The timekeeper update path uses a bulk memcpy() to synchronize the
timekeeper structure, which is not guaranteed to be atomic. This allows for
torn reads in ktime_get_real_seconds() on 64-bit systems, where the
sequence counter protection is bypassed for performance.
To prevent reading a torn 64-bit xtime_sec value, enforce atomic-like
access by using WRITE_ONCE() for the critical field before the bulk
memcpy() in timekeeping_update_from_shadow(). Correspondingly, use
READ_ONCE() in ktime_get_real_seconds() to ensure a fresh, consistent load
from memory.
[ tglx: Format changelog and add comment ]
Reported-by: syzbot+72789cd1697965e714ca@syzkaller.appspotmail.com
Signed-off-by: Dennis Moshegov <dennis@xzync.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260724154405.70-1-dennis@xzync.uk
Closes: https://syzkaller.appspot.com/bug?extid=72789cd1697965e714ca
Running kernel-doc on timer_migration.h reports:
Warning: kernel/time/timer_migration.h:105 bad line:
The empty line separating the @available paragraph from the @idle
member documentation in the struct tmigr_cpu kernel-doc block lacks
the " *" line prefix that kernel-doc requires on every line inside a
block. The header is not scanned by the build-time kernel-doc checks,
so the warning only shows up when kernel-doc is invoked on the file
directly.
Add the missing prefix. The empty line was introduced when the
@available documentation was expanded by commit 45a13ba52c
("timers/migration: Update stale @online doc to @available").
No functional change.
Signed-off-by: Babanpreet Singh <bbnpreetsingh@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Claude:claude-sonnet-5
Link: https://patch.msgid.link/20260717035947.7-1-bbnpreetsingh@gmail.com
Now that nothing inflates tick_length beyond tick_length_base (the
adjtime path was converted to use time_offset in the previous commit),
the two fields are always equal.
Remove tick_length_base and keep tick_length as the single field.
Remove the per-second reset and the delta update in
ntp_update_frequency() since there is no separate base to track.
No functional change intended.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.6-1m
Link: https://patch.msgid.link/20260621220051.1030462-8-dwmw2@infradead.org
time_offset (the exponential PLL phase slew) and time_adjust (the
linear adjtime() slew) can be asked to move the clock in opposite
directions. second_overflow() folds only their *net* into the per-tick
skew_delta, so the cancelling overlap would never be drained from
either tracker by the per-tick code — and if they cancel exactly,
skew_delta is zero and neither converges at all.
Arguably we could just let one of them entirely cancel out the other
immediately, but that would be a change in userspace-visible behaviour.
Instead, preserve the existing behaviour by calculating the "conflict"
portion between the opposing skew each second, and transferring that
amount directly from one tracker to the other.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-7-dwmw2@infradead.org
The legacy adjtime() slew (ADJ_OFFSET_SINGLESHOT) was the last user of
tick_length != tick_length_base: it slewed the clock by inflating
tick_length directly, which delivered the correction imprecisely (e.g.
delivering only 4997.5µs when asked for a 5ms skew).
Deliver it accurately through the same per-tick mechanism that is now
used for time_offset, allowing it to contribute to skew_delta and thus
drive the delivery through ntp_error and mult selection.
To allow for accurate accounting, store the sub-microsecond part of
time_adjust is separately, while keeping time_adjust in microseconds
as that's the external API.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-6-dwmw2@infradead.org
Currently, the phase offset of time_offset and time_adjust is delivered
by adjusting tick_length in second_overflow(), and immediately draining
time_offset/time_adjust by the amount that the tick_length adjustment is
*estimated* to cause. This is fairly approximate, in part because it is
not always correct to assume that precisely NTP_INTERVAL_FREQ ticks will
occur between one call to second_overflow() and the next. It could also
over and under-run in the final second of delivery.
Instead of inflating tick_length, transfer the intended skew directly
into ntp_error each tick to achieve the desired rate.
In second_overflow(), calculate skew_delta which is the per-tick slew
rate, in the same units as time_offset: (ns << NTP_SCALE_SHIFT) / HZ.
In logarithmic_accumulation(), drain up to 'skew_delta' time units from
time_offset into ntp_error to drive the overall effective rate. The new
ntp_drain_skew() function returns the amount which is actually 'claimed'
by time_offset (and in a future patch, time_adjust). Any overrun which
is delivered by the changed 'mult' (as described below) but not claimed
by ntp_drain_skew() will remain in ntp_error to be corrected away in
subsequent ticks.
Simply transferring the precise amount from time_offset to ntp_error
would be sufficent to make the time *eventually* converge, however the
skew delivered is limited by the choice of { mult, mult+1 } each tick
and thus the convergence would be extremely slow.
In theory we could inflate ntp_err_mult with the magnitude of ntp_error
in the general case — but that would cause overcorrection in a tickless
kernel. Instead, in timekeeping_adjust(), take skew_delta into account
when calculating 'mult', such that the available {mult, mult+1} choices
bracket the overall effective rate *including* the skew, to avoid the
delta just building up in ntp_error.
The effect is that the inflated 'mult' causes ntp_error to grow because
xtime_interval is (e.g.) longer than the true tick_length. But then the
same delta is removed again as it's drained from time_offset.
This gives behaviour equivalent to the old tick_length += delta approach
but with exact per-tick accounting of the time_offset actually imparted
to the clock, and no overrun.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Link: https://patch.msgid.link/20260621220051.1030462-5-dwmw2@infradead.org
cycle_interval is an integer number of counter cycles per NTP interval,
so the real time it represents differs from the nominal
NTP_INTERVAL_LENGTH by up to half a counter period. For coarse
clocksources this is significant: the 3.579545 MHz ACPI PM timer at
HZ=1000 rounds 3579.545 cycles up to 3580, making each tick 1.000127 ms
(+127 PPM).
Commit a386b5af8e ("time: Compensate for rounding on odd-frequency
clocksources") introduced xtime_remainder to compensate for exactly
this, citing the same 127 PPM ACPI PM example. The compensation is
correct and necessary, but it was applied inside the timekeeping
accumulation in timekeeping.c: subtracted in the mult computation in
timekeeping_adjust() and folded into the ntp_error update in
logarithmic_accumulation(). That keeps the base rate correct and leaves
NTP its full symmetric +/-MAXFREQ range rather than +373/-627 PPM, but
the NTP code in ntp.c never sees it: tick_length is computed without the
correction, so ntp.c's notion of how long a tick is disagrees with the
rate timekeeping actually produces.
Make the offset an explicit part of the NTP tick_length instead. Add
ntp_data::cs_tick_adj, a fixed per-second addend that
ntp_update_frequency() includes alongside ntp_tick_adj and time_freq.
tk_setup_internals() computes it from the difference between the real
cycle_interval duration and the nominal interval, stores it in the
timekeeper, and hands it to NTP through a new argument to ntp_clear() --
which already recomputes the frequency and is invoked after every
clocksource (re)configuration. timekeeping_init() now uses TK_UPDATE_ALL
for this; clearing NTP there is otherwise redundant since ntp_init() has
just initialised it.
ntp.c now computes the true tick rate, giving a single source of truth.
Like ntp_tick_adj, cs_tick_adj stays internal to the kernel: userspace
still sees the nominal 1.000000 ms tick via adjtimex and is unaware of
the addends. timekeeping_adjust() and logarithmic_accumulation() use
ntp_tick / xtime_interval directly, and xtime_remainder is removed.
The base-rate arithmetic is unchanged: ntp_tick becomes
xtime_interval << ntp_error_shift, so the mult division yields the same
base mult and the ntp_error accumulation still nets to zero per tick.
Beyond the cleanup of treating all the tick_length contributions
(nominal interval, ntp_tick_adj, cs_tick_adj, time_freq) consistently
as addends in one place, it also prepares for feed-forward discipline:
a future timekeeping_set_reference() will set tick_length to track an
absolute external reference such as a vmclock, and that path needs
ntp.c to own a tick_length that already reflects the clocksource
quantisation, with no hidden correction applied elsewhere.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.8
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/20260621220051.1030462-4-dwmw2@infradead.org
timekeeping_apply_adjustment() modifies xtime_nsec to ensure monotonicity
when mult changes:
xtime_nsec -= offset
This ensures that the time reported to userspace does not jump when the
multiplier is adjusted from one tick to the next. However, the ntp_error
accumulator which tracks the difference between intended and actual
clock position was not being updated to reflect this additional
discrepancy.
An earlier attempt at this compensation existed as:
ntp_error -= (interval - offset) << ntp_error_shift
but was removed in commit c2cda2a5bd ("timekeeping/ntp: Don't align
NTP frequency adjustments to ticks") because it was a major source of
NTP error. That's because (interval - offset) was wrong: the subtraction
of "interval" prematurely accounted for the changed xtime_interval of
the next tick, which would be correctly accounted in the next
accumulation anyway — a double subtraction.
What is actually needed is just the "offset" part: ntp_error must be
told that xtime_nsec moved by "offset" without a corresponding change
in the intended position. For the normal ±1 mult dithering this is
negligible (the adjustments cancel over time), but for larger mult
changes — such as when an external reference clock sets a new
frequency — the one-time uncompensated offset is significant.
Fix by adjusting ntp_error by the correct amount:
ntp_error += offset << ntp_error_shift
This keeps ntp_error consistent with the actual xtime_nsec position
after the adjustment, and ensures the discrepancy is correctly smoothed
away over time and the clock returns to where it should have been.
Fixes: c2cda2a5bd ("timekeeping/ntp: Don't align NTP frequency adjustments to ticks")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Assisted-by: Kiro:claude-opus-4.6-1m
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/20260621220051.1030462-3-dwmw2@infradead.org
hrtimer_get_next_event() runs on every tick-stop decision via
get_next_timer_interrupt() -> cmp_next_hrtimer_event(). When high
resolution timers are active it must return KTIME_MAX -- the caller
documents and depends on this.
The function takes cpu_base->lock, checks hres_active, and returns
KTIME_MAX.
Taking the lock is not required because cpu_base->hres_active is only
written by the local CPU in hrtimer_switch_to_hres() from hard interrupt
context and in hrtimers_cpu_starting() during bring-up.
All callers of hrtimer_get_next_event() reach it from the tick-stop /
cpuidle paths with interrupts disabled on that CPU. No writer can therefore
race with the read, so an unlocked hres_active check is stable and the lock
can be skipped in this case.
On a 176-thread AMD EPYC 9D64 running a production workload, bucketing
callers of native_queued_spin_lock_slowpath(), the slowpath had 199 samples
in total, of which 54 are attributed to hrtimer_get_next_event(), i.e. this
accounts for ~27% of slowpath hits on this specific workload.
Move the hres_active check before the lock guard region to address this.
[ tglx: Massaged change log and comments ]
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260707153800.542394-1-usama.arif@linux.dev
The function validates tv_sec to be within [-KTIME_SEC_MAX, KTIME_SEC_MAX]
but never validates that tv_nsec is within the valid range of
[0, NSEC_PER_SEC-1] before using it in timespec64_add().
timespec64_add() expects both timespec64 structures to have normalized
values with tv_nsec in the range [0, 999999999]. If off->val.tv_nsec
contains invalid values (negative or >= NSEC_PER_SEC), it could lead to
incorrect calculations or unexpected behavior.
Add validation to ensure tv_nsec is within the valid range before
performing the addition.
Fixes: 04a8682a71 ("fs/proc: Introduce /proc/pid/timens_offsets")
Signed-off-by: Malaya Kumar Rout <malayarout91@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260704093429.89350-1-malayarout91@gmail.com
When the WARN_ON_ONCE(i >= tmigr_hierarchy_levels) assertion triggers,
the function returns -EINVAL without freeing the 'stack' memory allocated
via kzalloc_objs() at the beginning of the function.
Add kfree(stack) before returning to prevent the memory leak.
Fixes: 6c181b5667 ("timers/migration: Convert "while" loops to use "for"")
Signed-off-by: Malaya Kumar Rout <malayarout91@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260704085533.87098-1-malayarout91@gmail.com
tk_aux_sysfs_init() creates one child kobject per auxiliary clock. If a
later child or sysfs group creation fails, the current error path only
puts the parent kobjects and leaves earlier children and groups behind.
Store the child kobjects during init and remove the successfully created
groups and kobjects on failure.
Fixes: 7b5ab04f03 ("timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260703165337.168445-1-dbgh9129@gmail.com
init_clocksource_sysfs() registers the clocksource subsystem before
registering the clocksource device. If device_register() fails, the
function returns the error while leaving the subsystem registered.
Unregister the clocksource subsystem on that failure path so the
successful subsystem registration is unwound before returning.
Fixes: d369a5d8fc ("clocksource: convert sysdev_class to a regular subsystem")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260702215733.84588-1-dbgh9129@gmail.com
WATCHDOG_INTERVAL_NS has been unused since it was introduced by commit
763aacf86f ("clocksource: Rewrite watchdog code completely"); the
watchdog timer rearming uses WATCHDOG_INTERVAL (in jiffies) directly and
the nanosecond variant has never had a user.
Remove the dead macro. No functional change.
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260706084557.3845091-3-zhanxusheng@xiaomi.com
__hrtimer_reprogram() takes a @next_timer argument but never references
it; it only stores @expires_next into cpu_base->expires_next and
reprograms the clock event device. The argument has been unused since
commit b14bca97c9 ("hrtimer: Consolidate reprogramming code").
Drop it and update the two callers. No functional change.
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260706084557.3845091-2-zhanxusheng@xiaomi.com
The comments related to raw monotonic timestamps for the various
snapshot mechanisms in code and struct documentation are ambiguous. They
reference them as CLOCK_MONOTONIC_RAW timestamps, but with the arrival
of AUX clocks that's not longer correct.
The raw monotonic timestamps only represent CLOCK_MONOTONIC_RAW for the
system time clock IDs, i.e. REALTIME, MONOTONIC, BOOTTIME, TAI.
For AUX clocks they refer to the monotonic raw clock which is related to
the individual AUX clocks. These monotonic raw timestamps have the same
conversion factor as CLOCK_MONOTONIC_RAW, but differ from that by an
offset:
MONORAW(AUX$N) = MONORAW(SYSTEM) + OFFSET(AUX$N)
The offset is established when a AUX clock is enabled and stays constant
for the lifetime of the AUX clock.
Update the comments so they reflect reality.
Reported-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/87wlv9k3wz.ffs@fw13
After commit f90fff1e15 ("posix-cpu-timers: fix race between
handle_posix_cpu_timers() and posix_cpu_timer_del()"), tsk->sighand is
stable in handle_posix_cpu_timers(), so it can use the plain
spin_lock_irqsave(&tsk->sighand->siglock).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Bradley Morgan <include@grrlz.net>
Link: https://patch.msgid.link/akjp8AGpY8eJG5I1@redhat.com
clock_base_next_timer_safe() was added by commit a64ad57e41 ("hrtimer:
Simplify run_hrtimer_queues()") but has never had a caller; the queue
iteration in __hrtimer_run_queues() uses clock_base_next_timer() instead.
The two are functionally equivalent: struct hrtimer embeds the timerqueue
node at offset 0, so container_of() of a NULL node yields NULL. Thus
clock_base_next_timer() already returns NULL on an empty queue and the
explicit NULL check in the _safe variant is redundant.
Being a static __always_inline function it does not trigger
-Wunused-function, so the dead code has gone unnoticed. Remove it.
No functional change.
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260625140901.929554-1-zhanxusheng@xiaomi.com
Pull power management fixes from Rafael Wysocki:
"These fix the schedutil cpufreq governor and drop a bogus warning
from the cpuidle core:
- Remove a misguided warning along with an inaccurate comment
next to it from the cpuidle core (Rafael Wysocki)
- Clear need_freq_update as appropriate in the .adjust_perf()
path of the schedutil cpufreq governor to avoid calling
cpufreq_driver_adjust_perf() unnecessarily on every scheduler
utilization update (Zhongqiu Han)"
* tag 'pm-7.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: Allow exit latency to exceed target residency
cpufreq: schedutil: Fix uncleared need_freq_update on the .adjust_perf() path
Pull block fixes from Jens Axboe:
- blk-cgroup locking rework and fixes:
- fix a use-after-free in __blkcg_rstat_flush()
- defer freeing policy data until after an RCU grace period
- defer the blkcg css_put until the blkg is unlinked from
the queue
- unwind the queue_lock nesting under RCU / blkcg->lock
across the lookup, create, associate and destroy paths
- NVMe fixes via Keith:
- Fix a crash and memory leak during invalid cdev teardown,
and related cdev cleanups (Maurizio, John)
- nvmet fixes: handle TCP_CLOSING in the tcp state_change
handler, reject short AUTH_RECEIVE buffers, handle inline
data with a nonzero offset in rdma, fix an sq refcount leak,
and allocate ana_state with the port (Maurizio, Michael,
Bryam, Wentao, Rosen)
- nvme-fc fix to not cancel requests on an IO target before it
is initialized (Mohamed)
- nvme-apple fix to prevent shared tags across queues on Apple
A11 (Nick)
- Various smaller fixes and cleanups (John)
- MD fixes via Yu Kuai:
- raid1/raid10 fixes for writes_pending and barrier reference
leaks on write and discard failures, plus REQ_NOWAIT handling
fixes (Abd-Alrhman)
- raid5 discard accounting and validation, and a batch of fixes
for stripe batch races (Yu Kuai, Chen)
- Protect raid1 head_position during read balancing (Chen)
- block bio-integrity fixes: correct an error injection static key
decrement, fix GFP flag confusion in bio_integrity_alloc_buf(), and
handle REQ_OP_ZONE_APPEND in __bio_integrity_action() (Christoph)
- Fixes for bio_iov_iter_bounce_write(): revert the iov_iter after a
short copy, and respect the iov_iter nofault flag (Qu)
- Invalidate the cached plug timestamp after a task switch, and clear
PF_BLOCK_TS in copy_process() (Usama)
- Fix the IORING_URING_CMD_REISSUE flags check in blkdev_uring_cmd()
(Yitang)
- Remove a redundant plug in __submit_bio() (Wen)
- Don't warn when reclassifying a busy socket lock in nbd (Deepanshu)
* tag 'block-7.2-20260625' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (45 commits)
block: handle REQ_OP_ZONE_APPEND in __bio_integrity_action
block: fix GFP_ flags confusion in bio_integrity_alloc_buf
block, bfq: don't grab queue_lock to initialize bfq
mm/page_io: don't nest queue_lock under rcu in bio_associate_blkg_from_page()
blk-cgroup: don't nest queue_lock under blkcg->lock in blkcg_destroy_blkgs()
blk-cgroup: don't nest queue_lock under rcu in bio_associate_blkg()
blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()
blk-cgroup: don't nest queue_lock under rcu in blkcg_print_blkgs()
blk-cgroup: delay freeing policy data after rcu grace period
blk-cgroup: protect iterating blkgs with blkcg->lock in blkcg_print_stat()
md/raid5: avoid R5_Overlap races while breaking stripe batches
md/raid5: use stripe state snapshot in break_stripe_batch_list()
blk-cgroup: defer blkcg css_put until blkg is unlinked from queue
blk-cgroup: fix UAF in __blkcg_rstat_flush()
block, bfq: protect async queue reset with blkcg locks
nbd: don't warn when reclassifying a busy socket lock
block: fix incorrect error injection static key decrement
md/raid5: let stripe batch bm_seq comparison wrap-safe
md/raid1: protect head_position for read balance
md/raid1: free r1_bio when REQ_NOWAIT is set and read would block on retry
...
Pull pci updates from Bjorn Helgaas:
"Enumeration:
- Remove MPS/MRRS Kconfig settings (CONFIG_PCIE_BUS_*) that worked
around a WiFi device defect; use a quirk or boot-time
"pci=pcie_bus_tune_*" kernel parameter instead (Bjorn Helgaas)
- Always lift 2.5GT/s restriction in PCIe failed link retraining to
avoid clamping a link to 2.5GT/s after hot-plug changes the device
(Maciej W. Rozycki)
- Request bus reassignment when not probe-only to fix an enumeration
regression on Marvell CN106XX and possibly other DT-based systems
(Ratheesh Kannoth)
- Fix procfs race between pci_proc_init() and pci_bus_add_device()
that resulted in 'proc_dir_entry ... already registered' warnings
and pointer corruption (Krzysztof Wilczyński)
- Fix sysfs race that causes 'duplicate filename' warnings and boot
panics by converting PCI resource files to static attributes
(Krzysztof Wilczyński)
- Expose sysfs 'resourceN_resize' attributes only on platforms with
PCI mmap (Krzysztof Wilczyński)
- Require CAP_SYS_ADMIN to write to sysfs 'resourceN_resize'
attributes (Krzysztof Wilczyński)
- Add security_locked_down(LOCKDOWN_PCI_ACCESS) to alpha PCI resource
mmap path to match the generic path (Krzysztof Wilczyński)
- Use kstrtobool() to parse the 'rom' attribute input to avoid the
unexpected behavior of enabling the ROM when writing '0' with no
trailing newline (Krzysztof Wilczyński)
Resource management:
- Improve resource claim logging for debuggability (Ilpo Järvinen)
- Clean up several uses of const parameters (Ilpo Järvinen)
- Check option ROM header signatures and lengths before accessing to
avoid page faults and alignment faults (Guixin Liu)
ASPM:
- Don't reconfigure ASPM when entering low-power D-state; only do it
when returning back to D0 (Carlos Bilbao)
Power management:
- During suspend, set power state to 'unknown' for all devices, not
just those with drivers (Lukas Wunner)
- Skip restoring Resizable BARs and VF Resizable BARs if device
doesn't respond to config reads, to avoid invalid array accesses
(Marco Nenciarini)
- Add pci_suspend_retains_context() so drivers can tell whether
devices retain internal state across suspend/resume, since some
platforms reset devices on suspend; use this in nvme to avoid
issues on Qcom RCs (Manivannan Sadhasivam)
Power control:
- Only to power on/off devices that actually support power control to
avoid poking at incompatible devices mentioned in DT (Manivannan
Sadhasivam)
Virtualization and resets:
- Log device readiness timeouts as errors, not warnings, because the
device is likely unusable in this case (Bjorn Helgaas)
- Wait for device readiness after soft reset (D3hot ->
D0uninitialized transition), when the device may respond with
Request Retry Status (RRS) if it needs more time to initialize
(Bjorn Helgaas)
- Drop unnecessary retries when restoring BARs because resets should
now already include all required delays (Lukas Wunner)
- Avoid FLR for MediaTek MT7925 WiFi, where FLR fails after a VM
terminates uncleanly (Jose Ignacio Tornos Martinez)
- Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems,
which seem not to support it correctly (Jose Ignacio Tornos
Martinez)
Peer-to-peer DMA:
- Prevent P2PDMA as well as CPU access to non-mappable BARs, e.g.,
s390 ISM BARs (Matt Evans)
- Add Intel QAT, DSA, IAA devices to whitelist (Lukas Wunner)
Endpoint framework:
- Add endpoint controller APIs for use by function drivers to
discover auxiliary blocks like DMA engines (Koichiro Den)
- Remember DesignWare eDMA engine base/size and expose them via the
EPC aux-resource API (Koichiro Den)
- Add endpoint embedded doorbell fallback, used if MSI allocation
fails (Koichiro Den)
- Validate BAR index and remove dead BAR read in endpoint doorbell
test (Carlos Bilbao)
- Unwind MSI/MSI-X vectors if NTB initialization fails part-way
through (Koichiro Den)
- Cache sleepable pci_irq_vector() value at ISR setup to avoid
calling it from hardirq context (Koichiro Den)
- Call sleepable pci_epc_raise_irq() from a work item instead of
atomic context, e.g., when setting bits in NTB peer doorbells in
the ntb_peer_db_set() path (Koichiro Den)
- Report 0-based vNTB doorbell vector to account for link event 0 and
historically skipped slot 1 (Koichiro Den)
- Prevent configfs writes to vNTB db_count and other values that are
already in use after EPC attach (Koichiro Den)
- Account for vNTB db_valid reserved slots (link event 0 and
historically skipped slot 1) so they don't appear as valid
doorbells (Koichiro Den)
- Implement vNTB .db_vector_count()/mask() for doorbells so clients
can use multiple vectors and avoid thundering herds (Koichiro Den)
- Report 0-based NTB doorbell vector to account for link event 0 and
historically skipped slot 1 (Koichiro Den)
- Fix doorbell bitmask and IRQ vector handling to clear only
specified bits, use the correct vector for non-contiguous Linux IRQ
numbers, and validate incoming vectors (Koichiro Den)
- Implement NTB .db_vector_count()/mask() for doorbells so clients
can use multiple vectors (Koichiro Den)
Native PCIe controller infrastructure:
- Add pci_host_common_link_train_delay() for the mandatory delay
after > 5GT/s Link training completes and use it for cadence HPA,
j721e, LGA; dwc; aardvark, mediatek-gen3, rzg3s (Hans Zhang)
- Protect root bus removal with rescan lock in altera, brcmstb,
cadence, dwc, iproc, mediatek, plda, rockchip to prevent
use-after-free or crashes when racing with sysfs rescan or hotplug
(Hans Zhang)
- Add pci_host_common_parse_ports() for use by any native driver to
parse Root Port properties (per-Link features like width, speed,
PHY, power and reset control, etc should be described in Root Port
stanzas, not the host bridge; currently only reset GPIOs
implemented) (Sherry Sun)
New native PCIe controller drivers:
- Add DT binding and driver for UltraRISC DP1000 PCIe controller
(Xincheng Zhang, Jia Wang)
Altera PCIe controller driver:
- Do not dispose of the parent IRQ mapping, which belongs to the
parent interrupt controller (Mahesh Vaidya)
- Fix chained IRQ handler ordering issue and resource leaks on probe
failure (Mahesh Vaidya)
AMD MDB PCIe controller driver:
- Assert PERST# on shutdown so any connected Endpoints are held in
reset during shutdown (Sai Krishna Musham)
Amlogic Meson PCIe controller driver:
- Propagate devm_add_action_or_reset() failure to fix probe error
path (Shuvam Pandey)
- Add .remove() callback to deinitialize the host bridge and power
off the PHY (Shuvam Pandey)
Broadcom iProc PCIe controller driver:
- Restore .map_irq() assignment; its removal broke INTx on the iproc
platform bus driver (Mark Tomlinson)
Broadcom STB PCIe controller driver:
- No change, but products using certain WiFi devices may be affected
by removal of CONFIG_PCIE_BUS_* (see above)
Freescale i.MX6 PCIe controller driver:
- Move IMX6SX_GPR12_PCIE_TEST_POWERDOWN handling into the core reset
functions (Richard Zhu)
- Assert PERST# before enabling regulators to ensure that even if
power is enabled, endpoint stays inactive until REFCLK is stable
(Sherry Sun)
- Parse reset properties in Root Port nodes (falling back to host
bridge) to help support Key E connectors and the pwrctrl framework
(Sherry Sun)
- Configure i.MX95 REF_USE_PAD before PHY reset (Richard Zhu)
- Assert i.MX95 ref_clk_en after reference clock stabilizes (Richard
Zhu)
- Integrate new pwrctrl API for DTs with Root Port-level power
supplies (Sherry Sun)
Intel Gateway PCIe controller driver:
- Enable clock before PHY init for correct ordering (Florian Eckert)
- Add .start_link() callback so the driver works again (Florian
Eckert)
- Stop overwriting the ATU base address discovered by
dw_pcie_get_resources() (Florian Eckert)
- Add DT 'atu' region since this is hardware-specific, and fall back
to driver default if lacking (Florian Eckert)
Loongson PCIe controller driver:
- Ignore downstream devices only on internal bridges to avoid
Loongson hardware issue (Rong Zhang)
- Quirk old Loongson-3C6000 bridges that advertise incorrect
supported link speeds (Ziyao Li)
Marvell MVEBU PCIe controller driver:
- Use fixed-width interrupt masks to avoid truncation in 64-bit
builds (Rosen Penev)
MediaTek PCIe controller driver:
- Use FIELD_PREP() to fix incorrect operator precedence in
PCIE_FTS_NUM_L0 (Li RongQing)
- Fix IRQ domain leak when port fails to enable (Manivannan
Sadhasivam)
- Use actual physical address for MSI message address instead of
virt_to_phys() (Manivannan Sadhasivam)
- Add EcoNet EN7528 to DT binding (Caleb James DeLisle)
MediaTek PCIe Gen3 controller driver:
- Deassert PCIE_PHY_RSTB so REFCLK is stable for at least 100ms
(PCIE_T_PVPERL_MS) before deasserting PERST# (Jian Yang)
- Add .shutdown() to assert PERST# before powering down device (Jian
Yang)
- Do full device power down on removal, including asserting PERST#,
when removing driver (Chen-Yu Tsai)
- Fix a 'failed to create pwrctrl devices' error message that was
inadvertently skipped (Chen-Yu Tsai)
NVIDIA Tegra194 PCIe controller driver:
- Program the DesignWare PORT_AFR L1 entrance latency based on the
'aspm-l1-entry-delay-ns' DT property (Manikanta Maddireddy)
Qualcomm PCIe controller driver:
- Add Eliza SoC compatible in DT binding (Krishna Chaitanya Chundru)
- Set max OPP during resume so DBI register accesses don't fail with
NoC errors (Qiang Yu)
- Add pci_host_common_d3cold_possible() to determine whether
downstream devices are already in D3hot and wakeup-enabled devices
are capable of generating PME from D3cold (Krishna Chaitanya
Chundru)
- Add .get_ltssm() callback to get the LTSSM status without DBI,
since DBI may be inaccessible after PME_Turn_Off (Krishna Chaitanya
Chundru)
- Power down PHY via PARF_PHY_CTRL before disabling rails/clocks to
avoid power leakage (Krishna Chaitanya Chundru)
- Decide whether suspend should put the link in L2 and power down
using pci_host_common_d3cold_possible() instead of checking whether
ASPM L1 is enabled (Krishna Chaitanya Chundru)
- Add qcom D3cold support to tear down interconnect bandwidth and OPP
votes (Krishna Chaitanya Chundru)
- Handle unsupported mixed PERST#/PHY DT configurations, e.g., PHY in
RP node while PERST# is in the RC node, but warn about the DT issue
(Qiang Yu)
- Program T_POWER_ON based on DT 't-power-on-us' property in case
hardware advertises incorrect values (Krishna Chaitanya Chundru)
- Disable ASPM L0s for SA8775P (Shawn Guo)
- Initialize DWC MSI lock for firmware-managed ECAM hosts, which
don't use the dw_pcie_host_init() path that initializes the lock
(Yadu M G)
Renesas RZ/G3S PCIe controller driver:
- Add RZ/V2N DT support (Lad Prabhakar)
SOPHGO PCIe controller driver:
- Add 'dma-coherent' DT property for sg2042-pcie driver (Han Gao)
Synopsys DesignWare PCIe controller driver:
- Apply ECRC TLP Digest workaround for all DesignWare cores prior to
5.10a, not just 4.90a and 5.00a (Manikanta Maddireddy)
- Use common struct dw_pcie 'mode' rather than duplicating it in
artpec6, dra7xx, dwc-pcie, and keembay driver structs (Hans Zhang)
- Use DEFINE_SHOW_ATTRIBUTE for ltssm_status debugfs to reduce
boilerplate and fix a seq_file memory leak by including a
.release() callback (Hans Zhang)
- Fix a signedness bug in fault injection test code (Dan Carpenter)
- Avoid NULL pointer dereference when tearing down debugfs for
controller that lacks RAS DES capability (Shuvam Pandey)
MicroSemi Switchtec management driver:
- Add Gen6 Device IDs (Ben Reed)
Miscellaneous:
- Remove unused gpio.h include from amd-mdb, designware-plat, fu740,
visconti drivers (Andy Shevchenko)
- Fix typos in documentation (josh ziegler)
- Use FIELD_MODIFY() instead of open-coding it (Hans Zhang)"
* tag 'pci-v7.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (168 commits)
PCI/sysfs: Use kstrtobool() to parse the ROM attribute input
PCI/sysfs: Limit BAR resize attribute scope to platforms with PCI mmap
PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()
PCI/sysfs: Convert legacy I/O and memory attributes to static definitions
PCI/sysfs: Add __weak pci_legacy_has_sparse() helper
alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()
PCI: Add macros for legacy I/O and memory address space sizes
PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()
alpha/PCI: Convert resource files to static attributes
alpha/PCI: Add static PCI resource attribute macros
alpha/PCI: Remove WARN from __pci_mmap_fits() and __legacy_mmap_fits()
alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs
alpha/PCI: Use PCI resource accessor macros
alpha/PCI: Use BAR index in sysfs attr->private instead of resource pointer
alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope
PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()
PCI/sysfs: Warn about BAR resize failure in __resource_resize_store()
PCI/sysfs: Convert PCI resource files to static attributes
PCI/proc: Fix race between pci_proc_init() and pci_bus_add_device()
...
Pull misc timer fixes from Ingo Molnar:
- Fix timekeeping locking order bug in the timekeeping init code
(Mikhail Gavrilov)
- Fix u64 multiplication bug in the posix-cpu-timers code on 32-bit
kernels (Zhan Xusheng)
- Fix macro name in comment block (Ethan Nelson-Moore)
- Fix off-by-one bug in the compat settimeofday() usecs validation code
(Wang Yan)
* tag 'timers-urgent-2026-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Fix off-by-one in compat settimeofday() usec validation
hrtimer: Correct CONFIG_NO_HZ_COMMON macro name in comment
posix-cpu-timers: Use u64 multiplication in update_rlimit_cpu()
timekeeping: Register default clocksource before taking tk_core.lock
Pull misc CPU hotplug fixes from Ingo Molnar:
- Fix CPU hotplug error handling rollback bug (Bradley Morgan)
- Fix possible output OOB write bug in the sysfs hotplug states
printing code (Bradley Morgan)
* tag 'smp-urgent-2026-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu: hotplug: Bound hotplug states sysfs output
cpu: hotplug: Preserve per instance callback errors
Pull locking fix from Ingo Molnar:
- Fix the incorrect RCU protection in rt_spin_unlock() (Thomas
Gleixner)
* tag 'locking-urgent-2026-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rt: Fix the incorrect RCU protection in rt_spin_unlock()
Pull misc core fixes from Ingo Molnar:
- Fix an MM-CID race that can cause an OOB write (Rik van Riel)
- Fix a debugobjects OOM handling race (Thomas Gleixner)
* tag 'core-urgent-2026-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Plug race against a concurrent OOM disable
sched/mmcid: Fix OOB clear_bit when CID is MM_CID_UNSET in fixup path
Pull sched_ext tree reorg from Tejun Heo:
"Pure source reorganization with no functional change:
- the kernel/sched/ext* files move into a new kernel/sched/ext/
subdirectory
- the headers and sources are made self-contained so editor tooling
can parse each file on its own"
* tag 'sched_ext-for-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Move shared helpers from ext.c into internal.h and cid.h
sched_ext: Make kernel/sched/ext/ sources self-contained for clangd
sched_ext: Move sources under kernel/sched/ext/
BPF LSM programs can currently attach to xfrm_decode_session(). That
hook may return an error, but security_skb_classify_flow() calls it
from a void path and triggers BUG_ON() if an error is returned.
Disable BPF attachment to the hook to prevent a BPF LSM program from
turning packet classification into a full panic.
Fixes: 9e4e01dfd3 ("bpf: lsm: Implement attach, detach and execution")
Signed-off-by: Bradley Morgan <include@grrlz.net>
Link: https://lore.kernel.org/r/20260619130305.27779-1-include@grrlz.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When the BPF verifier processes a context load of an LSM hook return
value, it calls __mark_reg_s32_range() to narrow the register to the
hook's valid range. However, __mark_reg_s32_range() intersects the new
range with the register's existing bounds using max_t()/min_t() rather
than replacing them.
If the destination register carries stale bounds from a prior instruction
(e.g. BPF_MOV64_IMM), the intersection can produce a range narrower than
reality. The verifier then believes it knows the register's exact value,
while at runtime the actual hook return value is loaded, creating a
verifier/runtime mismatch that can be used to bypass BPF memory safety
checks.
The else branch already calls mark_reg_unknown() to reset register state
before any narrowing. Apply the same reset in the is_retval path so
stale bounds are cleared before __mark_reg_s32_range() intersects.
Fixes: 5d99e198be ("bpf, lsm: Add check for BPF LSM return value")
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260622230123.3695446-2-tristmd@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
idle.c and cid.c are included into build_policy.c together with ext.c and
use helpers that ext.c defines. Because the helpers live in ext.c, the two
files can not parse as standalone units and clangd reports errors in them.
Move the helpers to the headers they belong to. The op-dispatch macros and
helpers plus scx_parent() to internal.h, and scx_cpu_arg()/scx_cpu_ret() to
cid.h. No functional change. idle.c and cid.c now parse clean standalone.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
The sources under kernel/sched/ext/ build as a single translation unit:
build_policy.c includes the source files and headers. An LSP/clangd editor
parses each as a standalone unit, sees no types, and reports a flood of
errors.
Give each header its dependencies and include guard, and have each source
include the headers it uses.
ext.c, arena.c and the ext headers now parse clean standalone. idle.c and
cid.c still reference a few macros and helpers defined in ext.c. The next
patch moves those to shared headers.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
__clean_func_state() cleans dead stack slots in 4-byte halves. When the
high half of a STACK_SPILL slot is dead and the low half remains live,
cleanup converts the live low half to STACK_MISC or STACK_ZERO and clears
the saved spilled_ptr metadata.
That conversion is safe only for scalar spills. For a pointer spill, this
metadata clear lets a later 32-bit fill from the still-live half avoid the
normal non-scalar register-fill check and be treated as an ordinary scalar
stack read.
Leave non-scalar spill slots intact in this half-live shape. This is
conservative for pruning and preserves the existing
check_stack_read_fixed_off() rejection path for partial fills from pointer
spills.
Fixes: be23266b4a ("bpf: 4-byte precise clean_verifier_state")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Link: https://lore.kernel.org/r/20260617-f01-06-half-slot-pointer-spill-v2-1-42b9cdc3cf64@mails.tsinghua.edu.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The sched_ext sources had grown to ten ext* files directly under
kernel/sched/. Move them into a new kernel/sched/ext/ subdirectory and drop
the now-redundant ext_ prefix. ext.c/h keep their names.
kernel/sched/ext.{c,h} -> kernel/sched/ext/ext.{c,h}
kernel/sched/ext_internal.h -> kernel/sched/ext/internal.h
kernel/sched/ext_types.h -> kernel/sched/ext/types.h
kernel/sched/ext_idle.{c,h} -> kernel/sched/ext/idle.{c,h}
kernel/sched/ext_cid.{c,h} -> kernel/sched/ext/cid.{c,h}
kernel/sched/ext_arena.{c,h} -> kernel/sched/ext/arena.{c,h}
The include paths in build_policy.c and sched.h, the MAINTAINERS glob, and a
few documentation and comment references are updated to match. No code or
symbol changes.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull more s390 updates from Alexander Gordeev:
- consolidate s390 idle time accounting by moving all CPU time tracking
to the architecture backend and eliminate the mix of architecture-
specific and common code accounting
- Add missing EXPORT_SYMBOL_GPL() to kcpustat_field_idle() and
kcpustat_field_iowait() functions
- Finalize ptep_get() conversion by replacing direct page table entry
dereferencing with proper accessors (ptep_get(), pmdp_get(), etc.)
- Explicitly check the buffer length in PKEY_VERIFYPROTK ioctl and
pkey_pckmo implementations and fail if the length is exceeded
* tag 's390-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/pkey: Check length in pkey_pckmo handler implementation
s390/pkey: Check length in PKEY_VERIFYPROTK ioctl
s390/idle: Add missing EXPORT_SYMBOL_GPL()
s390/mm: Complete ptep_get() conversion
s390/idle: Remove idle time and count sysfs files
s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait()
s390/irq/idle: Use stcke instead of stckf for time stamps
s390/timex: Move union tod_clock type to separate header
The compat version of settimeofday() uses '>' instead of '>=' when
validating tv_usec against USEC_PER_SEC, allowing the value 1000000 to pass
the check. After the subsequent conversion to nanoseconds (tv_nsec *=
NSEC_PER_USEC), this results in tv_nsec == NSEC_PER_SEC, which violates the
timespec invariant that tv_nsec must be strictly less than NSEC_PER_SEC.
The native settimeofday() was already fixed in commit ce4abda5e1 ("time:
Fix off-by-one in settimeofday() usec validation"), but the compat
counterpart was missed.
Fix it by using '>=' to reject tv_usec values outside the valid range [0,
USEC_PER_SEC - 1].
Fixes: 5e0fb1b57b ("y2038: time: avoid timespec usage in settimeofday()")
Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260622103348.120255-1-wangyan01@kylinos.cn
replace_effective_prog() and purge_effective_progs() located the slot in
the effective array by walking the program hlist and counting entries
linearly. That count does not match the array layout: compute_effective_
progs() places BPF_F_PREORDER programs at the front (ancestor cgroup
first, attach order within a cgroup) and the rest after them (descendant
cgroup first). So when a preorder program is present, the linear hlist
position no longer equals the program's index in the effective array.
For replace_effective_prog() (bpf_link_update()) this overwrote the
wrong slot, corrupting the effective order. For purge_effective_progs(),
it could dummy out a slot belonging to a different program and leave the
detached program in the array while bpf_prog_put() drops its reference,
i.e. a use-after-free.
Fix both by replaying compute_effective_progs()'s placement (including
the per-cgroup preorder reversal) in a shared effective_prog_pos()
helper. Identify the entry by its struct bpf_prog_list pointer rather
than by (prog, link) value, so the lookup resolves to exactly the
attachment the syscall selected even when the same bpf_prog is attached
to several cgroups in the hierarchy.
Fixes: 4b82b181a2 ("bpf: Allow pre-ordering for bpf cgroup progs")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260619063520.2690547-2-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm commit [1] allowed attaching type tag records to modifier BTF
records. This is useful for using typedefs that encompass a base type
and a type tag, e.g.:
typedef struct rbtree __arena rbtree_t;
Modify btf_check_type_tags() so that it allows this sequence of records.
The function now only checks for record loops in BTF modifier record
chains. Rename to btf_check_modifier_chain_length to reflect this.
Also expand the BTF modifier traversal code to take into account that
type record can be interleaved with other modifier records. In effect
this means traversing all modifiers to collect the type tags.
Also modify existing selftests to now accept modifier records (const,
typedef) that point to type tag records.
[1] https://github.com/llvm/llvm-project/pull/203089
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260616061454.7869-1-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When BPF_WRITE goes through a PTR_TO_BTF_ID register, check_ptr_to_btf_access()
delegates to env->ops->btf_struct_access(). Most implementations
(bpf_scx_btf_struct_access, tc_cls_act_btf_struct_access, etc.) return
-EACCES for disallowed fields without logging anything, so the verifier
rejects the program with an empty message. For example a scx program doing
1: R1=trusted_ptr_task_struct()
...
4: (7b) *(u64 *)(r1 +0) = r2
verification time 83 usec
the program is rejected
leaves the user guessing which field is off-limits.
Emit verbose message.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260615232146.5491-1-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
