James Morse [Fri, 8 May 2026 16:23:39 +0000 (17:23 +0100)]
arm_mpam: Check whether the config array is allocated before destroying it
__destroy_component_cfg() is called to free the configuration array.
It uses the embedded 'garbage' structure, which means the array has
to be allocated.
If __destroy_component_cfg() is called from mpam_disable() before the
configuration was ever allocated, then a NULL pointer is dereferenced.
Check for this case and return early if the configuration is not
allocated.
__destroy_component_cfg() also frees the mbwu_state as this is allocated
by __allocate_component_cfg(). As the mbwu_state is allocated after
comp->cfg is set, and is also under mpam_list_lock, only the first
pointer needs checking.
Fixes: 3bd04fe7d807 ("arm_mpam: Extend reset logic to allow devices to be reset any time") Cc: <stable@vger.kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
James Morse [Fri, 8 May 2026 16:23:38 +0000 (17:23 +0100)]
arm_mpam: Fix false positive assert failure during mpam_disable()
mpam_assert_partid_sizes_fixed() is used to document that the caller
doesn't expect the discovered PARTID size to change while it is walking
a list sized by PARTID. Typically the MSC state is not written to until
all the MSC have been discovered and this value is set.
However, if discovering the MSC fails and schedules mpam_disable(),
then the MSC state is written to reset it. In this case the
discovered PARTID size may be become smaller - but only PARTID 0
will be used once resctrl_exit() has been called.
Skip the WARN_ON_ONCE() if mpam_disable_reason has been set.
Fixes: 3bd04fe7d807 ("arm_mpam: Extend reset logic to allow devices to be reset any time") Cc: <stable@vger.kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ben Horgan [Thu, 7 May 2026 15:28:14 +0000 (16:28 +0100)]
arm_mpam: Improve check for whether or not NRDY is hardware managed
mpam_ris_hw_probe_csu_nrdy() sets and clears MSMON_CSU.NRDY and checks
whether it's configuration sticks. However, hardware isn't given a chance
to disagree. Based on rule LRTGP, in MPAM specification IHI0099 version
B.b, the hardware will set NRDY if it needs time to establish a count after
a configuration change.
Enable the monitor so that NRDY becomes relevant and change the
configuration after clearing NRDY to try and coax the hardware into setting
it.
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: <stable@vger.kernel.org> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ben Horgan [Thu, 7 May 2026 15:28:13 +0000 (16:28 +0100)]
arm_mpam: Pretend that NRDY is always hardware managed
Rule ZTXDS of the MPAM specification, IHI009 version B.b, states: "If a
monitor does not support automatic updates of NRDY, software can use that
bit for any purpose."
As software is not reliably informed whether or not the monitor supports
automatic updates of NRDY always assume that hardware may manage NRDY but
don't rely on it. When NRDY is truly untouched by hardware then, as it is
written to 0 on configuration, it will always read 0.
At probe it's checked if MSMON_CSU.NRDY and MSMON_MBWU.NRDY are hardware
managed but not MSMON_MBWU_L.NDRY. Specialize the checking for hardware
managed NRDY to CSU counters as this is the only case where hardware
management makes sense. Continue to inform the user if MSMON_CSU.NRDY
appears to be hardware managed but the firmware doesn't provide the
associated time limit for the automatic clearing of NRDY. Remove the NRDY
feature flags as they are now unused.
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: <stable@vger.kernel.org> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ben Horgan [Thu, 7 May 2026 15:28:12 +0000 (16:28 +0100)]
arm_mpam: Fix monitor instance selection when checking for hardware NRDY
In _mpam_ris_hw_probe_hw_nrdy() a new register value to select the first
monitor and relevant RIS is prepared in mon_sel. However, it is written to
the monitor value register, e.g. MSMON_CSU, rather than MSMON_CFG_MON_SEL.
As MSMON_CFG_MON_SEL is a 32 bit register update the type of mon_sel to
u32. Write mon_sel to the intended register, MSMON_CFG_MON_SEL.
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: <stable@vger.kernel.org> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Marco Elver [Mon, 11 May 2026 20:00:50 +0000 (22:00 +0200)]
slab: fix kernel-docs for mm-api
The mm-api kernel-docs have been disconnected from their symbols. While
the scripts were previously taught to handle the _noprof suffix added by
allocation tagging (in 51a7bf0238c2 "scripts/kernel-doc: drop "_noprof"
on function prototypes"), this does not handle cases where the internal
implementation function has an additional leading underscore. The added
optional parameters (via DECL_KMALLOC_PARAMS) further complicate parsing
the internal signatures.
When the kernel-doc block remains above the internal implementation
function but uses the public API name, the documentation generator fails
to associate the documented symbol.
Simply moving the docs to the macros in slab.h fixes the association but
causes loss of types in the generated documentation (rendering as e.g.
untyped 'kmalloc(size, flags)' macro).
Fix this by:
1. Moving the kernel-doc comment blocks from slub.c to slab.h, placing
them directly above the user-facing macros.
2. Providing explicit, typed C prototypes for the documented APIs inside
'#if 0 /* kernel-doc */' blocks.
3. Converting the variadic macros for the documented APIs to use
explicit arguments to match the documentation.
Marco Elver [Mon, 11 May 2026 20:00:49 +0000 (22:00 +0200)]
slab: improve KMALLOC_PARTITION_RANDOM randomness
When using CONFIG_KMALLOC_PARTITION_RANDOM, _RET_IP_ was previously used
to identify the allocation site. _RET_IP_, however, evaluates to the
caller's parent's instruction pointer rather than the actual allocation
site; this would lead to collisions where a function performs multiple
allocations.
With the generalization to kmalloc_token_t, we now generate the token at
the outermost macro, and using _THIS_IP_ would fix this for all cases.
Unfortunately, the generic implementation of _THIS_IP_ relies on taking
the address of a local label, which is considered broken by both GCC [1]
and Clang [2] because label addresses are only expected to be used with
computed gotos. While the generic version more or less works today, it
is known to be brittle. For example, Clang -O2 always returns 1 when
this function is inlined:
To provide a reliable unique identifier without breaking architectures
relying on the generic _THIS_IP_, introduce _CODE_LOCATION_: it resolves
to _THIS_IP_ where architectures provide a safe implementation, and
falls back to a zero-cost static marker where _THIS_IP_ is broken.
Marco Elver [Mon, 11 May 2026 20:00:48 +0000 (22:00 +0200)]
slab: support for compiler-assisted type-based slab cache partitioning
Rework the general infrastructure around RANDOM_KMALLOC_CACHES into more
flexible KMALLOC_PARTITION_CACHES, with the former being a partitioning
mode of the latter.
Introduce a new mode, KMALLOC_PARTITION_TYPED, which leverages a feature
available in Clang 22 and later, called "allocation tokens" via
__builtin_infer_alloc_token() [1]. Unlike KMALLOC_PARTITION_RANDOM
(formerly RANDOM_KMALLOC_CACHES), this mode deterministically assigns a
slab cache to an allocation of type T, regardless of allocation site.
The builtin __builtin_infer_alloc_token(<malloc-args>, ...) instructs
the compiler to infer an allocation type from arguments commonly passed
to memory-allocating functions and returns a type-derived token ID. The
implementation passes kmalloc-args to the builtin: the compiler performs
best-effort type inference, and then recognizes common patterns such as
`kmalloc(sizeof(T), ...)`, `kmalloc(sizeof(T) * n, ...)`, but also
`(T *)kmalloc(...)`. Where the compiler fails to infer a type the
fallback token (default: 0) is chosen.
Note: kmalloc_obj(..) APIs fix the pattern how size and result type are
expressed, and therefore ensures there's not much drift in which
patterns the compiler needs to recognize. Specifically, kmalloc_obj()
and friends expand to `(TYPE *)KMALLOC(__obj_size, GFP)`, which the
compiler recognizes via the cast to TYPE*.
Clang's default token ID calculation is described as [1]:
typehashpointersplit: This mode assigns a token ID based on the hash
of the allocated type's name, where the top half ID-space is reserved
for types that contain pointers and the bottom half for types that do
not contain pointers.
Separating pointer-containing objects from pointerless objects and data
allocations can help mitigate certain classes of memory corruption
exploits [2]: attackers who gains a buffer overflow on a primitive
buffer cannot use it to directly corrupt pointers or other critical
metadata in an object residing in a different, isolated heap region.
It is important to note that heap isolation strategies offer a
best-effort approach, and do not provide a 100% security guarantee,
albeit achievable at relatively low performance cost. Note that this
also does not prevent cross-cache attacks: while waiting for future
features like SLAB_VIRTUAL [3] to provide physical page isolation, this
feature should be deployed alongside SHUFFLE_PAGE_ALLOCATOR and
init_on_free=1 to mitigate cross-cache attacks and page-reuse attacks as
much as possible today.
With all that, my kernel (x86 defconfig) shows me a histogram of slab
cache object distribution per /proc/slabinfo (after boot):
The above /proc/slabinfo snapshot shows me there are 6673 allocated
objects (slabs 00 - 07) that the compiler claims contain no pointers or
it was unable to infer the type of, and 12015 objects that contain
pointers (slabs 08 - 15). On a whole, this looks relatively sane.
Additionally, when I compile my kernel with -Rpass=alloc-token, which
provides diagnostics where (after dead-code elimination) type inference
failed, I see 186 allocation sites where the compiler failed to identify
a type (down from 966 when I sent the RFC [4]). Some initial review
confirms these are mostly variable sized buffers, but also include
structs with trailing flexible length arrays.
David Ahern [Wed, 13 May 2026 16:49:14 +0000 (10:49 -0600)]
xfrm: Check for underflow in xfrm_state_mtu
Leo Lin reported OOB write issue in esp component:
xfrm_state_mtu() returns u32 but performs its arithmetic in unsigned
modulo-2^32 space using an attacker-influenced "header_len + authsize +
net_adj" subtracted from a small "mtu" argument. A nobody user can
install an IPv4 ESP tunnel SA with a large authentication key
(XFRMA_ALG_AUTH_TRUNC, e.g. hmac(sha512), 64-byte key, 64-byte trunc),
configure a small interface MTU (68 bytes), and set XFRMA_TFCPAD to a
large value. When a single UDP datagram is then sent through the
tunnel, xfrm_state_mtu() underflows to a near-2^32 value, and
esp_output() consumes it as a signed int via:
esp.tfclen ends up negative (e.g. -207). It is sign-extended to size_t
when passed to memset() inside esp_output_fill_trailer(), producing a
~16 EB write of zeroes at skb_tail_pointer(skb). KASAN logs it as
"Write of size 18446744073709551537 at addr ffff888...".
Check for underflow and return 1. This causes the sendmsg attempt to
fail with ENETUNREACH.
Fixes: c5c252389374 ("[XFRM]: Optimize MTU calculation") Reported-by: Leo Lin <leo@depthfirst.com> Assisted-by: Codex:26.506.31004 Signed-off-by: David Ahern <dahern@nvidia.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Shengming Hu [Thu, 30 Apr 2026 14:04:41 +0000 (22:04 +0800)]
mm/slub: defer freelist construction until after bulk allocation from a new slab
Allocations from a fresh slab can consume all of its objects, and the
freelist built during slab allocation is discarded immediately as a result.
Instead of special-casing the whole-slab bulk refill case, defer freelist
construction until after objects are emitted from a fresh slab.
new_slab() now only allocates the slab and initializes its metadata.
refill_objects() then obtains a fresh slab and lets alloc_from_new_slab()
emit objects directly, building a freelist only for the objects left
unallocated; the same change is applied to alloc_single_from_new_slab().
To keep CONFIG_SLAB_FREELIST_RANDOM=y/n on the same path, introduce a
small iterator abstraction for walking free objects in allocation order.
The iterator is used both for filling the sheaf and for building the
freelist of the remaining objects.
Also mark setup_object() inline. After this optimization, the compiler no
longer consistently inlines this helper in the hot path, which can hurt
performance. Explicitly marking it inline restores the expected code
generation.
This reduces per-object overhead when allocating from a fresh slab.
The most direct benefit is in the paths that allocate objects first and
only build a freelist for the remainder afterward: bulk allocation from
a new slab in refill_objects(), single-object allocation from a new slab
in ___slab_alloc(), and the corresponding early-boot paths that now use
the same deferred-freelist scheme. Since refill_objects() is also used to
refill sheaves, the optimization is not limited to the small set of
kmem_cache_alloc_bulk()/kmem_cache_free_bulk() users; regular allocation
workloads may benefit as well when they refill from a fresh slab.
In slub_bulk_bench, the time per object drops by about 42% to 70% with
CONFIG_SLAB_FREELIST_RANDOM=n, and by about 58% to 69% with
CONFIG_SLAB_FREELIST_RANDOM=y. This benchmark is intended to isolate the
cost removed by this change: each iteration allocates exactly
slab->objects from a fresh slab. That makes it a near best-case scenario
for deferred freelist construction, because the old path still built a
full freelist even when no objects remained, while the new path avoids
that work. Realistic workloads may see smaller end-to-end gains depending
on how often allocations reach this fresh-slab refill path.
The crash occurs because arch_irq_work_raise() calls preempt_disable()
from machine check exception (MCE) handlers running in real mode. In
this context, accessing the preempt_count can fault, leading to the panic.
The preempt_disable()/preempt_enable() pair in arch_irq_work_raise()
was originally added by commit 0fe1ac48bef0 ("powerpc/perf_event: Fix
oops due to perf_event_do_pending call") to avoid races while raising
irq work from exception context.
Later, commit 471ba0e686cb ("irq_work: Do not raise an IPI when
queueing work on the local CPU") added preemption protection in
irq_work_queue() path, while commit 20b876918c06 ("irq_work: Use per
cpu atomics instead of regular atomics") added equivalent
protection in irq_work_queue_on() before reaching arch_irq_work_raise():
As a result, callers other than mce_irq_work_raise() already execute
with preemption disabled, making the additional
preempt_disable()/preempt_enable() pair in arch_irq_work_raise()
redundant.
The arch_irq_work_raise() function executes in NMI context when called
from MCE handler. Hence we will not be preempted or scheduled out since
we are in NMI context with MSR[EE]=0. Therefore, it is safe to remove
the preempt_disable()/preempt_enable() calls from here.
Remove it to avoid accessing preempt_count from real mode context.
Nicolás Bazaes [Thu, 14 May 2026 01:35:49 +0000 (21:35 -0400)]
Input: synaptics - add LEN2058 to SMBus passlist for ThinkPad E490
The Lenovo ThinkPad E490 (PNP ID: LEN2058) has a Synaptics TM3471-020
touchpad that supports SMBus/RMI4 mode but is not listed in
smbus_pnp_ids[]. Without this entry, RMI4 over SMBus is not enabled
by default, and the touchpad falls back to PS/2 mode.
Adding LEN2058 to the passlist enables automatic RMI4 detection without
requiring the psmouse.synaptics_intertouch parameter, and matches
the behavior of similar ThinkPad models already in the list
(E480/LEN2054, E580/LEN2055).
Tested on ThinkPad E490 with kernel 7.0.5-zen1 and Arch Linux.
RMI4 over SMBus is confirmed working without any kernel parameters.
Vivian Wang [Wed, 1 Apr 2026 01:53:17 +0000 (09:53 +0800)]
riscv: misaligned: Make enabling delegation depend on NONPORTABLE
The unaligned access emulation code in Linux has various deficiencies.
For example, it doesn't emulate vector instructions [1] [2], and doesn't
emulate KVM guest accesses. Therefore, requesting misaligned exception
delegation with SBI FWFT actually regresses vector instructions' and KVM
guests' behavior.
Until Linux can handle it properly, guard these sbi_fwft_set() calls
behind RISCV_SBI_FWFT_DELEGATE_MISALIGNED, which in turn depends on
NONPORTABLE. Those who are sure that this wouldn't be a problem can
enable this option, perhaps getting better performance.
The rest of the existing code proceeds as before, except as if
SBI_FWFT_MISALIGNED_EXC_DELEG is not available, to handle any remaining
address misaligned exceptions on a best-effort basis. The KVM SBI FWFT
implementation is also not touched, but it is disabled if the firmware
emulates unaligned accesses.
The task loops inside io_cqring_wait() and never returns to userspace,
and SIGKILL has no effect.
This is caused by the CQ ring exposing rings->cq.head to userspace as
writable, while the authoritative tail lives in kernel-private
ctx->cached_cq_tail. io_cqe_cache_refill() computes free space as an
unsigned subtraction:
If userspace keeps head within [0, tail], the subtraction is well
defined and min() just acts as a defensive clamp. But if userspace
advances head past tail, (tail - head) wraps to a huge value, free
becomes 0, and io_cqe_cache_refill() fails. The CQE is pushed onto the
overflow list and IO_CHECK_CQ_OVERFLOW_BIT is set.
The wait loop in io_cqring_wait() relies on an invariant: refill() only
fails when the CQ is *physically* full, in which case rings->cq.tail has
been advanced to iowq->cq_tail and io_should_wake() returns true. The
tampered head breaks this: refill() fails while the ring is not full, no
OCQE is copied in, rings->cq.tail never catches up, io_should_wake()
stays false, and io_cqring_wait_schedule() keeps returning early because
IO_CHECK_CQ_OVERFLOW_BIT is still set. The result is a tight retry loop
that never returns to userspace.
Introduce io_cqring_queued() as the single point that converts the
(tail, head) pair into a trustworthy queued count. Since the real
head/tail distance is bounded by cq_entries (far below 2^31), a signed
comparison reliably detects userspace moving head past tail; in that
case treat the queue as empty so callers see the full cache as free and
forward progress is preserved.
====================
net/mlx5e: improve RSS indirection table sizing and resizing
This series by Yael improves mlx5e RSS indirection table handling around
channel count changes and large RSS configurations.
The series:
* removes the XOR8-specific channel count limitation,
* advertises the maximum supported RSS indirection table size,
* fixes resizing of non-default RSS contexts,
* allows resizing configured default RSS contexts during channel
changes,
* and increases the default RSS spread factor from 2x to 4x to improve
traffic distribution for large channel counts.
Together, these changes make RSS table sizing more flexible and robust,
while improving load balancing behavior on large systems.
====================
Increase the RQT uniform spread factor from 2 to 4 so that each channel
gets more indirection table entries and traffic is spread more evenly.
For num_channels > 64 imbalance drops from up to ~50% to up to ~25%.
For 64 or fewer channels the 256 entry minimum already provides at least
4x coverage and the table size is unchanged by this commit.
This satisfies the minimum 4x coverage requirement validated by the
generic RSS selftest commit 9e3d4dae9832 ("selftests: drv-net: rss:
validate min RSS table size").
The 4x spread factor is best-effort and the table size is always capped by
the device's log_max_rqt_size capability.
Yael Chemla [Mon, 11 May 2026 17:27:18 +0000 (20:27 +0300)]
net/mlx5e: resize configured default RSS context table on channel change
mlx5e_ethtool_set_channels() rejected channel count changes that
required a different RQT size when the default context indirection
table was user-configured. This restriction was introduced by
commit ee3572409f74 ("net/mlx5e: RSS, Block changing channels number
when RXFH is configured").
Lift the restriction. Validate the resize upfront with
ethtool_rxfh_indir_can_resize(), then fold or unfold the table
in-place via ethtool_rxfh_indir_resize() inside state_lock, before
mlx5e_safe_switch_params(), so the preactivate callback sees the
correct table content when it programs the HW.
Yael Chemla [Mon, 11 May 2026 17:27:17 +0000 (20:27 +0300)]
net/mlx5e: resize non-default RSS indirection tables on channel change
When the channel count changes and the RQT size changes with it, a
problem arise for non-default RSS contexts. The driver-side indirection
table grows actual_table_size without filling the new entries; stale
entries from a prior larger configuration may be re-exposed, causing
mlx5e_calc_indir_rqns() to WARN on an out-of-range index.
Replace mlx5e_rss_params_indir_modify_actual_size() with
mlx5e_rss_ctx_resize(), which fills new entries by replicating
the existing pattern, matching what ethtool_rxfh_ctxs_resize() does
for the same case. And restrict the loop to non-default contexts.
Call ethtool_rxfh_ctxs_can_resize() before acquiring state_lock to
validate that all non-default contexts can be resized, and
ethtool_rxfh_ctxs_resize() after releasing it to fold or unfold their
indirection tables. Both functions acquire rss_lock internally and
cannot be called under state_lock. RTNL, held by all set_channels
callers, serialises context creation and deletion making the pre-lock
check safe.
Guard both ethtool calls on mlx5e_rx_res_rss_cnt() > 1: skip the
validation and resize when no non-default contexts exist. This
naturally covers representors and IPoIB, which share
mlx5e_ethtool_set_channels() but cannot have non-default RSS contexts.
Yael Chemla [Mon, 11 May 2026 17:27:16 +0000 (20:27 +0300)]
net/mlx5e: advertise max RSS indirection table size to ethtool
Set rxfh_indir_space to the maximum indirection table size the driver
can support: the next power of two above MLX5E_MAX_NUM_CHANNELS times
MLX5E_UNIFORM_SPREAD_RQT_FACTOR.
Without this, ethtool_rxfh_ctxs_can_resize() returns -EINVAL, blocking
non-default RSS contexts from tracking indirection table size changes
when the channel count changes.
Yael Chemla [Mon, 11 May 2026 17:27:15 +0000 (20:27 +0300)]
net/mlx5e: remove channel count limit for XOR8 RSS hash
mlx5e_ethtool_set_channels() and mlx5e_rxfh_hfunc_check() rejected
channel counts that would produce an indirection table larger than 256
entries when the XOR8 hash function was active. This check was
introduced in commit 49e6c9387051 ("net/mlx5e: RSS, Block XOR hash
with over 128 channels").
XOR8 yields an 8-bit hash, so in practice only up to 256 entries in the
indirection table can be reached due to limited entropy. However, this
does not provide a strong justification for prohibiting larger
indirection tables. Remove the limitation.
====================
macsec: use rcu_work to fix crypto cleanup in softirq context
From: Jinliang Zheng <alexjlzheng@tencent.com>
crypto_free_aead() can internally call vunmap() (e.g. via dma_free_attrs()
in hardware crypto drivers like hisi_sec2), which must not be invoked from
softirq context. Both free_rxsa() and free_txsa() are RCU callbacks that
run in softirq, causing a kernel crash on affected hardware.
This series fixes the issue by deferring the actual cleanup to a workqueue
using rcu_work, which combines the RCU grace period and workqueue dispatch
into a single primitive.
Two design decisions worth noting:
1. rcu_work instead of schedule_work() + synchronize_rcu()
An alternative would be to call schedule_work() directly from
macsec_rxsa_put()/macsec_txsa_put(), then call synchronize_rcu() at
the start of the work handler to replace the grace period previously
provided by call_rcu(). However, synchronize_rcu() blocks the worker
thread for the duration of a full RCU grace period. Under high SA
churn (e.g. tearing down an interface with many SAs), each SA would
occupy a worker thread while waiting, and multiple concurrent calls
cannot share the same grace period — leading to unnecessary latency
and resource waste.
rcu_work uses call_rcu_hurry() internally, which is fully asynchronous:
the worker thread is only dispatched after the grace period has elapsed,
and multiple concurrent queue_rcu_work() calls naturally batch under the
same grace period via the RCU subsystem's existing coalescing mechanism.
2. Dedicated workqueue instead of system_wq
Using a dedicated workqueue (macsec_wq) allows macsec_exit() to drain
exactly the work items belonging to this module — by calling
destroy_workqueue() after rcu_barrier(). If system_wq were used,
flush_scheduled_work() would drain all pending work items across the
entire system, creating unnecessary coupling with unrelated subsystems
and potentially causing unexpected delays. The dedicated workqueue
provides a clean, contained teardown path.
====================
Jinliang Zheng [Mon, 11 May 2026 15:31:00 +0000 (23:31 +0800)]
macsec: use rcu_work to defer TX SA crypto cleanup out of softirq
free_txsa() is an RCU callback running in softirq context, but calls
crypto_free_aead() which can invoke vunmap() internally on hardware
crypto drivers (e.g. hisi_sec2), triggering a kernel crash.
Use rcu_work to defer the cleanup to a workqueue, for the same reasons
as the analogous fix to free_rxsa() in the previous patch.
Jinliang Zheng [Mon, 11 May 2026 15:30:59 +0000 (23:30 +0800)]
macsec: use rcu_work to defer RX SA crypto cleanup out of softirq
crypto_free_aead() can internally invoke vunmap() (e.g. via
dma_free_attrs() in hardware crypto drivers such as hisi_sec2).
vunmap() must not be called from softirq context, but free_rxsa()
is an RCU callback that runs in softirq, leading to a kernel crash:
Use rcu_work to defer the cleanup to a workqueue. rcu_work dispatches
the worker asynchronously after the RCU grace period, so no thread
blocks waiting, and concurrent releases of multiple SAs naturally
share the same grace period.
Jinliang Zheng [Mon, 11 May 2026 15:30:58 +0000 (23:30 +0800)]
macsec: introduce dedicated workqueue for SA crypto cleanup
Introduce a dedicated ordered workqueue, macsec_wq, which will be used
by subsequent patches to defer SA crypto cleanup (crypto_free_aead and
related teardown) out of softirq context.
Using a dedicated workqueue instead of system_wq allows macsec_exit()
to drain exactly the work items belonging to this module via
destroy_workqueue(), without interfering with unrelated work items on
system_wq or causing unexpected delays elsewhere.
rcu_barrier() in macsec_exit() ensures all in-flight rcu_work callbacks
have enqueued their work items before destroy_workqueue() drains and
destroys the queue, making the two-step teardown correct and complete.
The same sequence is kept in the error path of macsec_init() as a
precaution, to mirror macsec_exit() and stay safe if work ever becomes
queueable before this point in the future.
While at it, rename the error labels in macsec_init() from the
resource-named style (rtnl:, notifier:, wq:) to the err_xxx: style
(err_rtnl:, err_notifier:, err_destroy_wq:) to align with the broader
kernel convention.
Faicker Mo [Mon, 11 May 2026 14:05:51 +0000 (22:05 +0800)]
net: net_failover: Fix the deadlock in slave register
There is netdev_lock_ops() before the NETDEV_REGISTER notifier
in register_netdevice(), so use the non-locking functions
in net_failover_slave_register().
failover_slave_register() in failover_existing_slave_register() adds lock
and unlock ops too.
Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP") Signed-off-by: Faicker Mo <faicker.mo@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
bpf: Maximum combined stack depth
This patchset dumps the maximum combined stack depth in verifier logs
and parses it in veristat.
Changes in v3:
- Increment spec_cnt field in veristat for new MAX_STACK id (AI bot).
Changes in v2:
- Remove unnecessary max_stack_depth assignment (Eduard).
- Fix and test incorrect handling of private stacks.
- Add veristat metric (Eduard).
====================
Paul Chaignon [Wed, 13 May 2026 19:35:36 +0000 (21:35 +0200)]
veristat: Report max stack depth
This patch adds a new "Max stack depth" field to the set of gathered
statistics. This field reports the maximum combined stack depth compared
to the 512 bytes limit. It is null for rejected programs.
Paul Chaignon [Wed, 13 May 2026 19:35:01 +0000 (21:35 +0200)]
selftests/bpf: Test reported max stack depth
This patch tests the maximum stack depth reporting in verifier logs,
with a couple special cases covered: fastcall, private stacks (main
subprog & callee), and rounding up to 16 bytes. For that last one, we
need to skip the test when JIT compilation is disabled as the rounding
is then to 32 bytes.
Paul Chaignon [Wed, 13 May 2026 19:34:50 +0000 (21:34 +0200)]
bpf: Report maximum combined stack depth
We've hit the 512 bytes limit on stack depth a few times in Cilium
recently. As a result, we started reporting in CI our current maximum
stack depth across all configurations for each BPF program.
Unfortunately, that is not trivial to compute in userspace. The
verifier reports the stack depths of individual subprogs at the end of
the logs. However the maximum combined stack depth also depends on the
callgraph of those subprogs (the max combined stack depth is the height
of the callgraph weighted by per-subprog stack depths). We can compute
a callgraph in userspace from the loaded instructions, but it often
doesn't match the verifier's own callgraph because of dead code
elimination. Our current approach relies on dumping the BPF_LOG_LEVEL2
logs, but this feels overkill considering the verifier already has the
information we need.
The patch lets the verifier dump the maximum combined stack depth in
the logs, on the same line as the per-subprog stack depths:
stack depth 16+256 max 272
The per-subprog stack depths and the new max stack depth are not
directly comparable. The former is sometimes updated during fixups,
while the latter is not. As a result, even with a single subprog, we
may end up with two slightly different values. The aim of the new max
value is to be closest to what is actually enforced by the verifier.
====================
netpoll: move out netconsole-specific functions
netpoll and netconsole were created together and their code has
been intermixed in net/core/netpoll.c for decades. The result is
that netpoll exposes two send-side interfaces:
* a generic "give me an sk_buff" path used by every stacked-device
driver (bonding, team, vlan, bridge, macvlan, dsa),
* a second path that takes raw bytes and builds a UDP/IP/Ethernet
packet -- exclusively for netconsole.
The packet builder, an skb pool allocator, and several
netconsole-specific helpers all live next to the generic plumbing even
though no other consumer ever touches them.
Worse, every netpoll user pays for that overlap: struct netpoll carries
an skb_pool and a refill work_struct that only netconsole's find_skb()
ever reads from, and net-core has to review unrelated changes (TTL, hop
limit, IP ID generation, source MAC selection, pool sizing) just because
they happen to be coded inside netpoll.
This is a waste of memory for something useless.
This series splits the netconsole-specific code out:
* netpoll_send_udp() and its private helpers (push_ipv6, push_ipv4,
push_eth, push_udp, netpoll_udp_checksum, find_skb) move into
drivers/net/netconsole.c, leaving netpoll with a single skb-only
send interface that is the same for every user.
The moves are one function per patch for reviewability; helpers are
temporarily EXPORT_SYMBOL_GPL'd while netpoll_send_udp() is still in
netpoll calling them, then those exports are dropped together once
netpoll_send_udp() itself moves.
The only new permanent export is zap_completion_queue(), needed because
find_skb() still drains the per-CPU TX completion queue before
allocating.
struct netpoll is unchanged in this series; making the pool itself
netconsole-private (and reclaiming the skb_pool / refill_wq fields for
the rest of netpoll's users) is the natural follow-up, once this patchset
lands.
====================
Breno Leitao [Tue, 12 May 2026 10:46:42 +0000 (03:46 -0700)]
netconsole: move find_skb() from netpoll
find_skb() is the netconsole-specific entry into the netpoll skb
pool: every other netpoll consumer (bonding, team, vlan, bridge,
macvlan, dsa) builds its own sk_buff and never touches the pool.
With netpoll_send_udp() (its only caller) now living in netconsole,
find_skb() can join it.
Move find_skb() into drivers/net/netconsole.c as a file-static
helper, drop EXPORT_SYMBOL_GPL(find_skb) and remove its prototype
from include/linux/netpoll.h. find_skb() drains TX completions via
netpoll_zap_completion_queue(), which is already exported in the
NETDEV_INTERNAL namespace, so netconsole picks up
MODULE_IMPORT_NS("NETDEV_INTERNAL") to consume it.
The skb pool's lifecycle (np->skb_pool, np->refill_wq, refill_skbs(),
refill_skbs_work_handler(), skb_pool_flush()) stays in netpoll: it
is initialised in __netpoll_setup() and torn down in
__netpoll_cleanup(), both of which remain netpoll's responsibility.
The refill work queued via schedule_work(&np->refill_wq) from the
moved find_skb() runs refill_skbs_work_handler() in netpoll without
any further plumbing.
This is pure code motion: the function body is unchanged and its
sole caller (netpoll_send_udp(), already moved by an earlier patch)
keeps invoking it the same way. Pre-existing concerns about
find_skb() running from NMI/printk context (zap_completion_queue()
re-entry, skb_pool spinlocks, GFP_ATOMIC allocation, fallback skb
sizing vs. MAX_SKB_SIZE, PREEMPT_RT semantics of __kfree_skb()) are
inherited as-is and are not addressed here; they predate this
series and are out of scope. Fixing them is left for follow-up
work.
Breno Leitao [Tue, 12 May 2026 10:46:41 +0000 (03:46 -0700)]
netpoll: rename and export netpoll_zap_completion_queue()
zap_completion_queue() drains the per-CPU softnet completion queue.
Rename it with the netpoll_ prefix shared by the rest of the
subsystem's public API, and promote it from file-static to
EXPORT_SYMBOL_NS_GPL in the NETDEV_INTERNAL namespace so the upcoming
netconsole-side find_skb() can call it once the function moves out.
A forward declaration is added to include/linux/netpoll.h, and the
old file-static forward declaration is dropped.
Breno Leitao [Tue, 12 May 2026 10:46:40 +0000 (03:46 -0700)]
netconsole: move netpoll_udp_checksum() from netpoll
netpoll_udp_checksum() computes the UDP checksum for netconsole's
packets. Move it into drivers/net/netconsole.c as a file-static
helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from
include/linux/netpoll.h.
This was the last csum_ipv6_magic() consumer in net/core/netpoll.c,
so drop the now-stale <net/ip6_checksum.h> include there. Pull it
into netconsole.c so the moved code keeps building.
It was also the last udp_hdr() consumer in net/core/netpoll.c. The
file no longer needs anything from <net/udp.h> (the UDP socket-layer
helpers); MAX_SKB_SIZE only needs struct udphdr, which is provided
by the lighter <linux/udp.h>. Swap the include accordingly.
Breno Leitao [Tue, 12 May 2026 10:46:39 +0000 (03:46 -0700)]
netconsole: move push_udp() from netpoll
push_udp() builds the UDP header (and triggers the checksum) for
netconsole's UDP packets. Move it into drivers/net/netconsole.c as
a file-static helper; drop its EXPORT_SYMBOL_GPL and remove the
prototype from include/linux/netpoll.h.
Breno Leitao [Tue, 12 May 2026 10:46:38 +0000 (03:46 -0700)]
netconsole: move push_eth() from netpoll
push_eth() builds the Ethernet header for netconsole's UDP packets.
Move it into drivers/net/netconsole.c as a file-static helper; drop
its EXPORT_SYMBOL_GPL and remove the prototype from
include/linux/netpoll.h.
Breno Leitao [Tue, 12 May 2026 10:46:37 +0000 (03:46 -0700)]
netconsole: move push_ipv4() from netpoll
push_ipv4() builds the IPv4 header for netconsole's UDP packets.
Move it into drivers/net/netconsole.c as a file-static helper; drop
its EXPORT_SYMBOL_GPL and remove the prototype from
include/linux/netpoll.h.
put_unaligned() is no longer used in net/core/netpoll.c, so drop
the now-stale <linux/unaligned.h> include from there. Pull it into
netconsole.c so the moved code keeps building.
Breno Leitao [Tue, 12 May 2026 10:46:36 +0000 (03:46 -0700)]
netconsole: move push_ipv6() from netpoll
push_ipv6() builds the IPv6 header for netconsole's UDP packets.
Its only caller, netpoll_send_udp(), now lives in netconsole, so
the helper can move there as a file-static function. Drop its
EXPORT_SYMBOL_GPL and remove the prototype from
include/linux/netpoll.h.
Breno Leitao [Tue, 12 May 2026 10:46:35 +0000 (03:46 -0700)]
netconsole: move netpoll_send_udp() from netpoll
Move netpoll_send_udp() from net/core/netpoll.c into
drivers/net/netconsole.c as a static helper, drop EXPORT_SYMBOL(),
and remove the prototype from include/linux/netpoll.h.
netconsole was the only in-tree caller of this entry point. Every
other netpoll consumer (bonding, team, vlan, bridge, macvlan, dsa)
already builds its own sk_buff and hands it to netpoll_send_skb(),
so the netpoll send-side interface is now skb-only.
The helpers it depends on (find_skb(), push_ipv6(), push_ipv4(),
push_udp(), push_eth(), netpoll_udp_checksum()) were exposed in
the previous patches and stay in net/core/netpoll.c for now.
Subsequent patches move each of them into netconsole one at a time
and drop the corresponding EXPORT_SYMBOL_GPL.
Pull <linux/ip.h>, <linux/ipv6.h> and <linux/udp.h> into netconsole.c
so the moved code can name the header structures.
Breno Leitao [Tue, 12 May 2026 10:46:34 +0000 (03:46 -0700)]
netpoll: expose UDP packet builder helpers for netconsole
Promote each from file-static to EXPORT_SYMBOL_GPL and forward-
declare them in include/linux/netpoll.h so netconsole can call
them once netpoll_send_udp() moves out.
These exports are kept until the end of the series, when
al of them move into netconsole.
Zong Li [Tue, 28 Apr 2026 02:41:05 +0000 (19:41 -0700)]
riscv: cfi: reduce shadow stack size limit from 4GB to 2GB
Follow the ARM64 GCS (Guarded Control Stack) implementation approach
by reducing the shadow stack size allocation from min(RLIMIT_STACK, 4GB)
to min(RLIMIT_STACK/2, 2GB). See commit 506496bcbb42 ("arm64/gcs: Ensure
that new threads have a GCS")
Rationale:
1. Shadow stacks only store return addresses (8 bytes per entry), not
local variables, function parameters, or saved registers. A 2GB
shadow stack is far more than sufficient for any practical
application, even with extremely deep recursion. Using half the size
maintains adequate margin while being more resource-efficient.
2. On memory-constrained systems (e.g., platforms with only 4GB of
physical memory, which is a common configuration), allocating 4GB
of virtual address space for shadow stack per process/thread can
lead to virtual memory allocation failures when the overcommit mode
is set to OVERCOMMIT_GUESS or OVERCOMMIT_NEVER:
Error: "__vm_enough_memory: not enough memory for the allocation"
This reduces virtual address space consumption by 50% while maintaining
more than adequate space for return address storage.
Sajal Gupta [Sat, 9 May 2026 09:51:48 +0000 (15:21 +0530)]
net: usb: pegasus: replace simple_strtoul with kstrtouint
simple_strtoul() is deprecated as it has no error checking. Replace it
with kstrtouint() which returns an error code on invalid input, and add
appropriate error handling.
Also add a NULL check before parsing flags, since strsep() can set id
to NULL if the input has fewer tokens than expected.
Preserve the original behavior for a trailing colon by checking *id
before parsing flags, so an empty string results in flags = 0 rather
than an error.
Victor Nogueira [Mon, 11 May 2026 18:30:58 +0000 (14:30 -0400)]
selftests/tc-testing: Add QFQ/CBS qlen underflow test
Since CBS was not calling reset for its child qdisc, there are scenarios
where it could cause an underflow on its parent's qlen/backlog. When the
parent is QFQ, a null-ptr deref could occur.
Add a test case that reproduces the underflow followed by a null-ptr
deref scenario.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jamal Hadi Salim [Mon, 11 May 2026 18:30:57 +0000 (14:30 -0400)]
net/sched: sch_cbs: Call qdisc_reset for child qdisc
During a reset, CBS is not calling reset on its child qdisc, which
might cause qlen/backlog accounting issues. For example, if we have CBS
with a QFQ parent and a netem child with delay, we can create a scenario
where the parent's qlen underflows. QFQ, specifically, uses qlen to
check whether it should deference a pointer, so this scenario may cause
a null-ptr deref in QFQ:
Fix this by calling qdisc_reset for CBS' child qdisc.
Sashiko caught an issue which could result in a null ptr deref if
qdisc_create_dflt() is invoked on an unitialised cbs qdisc which is exposed
by this patch. We add an early return if the qdisc is null to address this.
This is a similar approach used by two other fixes[1][2].
The proper fix for this specific issue elucidated by sashiko is to remove
the call to qdisc_reset when qdisc_create_dflt fails. Since the dflt qdisc
isn't attached anywhere yet at that point, calling the reset callback doesn't
make much sense (and as stated has been a source of two other bugs).
We plan on submitting this fix in a later patch.
[1] https://lore.kernel.org/netdev/20221018063201.306474-2-shaozhengchao@huawei.com/
[2] https://lore.kernel.org/netdev/20221018063201.306474-4-shaozhengchao@huawei.com/
Fixes: 585d763af09c ("net/sched: Introduce Credit Based Shaper (CBS) qdisc") Reported-by: Junyoung Jang <graypanda.inzag@gmail.com> Tested-by: Junyoung Jang <graypanda.inzag@gmail.com> Tested-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
tun/tap & vhost-net: apply qdisc backpressure on full ptr_ring to reduce TX drops
This patch series deals with tun/tap & vhost-net which drop incoming
SKBs whenever their internal ptr_ring buffer is full. Instead, with this
patch series, the associated netdev queue is stopped - but only when a
qdisc is attached. If no qdisc is present the existing behavior is
preserved. The XDP transmit path is not affected. This patch series
touches tun/tap and vhost-net, as they share common logic and must be
updated together. Modifying only one of them would break the other.
By applying proper backpressure, this change allows the connected qdisc to
operate correctly, as reported in [1], and significantly improves
performance in real-world scenarios, as demonstrated in our paper [2]. For
example, we observed a 36% TCP throughput improvement for an OpenVPN
connection between Germany and the USA.
Synthetic pktgen benchmarks indicate a slight regression, and packet
loss is reduced to near zero. Pktgen benchmarks are provided per commit,
with the final commit showing the overall performance.
Simon Schippers [Sun, 10 May 2026 15:15:29 +0000 (17:15 +0200)]
tun/tap & vhost-net: avoid ptr_ring tail-drop when a qdisc is present
This commit prevents tail-drop when a qdisc is present and the ptr_ring
becomes full. Once the ring reaches capacity after a produce attempt,
the netdev queue is stopped instead of dropping subsequent packets.
If no qdisc is present, the previous tail-drop behavior is preserved.
If producing an entry fails anyway due to a race, tun_net_xmit() drops
the packet. Such races are expected because LLTX is enabled and the
transmit path operates without the usual locking.
The __tun_wake_queue() function of the consumer races with the producer
for waking/stopping the netdev queue, which could result in a stalled
queue. Therefore, an smp_mb__after_atomic() is introduced that pairs
with the smp_mb() of the consumer. It follows the principle of store
buffering described in tools/memory-model/Documentation/recipes.txt:
- The producer in tun_net_xmit() first sets __QUEUE_STATE_DRV_XOFF,
followed by an smp_mb__after_atomic() (= smp_mb()), and then reads the
ring with __ptr_ring_check_produce().
- The consumer in __tun_wake_queue() first writes zero to the ring in
__ptr_ring_consume(), followed by an smp_mb(), and then reads the queue
status with netif_tx_queue_stopped().
=> Following the aforementioned principle, it is impossible for the
producer to see a full ring (and therefore not wake the queue on the
re-check) while the consumer simultaneously fails to see a stopped
queue (and therefore also does not wake it).
Benchmarks:
The benchmarks show a slight regression in raw transmission performance
when using two sending threads. Packet loss also occurs only in the
two-thread sending case; no packet loss was observed with a single
sending thread.
Test setup:
AMD Ryzen 5 5600X at 4.3 GHz, 3200 MHz RAM, isolated QEMU threads;
Average over 50 runs @ 100,000,000 packets. SRSO and spectre v2
mitigations disabled.
Note for tap+vhost-net:
XDP drop program active in VM -> ~2.5x faster; slower for tap due to
more syscalls (high utilization of entry_SYSRETQ_unsafe_stack in perf)
Co-developed-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Simon Schippers <simon.schippers@tu-dortmund.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260510151529.43895-5-simon.schippers@tu-dortmund.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Simon Schippers [Sun, 10 May 2026 15:15:28 +0000 (17:15 +0200)]
ptr_ring: move free-space check into separate helper
This patch moves the check for available free space for a new entry into
a separate function. Existing callers that only check for a non-zero
return value are unaffected; __ptr_ring_produce() now returns -EINVAL
for a zero-size ring and -ENOSPC when full, whereas before both cases
returned -ENOSPC. The new helper allows callers to determine in advance
whether subsequent __ptr_ring_produce() calls will succeed. This
information can, for example, be used to temporarily stop producing until
__ptr_ring_check_produce() indicates that space is available again.
Co-developed-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Simon Schippers <simon.schippers@tu-dortmund.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260510151529.43895-4-simon.schippers@tu-dortmund.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Simon Schippers [Sun, 10 May 2026 15:15:27 +0000 (17:15 +0200)]
vhost-net: wake queue of tun/tap after ptr_ring consume
Add tun_wake_queue() to tun.c and export it for use by vhost-net. The
function validates that the file belongs to a tun/tap device and that
the tfile exists, dereferences the tun_struct under RCU, and delegates
to __tun_wake_queue().
vhost_net_buf_produce() now calls tun_wake_queue() after a successful
batched consume of the ring to allow the netdev subqueue to be woken up.
The point is to allow the queue to be stopped when it gets full, which
is required for traffic shaping - implemented by the following
"avoid ptr_ring tail-drop when a qdisc is present".
Without the corresponding queue stopping, this patch alone causes no
throughput regression for a tap+vhost-net setup sending to a qemu VM:
3.857 Mpps to 3.891 Mpps.
Details: AMD Ryzen 5 5600X at 4.3 GHz, 3200 MHz RAM, isolated QEMU
threads, XDP drop program active in VM, pktgen sender; Avg over
50 runs @ 100,000,000 packets. SRSO and spectre v2 mitigations disabled.
Co-developed-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Simon Schippers <simon.schippers@tu-dortmund.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260510151529.43895-3-simon.schippers@tu-dortmund.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Simon Schippers [Sun, 10 May 2026 15:15:26 +0000 (17:15 +0200)]
tun/tap: add ptr_ring consume helper with netdev queue wakeup
Introduce tun_ring_consume() that wraps ptr_ring_consume() and calls
__tun_wake_queue(). The latter wakes the stopped netdev subqueue once
half of the ring capacity has been consumed, tracked via the new
cons_cnt field in tun_file. As a safety net, the queue is also woken on
the last consumed entry if it leaves the ring empty. The point is to
allow the queue to be stopped when it gets full, which is required for
traffic shaping - implemented by the following "avoid ptr_ring tail-drop
when a qdisc is present".
Some implementation details:
- tun_ring_recv() replaces ptr_ring_consume() with tun_ring_consume()
to properly wake the queue.
- __tun_detach() locks the tx_ring.consumer_lock to avoid races with
the consumer on the queue_index.
- The ptr_ring_consume() call in tun_queue_purge() is not replaced with
tun_ring_consume(). Instead, within the same tx_ring.consumer_lock
in __tun_detach(), the netdev queue is woken for the ntfile taking
it over, to avoid a possible stall. This does not matter for
tun_detach_all(), as it is called during device teardown and no tfile
takes over any queue.
- Reset cons_cnt in tun_attach() so the half-ring wake threshold is
valid for the new ring size after ptr_ring_resize().
- tun_queue_resize() wakes all queues after resizing with the proper
tx_ring.consumer_lock and resets the cons_cnt to avoid a possible
stale queue.
- The aforementioned upcoming patch explains the pairing of the smp_mb()
of __tun_wake_queue().
Without the corresponding queue stopping, this patch alone causes no
regression for a tap setup sending to a qemu VM: 1.132 Mpps
to 1.134 Mpps.
Details: AMD Ryzen 5 5600X at 4.3 GHz, 3200 MHz RAM, isolated QEMU
threads, pktgen sender; Avg over 50 runs @ 100,000,000 packets;
SRSO and spectre v2 mitigations disabled.
Co-developed-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Tim Gebauer <tim.gebauer@tu-dortmund.de> Signed-off-by: Simon Schippers <simon.schippers@tu-dortmund.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260510151529.43895-2-simon.schippers@tu-dortmund.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Niranjan H Y [Wed, 13 May 2026 01:55:42 +0000 (07:25 +0530)]
ASoC: sdw_utils: Remove dead code in asoc_sdw_ti_add_tac5xx2_routes()
Remove unnecessary checks for scnprintf() return values in
asoc_sdw_ti_add_tac5xx2_routes(). The function scnprintf() never
returns negative values and cannot return zero given the format
strings used ("%s SPK_L" and "%s SPK_R").
The existing length validation at line 110 already ensures that
name_prefix won't cause buffer overflow, and scnprintf() guarantees
null-termination even in case of truncation.
Fixes: e812de61e9a0 ("ASoC: sdw_utils: TI amp utility for tac5xx2 family") Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/linux-sound/agF8GBcHYUaGJbXY@stanley.mountain/ Signed-off-by: Niranjan H Y <niranjan.hy@ti.com> Link: https://patch.msgid.link/20260513015542.2420-1-niranjan.hy@ti.com Signed-off-by: Mark Brown <broonie@kernel.org>
devm_kasprintf() can fail while building the temporary speaker
component string. If that happens, spk_components is set to NULL, but
the current code can still pass it to strlen() on a later loop iteration
or after the loop when appending the speaker component list to
card->components.
Use NULL to represent the initial "no speaker components" state, and
return -ENOMEM immediately if building spk_components fails.
Alistair Popple [Fri, 1 May 2026 06:51:16 +0000 (16:51 +1000)]
mm/memory: fix spurious warning when unmapping device-private/exclusive pages
Device private and exclusive entries are only supported for anonymous
folios. This condition is tested in __migrate_device_pages() and
make_device_exclusive() using folio_test_anon(). However the unmap path
tests this assumption using vma_is_anonymous().
This is wrong because whilst anonymous VMAs can only contain folios where
folio_test_anon() is true the opposite relation does not hold. A folio
for which folio_test_anon() is true does not imply vma_is_anonymous() is
true. Such a condition can occur if for example a folio is part of a
private filebacked mapping.
In this case vma_is_anonymous() is false as the mapping is filebacked, but
folio_test_anon() may be true, thus permitting devices to migrate the
folio to device private memory. This can lead to the following spurious
warnings during process teardown:
mm: fix __vm_normal_page() to handle missing support for pmd_special()/pud_special()
On x86 32-bit with THP enabled, zap_huge_pmd() is seen to generate a
"WARNING: mm/memory.c:735 at __vm_normal_page+0x6a/0x7d", from the
VM_WARN_ON_ONCE(is_zero_pfn(pfn) || is_huge_zero_pfn(pfn)); followed by
"BUG: Bad rss-counter state"s, then later "BUG: Bad page state"s when
reclaim gets to call shrink_huge_zero_folio_scan().
It's as if the _PAGE_SPECIAL bit never got set in the huge_zero pmd: and
indeed, whereas pte_special() and pte_mkspecial() are subject to a
dedicated CONFIG_ARCH_HAS_PTE_SPECIAL, pmd_special() and pmd_mkspecial()
are subject to CONFIG_ARCH_SUPPORTS_PMD_PFNMAP, which is never enabled on
any 32-bit architecture.
While the problem was exposed through commit d80a9cb1a64a
("mm/huge_memory: add and use normal_or_softleaf_folio_pmd()"), it was an
oversight in commit af38538801c6 ("mm/memory: factor out common code from
vm_normal_page_*()") and would result in other problems:
* huge zero folio accounted in smaps, pagemap (PAGE_IS_FILE) and
numamaps as file-backed THP
* folio_walk_start() returning the folio even without FW_ZEROPAGE set.
Callers seem to tolerate that, though.
... and triggering the VM_WARN_ON_ONE(), although never reported so far.
To fix it, teach vm_normal_page_pmd()/vm_normal_page_pud() to consider
whether pmd_special/pud_special is actually implemented.
Link: https://lore.kernel.org/20260430-pmd_special-v1-1-dbcbcfd72c20@kernel.org Fixes: af38538801c6 ("mm/memory: factor out common code from vm_normal_page_*()") Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reported-by: Hugh Dickins <hughd@google.com> Closes: https://lore.kernel.org/r/74a75b59-2e13-3985-ee99-d5521f39df2a@google.com Reported-by: Bibo Mao <maobibo@loongson.cn> Closes: https://lore.kernel.org/r/20260430041121.2839350-1-maobibo@loongson.cn Debugged-by: Hugh Dickins <hughd@google.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Bibo Mao <maobibo@loongson.cn> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Muchun Song [Tue, 28 Apr 2026 08:52:18 +0000 (16:52 +0800)]
drivers/base/memory: fix memory block reference leak in poison accounting
memblk_nr_poison_inc() and memblk_nr_poison_sub() look up a memory block
via find_memory_block_by_id(), which acquires a reference to the memory
block device.
Both helpers use the returned memory block without dropping that
reference, leaking the device reference on each successful lookup. Drop
the reference after updating nr_hwpoison.
Link: https://lore.kernel.org/20260428085219.1316047-3-songmuchun@bytedance.com Fixes: 5033091de814 ("mm/hwpoison: introduce per-memory_block hwpoison counter") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Huang, Ying" <huang.ying.caritas@gmail.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Muchun Song [Tue, 28 Apr 2026 08:52:17 +0000 (16:52 +0800)]
mm/memory_hotplug: fix memory block reference leak on remove
Patch series "mm: Fix memory block leaks and locking", v2.
This series fixes two memory block device reference leaks and one locking
issue around the per-memory_block hwpoison counter.
This patch (of 2):
remove_memory_blocks_and_altmaps() looks up each memory block with
find_memory_block(), which acquires a reference to the memory block
device.
That reference is never dropped on this path, resulting in a leaked device
reference when removing memory blocks and their altmaps. Drop the
reference after retrieving mem->altmap and clearing mem->altmap, before
removing the memory block device.
Link: https://lore.kernel.org/20260428085219.1316047-1-songmuchun@bytedance.com Link: https://lore.kernel.org/20260428085219.1316047-2-songmuchun@bytedance.com Fixes: 6b8f0798b85a ("mm/memory_hotplug: split memmap_on_memory requests across memblocks") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Huang, Ying" <huang.ying.caritas@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Increase buffer size to accommodate machines with 64K PAGE_SIZE.
Link: https://lore.kernel.org/20260421070707.992873-1-lk@c--e.de Fixes: 0913b7554726 ("lib: kunit_iov_iter: add tests for extract_iter_to_sg") Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Reported-by: David Gow <davidgow@google.com> Closes: https://lore.kernel.org/34a81ec2-af84-465d-9b5e-7bb5bf01680f@davidgow.net Tested-by: David Gow <davidgow@google.com> Tested-by: Josh Law <joshlaw48@gmail.com> Reviewed-by: Josh Law <joshlaw48@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/page_alloc: fix initialization of tags of the huge zero folio with init_on_free
__GFP_ZEROTAGS semantics are currently a bit weird, but effectively this
flag is only ever set alongside __GFP_ZERO and __GFP_SKIP_KASAN.
If we run with init_on_free, we will zero out pages during
__free_pages_prepare(), to skip zeroing on the allocation path.
However, when allocating with __GFP_ZEROTAG set, post_alloc_hook() will
consequently not only skip clearing page content, but also skip clearing
tag memory.
Not clearing tags through __GFP_ZEROTAGS is irrelevant for most pages that
will get mapped to user space through set_pte_at() later: set_pte_at() and
friends will detect that the tags have not been initialized yet
(PG_mte_tagged not set), and initialize them.
However, for the huge zero folio, which will be mapped through a PMD
marked as special, this initialization will not be performed, ending up
exposing whatever tags were still set for the pages.
The docs (Documentation/arch/arm64/memory-tagging-extension.rst) state
that allocation tags are set to 0 when a page is first mapped to user
space. That no longer holds with the huge zero folio when init_on_free is
enabled.
Fix it by decoupling __GFP_ZEROTAGS from __GFP_ZERO, passing to
tag_clear_highpages() whether we want to also clear page content.
Invert the meaning of the tag_clear_highpages() return value to have
clearer semantics.
Reproduced with the huge zero folio by modifying the check_buffer_fill
arm64/mte selftest to use a 2 MiB area, after making sure that pages have
a non-0 tag set when freeing (note that, during boot, we will not actually
initialize tags, but only set KASAN_TAG_KERNEL in the page flags).
$ ./check_buffer_fill
1..20
...
not ok 17 Check initial tags with private mapping, sync error mode and mmap memory
not ok 18 Check initial tags with private mapping, sync error mode and mmap/mprotect memory
...
This code needs more cleanups; we'll tackle that next, like
decoupling __GFP_ZEROTAGS from __GFP_SKIP_KASAN.
[akpm@linux-foundation.org: s/__GPF_ZERO/__GFP_ZERO/, per David] Link: https://lore.kernel.org/20260421-zerotags-v2-1-05cb1035482e@kernel.org Fixes: adfb6609c680 ("mm/huge_memory: initialise the tags of the huge zero folio") Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Lance Yang <lance.yang@linux.dev> Cc: Brendan Jackman <jackmanb@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20260428124833.1903302-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Baoquan He <baoquan.he@linux.dev> Cc: Dave Young <ruirui.yang@linux.dev> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Pratyush Yadav <pratyush@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20260428124833.1903302-1-rppt@kernel.org Link: https://lore.kernel.org/20260428124833.1903302-2-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Baoquan He <baoquan.he@linux.dev> Acked-by: Pratyush Yadav <pratyush@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Dave Young <ruirui.yang@linux.dev> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Destructive tests should be invoked with -d command-line option, but this
won't work today since 'd' is missing in getopts command-line. This
commit fixes it.
Link: https://lore.kernel.org/214fd9e4-5398-4c26-859e-c982c2e277c3@redhat.com Fixes: f16ff3b692ad ("selftests/mm: run_vmtests.sh: add missing tests") Signed-off-by: Luiz Capitulino <luizcap@redhat.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
scripts/gdb: slab: update field names of struct kmem_cache
The commit 5ba6bc27b1f9 ("slab: decouple pointer to barn from
kmem_cache_node") reorganized the struct kmem_cache to factor out the
per-node fields to the new struct kmem_cache_per_node_ptrs. This causes
the gdb scripts for lx-slabinfo and lx-slabtrace fail as they still
reference the old structure.
Adjust the gdb scripts to match the current state of struct kmem_cache.
Link: https://lore.kernel.org/20260427142448.666117-3-illia@yshyn.com Fixes: 5ba6bc27b1f9 ("slab: decouple pointer to barn from kmem_cache_node") Signed-off-by: Illia Ostapyshyn <illia@yshyn.com> Acked-by: Harry Yoo (Oracle) <harry@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Florian Fainelli <florian.fainelli@broadcom.com> Cc: Hao Li <hao.li@linux.dev> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Seongjun Hong <hsj0512@snu.ac.kr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
scripts/gdb: mm: cast untyped symbols in x86_page_ops
The symbols phys_base, _text, and _end, used in x86_page_ops are either
defined in assembly or implicitly by the linker. Thus, they lack type
information and cause a conversion error after gdb.parse_and_eval.
Explicitly cast these expressions to unsigned long.
Link: https://lore.kernel.org/20260427142448.666117-2-illia@yshyn.com Fixes: 55f8b4518d14 ("scripts/gdb: implement x86_page_ops in mm.py") Signed-off-by: Illia Ostapyshyn <illia@yshyn.com> Cc: Florian Fainelli <florian.fainelli@broadcom.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Vlastimil Babka <vbabka@suse.com> Cc: Hao Li <hao.li@linux.dev> Cc: Harry Yoo <harry@kernel.org> Cc: Seongjun Hong <hsj0512@snu.ac.kr> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_sysfs_memcg_path_to_id() breaks mem_cgroup_iter() loop without
calling mem_cgroup_iter_break(). This leaks the cgroup reference. Fix
the issue by calling mem_cgroup_iter_break() before the break.
mm/migrate_device: fix spinlock leak in migrate_vma_insert_huge_pmd_page
When check_stable_address_space() fails after the PMD spinlock has
been acquired via pmd_lock(), the code jumps directly to the abort
label, bypassing the spin_unlock() call in unlock_abort. This causes
the PMD spinlock to be permanently held, leading to a deadlock.
Change the goto target from abort to unlock_abort to ensure the
spinlock is always released on this error path.
Link: https://lore.kernel.org/20260425133537.17463-1-nueralspacetech@gmail.com Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages") Signed-off-by: Sunny Patel <nueralspacetech@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Balbir Singh <balbirs@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The reset actions of the DEFZA adapters are exceedingly slow, taking up
to 30 seconds to complete by the device spec and typically in the range
of 10 seconds in reality, as required for the device RTOS to boot, still
quite a lot. Therefore a state machine is used that's interrupt driven,
however a safety mechanism is required in case of adapter malfunction,
so that if no state change interrupt has arrived in time, then the
situation is taken care of.
The safety mechanism depends on the origin of the reset. For regular
adapter initialisation at the device probe time a sleep is requested.
However a reset is also required by the device spec when the adapter has
transitioned into the halted state, such as in response to a PC Trace
event in the course of ring fault recovery, possibly a common network
event. In that case no sleep is possible as a device halt is reported
at the hardirq level.
A timer is therefore set up to ensure progress in case no adapter state
change interrupt has arrived in time, but as from commit 168f6b6ffbee
("timers: Use del_timer_sync() even on UP") a warning is issued as the
timer is deleted in the hardirq handler upon an expected state change:
The immediate origin of the new warning is the switch away from aliasing
del_timer_sync() to del_timer() (timer_delete_sync() to timer_delete()
in terms of current function names) for UP configurations, which however
is the only choice for this driver anyway as no SMP hardware supports
the TURBOchannel bus this device interfaces to. Therefore there is a
very remote issue only this is a sign of.
Specifically if an adapter reset issued upon a transition to the halted
state times out and first triggers fza_reset_timer() for another reset
assertion, which then schedules fza_reset_timer() for reset deassertion
and then that second call is pre-empted after poking at the hardware,
but before the timer has been rearmed and owing to high system load
causing exceedingly high scheduling latency control is not handed back
before a transition to the uninitialised state has caused the timer to
be deleted even before it has been started, then fza_reset_timer() will
be called yet again and issue another reset even though by then the
adapter has already recovered.
Prevent this situation from happening by switching to timer_delete() for
the transition to the halted state and protect the code region affected
with a spinlock, also to make sure add_timer() has not been called twice
in a row due to an execution race between the interrupt handler and the
timer handler (though it could only happen on SMP, but let's keep the
driver clean). It's a very unlikely sequence of events to happen and
therefore there's no point in trying to be overly clever about it, such
as by placing printk() calls outside the protection. For the transition
to the uninitialised state switch to timer_delete_sync_try() instead, so
that a timer isn't deleted that's just been rearmed by the timer handler
and needs to watch for the device to come out of reset again (again, an
SMP scenario only).
Retain timer_delete_sync() invocations outside the hardirq context for a
stray timer not to fire once device structures have been released.
Fixes: 61414f5ec9834 ("FDDI: defza: Add support for DEC FDDIcontroller 700 TURBOchannel adapter") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Michael Kelley [Tue, 17 Feb 2026 18:23:35 +0000 (10:23 -0800)]
drm/hyperv: During panic do VMBus unload after frame buffer is flushed
In a VM, Linux panic information (reason for the panic, stack trace,
etc.) may be written to a serial console and/or a virtual frame buffer
for a graphics console. The latter may need to be flushed back to the
host hypervisor for display.
The current Hyper-V DRM driver for the frame buffer does the flushing
*after* the VMBus connection has been unloaded, such that panic messages
are not displayed on the graphics console. A user with a Hyper-V graphics
console is left with just a hung empty screen after a panic. The enhanced
control that DRM provides over the panic display in the graphics console
is similarly non-functional.
Commit 3671f3777758 ("drm/hyperv: Add support for drm_panic") added
the Hyper-V DRM driver support to flush the virtual frame buffer. It
provided necessary functionality but did not handle the sequencing
problem with VMBus unload.
Fix the full problem by using VMBus functions to suppress the VMBus
unload that is normally done by the VMBus driver in the panic path. Then
after the frame buffer has been flushed, do the VMBus unload so that a
kdump kernel can start cleanly. As expected, CONFIG_DRM_PANIC must be
selected for these changes to have effect. As a side benefit, the
enhanced features of the DRM panic path are also functional.
Fixes: 3671f3777758 ("drm/hyperv: Add support for drm_panic") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
Michael Kelley [Tue, 17 Feb 2026 18:23:34 +0000 (10:23 -0800)]
Drivers: hv: vmbus: Provide option to skip VMBus unload on panic
Currently, VMBus code initiates a VMBus unload in the panic path so
that if a kdump kernel is loaded, it can start fresh in setting up its
own VMBus connection. However, a driver for the VMBus virtual frame
buffer may need to flush dirty portions of the frame buffer back to
the Hyper-V host so that panic information is visible in the graphics
console. To support such flushing, provide exported functions for the
frame buffer driver to specify that the VMBus unload should not be
done by the VMBus driver, and to initiate the VMBus unload itself.
Together these allow a frame buffer driver to delay the VMBus unload
until after it has completed the flush.
Ideally, the VMBus driver could use its own panic-path callback to do
the unload after all frame buffer drivers have finished. But DRM frame
buffer drivers use the kmsg dump callback, and there are no callbacks
after that in the panic path. Hence this somewhat messy approach to
properly sequencing the frame buffer flush and the VMBus unload.
Fixes: 3671f3777758 ("drm/hyperv: Add support for drm_panic") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
Pengpeng Hou [Thu, 7 May 2026 08:18:11 +0000 (16:18 +0800)]
drivers/of: validate status properties in reconfig state changes
Live-tree reconfiguration properties also carry raw values plus explicit
lengths. `of_reconfig_get_state_change()` currently treats `status`
property values as NUL-terminated strings and feeds them straight into
`strcmp()`.
Factor the `"okay"` / `"ok"` check out into a helper that first verifies
that the property contains a bounded C string within `prop->length`.
Malformed `status` updates should be treated as not enabling the node.
Pengpeng Hou [Thu, 7 May 2026 08:18:10 +0000 (16:18 +0800)]
drivers/of: validate live-tree string properties before string use
`populate_properties()` stores live-tree property values as raw byte
sequences plus a separate `length`. They are not globally guaranteed to
be NUL-terminated.
`of_prop_next_string()` iterates string-list properties by walking raw
bytes, `__of_node_is_type()` checks `device_type`,
`__of_device_is_status()` checks `status`, and
`of_alias_from_compatible()` reads the first `compatible` entry. These
paths must validate that the relevant string fits within the property
bounds before they hand it to C string helpers.
Validate these live-tree string properties within their declared bounds.
In particular, make `of_prop_next_string()` reject malformed entries
before returning them, keep the `device_type` check inside the existing
no-lock helper path, and add unit coverage for malformed first and
trailing string-list entries.
i2c: tegra: make tegra_i2c_mutex_unlock() return void
tegra_i2c_mutex_unlock() returning an error that overwrites the transfer
result causes silent loss of I2C transfer errors. If the transfer failed
but the unlock succeeded, the error was lost and the function incorrectly
reported success.
Rather than propagating the unlock error (which is not actionable by the
caller - the I2C message may have been sent regardless), convert the
function to return void and WARN on the unexpected condition. If the
unlock fails, subsequent lock attempts will fail anyway, making the error
visible on the next transfer.
i2c: tegra: fix pm_runtime leak on mutex_lock failure
If tegra_i2c_mutex_lock() fails, the function returns without calling
pm_runtime_put(), leaking the runtime PM reference acquired by the
preceding pm_runtime_get_sync(). This prevents the device from ever
entering runtime suspend.
Add the missing pm_runtime_put() before returning on lock failure.
driver core: platform: remove software node on release()
If we pass a software node to a newly created device using struct
platform_device_info, it will not be removed when the device is
released. This may happen when a module creating the device is removed
or on failure in platform_device_add().
When we try to reuse that software node in a subsequent call to
platform_device_register_full(), it will fail with -EBUSY.
Provide a wrapper around the existing platform_device_release() that
additionally calls device_remove_software_node() and use it to replace
the former if we end up adding a software node.
While at it: check all three possible situations in which two software
nodes for a single platform device can be created/assigned in
platform_device_register_full() and bail-out early.
KVM: SEV: Allocate only as many bytes as needed for temp crypt buffers
When using a temporary buffer to {de,en}crypt unaligned memory for debug,
allocate only the number of bytes that are needed instead of allocating an
entire page. The most common case for unaligned accesses will be reading
or writing less than 16 bytes.
KVM: SEV: Rewrite logic to {de,en}crypt memory for debug
Wholesale rewrite the guts of the debug {de,en}crypt flows, as the existing
code is broken, e.g. doesn't handle cases where the access isn't naturally
sized and aligned, and is so wildly flawed that attempting to salvage the
current code in an iterative fashion would be more risky than a rewrite.
E.g. when encrypting 9 bytes at offset 8, KVM needs to _decrypt_
destination[31:0] into a temporary buffer, buffer[31:0], then copy 9 bytes
from source[8:0] to buffer[16:8], then encrypt buffer[31:0] back into
destination[31:0]. The current code only ever copies 16 bytes, and
bizarrely uses a temporary buffer for the source as well.
To keep the code easier to read and maintain, send the unaligned cases
down dedicated "slow" paths instead of trying to mix and match the possible
combinations in one helper.
For now, preserve the basic approach of the current code, e.g. allocate an
entire page for the temporary buffer, to minimize unwanted changes in
functionality.
KVM: SEV: Add helper function to pin/unpin a single page
Add helpers to pin/unpin a single page, and use it in all flows that pin
exactly one page. None of the single-page users actually check that the
correct number of pages was pinned, which is functionally ok, but visually
jarring, especially in the decrypt/encrypt flow, which separately pins two
pages, but uses a single variable to track how pages were pinned each time.
Again, it's functionally ok since core mm guarantees exactly one page will
be pinned on success, but it's ugly.
Opportunistically use page_to_phys() instead of open coding an equivalent
via page_to_pfn().
Note, all users of the single-page helper pre-validate the address and
length, i.e. don't rely on the sanity check in sev_pin_memory().
KVM: SEV: Explicitly validate the dst buffer for debug operations
When encrypting/decrypting guest memory, explicitly check that the
destination is non-NULL and doesn't wrap instead of subtly relying on
sev_pin_memory() to perform the check. This will allow adding and using
a more focused single-page pinning helper.
KVM: selftests: Add a test to verify SEV {en,de}crypt debug ioctls
Add a selftest to verify KVM's handling of {de,en}crypt debug ioctls,
specifically focusing on edge cases around the chunk (16 bytes) and page
(4096) sizes, where KVM had multiple bugs. E.g. KVM would fail to handle
small sizes that aren't naturally aligned and sized, would buffer overflow
if the destination was unaligned but the source was not, etc.
Attempt to strike a balance between an exhaustive test and a reasonable
runtime. On a system with both SEV and SEV-ES support, the current runtime
is under 45 seconds. Which isn't great, but it's tolerable, and it's not
obvious which of the combinations are "better" than the others.
Linus Torvalds [Wed, 13 May 2026 22:00:40 +0000 (15:00 -0700)]
Merge tag 'sched_ext-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
"The bulk of this is hardening of the new sub-scheduler infrastructure.
- UAFs and lifecycle bugs on the sub-sched attach/detach paths:
parent sub_kset freed under a racing child, list_del_rcu on an
uninitialized list head, ops->priv stomped by concurrent
attach/detach, and a UAF in the init-failure error path
- Task state-machine reorg closing concurrent enable-vs-dead races: a
task exiting during the unlocked init window could trip NULL ops
derefs or skip exit_task() cleanup
- A scx_link_sched() self-deadlock on scx_sched_lock
- isolcpus: stop dereferencing the now-RCU-protected HK_TYPE_DOMAIN
cpumask without RCU, and stop rejecting BPF schedulers when only
cpuset isolated partitions are active
- PREEMPT_RT: disable irq_work runs in hardirq context so dumps show
the failing task rather than the irq_work kthread
- Assorted !CONFIG_EXT_SUB_SCHED, randconfig, and selftest build
fixes"
* tag 'sched_ext-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Use HK_TYPE_DOMAIN_BOOT to detect isolcpus= domain isolation
sched_ext: Defer sub_kset base put to scx_sched_free_rcu_work
sched_ext: INIT_LIST_HEAD() &sch->all in scx_alloc_and_add_sched()
sched_ext: Drop NONE early return in scx_disable_and_exit_task()
sched_ext: Avoid UAF in scx_root_enable_workfn() init failure path
sched_ext: Clear ops->priv on scx_alloc_and_add_sched() error paths
sched_ext: Fix ops->priv clobber on concurrent attach/detach
selftests/sched_ext: Fix build error in dequeue selftest
sched_ext: Handle SCX_TASK_NONE in disable/switched_from paths
sched_ext: Close sub-sched init race with post-init DEAD recheck
sched_ext: Close root-enable vs sched_ext_dead() race with SCX_TASK_INIT_BEGIN
sched_ext: Replace SCX_TASK_OFF_TASKS flag with SCX_TASK_DEAD state
sched_ext: Inline scx_init_task() and move RESET_RUNNABLE_AT into scx_set_task_state()
sched_ext: Cleanups in preparation for the SCX_TASK_INIT_BEGIN/DEAD work
sched_ext: Use IRQ_WORK_INIT_HARD() to initialize sch->disable_irq_work
sched_ext: Fix !CONFIG_EXT_SUB_SCHED build warnings
sched_ext: Drop unused scx_find_sub_sched() stub
sched_ext: Move scx_error() out of scx_link_sched()'s lock region
Dmitry Osipenko [Fri, 1 May 2026 00:00:43 +0000 (03:00 +0300)]
drm/virtio: Extend blob UAPI with deferred-mapping hinting
If userspace never maps GEM object, then BO wastes hostmem space
because VirtIO-GPU driver maps VRAM BO at the BO's creating time.
Make mappings on-demand by adding new RESOURCE_CREATE_BLOB IOCTL/UAPI
hinting flag telling that host mapping should be deferred until first
mapping is made when the flag is set by userspace.
Chaitanya Sabnis [Wed, 13 May 2026 12:37:57 +0000 (18:07 +0530)]
dt-bindings: i2c: convert davinci i2c to dt-schema
Convert the Texas Instruments DaVinci and Keystone I2C controller
bindings from legacy text format to modern dt-schema (YAML).
During the conversion, the `interrupts` property was made required
to match the strict requirement in the driver probe function. The
custom `ti,has-pfunc` and `power-domains` properties were also
properly defined to match SoC-specific hardware features.
Linus Torvalds [Wed, 13 May 2026 21:56:31 +0000 (14:56 -0700)]
Merge tag 'cgroup-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- cpuset fixes:
- Partition invalidation could return CPUs still in use by sibling
partitions, producing overlapping effective_cpus
- cpuset_can_attach() over-reserved DL bandwidth on moves that
stayed within the same root domain
- Pending DL migration state leaked into later attaches when a
later can_attach() check failed
- Reorder PF_EXITING and __GFP_HARDWALL checks so dying tasks can
allocate from any node and exit quickly
- dmem: propagate -ENOMEM instead of spinning forever when the fallback
pool allocation also fails
- selftests/cgroup: percpu test error-path leak, bogus numeric
comparison of cpuset strings, and a zero-length read() that silently
passed OOM-kill tests
* tag 'cgroup-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Return only actually allocated CPUs during partition invalidation
selftests/cgroup: Fix error path leaks in test_percpu_basic
cgroup/cpuset: Reserve DL bandwidth only for root-domain moves
cgroup/cpuset: Reset DL migration state on can_attach() failure
selftests/cgroup: Fix string comparison in write_test
selftests/cgroup: Fix cg_read_strcmp() empty string comparison
cgroup/dmem: Return -ENOMEM on failed pool preallocation
cgroup/cpuset: move PF_EXITING check before __GFP_HARDWALL in cpuset_current_node_allowed()
Linus Torvalds [Wed, 13 May 2026 21:49:13 +0000 (14:49 -0700)]
Merge tag 'wq-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
- Plug a wq->cpu_pwq leak on the WQ_UNBOUND allocation failure path
- Fix a cancel_delayed_work_sync() livelock against drain_workqueue()
caused by the drain/destroy reject path leaving WORK_STRUCT_PENDING
set with no owner
* tag 'wq-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Fix wq->cpu_pwq leak in alloc_and_link_pwqs() WQ_UNBOUND path
workqueue: Release PENDING in __queue_work() drain/destroy reject path
Mikko Perttunen [Tue, 21 Apr 2026 04:02:38 +0000 (13:02 +0900)]
drm/msm: Fix iommu_map_sgtable() return value check and avoid WARN
Commit "iommu: return full error code from iommu_map_sg[_atomic]()"
changed iommu_map_sgtable() to return an ssize_t and negative values
in error cases, rather than a size_t and a zero.
Store the return value in the appropriate type and in case of error,
return it rather than WARNing.
Fixes: ad8f36e4b6b1 ("iommu: return full error code from iommu_map_sg[_atomic]()") Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Patchwork: https://patchwork.freedesktop.org/patch/719685/
Message-ID: <20260421-iommu_map_sgtable-return-v1-3-fb484c07d2a1@nvidia.com> Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Rob Clark [Sat, 11 Apr 2026 15:03:12 +0000 (08:03 -0700)]
drm/msm/a6xx: Restore sysprof_active
This got lost in the shuffle somehow when moving the vfunc table to
catalogue. Fixes inhibiting IFPC when userspace is collecting perfcntr
data.
Fixes: 491fadb2b818 ("drm/msm/adreno: Move adreno_gpu_func to catalogue") Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com> Reviewed-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/717780/
Message-ID: <20260411150312.257937-1-robin.clark@oss.qualcomm.com>
drm/msm/adreno: fix userspace-triggered crash on a2xx-a4xx
Before a5xx Adreno driver will not try fetching UBWC params (because
those generations didn't support UBWC anyway), however it's still
possible to query UBWC-related params from the userspace, triggering
possible NULL pointer dereference. Check for UBWC config in
adreno_get_param() and return sane defaults if there is none.
Fixes: a452510aad53 ("drm/msm/adreno: Switch to the common UBWC config struct") Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Reviewed-by: Rob Clark <rob.clark@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/717778/
Message-ID: <20260411-adreno-fix-ubwc-v3-1-4983156f3f80@oss.qualcomm.com> Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
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