ltc4282_parse_dt() evaluates the wrong variable when parsing the current
limit.
When the adi,current-limit-sense-microvolt property is parsed into
st->vsense_max, the subsequent switch statement evaluates the unrelated
val variable instead of st->vsense_max:
drivers/hwmon/ltc4282.c:ltc4282_parse_dt() {
...
ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt",
&st->vsense_max);
if (!ret) {
int reg_val;
switch (val) {
case 12500:
reg_val = 0;
break;
...
}
Because val holds a small integer representing vin_mode (from 0 to 3), it
never matches any of the valid current limit cases.
This causes it to always fall through to the default error case, return
-EINVAL, and aborts probe initialization for any device tree using this
property.
Validate st->vsense_max instead to fix the problem.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: cbc29538db ("hwmon: Add driver for LTC4282")
Cc: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
When a negative value is passed to ltc4282_write_curr(), the signed long
val is cast directly to u64:
drivers/hwmon/ltc4282.c:ltc4282_write_curr() {
/* need to pass it in millivolt */
u32 in = DIV_ROUND_CLOSEST_ULL((u64)val * st->rsense, DECA * MICRO);
...
}
This cast converts negative inputs into large positive values. The
subsequent division result overflows the u32 in variable, truncating
to a pseudo-random positive value. When this is passed to
ltc4282_write_voltage_byte(), it is clamped to the maximum limit instead
of zero.
Clamp val to 0 and to the maximum supported upper limit before the cast
and assign the result to a 64-bit temporary variable before the division
to avoid the underflow and an also possible overflow.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: cbc29538db ("hwmon: Add driver for LTC4282")
Cc: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
During device initialization in ltc4282_set_max_limits(), the calculation
of the maximum power limit can suffer from a 32-bit integer overflow.
static int ltc4282_set_max_limits(struct ltc4282_state *st)
{
...
st->power_max = DIV_ROUND_CLOSEST(st->vsense_max * DECA * MILLI,
st->rsense) * st->vfs_out;
...
}
The result of DIV_ROUND_CLOSEST() evaluates to a 32-bit unsigned integer
on 32-bit architectures. This result is then multiplied by st->vfs_out,
which is a 16-bit unsigned integer. According to C promotion rules, since
both operands are 32-bit or smaller, the multiplication is performed in
32-bit precision.
If the device is configured with a low sense resistor value via the device
tree (for example, 100 nano-ohms, resulting in st->rsense = 1) and the
voltage is high, the division result can reach 343,750,000 and st->vfs_out
can be 33,280. The product of these values is approximately 11.44 trillion,
which exceeds the maximum capacity of a 32-bit integer and overflows
before being stored in st->power_max.
This overflow causes a truncated value to be assigned to st->power_max and
written to the hardware limit register. An incorrect maximum power limit
can trigger spurious power-bad faults or alarms, which may lead to the
shutdown of the monitored power rail.
Avoid the problem by calculating and storing the maximum power using 64-bit
variables.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: cbc29538db ("hwmon: Add driver for LTC4282")
Cc: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The driver currently has two issues with the external VREF regulator
handling in ads7828_probe():
1. All errors from devm_regulator_get_optional() are ignored, causing the
driver to incorrectly fall back to internal VREF even for transient
errors like -EPROBE_DEFER or genuine failures like -ENOMEM.
2. The external regulator is never enabled. The driver calls
regulator_get_voltage() without first calling regulator_enable(),
so the VREF pin may remain unpowered if the regulator is not
configured as always-on.
Fix both issues by switching to devm_regulator_get_enable_read_voltage(),
which handles regulator get, enable, and voltage read in one call.
Only -ENODEV (no regulator specified in device tree) should trigger the
fallback to internal VREF. All other errors are propagated to the caller.
Fixes: a8ddfea095 ("hwmon: (ads7828) Accept optional parameters from device tree")
Signed-off-by: Qingshuang Fu <fuqingshuang@kylinos.cn>
Link: https://lore.kernel.org/r/20260805061645.1331652-1-fffsqian@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
In theory it could be possible that the REPLY_SIZE sized buffers for
holding the vendor and product strings could be end up missing the null
termination (for example by malicious hardware built on purpose)
required by the seq_printf() call. That limits the debugfs printf calls
to a maximum string length of REPLY_SIZE.
Fixes: d115b51e0e ("hwmon: add Corsair PSU HID controller driver")
Signed-off-by: Wilken Gottwalt <wilken.gottwalt@posteo.net>
Link: https://lore.kernel.org/r/anLj9gPWRoRDbQBV@monster.localdomain
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Ihor Solodrai says:
====================
resolve_btfids: Implement BTF tags emission for kfuncs
BTF data for the kernel is generated through the following pipeline:
* DWARF is emitted by the compiler
* pahole reads in DWARF and produces BTF
* resolve_btfids makes kernel-specific btf2btf transformation and
patches .BTF_ids section
This is orchestrated by link-vmlinux.sh, gen-btf.sh and Makefile.btf
in ./scripts directory.
Historically kernel-specific BTF features were implemented in pahole,
and controlled by the feature flags. This requires kernel build
process to be aware of pahole version used for the build to set
correct runtime arguments for BTF encoding [1].
This is a burden which can be alleviated by splitting kernel/module
BTF generation in two stages:
1. Generic BTF generation from the kernel source code.
2. Kernel-specific BTF modifications to support various BPF features.
So far both stages were fused in pahole's BTF encoding. By moving
stage (2) in-tree, the dependency of kernel build on pahole can become
much more loose.
resolve_btfids is already responsible for a few kernel-specific BTF
modifications:
* .BTF.base generation for modules [2]
* BTF sorting [3]
* KF_IMPLICIT_ARGS support [4]
This series completes the migration by emitting BTF kfunc annotations
in-tree: the "bpf_kfunc" and "bpf_fastcall" decl tags and the arena
"address_space(1)" type attribute, dropping the corresponding pahole
feature flags.
The three annotations depend on two pahole feature flags:
"decl_tag_kfuncs" and "attributes". Since emission is unconditional,
each flag has to be dropped in the same commit as the emission that
replaces it.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/Makefile.btf?h=v7.1-rc5
[2] https://docs.kernel.org/bpf/btf.html#btf-base-section
[3] https://lore.kernel.org/bpf/20260109130003.3313716-4-dolinux.peng@gmail.com/
[4] https://lore.kernel.org/bpf/20260120222638.3976562-1-ihor.solodrai@linux.dev/
[5] https://lore.kernel.org/bpf/20260722233518.778854-1-ihor.solodrai@linux.dev/
[6] https://lore.kernel.org/bpf/20260617210619.1562858-1-ihor.solodrai@linux.dev/
---
v2->v3:
* Refactoring in patch #2 (Eduard)
* restructure add_arena_tagged_proto() such that first we copy the
func proto and then update param types in place
* push error messages down to arena_tag_ptr()
* introduce is_arena_arg() helper
* Docs cleanup in patch #6 (Eduard)
* Add stats in commit message for patch #1
v2: https://lore.kernel.org/bpf/20260805230648.2354989-1-ihor.solodrai@linux.dev/
v1->v2:
* The bottom part of v1 has already been landed [5][6].
* New patch #1: run btf__dedup() in finalize_btf().
* Drop the "ensure" pattern. Emission is unconditional; kbuild owns
the pahole flags, so assume input BTF is not already tagged.
* Each pahole flag is now dropped in the same commit as the emission
that replaces it.
* Fail hard with an error on invalid kfunc declarations such as an
arena flag naming a missing argument or a non-pointer type.
* Various cleanups and nits (Andrii, Emil, Jiri, Sashiko).
v1: https://lore.kernel.org/bpf/20260601221805.821394-1-ihor.solodrai@linux.dev/
---
====================
Link: https://patch.msgid.link/20260807032029.78092-1-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
resolve_btfids now emits the bpf_kfunc and bpf_fastcall BTF decl tags and
the arena address_space(1) type attribute for kfuncs, which were
previously produced by pahole.
Reflect this in the in-tree comments and documentation.
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://patch.msgid.link/20260807032029.78092-7-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Extend test_resolve_btfids() to assert that resolve_btfids emits a
BTF_KIND_DECL_TAG named "bpf_kfunc" for every kfunc, and
"bpf_fastcall" for kfuncs marked KF_FASTCALL.
Add a btf_has_decl_tag() helper that scans the output BTF for a decl
tag matching name and target.
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260807032029.78092-6-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Emit the bpf_kfunc decl tag for every discovered kfunc, and bpf_fastcall
for kfuncs flagged KF_FASTCALL. These were previously produced by pahole
under --btf_features=decl_tag_kfuncs.
resolve_btfids now discovers kfuncs from the BTF ID sets [1] and
becomes the source of truth for their annotations.
Drop decl_tag_kfuncs pahole feature flag from scripts/Makefile.btf
[1] https://lore.kernel.org/all/20260722233518.778854-1-ihor.solodrai@linux.dev/
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260807032029.78092-5-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Extend test_resolve_btfids() to assert that resolve_btfids emits the
address_space(1) type attribute (a BTF_KIND_TYPE_TAG with kflag=1) on
the return type and/or arguments of kfuncs marked KF_ARENA_RET,
KF_ARENA_ARG1 or KF_ARENA_ARG2.
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260807032029.78092-4-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
For kfuncs flagged with KF_ARENA_RET, KF_ARENA_ARG1 or KF_ARENA_ARG2,
the address_space(1) attribute (a type tag with kflag=1) must be
emitted for the corresponding type in BTF. This was previously done by
pahole via the "attributes" BTF feature [1].
Implement the emission of the arena attributes in resolve_btfids: for
flagged kfuncs create a new function prototype with updated BTF types.
The original proto may be shared with sibling FUNCs, so it is not
modified in place.
Emission is unconditional: kbuild controls the pahole flags, so the
input BTF is expected to not have these attributes. Invalid
declarations are reported as errors.
Drop the "attributes" pahole feature from scripts/Makefile.btf
resolve_btfids now emits them for all supported pahole versions.
[1] https://lore.kernel.org/dwarves/20250228194654.1022535-1-ihor.solodrai@linux.dev/
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://patch.msgid.link/20260807032029.78092-3-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
btf2btf() adds new types to the BTF: the KF_IMPLICIT_ARGS transform
synthesizes an _impl FUNC together with its FUNC_PROTO and copies of the
kfunc's decl tags. Nothing deduplicates them afterwards. pahole runs
btf__dedup() on its own output, but that happens before resolve_btfids
sees the BTF, so any type the tool itself creates is emitted as-is, even
when a structurally identical type is already present.
Call btf__dedup() at the start of finalize_btf(), so that base
distillation and the by-name sort both operate on the canonical set of
types.
On an x86_64 build with the BPF selftests config this removes 17
duplicate FUNC_PROTOs from vmlinux BTF.
The dedup call increases runtime of resolve_btfids on vmlinux by 30-40%.
The performance hit is an acceptable cost to keep kernel BTF deduped [1].
[1] https://lore.kernel.org/bpf/986e6f4e-4b51-4440-a37c-9624906d7370@linux.dev/
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://patch.msgid.link/20260807032029.78092-2-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
This module sets the acpi_device_id::driver_data to 0 but
the field is not actually used within the module, we can
just drop it from the table.
While we are at it - use a named initializer for the
acpi_device_id::id field as well to make the code more
readable.
Signed-off-by: Pawel Zalewski (The Capable Hub) <pzalewski@thegoodpenguin.co.uk>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260728-acpi-bus-v1-1-12ff25fdea9b@thegoodpenguin.co.uk
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
qe_ic_of_init() ignored the return value of platform_driver_register()
and always returned success. Propagate the error to the initcall.
Fixes: be7ecbd240 ("soc: fsl: qe: convert QE interrupt controller to platform_device")
Signed-off-by: Linkai Gong <gonglinkai@kylinos.cn>
Reviewed-by: Maxim Kochetkov <fido_max@inbox.ru>
Link: https://lore.kernel.org/r/20260731094608.1883391-1-gonglinkai@kylinos.cn
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Up until this patch, the only protocol change supported was between
1000Base-X/SGMII and 2500Base-X. The others require an RCW override
procedure which was lacking.
Since now the guts driver provides the means of applying this procedure,
make use of it and remove any comment which mentioned the limitation.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-10-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Add support for the RCW override procedure which enables runtime
reconfiguration of the protocol running on a SerDes lane. The procedure
is done through the DCFG DCSR space which now can be defined as the
second memory region of the guts DT node.
Support is added on the following SoCs: LS1046A, LS1088A, LS2088A.
The procedure is exported to the "client" driver - the Lynx10G SerDes
PHY driver - through the following functions:
- fsl_guts_lane_validate() used to validate that changing the protocol
on a specific lane is supported.
- fsl_guts_lane_set_mode() which can be used to request the RCW
procedure be executed for a specific lane.
Since the RCW override procedure is different depending on the SoC, the
private fsl_soc_data structure is updated with two new per SoC callbacks
(.serdes_get_rcw_override() and .serdes_init_rcwcr()) which get used
from the generic fsl_guts_lane_set_mode() function. These two callbacks
hide all the SoC specific register offsets, masks and values so that the
_set_mode() procedure is straightforward.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-9-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
In Layerscape (Arm) and QorIQ (PowerPC) devices, hardware peripherals
are accessed by the CPU through a portion of the SoC address space
called CCSR ("Configuration, Control, and Status Registers"). All
hardware IP blocks have their registers mapped here, and the Device
Configuration block makes no exception.
However, there exists a secondary range of the address space named DCSR
("Debug Control and Status Registers") which, like CCSR, also holds
registers of hardware IP blocks, except the DCSR contents is hidden in
all public reference manuals.
The intention of the CCSR/DCSR split, to the best of my knowledge, was
to place the functionality that is too low level for normal use, and
which is necessary only for debug, in a completely separate address
space which can be hidden.
A use case has appeared where networking SerDes lanes need to be
reconfigured at runtime for a different protocol (example: 10GBase-R to
SGMII), and the architecture of the SoCs does not normally permit that.
The Reset Configuration Word (RCW) is a data structure read by the SoC
preboot loader (PBL) which contains stuff like pinmuxing and SerDes
protocol mapping for each lane.
The RCW that the PBL has loaded is visible in the DCFG block's normal
status registers (from CCSR), as read only. Turns out, the RCW is also
mapped in the DCFG's shadow register map (in DCSR), in a write-only
form. Writing to the RCW registers from the DCFG's DCSR space to change
what the PBL has loaded is called "RCW override".
It has been validated that the RCW override procedure is necessary to
reconfigure the networking data path when a SerDes lane performs a major
protocol change. It changes some internal muxes which connect the PCS to
either the 10G MAC or to the 1G MAC.
Defining the DCSR area of the DCFG as a secondary 'reg' array element
allows operating systems to perform RCW overrides. Since it is
introduced late in the binding's lifetime, it is optional. It can be
identified by name, but also by index (first 'reg' is CCSR).
Note that while all SoCs should have a DCFG register block in DCSR, we
only need to expose it for the SoCs where the RCW override procedure is
known to be needed and has been validated.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20260721231603.67865-8-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
In a future change, struct fsl_soc_data will be extended with methods
for performing RCW override.
Since this will be performed from a calling context outside
fsl_guts_init(), we need to keep track of the soc_data that we determine
at fsl_guts_init() time, so we can reference it later.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-7-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
The guts driver will need to easily determine on which SoC it's running
when it will need to perform RCW override at runtime. The guts driver
knows this already because fsl_guts_init() reads the QorIQ/Layerscape
architectural System Version Register (SVR), but it doesn't save this
for later lookups.
Add a new qoriq_die enum to be used as an index in the fsl_soc_die
array. A new fsl_soc_die_match_one() function is also added so that we
can directly determine if the SVR is a match with a specific die.
The SVR value read from the DCFG CCSR is also kept in the global soc
structure so that it can be accessed when needed.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-6-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Add a central fsl_guts_read() function which will take into account the
endianness that was already determined. No point is duplicating the
if-else statement each time we need to read a DCFG register.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-5-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Add the fsl_soc_guts structure in order to pass information like base
addresses, endianness etc between the init time and the runtime
operations (RCW override) which will get added in future patches.
There is no point in mapping and unmapping the DCFG CCSR space every
time we need to make a read, just map it once and keep its reference in
this new global structure.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-4-vladimir.oltean@nxp.com
[chleroy: fixed typo on 'structure' in commit message]
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Instead of using a hardcoded value when iomapping the DCFG CCSR space,
add a new macro for it. The code will be easier to follow this way,
especially when we add support for the DCFG DCSR space as well.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-3-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
fsl_guts_init() is about to get much more complicated and the central
error handling procedure cannot scale in its current design, unless we
add a lot of "if" conditions to detect what has been allocated and what
hasn't.
Currently the code relies on the fact that kfree(NULL) is safe, but this
doesn't scale to the case where "soc_dev_attr" itself is NULL, because
this would dereference "soc_dev_attr->family" and friends of a NULL
pointer.
Convert to the more typical error handling pattern where the teardown is
in the strict reverse order of setup, and a teardown step is only called
if its corresponding setup step was executed.
At the same time, maintain the optionality of soc_dev_attr->serial_number
by not checking whether that kasprintf() has returned NULL. In the error
path, kfree(NULL) is safe, so we don't need to add an "if" condition for
it. Michael Walle has confirmed that ignoring the error was intentional,
and we preserve that:
https://lore.kernel.org/linux-phy/DK44809N7Y8I.J2Z3U4N32H0Q@kernel.org/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260721231603.67865-2-vladimir.oltean@nxp.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Correct spelling of "list".
Fix a kernel-doc warning by describing the nested structure completely:
include/soc/fsl/dpaa2-fd.h:52: warning: Function parameter or member 'simple' not described in 'dpaa2_fd'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Li Yang <leoyang.li@nxp.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Frank Li <Frank.Li@nxp.com>
Cc: Guanhua Gao <guanhua.gao@nxp.com>
Cc: Roy Pledge <Roy.Pledge@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20260728004924.904210-1-rdunlap@infradead.org
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Some QE GPIO pins have an associated interrupt line in the QE PIC to
signal state changes on the pin.
Because the GPIO controller does not perform any interrupt handling
itself, a nexus node (interrupt-map) is used to map each GPIO line
supporting IRQ to the parent QE PIC interrupt domain.
Add the to_irq() method in the corresponding GPIO controller driver,
that uses the nexus node to perform the translation.
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://lore.kernel.org/r/20260708-qe-pic-gpios-v2-10-1972044cfbd1@bootlin.com
[chleroy: Added dependency on !SPARC to fix build on sparc reported by 0-day kernel robot]
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
There's a 3 patch series from Lorenzo "mm: fix UAF caused by race between
ptdump and vmap pgtable freeing" which addresses a quite old bug in the
ptdump code.
And a 2 patch series also from Lorenzo which fixes a four year old bug in
the huge_zero_folio handling.
A 3 patch series from SJ fixes a few possible divide-by-zero issues which
Sashiko sniffed out. And a 2 patch series which fixes handling of the
commit_inputs parameters.
The remainder are singletons, please see their changelogs for details.
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Merge tag 'mm-hotfixes-stable-2026-08-06-18-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM fixes from Andrew Morton:
"17 hotfixes. 15 are cc:stable. 16 are for MM.
There's a patch series from Lorenzo "mm: fix UAF caused by race
between ptdump and vmap pgtable freeing" which addresses a quite old
bug in the ptdump code.
And another series also from Lorenzo which fixes a four year old bug
in the huge_zero_folio handling.
A series from SJ fixes a few possible divide-by-zero issues which
Sashiko sniffed out. And a series which fixes handling of the
commit_inputs parameters.
The remainder are singletons, please see their changelogs for details"
* tag 'mm-hotfixes-stable-2026-08-06-18-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/damon: adjust isolated pages stat for DAMOS_MIGRATE_{HOT,COLD}
mm/damon/ops-common: putback folios on invalid migrate nid
mm/huge_memory: initialise workingset state before folio split
mm/page_table_check: skip special zero mappings
mm/damon/lru_sort: skip damon_call() if ctx has not started
mm/damon/reclaim: skip damon_call() if ctx has not started
mm/damon/lru_sort: error out for >10000 active_mem_bp
samples/damon/mtier: error out for zero quota goal target values
mailmap: map old addresses to Danila Tikhonov
mm/huge_memory: separate out CONFIG_PERSISTENT_HUGE_ZERO_FOLIO logic
mm/huge_memory: fix huge_zero_pfn race
MAINTAINERS: update address for Brendan Jackman
mm/filemap: __filemap_add_folio() restore index before retrying
microblaze: restore the page alignment of swapper_pg_dir
arm64: remove redundant concurrent ptdump UAF mitigation
mm/ptdump: always stabilise against page table freeing using init_mm
mm/vmalloc: acquire init_mm lock on huge vmap to avoid ptdump UAF
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Merge tag 'v7.2-rc6-smb3-server-fixes' of git://git.samba.org/ksmbd
Pull smb server fixes from Steve French:
- Reject Pattern_V1 payloads when Pattern_V1 support was not
negotiated
- Validate compression transform flags and chained mode before
allocating the decompression buffer
- Enforce the pre-authentication PDU size limit before allocating
the decompression buffer, preventing compressed requests from
bypassing the limit
* tag 'v7.2-rc6-smb3-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: apply the pre-authentication PDU limit when decompressing
ksmbd: validate compression Flags before kvmalloc
smb: compress: reject Pattern_V1 when not negotiated
We are frequently hitting the following splat during the riscv bpf
selftests:
00000000026dc75a: expected (7c3ff297) but got (00100073)
------------[ ftrace bug ]------------
ftrace failed to modify
[<ffffffff03c44c1c>] bpf_kfunc_common_test+0x4/0x20 [bpf_testmod]
actual: e7:82:c2:ce
Updating ftrace call site to call a different ftrace function
ftrace record flags: 80100002
(2)
expected tramp: ffffffff80043904
------------[ cut here ]------------
WARNING: kernel/trace/ftrace.c:2278 at ftrace_bug+0x46e/0x4b0, CPU#1: test_progs/98
...
[<ffffffff80008f4e>] ftrace_bug+0x46e/0x4b0
[<ffffffff803d3e86>] ftrace_replace_code+0x16e/0x170
[<ffffffff803d42b6>] ftrace_modify_all_code+0x12e/0x1b8
[<ffffffff800430f4>] arch_ftrace_update_code+0x14/0x28
[<ffffffff803e0324>] ftrace_startup+0x14c/0x2a0
[<ffffffff803e133c>] ftrace_startup_subops+0x584/0x1050
[<ffffffff804500e6>] register_ftrace_graph+0x4e6/0x1018
[<ffffffff804cf9f6>] register_fprobe_ips+0xc66/0x12f8
[<ffffffff8049abe8>] bpf_kprobe_multi_link_attach+0x5d8/0xe68
[<ffffffff8050fcaa>] __sys_bpf+0x3d5a/0x47f0
[<ffffffff805107ee>] __riscv_sys_bpf+0xae/0x168
[<ffffffff80034d78>] syscall_handler+0x60/0x100
[<ffffffff8228b4f4>] do_trap_ecall_u+0x174/0x208
[<ffffffff822b69c4>] handle_exception+0x16c/0x178
After debugging, it can be triggered by similar commands below:
```
echo do_nanosleep > set_ftrace_filter
echo function > current_tracer
echo 'p do_nanosleep' > kprobe_events
echo 1 > events/kprobes/enable
echo 'f do_nanosleep' > dynamic_events
echo 1 > events/fprobes/enable
```
The reason is that attaching a kprobe to an ftrace-traced function entry
replaces its initial auipc insn with ebreak. When ftrace_modify_call
later runs, it expects auipc insn, so verification fails and triggers
ftrace_bug.
The expected auipc logic remains conceptually unchanged, and kprobe
single-stepping ensures normal execution. Therefore, if the first insn
is ebreak, bypassing the check to continue patching the jalr insn is
safe and avoids ftrace failures.
Fixes: b2137c3b6d ("riscv: ftrace: prepare ftrace for atomic code patching")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Link: https://patch.msgid.link/20260802094929.3978390-1-pulehui@huaweicloud.com
[pjw@kernel.org: fixed reproducer in commit message]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
The estimate of the number of impacted extent tree index blocks could be
one-too-low. If we modify say 2 extents, already two leaf index blocks
could be impacted, not just one the current estimate counts with. Fix
the estimate.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260805153605.166545-6-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Commit 95ad8ee45c ("ext4: correct the reserved credits for extent
conversion") was correct to note that we need to reserve enough credits
for all extents possibly underlying a large folio. However it was too
eager to reduce the number of reserved credits. Extent conversion may
not only need to touch several leaf extent blocks, it may also need to
split extents - for example a single large unwritten extent may need to
be split into many small written ones in case of sparse folio dirtying.
This can thus result not only in extent leaf modifications but also in a
need to allocate new extent tree nodes. As a result the reserved
transaction credits were not sufficient in some corner cases. Use
ext4_meta_trans_blocks() for correct upper bound credit estimate.
Fixes: 95ad8ee45c ("ext4: correct the reserved credits for extent conversion")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260805153605.166545-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
So far ext4_meta_trans_blocks() expects that each extent counted in
@pextents will be allocated in the transaction we estimate credits for.
This is correct for the use in ext4_chunk_trans_blocks() and
ext4_chunk_trans_extent() however the use in atomic write path
(ext4_convert_unwritten_extents_atomic() and ext4_iomap_alloc() for
IOMAP_ATOMIC) unnecessarily overestimates the number of necessary
credits as neither of them allocates any data. Add argument to
ext4_meta_trans_blocks() for number of extents that are going to be
allocated in the transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260805153605.166545-4-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The memory-failure tests call cleanup() only after all result checks. A
failed ASSERT_* invokes fixture teardown and aborts the test, so it skips
cleanup() and leaves the injected page hardware-poisoned.
Invoke cleanup() from FIXTURE_TEARDOWN() instead. Guard it with
self->injection_attempted so tests that exit before injection do not try
to unpoison a page when no injection was attempted. Injection can poison
a page before returning an error or delivering SIGBUS, so teardown must
clean up after every injection attempt. This runs the existing HWPoison
and HardwareCorrupted checks on both normal and assertion-failure paths.
Link: https://lore.kernel.org/20260729091127.1001179-1-usama.anjum@arm.com
Fixes: ff4ef2fbd1 ("selftests/mm: add memory failure anonymous page test")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
shmem_evict_inode() ends with WARN_ON(inode->i_blocks) as a final
consistency check of shmem's block accounting. When it fires, the
inode-local counters die with the inode; what may linger is a small
residue in accounting kept outside the inode, such as per-mount or
per-user charges. No data is lost, and no corruption follows.
On kernels running with panic_on_warn=1, this accounting inconsistency
escalates to a full machine panic, which is disproportionate to the
impact.
Downgrade the WARN_ON() to a pr_warn() that reports the inode together
with its accounting counters (i_blocks, alloced, swapped, nrpages),
keeping the inconsistency visible in the logs.
The accounting bugs this check has caught over the years -- the swapout
race described in commit 0f3c42f522 ("tmpfs: change final i_blocks BUG
to WARNING") and the error recovery race fixed in commit 267a4c76bb
("tmpfs: fix shmem_evict_inode() warnings on i_blocks") -- are real and
should still be fixed; this change only removes the disproportionate
escalation.
One way to hit this race: soft_offline_in_use_page()'s fast path drops a
clean, unmapped shmem folio via mapping_evict_folio(), where the
xas_store() and the nrpages decrement are not atomic against a concurrent
shmem_evict_inode(); the final shmem_recalc_inode() can then read the
pre-decrement nrpages, compute freed = 0, and leave one page charged.
Same class as the races in 0f3c42f522 and 267a4c76bb, this time in the
under-count direction; reproduced on 7.2-rc4 with
madvise(MADV_SOFT_OFFLINE) racing MAP_FIXED replacement of a
shared-anonymous VMA.
[yujiacheng3@huawei.com: drop redundant casts in shmem_evict_inode() pr_warn]
Link: https://lore.kernel.org/20260729121201.776566-1-yujiacheng3@huawei.com
Link: https://lore.kernel.org/20260728091014.3876715-1-yujiacheng3@huawei.com
Fixes: 0f3c42f522 ("tmpfs: change final i_blocks BUG to WARNING")
Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, khugepaged locks the khugepaged_mutex in two functions:
start_stop_khugepaged and khugepaged_min_free_kbytes_update. Remove
mutex_lock/mutex_unlock usage in these functions and replace it with the
guard macro. This makes the code more readable (removing a goto
statement) and makes it harder to introduce bugs in the future. No
functional changes introduced.
Link: https://lore.kernel.org/20260730204724.16912-1-jakovnovak30@gmail.com
Signed-off-by: Jakov Novak <jakovnovak30@gmail.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In zs_page_migrate(), locks are acquired in the following order:
1. write_lock(&pool->lock)
2. spin_lock(&class->lock)
3. zspage_write_trylock(zspage)
However, upon successful page migration, they were being released in
forward acquisition (FIFO) order:
1. write_unlock(&pool->lock)
2. spin_unlock(&class->lock)
3. zspage_write_unlock(zspage)
Fix the unlocking order to release locks in strict reverse (LIFO)
order of acquisition:
3. zspage_write_unlock(zspage)
2. spin_unlock(&class->lock)
1. write_unlock(&pool->lock)
Releasing locks in reverse order of acquisition adheres to standard
kernel locking hygiene, prevents potential lock ordering and lockdep
inconsistencies.
Link: https://lore.kernel.org/20260728055333.421080-1-richardycc@google.com
Signed-off-by: Richard Chang <richardycc@google.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Martin Liu <liumartin@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Those numbers are difficult to maintain and in fact
we can refer to sections by their names (in html).
Link: https://lore.kernel.org/20260728021229.181627-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In scan_get_next_rmap_item() the break statement only exits the inner
while loop, leaving remaining VMAs to be iterated even if ksm_test_exit()
returns true. Replace it with a goto statement to avoid the unnecessary
work.
Link: https://lore.kernel.org/20260726133501.504048-1-wsw9603@163.com
Signed-off-by: Wang Wensheng <wsw9603@163.com>
Reviewed-by: Xu Xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
RWP tracks accesses by installing PAGE_NONE (protnone) PTEs, so its code
paths are gated on userfaultfd_rwp(). Without
CONFIG_ARCH_HAS_PTE_PROTNONE there is no PAGE_NONE -- <linux/pgtable.h>
defines it to a BUILD_BUG() stub, relying on callers folding such paths to
dead code via IS_ENABLED(CONFIG_ARCH_HAS_PTE_PROTNONE).
userfaultfd_rwp() was not a compile-time constant, so the compiler could
not fold those paths. With an older compiler (gcc 8.5.0, sparc64) the
PAGE_NONE reference in move_pages_huge_pmd() survived to codegen:
mm/huge_memory.c:2874: _dst_pmd = pmd_modify(_dst_pmd, PAGE_NONE);
compiler_types.h:702: error: call to '__compiletime_assert_501'
declared with attribute error: BUILD_BUG failed
RWP cannot exist without protnone, so return a compile-time false when
CONFIG_ARCH_HAS_PTE_PROTNONE is unset; every RWP path then folds away.
Link: https://lore.kernel.org/amcitKvUvFYr8W38@thinkstation
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202607250853.VaJWGLeA-lkp@intel.com/
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
migrate_pages_batch() unmaps each folio before moving it, and every
unmap runs the mmu_notifier invalidate callbacks. On KVM hosts
try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() ->
tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps
the CPU busy for a long time.
The loop already calls cond_resched(), but on PREEMPTION kernels that is
a no-op, and involuntary preemption is not a Tasks-RCU quiescent state.
A long batch therefore never reports a quiescent state, and the
migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the
Tasks-RCU grace period for minutes, which is common at Meta fleet:
INFO: rcu_tasks detected stalls on tasks:
0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task
Call Trace:
tdp_mmu_zap_leafs
tdp_mmu_next_root
gfn_to_pfn_cache_invalidate_start
kvm_mmu_notifier_invalidate_range_start
__mmu_notifier_invalidate_range_start
try_to_migrate_one
try_to_migrate
migrate_pages_batch
migrate_pages
compact_zone
compact_node
kcompactd
kthread
Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even
when cond_resched() does nothing.
This has also been discussed at [1]
Link: https://lore.kernel.org/20260727-kcompact-v1-1-bdfefddd6874@debian.org
Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
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>
Each struct zram uses the same key for its struct lockdep_map which is
used for locking analysis.
According to Sergey the lock chains might be different if zram1 is used
for and zram2 is for ext4. This might lead to false dead lock reports if
it mixes a zram1 chain with a zram2. This can be avoided if each lockmap
gets its own unique key.c
Use a dynamic lock_class_key for the table_lock_map.
Link: https://lore.kernel.org/20260714141300.3945672-3-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "zram: lockmap tweaks".
This patch (of 2):
The zram object contains an array zram_table_entry. Each one has a `lock'
variable and each has a matching struct lockdep_map. This mimics a struct
mutex.
It uses always the same key for all lockdep_map instances. This makes it
look like the same lock to lockdep. Therefore it could be reduced to have
one lockdep_map per struct zram.
Use only one struct lockdep_map per struct zram.
Link: https://lore.kernel.org/20260714141300.3945672-1-bigeasy@linutronix.de
Link: https://lore.kernel.org/20260714141300.3945672-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The gup_longterm test prints a literal "n" when PIN_LONGTERM_TEST_START
fails with EINVAL because the string is missing the newline escape
sequence.
Print a newline instead.
Link: https://lore.kernel.org/23557F4CB8CF36FF+20260724074603.1479243-1-zhaozhengzhuo@uniontech.com
Signed-off-by: zhaozhengzhuo <zhaozhengzhuo@uniontech.com>
Reviewed-by: Sarthak Sharma <sarthak.sharma@arm.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand (arm) <david@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As we deployed defrag_mode into Meta production, pressure spikes and
excessive swapping were observed on some workloads. Tracing confirmed
that this is unmovable/reclaimable requests spinning in the allocator and
direct reclaim, causing excessive amounts of swap.
The initial plan for defrag_mode was to rely on kswapd/kcompactd to
produce blocks, and if those are overwhelmed under high pressure, let the
allocator fall back (__rmqueue_steal()) after its retry loops. However,
that retrying results in more reclaim on some of these workloads than we'd
hoped, sometimes excessively so, spurred on by the !costly order
conditions in should_reclaim_retry().
The storms are dependent on the request type. Reclaim will inevitably
make room in existing movable blocks, since that's where the LRU pages
live. So if movable requests retry on reclaim, they make progress.
When non-movable requests spin in reclaim that isn't productive. They
cannot use the individually freed pages, and the process is unlikely to
accidentally free whole blocks to meet the ALLOC_NOFRAGMENT bar. They
spin and overreclaim excessively, which tanks performance and triggers
userspace guards like swap exhaustion or pressure based OOM.
To fix this, send non-movable requests, regardless of order, into
pageblock reclaim/compaction. This way, they help move things along to
meet the ALLOC_NOFRAGMENT bar. After this patch, the reclaim storms and
excess OOM rates are no longer observed in production.
The longer-term plan is still to have all requests, including the movable
ones, help make blocks to spread the cost of defragmenting more evenly and
fairly; combined with proper watermarking to reduce allocation latencies
in the common case. However, doing this naively unearths scaling and
concurrency limitations in compaction that need to be addressed first.
Promoting just non-movables for now is the minimally viable bug fix for
the above issue.
[brendan.jackman@linux.dev: fix try_to_compact_pages() kerneldoc]
Link: https://lore.kernel.org/DK7NM9RPUJOD.11PNJJ5N2OBED@linux.dev
Link: https://lore.kernel.org/20260722150006.3848560-5-hannes@cmpxchg.org
Fixes: e3aa7df331 ("mm: page_alloc: defrag_mode")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: "Brendan Jackman" <brendan.jackman@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The compaction capturing code assumes the allocation request order and
compaction target order are the same. That won't be true once defrag_mode
promotes sub-block allocations to pageblock-order compaction: compaction
targets the larger order, while capture should remain at the original
allocation order.
Move the capture_control to the page allocator and give it its own copies
of what the page freeing path matches against - zone, migratetype and the
allocation order - rather than reaching into compaction's live
compact_control. __alloc_pages_direct_compact() fills in migratetype and
order, and installs and hides current->capture_control around the whole
compaction call; try_to_compact_pages() aims capc->zone at each zone while
it is being compacted. compact_zone_order() no longer deals with capture
at all.
Pass the capture_control through try_to_compact_pages() /
compact_zone_order() in place of the bare struct page **.
No functional change.
Link: https://lore.kernel.org/20260722150006.3848560-4-hannes@cmpxchg.org
Fixes: e3aa7df331 ("mm: page_alloc: defrag_mode")
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Co-developed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Gregory Price <gourry@gourry.net>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Brendan Jackman <jackmanb@google.com>
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: Mike Rapoport <rppt@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
While trying to fix a reclaim storm in defrag_mode, I noticed that
non-movable direct compaction is extremely inefficient.
When searching for space to evacuate, compaction only allows blocks of the
same type as the incoming request. This is to prevent migratetype
pollution, where a small non-movable request frees space in a movable
block and provokes the allocator to fall back and pollute it.
This protection is reasonable on one hand, but the downside is that it
makes non-movable direct compaction nearly useless: if we get the type
annotations right, by definition there aren't any movable pages inside the
non-movable blocks it is allowed to scan.
With defrag_mode, the goal is the production of whole blocks, which are
essentially type neutral: __rmqueue_claim() will convert them wholesale on
alloc. This makes type mixing and pollution a non-issue.
Fix the pollution gates to take the requested order into account, and
allow whole-block requests to scan blocks of other types.
The only exception is CMA blocks. That type is sticky and these blocks
cannot be claimed to other types. Continue to be strict with them, and
allow only explicit ALLOC_CMA requests and kcompactd to evacuate them.
Link: https://lore.kernel.org/20260722150006.3848560-3-hannes@cmpxchg.org
Fixes: e3aa7df331 ("mm: page_alloc: defrag_mode")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Reviewed-by: Gregory Price <gourry@gourry.net>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Brendan Jackman <jackmanb@google.com>
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: Mike Rapoport <rppt@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: fix reclaim storms in defrag_mode", v2.
As we deployed vm.defrag_mode=1 in Meta production, some workloads
regressed with recurring pressure spikes and swap storms (which in turn
triggered userspace OOM rules on pressure and swap utilization levels).
Tracing pinned this to non-movable requests spinning and reclaiming
unproductively when kswapd/kcompactd are overwhelmed. Direct reclaim
predominantly frees up pages in movable blocks, but those requests cannot
use that space under defrag_mode rules; and it is unlikely to free up
whole blocks incidentally for __rmqueue_claim() to work.
This series fixes it by making non-movable requests participate in
pageblock production in the allocator slowpath - meaning, they will invoke
direct reclaim and direct compaction with pageblock_order.
That requires some small-ish adjustments up front in the allocator and the
compaction code: three prep patches and the fix last.
The series has been in production against one of the affected workloads
for several weeks and restores the OOM kill rate to !defrag_mode baseline.
This patch (of 4):
A subsequent patch will have some order-0 allocations participate in
compaction under defrag_mode, to stave off extfrag events.
Since this is a sprawling expansion of entry points, and compaction can
enter filesystem paths, add lockdep annotations that catches __GFP_FS
passing errors.
Direct reclaim has had this annotation for a while, and since reclaim and
compaction are usually used in conjunction, this is unlikely to unearth
old bugs. It's more about future proofing and peace of mind.
Link: https://lore.kernel.org/20260722150006.3848560-1-hannes@cmpxchg.org
Link: https://lore.kernel.org/20260722150006.3848560-2-hannes@cmpxchg.org
Fixes: e3aa7df331 ("mm: page_alloc: defrag_mode")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
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: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Gregory Price <gourry@gourry.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
unlock_or_release_subpool() drops spool->lock before calling
subpool_is_free(). However, subpool_is_free() reads fields that are
updated under spool->lock, including count, used_hpages and rsv_hpages.
Keep the free-state evaluation under the same lock that protects those
fields. The reservation accounting and kfree() calls still happen after
dropping spool->lock.
Link: https://lore.kernel.org/20260721035207.1437935-1-chenyichong@uniontech.com
Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Three function definitions terminate with '};' instead of '}', which is
unnecessary and inconsistent with kernel coding style:
- damon_pa_initcall() in paddr.c
- damon_va_initcall() in vaddr.c
- damos_get_some_mem_psi_total() in core.c
No functional change intended.
Link: https://lore.kernel.org/20260721135333.241106-1-sj@kernel.org
Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
