtime_nsec. Both operations are done
together under the tk_core.lock, so the net change to xtime_nsec is always
always be positive.
However, do_adjtimex() calls into timekeeping_advance() as well, to to
apply the NTP frequency adjustment immediately. In this case,
timekeeping_advance() does not return early when the offset is smaller then
interval_cycles. In that case there is no time accumulated into
xtime_nsec. But the subsequent call into timekeeping_adjust(), which
modifies the multiplicator, subtracts from xtime_nsec to correct
for the new multiplicator.
Here because there was no accumulation, xtime_nsec becomes smaller than
before, which opens a window up to the next accumulation, where the _COARSE
clockid getters, which don't compensate for the offset, can observe the
inconsistency.
To fix this, rework the timekeeping_advance() logic so that when invoked
from do_adjtimex(), the time is immediately forwarded to accumulate also
the sub-interval portion into xtime. That means the remaining offset
becomes zero and the subsequent multiplier adjustment therefore does not
modify xtime_nsec.
There is another related inconsistency. If xtime is forwarded due to the
instantaneous multiplier adjustment, the NTP error, which was accumulated
with the previous setting, becomes meaningless.
Therefore clear the NTP error as well, after forwarding the clock for the
instantaneous multiplier update.
Fixes: da15cfdae033 ("time: Introduce CLOCK_REALTIME_COARSE") Reported-by: Lei Chen <lei.chen@smartx.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250320200306.1712599-1-jstultz@google.com Closes: https://lore.kernel.org/lkml/20250310030004.3705801-1-lei.chen@smartx.com/
Cyrill Gorcunov [Sun, 16 Mar 2025 19:58:15 +0000 (22:58 +0300)]
posix-timers: Drop redundant memset() invocation
Initially in commit 6891c4509c79 memset() was required to clear a variable
allocated on stack. Commit 2482097c6c0f removed the on stack variable and
retained the memset() despite the fact that the memory is allocated via
kmem_cache_zalloc() and therefore zereoed already.
Thomas Gleixner [Tue, 11 Mar 2025 22:07:44 +0000 (23:07 +0100)]
posix-timers: Provide a mechanism to allocate a given timer ID
Checkpoint/Restore in Userspace (CRIU) requires to reconstruct posix timers
with the same timer ID on restore. It uses sys_timer_create() and relies on
the monotonic increasing timer ID provided by this syscall. It creates and
deletes timers until the desired ID is reached. This is can loop for a long
time, when the checkpointed process had a very sparse timer ID range.
It has been debated to implement a new syscall to allow the creation of
timers with a given timer ID, but that's tideous due to the 32/64bit compat
issues of sigevent_t and of dubious value.
The restore mechanism of CRIU creates the timers in a state where all
threads of the restored process are held on a barrier and cannot issue
syscalls. That means the restorer task has exclusive control.
This allows to address this issue with a prctl() so that the restorer
thread can do:
if (prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_ON))
goto linear_mode;
create_timers_with_explicit_ids();
prctl(PR_TIMER_CREATE_RESTORE_IDS, PR_TIMER_CREATE_RESTORE_IDS_OFF);
This is backwards compatible because the prctl() fails on older kernels and
CRIU can fall back to the linear timer ID mechanism. CRIU versions which do
not know about the prctl() just work as before.
Implement the prctl() and modify timer_create() so that it copies the
requested timer ID from userspace by utilizing the existing timer_t
pointer, which is used to copy out the allocated timer ID on success.
If the prctl() is disabled, which it is by default, timer_create() works as
before and does not try to read from the userspace pointer.
There is no problem when a broken or rogue user space application enables
the prctl(). If the user space pointer does not contain a valid ID, then
timer_create() fails. If the data is not initialized, but constains a
random valid ID, timer_create() will create that random timer ID or fail if
the ID is already given out.
As CRIU must use the raw syscall to avoid manipulating the internal state
of the restored process, this has no library dependencies and can be
adopted by CRIU right away.
Recreating two timers with IDs 1000000 and 2000000 takes 1.5 seconds with
the create/delete method. With the prctl() it takes 3 microseconds.
Thomas Gleixner [Sat, 8 Mar 2025 16:48:45 +0000 (17:48 +0100)]
posix-timers: Dont iterate /proc/$PID/timers with sighand:: Siglock held
The readout of /proc/$PID/timers holds sighand::siglock with interrupts
disabled. That is required to protect against concurrent modifications of
the task::signal::posix_timers list because the list is not RCU safe.
With the conversion of the timer storage to a RCU protected hlist, this is
not longer required.
The only requirement is to protect the returned entry against a concurrent
free, which is trivial as the timers are RCU protected.
Removing the trylock of sighand::siglock is benign because the life time of
task_struct::signal is bound to the life time of the task_struct itself.
There are two scenarios where this matters:
1) The process is life and not about to be checkpointed
2) The process is stopped via ptrace for checkpointing
#1 is a racy snapshot of the armed timers and nothing can rely on it. It's
not more than debug information and it has been that way before because
sighand lock is dropped when the buffer is full and the restart of
the iteration might find a completely different set of timers.
The task and therefore task::signal cannot be freed as timers_start()
acquired a reference count via get_pid_task().
#2 the process is stopped for checkpointing so nothing can delete or create
timers at this point. Neither can the process exit during the traversal.
If CRIU fails to observe an exit in progress prior to the dissimination
of the timers, then there are more severe problems to solve in the CRIU
mechanics as they can't rely on posix timers being enabled in the first
place.
Therefore replace the lock acquisition with rcu_read_lock() and switch the
timer storage traversal over to seq_hlist_*_rcu().
Thomas Gleixner [Sat, 8 Mar 2025 16:48:42 +0000 (17:48 +0100)]
posix-timers: Avoid false cacheline sharing
struct k_itimer has the hlist_node, which is used for lookup in the hash
bucket, and the timer lock in the same cache line.
That's obviously bad, if one CPU fiddles with a timer and the other is
walking the hash bucket on which that timer is queued.
Avoid this by restructuring struct k_itimer, so that the read mostly (only
modified during setup and teardown) fields are in the first cache line and
the lock and the rest of the fields which get written to are in cacheline
2-N.
Reduces cacheline contention in a test case of 64 processes creating and
accessing 20000 timers each by almost 30% according to perf.
Thomas Gleixner [Sat, 8 Mar 2025 16:48:40 +0000 (17:48 +0100)]
posix-timers: Switch to jhash32()
The hash distribution of hash_32() is suboptimal. jhash32() provides a way
better distribution, which evens out the length of the hash bucket lists,
which in turn avoids large outliers in list walk times.
Due to the sparse ID space (thanks CRIU) there is no guarantee that the
timers will be fully evenly distributed over the hash buckets, but the
behaviour is way better than with hash_32() even for randomly sparse ID
spaces.
For a pathological test case with 64 processes creating and accessing
20000 timers each, this results in a runtime reduction of ~10% and a
significantly reduced runtime variation.
Thomas Gleixner [Sat, 8 Mar 2025 16:48:38 +0000 (17:48 +0100)]
posix-timers: Improve hash table performance
Eric and Ben reported a significant performance bottleneck on the global
hash, which is used to store posix timers for lookup.
Eric tried to do a lockless validation of a new timer ID before trying to
insert the timer, but that does not solve the problem.
For the non-contended case this is a pointless exercise and for the
contended case this extra lookup just creates enough interleaving that all
tasks can make progress.
There are actually two real solutions to the problem:
1) Provide a per process (signal struct) xarray storage
2) Implement a smarter hash like the one in the futex code
#1 works perfectly fine for most cases, but the fact that CRIU enforced a
linear increasing timer ID to restore timers makes this problematic.
It's easy enough to create a sparse timer ID space, which amounts very
fast to a large junk of memory consumed for the xarray. 2048 timers with
a ID offset of 512 consume more than one megabyte of memory for the
xarray storage.
#2 The main advantage of the futex hash is that it uses per hash bucket
locks instead of a global hash lock. Aside of that it is scaled
according to the number of CPUs at boot time.
Experiments with artifical benchmarks have shown that a scaled hash with
per bucket locks comes pretty close to the xarray performance and in some
scenarios it performes better.
Test 1:
A single process creates 20000 timers and afterwards invokes
timer_getoverrun(2) on each of them:
mainline Eric newhash xarray
create 23 ms 23 ms 9 ms 8 ms
getoverrun 14 ms 14 ms 5 ms 4 ms
Test 2:
A single process creates 50000 timers and afterwards invokes
timer_getoverrun(2) on each of them:
mainline Eric newhash xarray
create 98 ms 219 ms 20 ms 18 ms
getoverrun 62 ms 62 ms 10 ms 9 ms
Test 3:
A single process creates 100000 timers and afterwards invokes
timer_getoverrun(2) on each of them:
mainline Eric newhash xarray
create 313 ms 750 ms 48 ms 33 ms
getoverrun 261 ms 260 ms 20 ms 14 ms
Erics changes create quite some overhead in the create() path due to the
double list walk, as the main issue according to perf is the list walk
itself. With 100k timers each hash bucket contains ~200 timers, which in
the worst case need to be all inspected. The same problem applies for
getoverrun() where the lookup has to walk through the hash buckets to find
the timer it is looking for.
The scaled hash obviously reduces hash collisions and lock contention
significantly. This becomes more prominent with concurrency.
Test 4:
A process creates 63 threads and all threads wait on a barrier before
each instance creates 20000 timers and afterwards invokes
timer_getoverrun(2) on each of them. The threads are pinned on
seperate CPUs to achive maximum concurrency. The numbers are the
average times per thread:
mainline Eric newhash xarray
create 180239 ms 38599 ms 579 ms 813 ms
getoverrun 2645 ms 2642 ms 32 ms 7 ms
Test 5:
A process forks 63 times and all forks wait on a barrier before each
instance creates 20000 timers and afterwards invokes
timer_getoverrun(2) on each of them. The processes are pinned on
seperate CPUs to achive maximum concurrency. The numbers are the
average times per process:
mainline eric newhash xarray
create 157253 ms 40008 ms 83 ms 60 ms
getoverrun 2611 ms 2614 ms 40 ms 4 ms
So clearly the reduction of lock contention with Eric's changes makes a
significant difference for the create() loop, but it does not mitigate the
problem of long list walks, which is clearly visible on the getoverrun()
side because that is purely dominated by the lookup itself. Once the timer
is found, the syscall just reads from the timer structure with no other
locks or code paths involved and returns.
The reason for the difference between the thread and the fork case for the
new hash and the xarray is that both suffer from contention on
sighand::siglock and the xarray suffers additionally from contention on the
xarray lock on insertion.
The only case where the reworked hash slighly outperforms the xarray is a
tight loop which creates and deletes timers.
Test 4:
A process creates 63 threads and all threads wait on a barrier before
each instance runs a loop which creates and deletes a timer 100000
times in a row. The threads are pinned on seperate CPUs to achive
maximum concurrency. The numbers are the average times per thread:
mainline Eric newhash xarray
loop 5917 ms 5897 ms 5473 ms 7846 ms
Test 5:
A process forks 63 times and all forks wait on a barrier before each
each instance runs a loop which creates and deletes a timer 100000
times in a row. The processes are pinned on seperate CPUs to achive
maximum concurrency. The numbers are the average times per process:
mainline Eric newhash xarray
loop 5137 ms 7828 ms 891 ms 872 ms
In both test there is not much contention on the hash, but the ucount
accounting for the signal and in the thread case the sighand::siglock
contention (plus the xarray locking) contribute dominantly to the overhead.
As the memory consumption of the xarray in the sparse ID case is
significant, the scaled hash with per bucket locks seems to be the better
overall option. While the xarray has faster lookup times for a large number
of timers, the actual syscall usage, which requires the lookup is not an
extreme hotpath. Most applications utilize signal delivery and all syscalls
except timer_getoverrun(2) are all but cheap.
So implement a scaled hash with per bucket locks, which offers the best
tradeoff between performance and memory consumption.
Reported-by: Eric Dumazet <edumazet@google.com> Reported-by: Benjamin Segall <bsegall@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20250308155624.216091571@linutronix.de
Eric Dumazet [Sat, 8 Mar 2025 16:48:36 +0000 (17:48 +0100)]
posix-timers: Make signal_struct:: Next_posix_timer_id an atomic_t
The global hash_lock protecting the posix timer hash table can be heavily
contended especially when there is an extensive linear search for a timer
ID.
Timer IDs are handed out by monotonically increasing next_posix_timer_id
and then validating that there is no timer with the same ID in the hash
table. Both operations happen with the global hash lock held.
To reduce the hash lock contention the hash will be reworked to a scaled
hash with per bucket locks, which requires to handle the ID counter
lockless.
Prepare for this by making next_posix_timer_id an atomic_t, which can be
used lockless with atomic_inc_return().
[ tglx: Adopted from Eric's series, massaged change log and simplified it ]
Peter Zijlstra [Sat, 8 Mar 2025 16:48:34 +0000 (17:48 +0100)]
posix-timers: Make lock_timer() use guard()
The lookup and locking of posix timers requires the same repeating pattern
at all usage sites:
tmr = lock_timer(tiner_id);
if (!tmr)
return -EINVAL;
....
unlock_timer(tmr);
Solve this with a guard implementation, which works in most places out of
the box except for those, which need to unlock the timer inside the guard
scope.
Though the only places where this matters are timer_delete() and
timer_settime(). In both cases the timer pointer needs to be preserved
across the end of the scope, which is solved by storing the pointer in a
variable outside of the scope.
timer_settime() also has to protect the timer with RCU before unlocking,
which obviously can't use guard(rcu) before leaving the guard scope as that
guard is cleaned up before the unlock. Solve this by providing the RCU
protection open coded.
Thomas Gleixner [Mon, 10 Mar 2025 08:13:32 +0000 (09:13 +0100)]
posix-timers: Rework timer removal
sys_timer_delete() and the do_exit() cleanup function itimer_delete() are
doing the same thing, but have needlessly different implementations instead
of sharing the code.
The other oddity of timer deletion is the fact that the timer is not
invalidated before the actual deletion happens, which allows concurrent
lookups to succeed.
That's wrong because a timer which is in the process of being deleted
should not be visible and any actions like signal queueing, delivery and
rearming should not happen once the task, which invoked timer_delete(), has
the timer locked.
Rework the code so that:
1) The signal queueing and delivery code ignore timers which are marked
invalid
2) The deletion implementation between sys_timer_delete() and
itimer_delete() is shared
3) The timer is invalidated and removed from the linked lists before
the deletion callback of the relevant clock is invoked.
That requires to rework timer_wait_running() as it does a lookup of
the timer when relocking it at the end. In case of deletion this
lookup would fail due to the preceding invalidation and the wait loop
would terminate prematurely.
But due to the preceding invalidation the timer cannot be accessed by
other tasks anymore, so there is no way that the timer has been freed
after the timer lock has been dropped.
Move the re-validation out of timer_wait_running() and handle it at
the only other usage site, timer_settime().
Thomas Gleixner [Sat, 8 Mar 2025 16:48:30 +0000 (17:48 +0100)]
posix-timers: Simplify lock/unlock_timer()
Since the integration of sigqueue into the timer struct, lock_timer() is
only used in task context. So taking the lock with irqsave() is not longer
required.
Thomas Gleixner [Sat, 8 Mar 2025 16:48:24 +0000 (17:48 +0100)]
posix-timers: Remove a few paranoid warnings
Warnings about a non-initialized timer or non-existing callbacks are just
useful for implementing new posix clocks, but there a NULL pointer
dereference is expected anyway. :)
Eric Dumazet [Sat, 8 Mar 2025 16:48:14 +0000 (17:48 +0100)]
posix-timers: Initialise timer before adding it to the hash table
A timer is only valid in the hashtable when both timer::it_signal and
timer::it_id are set to their final values, but timers are added without
those values being set.
The timer ID is allocated when the timer is added to the hash in invalid
state. The ID is taken from a monotonically increasing per process counter
which wraps around after reaching INT_MAX. The hash insertion validates
that there is no timer with the allocated ID in the hash table which
belongs to the same process. That opens a mostly theoretical race condition:
If other threads of the same process manage to create/delete timers in
rapid succession before the newly created timer is fully initialized and
wrap around to the timer ID which was handed out, then a duplicate timer ID
will be inserted into the hash table.
Prevent this by:
1) Setting timer::it_id before inserting the timer into the hashtable.
2) Storing the signal pointer in timer::it_signal with bit 0 set before
inserting it into the hashtable.
Bit 0 acts as a invalid bit, which means that the regular lookup for
sys_timer_*() will fail the comparison with the signal pointer.
But the lookup on insertion masks out bit 0 and can therefore detect a
timer which is not yet valid, but allocated in the hash table. Bit 0
in the pointer is cleared once the initialization of the timer
completed.
[ tglx: Fold ID and signal iniitializaion into one patch and massage change
log and comments. ]
Thomas Gleixner [Sat, 8 Mar 2025 16:48:10 +0000 (17:48 +0100)]
posix-timers: Ensure that timer initialization is fully visible
Frederic pointed out that the memory operations to initialize the timer are
not guaranteed to be visible, when __lock_timer() observes timer::it_signal
valid under timer::it_lock:
T0 T1
--------- -----------
do_timer_create()
// A
new_timer->.... = ....
spin_lock(current->sighand)
// B
WRITE_ONCE(new_timer->it_signal, current->signal)
spin_unlock(current->sighand)
sys_timer_*()
t = __lock_timer()
spin_lock(&timr->it_lock)
// observes B
if (timr->it_signal == current->signal)
return timr;
if (!t)
return;
// Is not guaranteed to observe A
Protect the write of timer::it_signal, which makes the timer valid, with
timer::it_lock as well. This guarantees that T1 must observe the
initialization A completely, when it observes the valid signal pointer
under timer::it_lock. sighand::siglock must still be taken to protect the
signal::posix_timers list.
The size argument of strscpy() is only required when the destination
pointer is not a fixed sized array or when the copy needs to be smaller
than the size of the fixed sized destination array.
For fixed sized destination arrays and full copies, strscpy() automatically
determines the length of the destination buffer if the size argument is
omitted.
This makes the explicit sizeof() unnecessary. Remove it.
Thomas Weißschuh [Tue, 11 Mar 2025 09:54:47 +0000 (10:54 +0100)]
timer_list: Don't use %pK through printk()
This reverts commit f590308536db ("timer debug: Hide kernel addresses via
%pK in /proc/timer_list")
The timer list helper SEQ_printf() uses either the real seq_printf() for
procfs output or vprintk() to print to the kernel log, when invoked from
SysRq-q. It uses %pK for printing pointers.
In the past %pK was prefered over %p as it would not leak raw pointer
values into the kernel log. Since commit ad67b74d2469 ("printk: hash
addresses printed with %p") the regular %p has been improved to avoid this
issue.
Furthermore, restricted pointers ("%pK") were never meant to be used
through printk(). They can still unintentionally leak raw pointers or
acquire sleeping looks in atomic contexts.
Switch to the regular pointer formatting which is safer, easier to reason
about and sufficient here.
The normal and compat ioctl handlers are identical,
which is fine as compat ioctls are detected and handled dynamically
inside the underlying clock implementation.
The duplicate definition however is unnecessary.
Just reuse the regular ioctl handler also for compat ioctls.
Benjamin Segall [Fri, 14 Feb 2025 22:12:20 +0000 (14:12 -0800)]
posix-timers: Invoke cond_resched() during exit_itimers()
exit_itimers() loops through every timer in the process to delete it. This
requires taking the system-wide hash_lock for each of these timers, and
contends with other processes trying to create or delete timers.
When a process creates hundreds of thousands of timers, and then exits
while other processes contend with it, this can trigger softlockups on
CONFIG_PREEMPT=n.
Add a cond_resched() invocation into the loop to allow the system to make
progress.
Andy Shevchenko [Fri, 14 Feb 2025 13:43:33 +0000 (15:43 +0200)]
hrtimers: Replace hrtimer_clock_to_base_table with switch-case
Clang and GCC complain about overlapped initialisers in the
hrtimer_clock_to_base_table definition. With `make W=1` and CONFIG_WERROR=y
(which is default nowadays) this breaks the build:
CC kernel/time/hrtimer.o
kernel/time/hrtimer.c:124:21: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
124 | [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
kernel/time/hrtimer.c:122:27: note: previous initialization is here
122 | [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES,
(and similar for CLOCK_MONOTONIC, CLOCK_BOOTTIME, and CLOCK_TAI).
hrtimer_clockid_to_base(), which uses the table, is only used in
__hrtimer_init(), which is not a hotpath.
Therefore replace the table lookup with a switch case in
hrtimer_clockid_to_base() to avoid this warning.
Linus Torvalds [Sun, 9 Feb 2025 18:05:32 +0000 (10:05 -0800)]
Merge tag 'kbuild-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Suppress false-positive -Wformat-{overflow,truncation}-non-kprintf
warnings regardless of the W= option
- Avoid CONFIG_TRIM_UNUSED_KSYMS dropping symbols passed to symbol_get()
- Fix a build regression of the Debian linux-headers package
* tag 'kbuild-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: install-extmod-build: add missing quotation marks for CC variable
kbuild: fix misspelling in scripts/Makefile.lib
kbuild: keep symbols for symbol_get() even with CONFIG_TRIM_UNUSED_KSYMS
scripts/Makefile.extrawarn: Do not show clang's non-kprintf warnings at W=1
Linus Torvalds [Sun, 9 Feb 2025 17:47:06 +0000 (09:47 -0800)]
Merge tag 'pm-6.14-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki:
"Fix a recently introduced kernel crash due to a NULL pointer
dereference during system-wide suspend (Rafael Wysocki)"
* tag 'pm-6.14-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: sleep: core: Restrict power.set_active propagation
Linus Torvalds [Sun, 9 Feb 2025 17:41:38 +0000 (09:41 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"ARM:
- Correctly clean the BSS to the PoC before allowing EL2 to access it
on nVHE/hVHE/protected configurations
- Propagate ownership of debug registers in protected mode after the
rework that landed in 6.14-rc1
- Stop pretending that we can run the protected mode without a GICv3
being present on the host
- Fix a use-after-free situation that can occur if a vcpu fails to
initialise the NV shadow S2 MMU contexts
- Always evaluate the need to arm a background timer for fully
emulated guest timers
- Fix the emulation of EL1 timers in the absence of FEAT_ECV
- Correctly handle the EL2 virtual timer, specially when HCR_EL2.E2H==0
s390:
- move some of the guest page table (gmap) logic into KVM itself,
inching towards the final goal of completely removing gmap from the
non-kvm memory management code.
As an initial set of cleanups, move some code from mm/gmap into kvm
and start using __kvm_faultin_pfn() to fault-in pages as needed;
but especially stop abusing page->index and page->lru to aid in the
pgdesc conversion.
x86:
- Add missing check in the fix to defer starting the huge page
recovery vhost_task
- SRSO_USER_KERNEL_NO does not need SYNTHESIZED_F"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (31 commits)
KVM: x86/mmu: Ensure NX huge page recovery thread is alive before waking
KVM: remove kvm_arch_post_init_vm
KVM: selftests: Fix spelling mistake "initally" -> "initially"
kvm: x86: SRSO_USER_KERNEL_NO is not synthesized
KVM: arm64: timer: Don't adjust the EL2 virtual timer offset
KVM: arm64: timer: Correctly handle EL1 timer emulation when !FEAT_ECV
KVM: arm64: timer: Always evaluate the need for a soft timer
KVM: arm64: Fix nested S2 MMU structures reallocation
KVM: arm64: Fail protected mode init if no vgic hardware is present
KVM: arm64: Flush/sync debug state in protected mode
KVM: s390: selftests: Streamline uc_skey test to issue iske after sske
KVM: s390: remove the last user of page->index
KVM: s390: move PGSTE softbits
KVM: s390: remove useless page->index usage
KVM: s390: move gmap_shadow_pgt_lookup() into kvm
KVM: s390: stop using lists to keep track of used dat tables
KVM: s390: stop using page->index for non-shadow gmaps
KVM: s390: move some gmap shadowing functions away from mm/gmap.c
KVM: s390: get rid of gmap_translate()
KVM: s390: get rid of gmap_fault()
...
Commit 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM status of
parents and children") exposed an issue related to simple_pm_bus_pm_ops
that uses pm_runtime_force_suspend() and pm_runtime_force_resume() as
bus type PM callbacks for the noirq phases of system-wide suspend and
resume.
The problem is that pm_runtime_force_suspend() does not distinguish
runtime-suspended devices from devices for which runtime PM has never
been enabled, so if it sees a device with runtime PM status set to
RPM_ACTIVE, it will assume that runtime PM is enabled for that device
and so it will attempt to suspend it with the help of its runtime PM
callbacks which may not be ready for that. As it turns out, this
causes simple_pm_bus_runtime_suspend() to crash due to a NULL pointer
dereference.
Another problem related to the above commit and simple_pm_bus_pm_ops is
that setting runtime PM status of a device handled by the latter to
RPM_ACTIVE will actually prevent it from being resumed because
pm_runtime_force_resume() only resumes devices with runtime PM status
set to RPM_SUSPENDED.
To mitigate these issues, do not allow power.set_active to propagate
beyond the parent of the device with DPM_FLAG_SMART_SUSPEND set that
will need to be resumed, which should be a sufficient stop-gap for the
time being, but they will need to be properly addressed in the future
because in general during system-wide resume it is necessary to resume
all devices in a dependency chain in which at least one device is going
to be resumed.
Fixes: 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM status of parents and children") Closes: https://lore.kernel.org/linux-pm/1c2433d4-7e0f-4395-b841-b8eac7c25651@nvidia.com/ Reported-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/6137505.lOV4Wx5bFT@rjwysocki.net
Linus Torvalds [Sat, 8 Feb 2025 22:12:17 +0000 (14:12 -0800)]
Merge tag 'hardening-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook:
"Address a KUnit stack initialization regression that got tickled on
m68k, and solve a Clang(v14 and earlier) bug found by 0day:
- Fix stackinit KUnit regression on m68k
- Use ARRAY_SIZE() for memtostr*()/strtomem*()"
* tag 'hardening-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
string.h: Use ARRAY_SIZE() for memtostr*()/strtomem*()
compiler.h: Introduce __must_be_byte_array()
compiler.h: Move C string helpers into C-only kernel section
stackinit: Fix comment for test_small_end
stackinit: Keep selftest union size small on m68k
Linus Torvalds [Sat, 8 Feb 2025 22:04:21 +0000 (14:04 -0800)]
Merge tag 'seccomp-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull seccomp fix from Kees Cook:
"This is really a work-around for x86_64 having grown a syscall to
implement uretprobe, which has caused problems since v6.11.
This may change in the future, but for now, this fixes the unintended
seccomp filtering when uretprobe switched away from traps, and does so
with something that should be easy to backport.
- Allow uretprobe on x86_64 to avoid behavioral complications (Eyal
Birger)"
* tag 'seccomp-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
selftests/seccomp: validate uretprobe syscall passes through seccomp
seccomp: passthrough uretprobe systemcall without filtering
Linus Torvalds [Sat, 8 Feb 2025 21:59:24 +0000 (13:59 -0800)]
Merge tag 'execve-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull execve fix from Kees Cook:
"This is an alpha-specific fix, but since it touched ELF I was asked to
carry it.
- alpha/elf: Fix misc/setarch test of util-linux by removing 32bit
support (Eric W. Biederman)"
* tag 'execve-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
alpha/elf: Fix misc/setarch test of util-linux by removing 32bit support
Linus Torvalds [Sat, 8 Feb 2025 21:45:34 +0000 (13:45 -0800)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"A number of fairly small fixes, mostly in drivers but two in the core
to change a retry for depopulation (a trendy new hdd thing that
reorganizes blocks away from failing elements) and one to fix a GFP_
annotation to avoid a lock dependency (the third core patch is all in
testing)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: qla1280: Fix kernel oops when debug level > 2
scsi: ufs: core: Fix error return with query response
scsi: storvsc: Set correct data length for sending SCSI command without payload
scsi: ufs: core: Fix use-after free in init error and remove paths
scsi: core: Do not retry I/Os during depopulation
scsi: core: Use GFP_NOIO to avoid circular locking dependency
scsi: ufs: Fix toggling of clk_gating.state when clock gating is not allowed
scsi: ufs: core: Ensure clk_gating.lock is used only after initialization
scsi: ufs: core: Simplify temperature exception event handling
scsi: target: core: Add line break to status show
scsi: ufs: core: Fix the HIGH/LOW_TEMP Bit Definitions
scsi: core: Add passthrough tests for success and no failure definitions
Linus Torvalds [Sat, 8 Feb 2025 20:22:21 +0000 (12:22 -0800)]
Merge tag 'rust-fixes-6.14' of https://github.com/Rust-for-Linux/linux
Pull rust fixes from Miguel Ojeda:
- Do not export KASAN ODR symbols to avoid gendwarfksyms warnings
- Fix future Rust 1.86.0 (to be released 2025-04-03) x86_64 builds
- Clean future Rust 1.86.0 (to be released 2025-04-03) warning
- Fix future GCC 15 (to be released in a few months) builds
- Fix `rusttest` target in macOS
* tag 'rust-fixes-6.14' of https://github.com/Rust-for-Linux/linux:
x86: rust: set rustc-abi=x86-softfloat on rustc>=1.86.0
rust: kbuild: do not export generated KASAN ODR symbols
rust: kbuild: add -fzero-init-padding-bits to bindgen_skip_cflags
rust: init: use explicit ABI to clean warning in future compilers
rust: kbuild: use host dylib naming in rusttestlib-kernel
Linus Torvalds [Sat, 8 Feb 2025 20:18:02 +0000 (12:18 -0800)]
Merge tag 'ftrace-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace fix from Steven Rostedt:
"Function graph fix of notrace functions.
When the function graph tracer was restructured to use the global
section of the meta data in the shadow stack, the bit logic was
changed. There's a TRACE_GRAPH_NOTRACE_BIT that is the bit number in
the mask that tells if the function graph tracer is currently in the
"notrace" mode. The TRACE_GRAPH_NOTRACE is the mask with that bit set.
But when the code we restructured, the TRACE_GRAPH_NOTRACE_BIT was
used when it should have been the TRACE_GRAPH_NOTRACE mask. This made
notrace not work properly"
* tag 'ftrace-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
fgraph: Fix set_graph_notrace with setting TRACE_GRAPH_NOTRACE_BIT
Linus Torvalds [Sat, 8 Feb 2025 20:04:00 +0000 (12:04 -0800)]
Merge tag 'x86-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Ingo Molnar:
"Fix a build regression on GCC 15 builds, caused by GCC changing the
default C version that is overriden in the main Makefile but not in
the x86 boot code Makefile"
* tag 'x86-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Use '-std=gnu11' to fix build with GCC 15
Linus Torvalds [Sat, 8 Feb 2025 19:55:03 +0000 (11:55 -0800)]
Merge tag 'timers-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
"Fix a PREEMPT_RT bug in the clocksource verification code that caused
false positive warnings.
Also fix a timer migration setup bug when new CPUs are added"
* tag 'timers-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers/migration: Fix off-by-one root mis-connection
clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context
Linus Torvalds [Sat, 8 Feb 2025 19:16:22 +0000 (11:16 -0800)]
Merge tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Fix a cfs_rq->h_nr_runnable accounting bug that trips up a defensive
SCHED_WARN_ON() on certain workloads. The bug is believed to be
(accidentally) self-correcting, hence no behavioral side effects are
expected.
Also print se.slice in debug output, since this value can now be set
via the syscall ABI and can be useful to track"
* tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Provide slice length for fair tasks
sched/fair: Fix inaccurate h_nr_runnable accounting with delayed dequeue
Linus Torvalds [Sat, 8 Feb 2025 19:05:54 +0000 (11:05 -0800)]
Merge tag 'irq-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Ingo Molnar:
"Another followup fix for the procps genirq output formatting
regression caused by an optimization"
* tag 'irq-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Remove leading space from irq_chip::irq_print_chip() callbacks
Linus Torvalds [Sat, 8 Feb 2025 18:54:11 +0000 (10:54 -0800)]
Merge tag 'locking-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Ingo Molnar:
"Fix a dangling pointer bug in the futex code used by the uring code.
It isn't causing problems at the moment due to uring ABI limitations
leaving it essentially unused in current usages, but is a good idea to
fix nevertheless"
* tag 'locking-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Pass in task to futex_queue()
Steven Rostedt [Sat, 8 Feb 2025 05:15:11 +0000 (00:15 -0500)]
fgraph: Fix set_graph_notrace with setting TRACE_GRAPH_NOTRACE_BIT
The code was restructured where the function graph notrace code, that
would not trace a function and all its children is done by setting a
NOTRACE flag when the function that is not to be traced is hit.
There's a TRACE_GRAPH_NOTRACE_BIT which defines the bit in the flags and a
TRACE_GRAPH_NOTRACE which is the mask with that bit set. But the
restructuring used TRACE_GRAPH_NOTRACE_BIT when it should have used
TRACE_GRAPH_NOTRACE.
-Wenum-enum-conversion was strengthened in clang-19 to warn for C, which
caused the kernel to move it to W=1 in commit 75b5ab134bb5 ("kbuild:
Move -Wenum-{compare-conditional,enum-conversion} into W=1") because
there were numerous instances that would break builds with -Werror.
Unfortunately, this is not a full solution, as more and more developers,
subsystems, and distributors are building with W=1 as well, so they
continue to see the numerous instances of this warning.
Since the move to W=1, there have not been many new instances that have
appeared through various build reports and the ones that have appeared
seem to be following similar existing patterns, suggesting that most
instances of this warning will not be real issues. The only alternatives
for silencing this warning are adding casts (which is generally seen as
an ugly practice) or refactoring the enums to macro defines or a unified
enum (which may be undesirable because of type safety in other parts of
the code).
Move the warning to W=2, where warnings that occur frequently but may be
relevant should reside.
Linus Torvalds [Sat, 8 Feb 2025 03:23:06 +0000 (19:23 -0800)]
Merge tag 'v6.14rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fixes from Steve French:
- Three DFS fixes: DFS mount fix, fix for noisy log msg and one to
remove some unused code
- SMB3 Lease fix
* tag 'v6.14rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb: client: change lease epoch type from unsigned int to __u16
smb: client: get rid of kstrdup() in get_ses_refpath()
smb: client: fix noisy when tree connecting to DFS interlink targets
smb: client: don't trust DFSREF_STORAGE_SERVER bit
Linus Torvalds [Fri, 7 Feb 2025 20:21:54 +0000 (12:21 -0800)]
Merge tag 'drm-fixes-2025-02-08' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie:
"Just regular drm fixes, amdgpu, xe and i915 mostly, but a few
scattered fixes. I think one of the i915 fixes fixes some build combos
that Guenter was seeing.
amdgpu:
- Add new tiling flag for DCC write compress disable
- Add BO metadata flag for DCC
- Fix potential out of bounds access in display
- Seamless boot fix
- CONFIG_FRAME_WARN fix
- PSR1 fix
xe:
- OA uAPI related fixes
- Fix SRIOV migration initialization
- Restore devcoredump to a sane state
i915:
- Fix the build error with clamp after WARN_ON on gcc 13.x+
- HDCP related fixes
- PMU fix zero delta busyness issue
- Fix page cleanup on DMA remap failure
- Drop 64bpp YUV formats from ICL+ SDR planes
- GuC log related fix
- DisplayPort related fixes
ivpu:
- Fix error handling
komeda:
- add return check
zynqmp:
- fix locking in DP code
ast:
- fix AST DP timeout
cec:
- fix broken CEC adapter check"
* tag 'drm-fixes-2025-02-08' of https://gitlab.freedesktop.org/drm/kernel: (29 commits)
drm/i915/dp: Fix potential infinite loop in 128b/132b SST
Revert "drm/amd/display: Use HW lock mgr for PSR1"
drm/amd/display: Respect user's CONFIG_FRAME_WARN more for dml files
accel/amdxdna: Add MODULE_FIRMWARE() declarations
drm/i915/dp: Iterate DSC BPP from high to low on all platforms
drm/xe: Fix and re-enable xe_print_blob_ascii85()
drm/xe/devcoredump: Move exec queue snapshot to Contexts section
drm/xe/oa: Set stream->pollin in xe_oa_buffer_check_unlocked
drm/xe/pf: Fix migration initialization
drm/xe/oa: Preserve oa_ctrl unused bits
drm/amd/display: Fix seamless boot sequence
drm/amd/display: Fix out-of-bound accesses
drm/amdgpu: add a BO metadata flag to disable write compression for Vulkan
drm/i915/backlight: Return immediately when scale() finds invalid parameters
drm/i915/dp: Return min bpc supported by source instead of 0
drm/i915/dp: fix the Adaptive sync Operation mode for SDP
drm/i915/guc: Debug print LRC state entries only if the context is pinned
drm/i915: Drop 64bpp YUV formats from ICL+ SDR planes
drm/i915: Fix page cleanup on DMA remap failure
drm/i915/pmu: Fix zero delta busyness issue
...
Linus Torvalds [Fri, 7 Feb 2025 19:00:33 +0000 (11:00 -0800)]
Merge tag 'block-6.14-20250207' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- MD pull request via Song:
- fix an error handling path for md-linear
- NVMe pull request via Keith:
- Connection fixes for fibre channel transport (Daniel)
- Endian fixes (Keith, Christoph)
- Cleanup fix for host memory buffer (Francis)
- Platform specific power quirks (Georg)
- Target memory leak (Sagi)
- Use appropriate controller state accessor (Daniel)
- Fixup for a regression introduced last week, where sunvdc wasn't
updated for an API change, causing compilation failures on sparc64.
* tag 'block-6.14-20250207' of git://git.kernel.dk/linux:
drivers/block/sunvdc.c: update the correct AIP call
md: Fix linear_set_limits()
nvme-fc: use ctrl state getter
nvme: make nvme_tls_attrs_group static
nvmet: add a missing endianess conversion in nvmet_execute_admin_connect
nvmet: the result field in nvmet_alloc_ctrl_args is little endian
nvmet: fix a memory leak in controller identify
nvme-fc: do not ignore connectivity loss during connecting
nvme: handle connectivity loss in nvme_set_queue_count
nvme-fc: go straight to connecting state when initializing
nvme-pci: Add TUXEDO IBP Gen9 to Samsung sleep quirk
nvme-pci: Add TUXEDO InfinityFlex to Samsung sleep quirk
nvme-pci: remove redundant dma frees in hmb
nvmet: fix rw control endian access
WangYuli [Fri, 7 Feb 2025 07:08:55 +0000 (15:08 +0800)]
kbuild: install-extmod-build: add missing quotation marks for CC variable
While attempting to build a Debian packages with CC="ccache gcc", I
saw the following error as builddeb builds linux-headers-$KERNELVERSION:
make HOSTCC=ccache gcc VPATH= srcroot=. -f ./scripts/Makefile.build obj=debian/linux-headers-6.14.0-rc1/usr/src/linux-headers-6.14.0-rc1/scripts
make[6]: *** No rule to make target 'gcc'. Stop.
Upon investigation, it seems that one instance of $(CC) variable reference
in ./scripts/package/install-extmod-build was missing quotation marks,
causing the above error.
Add the missing quotation marks around $(CC) to fix build.
Linus Torvalds [Fri, 7 Feb 2025 18:34:50 +0000 (10:34 -0800)]
Merge tag 'pm-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix a handful of issues in the amd-pstate driver, the airoha
cpufreq driver build, a (recently added) possible NULL pointer
dereference in the cpufreq code and a possible memory leak in the
power capping subsystem:
- Fix cpufreq_policy reference counting and prevent max_perf from
going above the current limit in amd-pstate, and drop a redundant
goto label from it (Dhananjay Ugwekar)
- Prevent the per-policy boost_enabled flag in amd-pstate from
getting out of sync with the actual state after boot failures
(Lifeng Zheng)
- Fix a recently added possible NULL pointer dereference in the
cpufreq core (Aboorva Devarajan)
- Fix a build issue related to CONFIG_OF and COMPILE_TEST
dependencies in the airoha cpufreq driver (Arnd Bergmann)
- Fix a possible memory leak in the power capping subsystem (Joe
Hattori)"
* tag 'pm-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq/amd-pstate: Fix cpufreq_policy ref counting
cpufreq: prevent NULL dereference in cpufreq_online()
cpufreq: airoha: modify CONFIG_OF dependency
cpufreq/amd-pstate: Fix max_perf updation with schedutil
cpufreq/amd-pstate: Remove the goto label in amd_pstate_update_limits
cpufreq/amd-pstate: Fix per-policy boost flag incorrect when fail
powercap: call put_device() on an error path in powercap_register_control_type()
Linus Torvalds [Fri, 7 Feb 2025 17:50:33 +0000 (09:50 -0800)]
Merge tag 'gpio-fixes-for-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix interrupt support in gpio-pca953x
- fix configfs attribute locking in gpio-sim
- limit the visibility of the GPIO_GRGPIO Kconfig symbol to OF systems
only
- update MAINTAINERS
* tag 'gpio-fixes-for-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
MAINTAINERS: Use my kernel.org address for ACPI GPIO work
gpio: GPIO_GRGPIO should depend on OF
gpio: sim: lock hog configfs items if present
gpio: pca953x: Improve interrupt support
Linus Torvalds [Fri, 7 Feb 2025 17:22:31 +0000 (09:22 -0800)]
Merge tag 'vfs-6.14-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix fsnotify FMODE_NONOTIFY* handling.
This also disables fsnotify on all pseudo files by default apart from
very select exceptions. This carries a regression risk so we need to
watch out and adapt accordingly. However, it is overall a significant
improvement over the current status quo where every rando file can
get fsnotify enabled.
- Cleanup and simplify lockref_init() after recent lockref changes.
- Fix vboxfs build with gcc-15.
- Add an assert into inode_set_cached_link() to catch corrupt links.
- Allow users to also use an empty string check to detect whether a
given mount option string was empty or not.
- Fix how security options were appended to statmount()'s ->mnt_opt
field.
- Fix statmount() selftests to always check the returned mask.
- Fix uninitialized value in vfs_statx_path().
- Fix pidfs_ioctl() sanity checks to guard against ioctl() overloading
and preserve extensibility.
* tag 'vfs-6.14-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
vfs: sanity check the length passed to inode_set_cached_link()
pidfs: improve ioctl handling
fsnotify: disable pre-content and permission events by default
selftests: always check mask returned by statmount(2)
fsnotify: disable notification by default for all pseudo files
fs: fix adding security options to statmount.mnt_opt
fsnotify: use accessor to set FMODE_NONOTIFY_*
lockref: remove count argument of lockref_init
gfs2: switch to lockref_init(..., 1)
gfs2: use lockref_init for gl_lockref
statmount: let unset strings be empty
vboxsf: fix building with GCC 15
fs/stat.c: avoid harmless garbage value problem in vfs_statx_path()
Linus Torvalds [Fri, 7 Feb 2025 17:16:07 +0000 (09:16 -0800)]
Merge tag 'bcachefs-2025-02-06.2' of git://evilpiepirate.org/bcachefs
Pull bcachefs fixes from Kent Overstreet:
"Nothing major, things continue to be fairly quiet over here.
- add a SubmittingPatches to clarify that patches submitted for
bcachefs do, in fact, need to be tested
- discard path now correctly issues journal flushes when needed, this
fixes performance issues when the filesystem is nearly full and
we're bottlenecked on copygc
- fix a bug that could cause the pending rebalance work accounting to
be off when devices are being onlined/offlined; users should report
if they are still seeing this
- and a few more trivial ones"
* tag 'bcachefs-2025-02-06.2' of git://evilpiepirate.org/bcachefs:
bcachefs: bch2_bkey_sectors_need_rebalance() now only depends on bch_extent_rebalance
bcachefs: Fix rcu imbalance in bch2_fs_btree_key_cache_exit()
bcachefs: Fix discard path journal flushing
bcachefs: fix deadlock in journal_entry_open()
bcachefs: fix incorrect pointer check in __bch2_subvolume_delete()
bcachefs docs: SubmittingPatches.rst
Hector Martin [Thu, 6 Feb 2025 18:21:46 +0000 (03:21 +0900)]
MAINTAINERS: Remove myself
I no longer have any faith left in the kernel development process or
community management approach.
Apple/ARM platform development will continue downstream. If I feel like
sending some patches upstream in the future myself for whatever subtree
I may, or I may not. Anyone who feels like fighting the upstreaming
fight themselves is welcome to do so.
Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branches 'acpi-property' and 'acpi-resource'
Merge a new ACPI IRQ override quirk for Eluktronics MECH-17 (Gannon
Kolding) and an acpi_data_prop_read() fix making it reflect the OF
counterpart behavior in error cases (Andy Shevchenko).
* acpi-property:
ACPI: property: Fix return value for nval == 0 in acpi_data_prop_read()
* acpi-resource:
ACPI: resource: IRQ override for Eluktronics MECH-17
Mateusz Guzik [Tue, 4 Feb 2025 21:32:07 +0000 (22:32 +0100)]
vfs: sanity check the length passed to inode_set_cached_link()
This costs a strlen() call when instatianating a symlink.
Preferably it would be hidden behind VFS_WARN_ON (or compatible), but
there is no such facility at the moment. With the facility in place the
call can be patched out in production kernels.
In the meantime, since the cost is being paid unconditionally, use the
result to a fixup the bad caller.
This is not expected to persist in the long run (tm).
Sample splat:
bad length passed for symlink [/tmp/syz-imagegen43743633/file0/file0] (got 131109, expected 37)
[rest of WARN blurp goes here]
Pidfs supports extensible and non-extensible ioctls. The extensible
ioctls need to check for the ioctl number itself not just the ioctl
command otherwise both backward- and forward compatibility are broken.
The pidfs ioctl handler also needs to look at the type of the ioctl
command to guard against cases where "[...] a daemon receives some
random file descriptor from a (potentially less privileged) client and
expects the FD to be of some specific type, it might call ioctl() on
this FD with some type-specific command and expect the call to fail if
the FD is of the wrong type; but due to the missing type check, the
kernel instead performs some action that userspace didn't expect."
(cf. [1]]
Merge patch series "Fix for huge faults regression"
Amir Goldstein <amir73il@gmail.com> says:
The two Fix patches have been tested by Alex together and each one
independently.
I also verified that they pass the LTP inoityf/fanotify tests.
* patches from https://lore.kernel.org/r/20250203223205.861346-1-amir73il@gmail.com:
fsnotify: disable pre-content and permission events by default
fsnotify: disable notification by default for all pseudo files
fsnotify: use accessor to set FMODE_NONOTIFY_*
Amir Goldstein [Mon, 3 Feb 2025 22:32:05 +0000 (23:32 +0100)]
fsnotify: disable pre-content and permission events by default
After introducing pre-content events, we had a regression related to
disabling huge faults on files that should never have pre-content events
enabled.
This happened because the default f_mode of allocated files (0) does
not disable pre-content events.
Pre-content events are disabled in file_set_fsnotify_mode_by_watchers()
but internal files may not get to call this helper.
Initialize f_mode to disable permission and pre-content events for all
files and if needed they will be enabled for the callers of
file_set_fsnotify_mode_by_watchers().
Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson <alex.williamson@redhat.com> Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20250203223205.861346-4-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
Miklos Szeredi [Wed, 29 Jan 2025 16:06:41 +0000 (17:06 +0100)]
selftests: always check mask returned by statmount(2)
STATMOUNT_MNT_OPTS can actually be missing if there are no options. This
is a change of behavior since 75ead69a7173 ("fs: don't let statmount return
empty strings").
The other checks shouldn't actually trigger, but add them for correctness
and for easier debugging if the test fails.
Amir Goldstein [Mon, 3 Feb 2025 22:32:04 +0000 (23:32 +0100)]
fsnotify: disable notification by default for all pseudo files
Most pseudo files are not applicable for fsnotify events at all,
let alone to the new pre-content events.
Disable notifications to all files allocated with alloc_file_pseudo()
and enable legacy inotify events for the specific cases of pipe and
socket, which have known users of inotify events.
Pre-content events are also kept disabled for sockets and pipes.
Amir Goldstein [Mon, 3 Feb 2025 22:32:03 +0000 (23:32 +0100)]
fsnotify: use accessor to set FMODE_NONOTIFY_*
The FMODE_NONOTIFY_* bits are a 2-bits mode. Open coding manipulation
of those bits is risky. Use an accessor file_set_fsnotify_mode() to
set the mode.
Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers()
to make way for the simple accessor name.
Here's an updated version with an additional comment saying that
lockref_init() initializes count to 1.
* patches from https://lore.kernel.org/r/20250130135624.1899988-1-agruenba@redhat.com:
lockref: remove count argument of lockref_init
gfs2: switch to lockref_init(..., 1)
gfs2: use lockref_init for gl_lockref
In qd_alloc(), initialize the lockref count to 1 to cover the common
case. Compensate for that in gfs2_quota_init() by adjusting the count
back down to 0; this only occurs when mounting the filesystem rw.
Miklos Szeredi [Thu, 30 Jan 2025 12:15:00 +0000 (13:15 +0100)]
statmount: let unset strings be empty
Just like it's normal for unset values to be zero, unset strings should be
empty instead of containing random values.
It seems to be a typical mistake that the mask returned by statmount is not
checked, which can result in various bugs.
With this fix, these bugs are prevented, since it is highly likely that
userspace would just want to turn the missing mask case into an empty
string anyway (most of the recently found cases are of this type).
Brahmajit Das [Tue, 21 Jan 2025 16:26:48 +0000 (21:56 +0530)]
vboxsf: fix building with GCC 15
Building with GCC 15 results in build error
fs/vboxsf/super.c:24:54: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
24 | static const unsigned char VBSF_MOUNT_SIGNATURE[4] = "\000\377\376\375";
| ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Due to GCC having enabled -Werror=unterminated-string-initialization[0]
by default. Separately initializing each array element of
VBSF_MOUNT_SIGNATURE to ensure NUL termination, thus satisfying GCC 15
and fixing the build error.
Su Hui [Sun, 19 Jan 2025 02:59:47 +0000 (10:59 +0800)]
fs/stat.c: avoid harmless garbage value problem in vfs_statx_path()
Clang static checker(scan-build) warning:
fs/stat.c:287:21: warning: The left expression of the compound assignment is
an uninitialized value. The computed value will also be garbage.
287 | stat->result_mask |= STATX_MNT_ID_UNIQUE;
| ~~~~~~~~~~~~~~~~~ ^
fs/stat.c:290:21: warning: The left expression of the compound assignment is
an uninitialized value. The computed value will also be garbage.
290 | stat->result_mask |= STATX_MNT_ID;
When vfs_getattr() failed because of security_inode_getattr(), 'stat' is
uninitialized. In this case, there is a harmless garbage problem in
vfs_statx_path(). It's better to return error directly when
vfs_getattr() failed, avoiding garbage value and more clearly.
Before attaching a new root to the old root, the children counter of the
new root is checked to verify that only the upcoming CPU's top group have
been connected to it. However since the recently added commit b729cc1ec21a
("timers/migration: Fix another race between hotplug and idle entry/exit")
this check is not valid anymore because the old root is pre-accounted
as a child to the new root. Therefore after connecting the upcoming
CPU's top group to the new root, the children count to be expected must
be 2 and not 1 anymore.
This omission results in the old root to not be connected to the new
root. Then eventually the system may run with more than one top level,
which defeats the purpose of a single idle migrator.
Also the old root is pre-accounted but not connected upon the new root
creation. But it can be connected to the new root later on. Therefore
the old root may be accounted twice to the new root. The propagation of
such overcommit can end up creating a double final top-level root with a
groupmask incorrectly initialized. Although harmless given that the final
top level roots will never have a parent to walk up to, this oddity
opportunistically reported the core issue:
genirq: Remove leading space from irq_chip::irq_print_chip() callbacks
The space separator was factored out from the multiple chip name prints,
but several irq_chip::irq_print_chip() callbacks still print a leading
space. Remove the superfluous double spaces.
Dave Airlie [Fri, 7 Feb 2025 04:47:11 +0000 (14:47 +1000)]
Merge tag 'drm-misc-fixes-2025-02-06' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes
A couple of fixes for ivpu to error handling, komeda for format
handling, AST DP timeout fix when enabling the output, locking fix for
zynqmp DP support, tiled format handling in drm/client, and refcounting
fix for bochs
Kent Overstreet [Sun, 26 Jan 2025 02:29:45 +0000 (21:29 -0500)]
bcachefs: bch2_bkey_sectors_need_rebalance() now only depends on bch_extent_rebalance
Previously, bch2_bkey_sectors_need_rebalance() called
bch2_target_accepts_data(), checking whether the target is writable.
However, this means that adding or removing devices from a target would
change the value of bch2_bkey_sectors_need_rebalance() for an existing
extent; this needs to be invariant so that the extent trigger can
correctly maintain rebalance_work accounting.
Instead, check target_accepts_data() in io_opts_to_rebalance_opts(),
before creating the bch_extent_rebalance entry.
This fixes (one?) cause of rebalance_work accounting being off.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Mon, 27 Jan 2025 06:21:44 +0000 (01:21 -0500)]
bcachefs: Fix discard path journal flushing
The discard path is supposed to issue journal flushes when there's too
many buckets empty buckets that need a journal commit before they can be
written to again, but at some point this code seems to have been lost.
Bring it back with a new optimization to make sure we don't issue too
many journal flushes: the journal now tracks the sequence number of the
most recent flush in progress, which the discard path uses when deciding
which buckets need a journal flush.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Jeongjun Park [Sun, 2 Feb 2025 06:13:51 +0000 (15:13 +0900)]
bcachefs: fix deadlock in journal_entry_open()
In the previous commit b3d82c2f2761, code was added to prevent journal sequence
overflow. Among them, the code added to journal_entry_open() uses the
bch2_fs_fatal_err_on() function to handle errors.
However, __journal_res_get() , which calls journal_entry_open() , calls
journal_entry_open() while holding journal->lock , but bch2_fs_fatal_err_on()
internally tries to acquire journal->lock , which results in a deadlock.
So we need to add a locked helper to handle fatal errors even when the
journal->lock is held.
Fixes: b3d82c2f2761 ("bcachefs: Guard against journal seq overflow") Signed-off-by: Jeongjun Park <aha310510@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Jeongjun Park [Fri, 31 Jan 2025 16:20:31 +0000 (01:20 +0900)]
bcachefs: fix incorrect pointer check in __bch2_subvolume_delete()
For some unknown reason, checks on struct bkey_s_c_snapshot and struct
bkey_s_c_snapshot_tree pointers are missing.
Therefore, I think it would be appropriate to fix the incorrect pointer checking
through this patch.
Fixes: 4bd06f07bcb5 ("bcachefs: Fixes for snapshot_tree.master_subvol") Signed-off-by: Jeongjun Park <aha310510@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kees Cook [Wed, 5 Feb 2025 21:45:26 +0000 (13:45 -0800)]
string.h: Use ARRAY_SIZE() for memtostr*()/strtomem*()
The destination argument of memtostr*() and strtomem*() must be a
fixed-size char array at compile time, so there is no need to use
__builtin_object_size() (which is useful for when an argument is
either a pointer or unknown). Instead use ARRAY_SIZE(), which has the
benefit of working around a bug in Clang (fixed[1] in 15+) that got
__builtin_object_size() wrong sometimes.
Kees Cook [Wed, 5 Feb 2025 20:48:07 +0000 (12:48 -0800)]
compiler.h: Introduce __must_be_byte_array()
In preparation for adding stricter type checking to the str/mem*()
helpers, provide a way to check that a variable is a byte array
via __must_be_byte_array().
Suggested-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Kees Cook <kees@kernel.org>
Kees Cook [Wed, 5 Feb 2025 20:32:49 +0000 (12:32 -0800)]
compiler.h: Move C string helpers into C-only kernel section
The C kernel helpers for evaluating C Strings were positioned where they
were visible to assembly inclusion, which was not intended. Move them
into the kernel and C-only area of the header so future changes won't
confuse the assembler.
Fixes: d7a516c6eeae ("compiler.h: Fix undefined BUILD_BUG_ON_ZERO()") Fixes: 559048d156ff ("string: Check for "nonstring" attribute on strscpy() arguments") Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Kees Cook <kees@kernel.org>
Alice Ryhl [Mon, 3 Feb 2025 08:40:57 +0000 (08:40 +0000)]
x86: rust: set rustc-abi=x86-softfloat on rustc>=1.86.0
When using Rust on the x86 architecture, we are currently using the
unstable target.json feature to specify the compilation target. Rustc is
going to change how softfloat is specified in the target.json file on
x86, thus update generate_rust_target.rs to specify softfloat using the
new option.
Note that if you enable this parameter with a compiler that does not
recognize it, then that triggers a warning but it does not break the
build.
[ For future reference, this solves the following error:
RUSTC L rust/core.o
error: Error loading target specification: target feature
`soft-float` is incompatible with the ABI but gets enabled in
target spec. Run `rustc --print target-list` for a list of
built-in targets
Eyal Birger [Sun, 2 Feb 2025 16:29:21 +0000 (08:29 -0800)]
selftests/seccomp: validate uretprobe syscall passes through seccomp
The uretprobe syscall is implemented as a performance enhancement on
x86_64 by having the kernel inject a call to it on function exit; User
programs cannot call this system call explicitly.
As such, this syscall is considered a kernel implementation detail and
should not be filtered by seccomp.
Enhance the seccomp bpf test suite to check that uretprobes can be
attached to processes without the killing the process regardless of
seccomp policy.
Eyal Birger [Sun, 2 Feb 2025 16:29:20 +0000 (08:29 -0800)]
seccomp: passthrough uretprobe systemcall without filtering
When attaching uretprobes to processes running inside docker, the attached
process is segfaulted when encountering the retprobe.
The reason is that now that uretprobe is a system call the default seccomp
filters in docker block it as they only allow a specific set of known
syscalls. This is true for other userspace applications which use seccomp
to control their syscall surface.
Since uretprobe is a "kernel implementation detail" system call which is
not used by userspace application code directly, it is impractical and
there's very little point in forcing all userspace applications to
explicitly allow it in order to avoid crashing tracked processes.
Pass this systemcall through seccomp without depending on configuration.
Note: uretprobe is currently only x86_64 and isn't expected to ever be
supported in i386.
Linus Torvalds [Thu, 6 Feb 2025 20:32:03 +0000 (12:32 -0800)]
Merge tag 'pci-v6.14-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull pci fixes from Bjorn Helgaas:
- When saving a device's state, always save the upstream bridge's PM L1
Substates configuration as well because the bridge never saves its
own state, and restoring a device needs the state for both ends; this
was a regression that caused link and power management errors after
suspend/resume (Ilpo Järvinen)
- Correct TPH Control Register write, where we wrote the ST Mode where
the THP Requester Enable value was intended (Robin Murphy)
* tag 'pci-v6.14-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/TPH: Restore TPH Requester Enable correctly
PCI/ASPM: Fix L1SS saving
Linus Torvalds [Thu, 6 Feb 2025 20:25:35 +0000 (12:25 -0800)]
Merge tag 'for-linus-6.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"Three fixes for xen_hypercall_hvm() that was introduced in the 6.13
cycle"
* tag 'for-linus-6.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: remove unneeded dummy push from xen_hypercall_hvm()
x86/xen: add FRAME_END to xen_hypercall_hvm()
x86/xen: fix xen_hypercall_hvm() to not clobber %rbx
Merge tag 'amd-pstate-v6.14-2025-02-06' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux
Merge amd-pstate driver fixes for 6.14-rc2 from Mario Limonciello:
"* Fix some error cleanup paths with mutex use and boost
* Fix a ref counting issue
* Fix a schedutil issue"
* tag 'amd-pstate-v6.14-2025-02-06' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux:
cpufreq/amd-pstate: Fix cpufreq_policy ref counting
cpufreq/amd-pstate: Fix max_perf updation with schedutil
cpufreq/amd-pstate: Remove the goto label in amd_pstate_update_limits
cpufreq/amd-pstate: Fix per-policy boost flag incorrect when fail
Kees Cook [Tue, 4 Feb 2025 17:45:13 +0000 (09:45 -0800)]
stackinit: Keep selftest union size small on m68k
The stack frame on m68k is very sensitive to the size of what needs to
be stored. Like done for long string testing, reduce the size of the
large trailing struct in the union initialization testing.
Matthew Maurer [Wed, 22 Jan 2025 00:14:43 +0000 (00:14 +0000)]
rust: kbuild: do not export generated KASAN ODR symbols
ASAN generates special synthetic symbols to help check for ODR
violations. These synthetic symbols lack debug information, so
gendwarfksyms emits warnings when processing them. No code should ever
have a dependency on these symbols, so we should not be exporting them,
just like the __cfi symbols.
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