In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "state_synced" over to the "flags"
field so modifications are safe.
Cc: Saravana Kannan <saravanak@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.6.Idb4818e1159fef104c7756bfd6e7ba8f374bebcd@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "dma_ops_bypass" over to the "flags"
field so modifications are safe.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.5.If62b84471ef2c85e7ad250f0468867d6dba965ab@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "dma_skip_sync" over to the "flags"
field so modifications are safe.
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.4.Icf072aa4184dd86a88fa8ca195b09d1651984000@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "dma_iommu" over to the "flags" field
so modifications are safe.
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.3.Id20d5973cbff542fea290e13177e9423f5d81342@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "can_match" over to the "flags" field
so modifications are safe.
Cc: Saravana Kannan <saravanak@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.2.I54b3ae6311ff34ad30227659d91bb109911a4aea@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add support for an optional "reset-gpios" property. If present, the
driver drives the reset line high at probe time and releases it during
power-on, after the regulators have been enabled.
Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Co-developed-by: David Heidelberg <david@ixit.cz>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-8-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Make code cleaner, compiler will optimize it away anyway.
Preparation for FTM5 support, where more steps are needed.
Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-6-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
We must power off regulators and ensure that IRQ is disabled when
failing at power on phase. Create stmfts_configure function to limit
use of goto.
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-5-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Switch to devm_regulator_bulk_get_const() to stop setting the supplies
list in probe(), and move the regulator_bulk_data struct in static const.
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-3-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Replace the bogus "GPL v2" with "GPL" as MODULE_LICNSE() string. The
value does not declare the module's exact license, but only lets the
module loader test whether the module is Free Software or not.
See commit bf7fbeeae6 ("module: Cure the MODULE_LICENSE "GPL" vs.
"GPL v2" bogosity") in the details of the issue. The fix is to use
"GPL" for all modules under any variant of the GPL.
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-1-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Raspberry Pi 3B by marking the VEC clk critical so it doesn't get
turned off and hang the bus.
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Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fix from Stephen Boyd:
"One more fix for the merge window to avoid a boot hang on
Raspberry Pi 3B by marking the VEC clk critical so that it
doesn't get turned off and hang the bus"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: bcm: rpi: Mark VEC clock as CLK_IGNORE_UNUSED
- Drop class_create() for the "tsm" class
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Merge tag 'tsm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm
Pull PCIe TSP update from Dan Williams:
"A small update for the TSM core. It is arguably a fix and coming in
late as I have been offline the past few weeks:
- Drop class_create() for the 'tsm' class"
* tag 'tsm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm:
virt: coco: change tsm_class to a const struct
VMBUS ring buffers must be page aligned. So, use VMBUS_RING_SIZE() to
ensure they are always aligned and large enough to hold all of the
relevant data.
Cc: stable@kernel.vger.org
Fixes: 76c56a5aff ("drm/hyperv: Add DRM driver for hyperv synthetic video device")
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://patch.msgid.link/20260425181719.1538483-2-hamzamahfooz@linux.microsoft.com
Video Format Data Blocks (VFDBs) contain the necessary information that
needs to be fed to the Optimized Video Timings (OVT) Algorithm.
Also, we require OVT support to cover modes that aren't supported by
earlier standards (e.g. CVT). So, parse all of the relevant VFDB data
and feed it to the OVT Algorithm, to extract all of the missing OVT
modes.
Suggested-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Link: https://patch.msgid.link/20260225175709.408010-1-someguy@effective-light.com
- kbuild: builddeb - avoid recompiles for non-cross-compiles
Avoid triggering complete rebuilds for non-cross-compile Debian
package builds by only triggering the rebuild of host tools for
actual cross-compile builds.
- kbuild: Never respect CONFIG_WERROR / W=e to fixdep
Avoid spurious rebuilds of fixdep w/ and w/o -Werror during a single
kbuild invocation by never respecting CONFIG_WERROR for fixdep.
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mathias Krause <minipli@grsecurity.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Thomas Weißschuh <linux@weissschuh.net>
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Merge tag 'kbuild-fixes-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild fixes from Nicolas Schier:
- builddeb - avoid recompiles for non-cross-compiles
Avoid triggering complete rebuilds for non-cross-compile Debian
package builds by only triggering the rebuild of host tools for
actual cross-compile builds
- Never respect CONFIG_WERROR / W=e to fixdep
Avoid spurious rebuilds of fixdep w/ and w/o -Werror during a single
kbuild invocation by never respecting CONFIG_WERROR for fixdep
* tag 'kbuild-fixes-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
kbuild: Never respect CONFIG_WERROR / W=e to fixdep
kbuild: builddeb - avoid recompiles for non-cross-compiles
Subsystem:
- add data_race() in rtc_dev_poll()
Drivers:
- remove i2c_match_id usage
- abx80x: Disable alarm feature if no interrupt attached
- ti-k3: support resuming from IO DDR low power mode
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Merge tag 'rtc-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"Subsystem:
- add data_race() in rtc_dev_poll()
Drivers:
- remove i2c_match_id usage
- abx80x: Disable alarm feature if no interrupt attached
- ti-k3: support resuming from IO DDR low power mode"
* tag 'rtc-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
rtc: abx80x: Disable alarm feature if no interrupt attached
rtc: ntxec: fix OF node reference imbalance
rtc: pic32: allow driver to be compiled with COMPILE_TEST
rtc: ti-k3: Add support to resume from IO DDR low power mode
rtc: cmos: Use platform_get_irq_optional() in cmos_platform_probe()
dt-bindings: rtc: add olpc,xo1-rtc to trivial-rtc
dt-bindings: rtc: sc2731: Add compatible for SC2730
rtc: add data_race() in rtc_dev_poll()
rtc: armada38x: zalloc + calloc to single allocation
dt-bindings: rtc: isl12026: convert to YAML schema
dt-bindings: rtc: microcrystal,rv3028: Allow to specify vdd-supply
rtc: max77686: convert to i2c_new_ancillary_device
dt-bindings: rtc: mpfs-rtc: permit resets
rtc: rx8025: Remove use of i2c_match_id()
rtc: rv8803: Remove use of i2c_match_id()
rtc: rs5c372: Remove use of i2c_match_id()
rtc: pcf2127: Remove use of i2c_match_id()
rtc: m41t80: Remove use of i2c_match_id()
rtc: abx80x: Remove use of i2c_match_id()
mentioning separately: Rafael's commit converting tpm_crb from ACPI driver
to a platform driver. Starting from this release cycle, the branch with TPM
changes mirrored to next is 'for-next-tpm', and patches for keys have their
own separate 'for-next-keys' branch.
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Merge tag 'for-next-tpm-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd
Pull tpm updates from Jarkko Sakkinen:
"Here are the accumulated fixes for 7.1-rc1 and a single structural
change worth mentioning separately: Rafael's commit converting tpm_crb
from ACPI driver to a platform driver"
* tag 'for-next-tpm-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
tpm: tpm_tis: stop transmit if retries are exhausted
tpm: tpm_tis: add error logging for data transfer
tpm: avoid -Wunused-but-set-variable
tpm: Use kfree_sensitive() to free auth session in tpm_dev_release()
tpm2-sessions: Fix missing tpm_buf_destroy() in tpm2_read_public()
tpm: Fix auth session leak in tpm2_get_random() error path
tpm: i2c: atmel: fix block comment formatting
tpm_crb: Convert ACPI driver to a platform one
tpm: Make tcpci_pm_ops variable static const
Since v2025.11.22:
Initial SoC Slider support
SoC Slider is an SoC-wide power/performance policy setting.
On SoC Slider systems, EPP plays a diminished role.
Whitespace cleanup via: indent -npro -kr -i8 -ts8 -sob -l160 -ss -ncs -cp1
No functional changes
Signed-off-by: Len Brown <len.brown@intel.com>
x86_energy_perf_policy accesses the SoC Slider via standard
user/kernel APIs to the processor_thermal_soc_slider driver.
Machines that support SoC Slider largely use it instead of EPP,
which may continue to exist in a diminished role, or vanish entirely.
Signed-off-by: Len Brown <len.brown@intel.com>
When processor_thermal_soc_slider is loaded, its slider
and offset modparams are visible. Check that the driver
actually registered the profile named "SoC Slider" before
reading or writing these modparams.
n.b. This utility allows writing the Slider and Offset modparams
even if the driver policy is not "balanced". Currently the
processor_thermal_soc_slider consults those modparams
only in "balanced" mode.
Signed-off-by: Len Brown <len.brown@intel.com>
On Raspberry Pi 3B, the VEC clock is used by the VideoCore firmware
display driver, which remains active until the vc4 driver loads and
sends NOTIFY_DISPLAY_DONE. If this clock is disabled during boot, a bus
lockup happens and the firmware becomes unresponsive, causing a complete
system lockup.
Mark the VEC clock with CLK_IGNORE_UNUSED so it survives the unused
clock disablement and remains available until the vc4 driver takes over
display management.
Fixes: 672299736a ("clk: bcm: rpi: Manage clock rate in prepare/unprepare callbacks")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/r/5f0bec08-f458-4fba-8bf3-06817a100c4c@sirena.org.uk
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patch.msgid.link/20260401111416.562279-2-mcanal@igalia.com
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Brian Masney <bmasney@redhat.com> # Active contributor to clk
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Several development updates for 7.1-rc1:
- fix a race condition handling PG_dcache_clean
- further cleanups for the fault handling, allowing RT to be enabled
- fixing nzones validation in adfs filesystem driver
- fix for module unwinding
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux
Pull ARM updates from Russell King:
- fix a race condition handling PG_dcache_clean
- further cleanups for the fault handling, allowing RT to be enabled
- fixing nzones validation in adfs filesystem driver
- fix for module unwinding
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
ARM: 9463/1: Allow to enable RT
ARM: 9472/1: fix race condition on PG_dcache_clean in __sync_icache_dcache()
ARM: 9471/1: module: fix unwind section relocation out of range error
fs/adfs: validate nzones in adfs_validate_bblk()
ARM: provide individual is_translation_fault() and is_permission_fault()
ARM: move FSR fault status definitions before fsr_fs()
ARM: use BIT() and GENMASK() for fault status register fields
ARM: move is_permission_fault() and is_translation_fault() to fault.h
ARM: move vmalloc() lazy-page table population
ARM: ensure interrupts are enabled in __do_user_fault()
Eduard Zingerman says:
====================
bpf: replace min/max fields with struct cnum{32,64}
This RFC replaces s64, u64, s32, u32 scalar range domains tracked by
verifier by a pair of circular numbers (cnums): one for 64-bit domain
and another for 32-bit domain. Each cnum represents a range as a
single arc on the circular number line, from which signed and unsigned
bounds are derived on demand. See also wrapped intervals
representation as in [1].
The use of such representation simplifies arithmetic and conditions
handling in verifier.c and allows to express 32 <-> 64 bit deductions
in a more mathematically rigorous way.
[1] https://jorgenavas.github.io/papers/ACM-TOPLAS-wrapped.pdf
Changelog
=========
v2 -> v1:
- Fixes in source code comments highlighted by bot+bpf-ci.
RFCv1 -> v2:
- Dropped RFC tag.
- Dropped cnum{32,64}_mul(), too much complexity and no veristat
or selftests gains.
- cnum32_from_cnum64() normalizes to CNUM32_EMPTY when input
cnum64.size >= U32_MAX, previously only checked for > U32_MAX
(bot+bpf-ci).
- cnum32_from_cnum64() and cnum64_cnum32_intersect() now check for
empty inputs (sashiko).
- In regs_refine_cond_op() case BPF_JSLT use cnum{32,64}_from_srange
constructors instead of unsigned variants (sashiko).
- cnum{32,64}_intersect_with{,_urange,_srange}() helpers added
(Alexei)
[RFCv1] https://lore.kernel.org/bpf/0c47b0b7ea476647746806c46fded4353be885f7.camel@gmail.com/T/
[v2] https://lore.kernel.org/bpf/c4fb60bafd526ae2d92b86e2250255aef0ba5ee1.camel@gmail.com/T/
Patch set layout
================
Patch #1 introduces the cnum (circular number) data type and basic
operations: intersection, addition, multiplication, negation, 32-to-64
and 64-to-32 projections.
CBMC based proofs for these operations are available at [2].
(The proofs lag behind the current patch set and need an update if
this RFC moves further. Although, I don't expect any significant
changes).
[2] https://github.com/eddyz87/cnum-verif
Patch #2 mechanically converts all direct accesses to bpf_reg_state's
min/max fields to use accessor functions, preparing for the field
replacement.
Patch #3 replaces the eight independent min/max fields in
bpf_reg_state with two cnum fields. The signed and unsigned bounds are
derived on demand from the cnum via the accessor functions.
This eliminates the separate signed<->unsigned cross-deduction logic,
simplifies reg_bounds_sync(), regs_refine_cond_op() and some
arithmetic operations.
Patch #4 adds selftest cases for improved 32->64 range refinements
enabled by cnum64_cnum32_intersect().
Precision trade-offs
====================
A cnum represents a contiguous arc on the circular number line.
Current master tracks four independent ranges (s64, u64, s32, u32)
whose intersection could implicitly represent value sets that are
two disjoint arcs on the circle - something a single cnum cannot.
Cnums lose precision when a cross-domain conditional comparison
(e.g., unsigned comparison on a register with a signed-derived range)
produces an intersection that would be two disjoint arcs.
The cnum must over-approximate by returning one of the input arcs.
E.g. a pair of ranges u64:[1,U64_MAX] s:[-1,1] represents a set of two
values: {-1,1}, this can only be approximated as a set of three values
by cnum: {-1,0,1}.
Cnums gain precision in arithmetic: when addition, subtraction or
multiplication causes register value to cross both signed and unsigned
min/max boundaries. Current master resets the register as unbound in
such cases, while cnums preserve the exact wrapping arc.
In practice precision loss turned out to matter only for a set of
specifically crafted selftests from reg_bounds.c (see patch #3 for
more details). On the other hand, precision gains are observable for a
set real-life programs.
Verification performance measurements
=====================================
Tested on 6683 programs across four corpora: Cilium (134 programs),
selftests (4635), sched_ext (376), and Meta internal BPF corpus
(1540). Program verification verdicts are identical across all four
program sets - no program changes between success and failure.
Instruction count comparison (cnum vs signed/unsigned pair):
- 83 programs improve, 44 regress, 6596 unchanged
- Total saved: ~290K insns, total added: 10K insns
- Largest improvements:
-26% insns in a internal network firewall program;
-47% insns in rusty/wd40 sched_ext schedulers.
- Largest regression: +24% insns in one Cilium program (5062 insns
added).
Raw performance data is at the bottom of the email.
Raw verification performance metrics
====================================
Filtered out by -f insns_pct>5 -f !insns<10000
========= selftests: master vs cnums-everywhere-v2 =========
File Program Insns (A) Insns (B) Insns (DIFF)
---- ------- --------- --------- ------------
Total progs: 4665
total_insns diff min: -15.71%
total_insns diff max: 45.45%
-20 .. -10 %: 3
-5 .. 0 %: 6
0 .. 5 %: 4654
45 .. 50 %: 2
========= scx: master vs cnums-everywhere-v2 =========
File Program Insns (A) Insns (B) Insns (DIFF)
--------------- -------------- --------- --------- ----------------
scx_rusty.bpf.o rusty_enqueue 39842 22053 -17789 (-44.65%)
scx_rusty.bpf.o rusty_stopping 37738 19949 -17789 (-47.14%)
scx_wd40.bpf.o wd40_stopping 37729 19880 -17849 (-47.31%)
Total progs: 376
total_insns diff min: -47.31%
total_insns diff max: 19.61%
-50 .. -40 %: 3
-5 .. 0 %: 5
0 .. 5 %: 366
5 .. 15 %: 1
15 .. 20 %: 1
========= meta: master vs cnums-everywhere-v2 =========
File Program Insns (A) Insns (B) Insns (DIFF)
--------------------------------- ---------- --------- --------- ----------------
<meta-internal-firewall-program> ...egress 222327 164648 -57679 (-25.94%)
<meta-internal-firewall-program> ..._tc_eg 222839 164772 -58067 (-26.06%)
<meta-internal-firewall-program> ...egress 222327 164648 -57679 (-25.94%)
<meta-internal-firewall-program> ..._tc_eg 222839 164772 -58067 (-26.06%)
Total progs: 1540
total_insns diff min: -26.06%
total_insns diff max: 6.69%
-30 .. -20 %: 4
-15 .. -5 %: 6
-5 .. 0 %: 36
0 .. 5 %: 1493
5 .. 10 %: 1
========= cilium: master vs cnums-everywhere-v2 =========
File Program Insns (A) Insns (B) Insns (DIFF)
---------- ------------------------------- --------- --------- ---------------
bpf_host.o tail_handle_ipv4_cont_from_host 20962 26024 +5062 (+24.15%)
bpf_host.o tail_handle_ipv6_cont_from_host 17036 18672 +1636 (+9.60%)
Total progs: 134
total_insns diff min: -3.32%
total_insns diff max: 24.15%
-5 .. 0 %: 12
0 .. 5 %: 120
5 .. 15 %: 1
20 .. 25 %: 1
---
====================
Link: https://patch.msgid.link/20260424-cnums-everywhere-rfc-v1-v3-0-ca434b39a486@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1. 32-bit range starts before 64-bit range's low bits in each block,
causing intersection to skip entire blocks.
2. 32-bit range crosses the U32_MAX/0 boundary, represented as s32
range crossing sign boundary.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260424-cnums-everywhere-rfc-v1-v3-4-ca434b39a486@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Replace eight independent s64, u64, s32, u32 min/max fields in
bpf_reg_state with two circular number fields:
- cnum64 for a unified signed/unsigned 64-bit range tracking;
- cnum32 for a unified signed/unsigned 32-bit range tracking.
Each cnum represents a range as a single arc on the circular number
line (base + size), from which signed and unsigned bounds are derived
on demand via accessor functions introduced in the preceding commit.
Notable changes:
- Signed<->unsigned deductions in __reg_deduce_bounds() are removed.
- 64<->32 bit deductions are replaced with:
- reg->r32 = cnum32_intersect(reg->r32, cnum32_from_cnum64(reg->r64));
this is functionally equivalent to the old code.
- reg->r64 = cnum64_cnum32_intersect(reg->r64, reg->r32);
this handles a few additional cases, see commit message for
"bpf: representation and basic operations on circular numbers".
- regs_refine_cond_op() now computes results in terms of operations on
sets, e.g. for JNE:
/* Complement of the range [val, val] as cnum64. */
lo = (struct cnum64){ val + 1, U64_MAX - 1 };
reg1->r64 = cnum64_intersect(reg1->r64, lo);
- For add, sub operations on scalars replace explicit bounds
computations with cnum{32,64}_{add,negate}.
- For add, sub operations on pointers deduplicate with arithmetic
operations on scalars and use cnum{32,64}_{add,negate}.
- For and, or, xor operations on scalars remove explicit signed bounds
computations.
- range_bounds_violation() reduces to checking cnum_is_empty().
- const_tnum_range_mismatch() reduces to checking cnum_is_const().
Selftest adjustments: a few existing tests are updated because a
single cnum arc cannot always represent what the old system expressed
as the intersection of independent signed and unsigned ranges.
For example, if the old system tracked u64=[0, U64_MAX-U32_MAX+2] and
s64=[S64_MIN+2, 2] independently, their intersection is a tight
two-point set. A single cnum must pick the shorter arc, losing the
other constraint. These cases are documented with comments in the
adjusted tests.
reg_bounds.c is updated with logic similar to
cnum64_cnum32_intersect(). Instead of using cnums it inspects
intersection between 'b' and first / last / next-after-first /
previous-before-last sub-ranges of 'a'.
reg_bounds.c is also updated to skip test cases that rely
in signed and unsigned ranges intersecting in two intervals,
as such cases are not representable by a single cnum.
The following "crafted" test cases are affected:
- reg_bounds_crafted/(s64)[0xffffffffffff8000; 0x7fff] (u32)<op> [0; 0x1f]
- reg_bounds_crafted/(s64)[0; 0x1f] (u32)<op> [0xffffffffffffff80; 0x7f]
- reg_bounds_crafted/(s64)[0xffffffffffffff80; 0x7f] (u32)<op> [0; 0x1f]
- reg_bounds_crafted/(u64)[0; 1] (s32)<op> [1; 2147483648]
- reg_bounds_crafted/(u64)[1; 2147483648] (s32)<op> [0; 1]
- reg_bounds_crafted/(u64)[0; 0xffffffff00000000] (s64)<op> 0
- reg_bounds_crafted/(u64)0 (s64)<op> [0; 0xffffffff00000000]
- reg_bounds_crafted/(u64)[0; 0xffffffff00000000] (s32)<op> 0
- reg_bounds_crafted/(u64)0 (s32)<op> [0; 0xffffffff00000000]
- reg_bounds_crafted/(s64)[S64_MIN; 0] (u64)<op> S64_MIN
- reg_bounds_crafted/(s64)S64_MIN (u64)<op> [S64_MIN; 0]
- reg_bounds_crafted/(s32)[S32_MIN; 0] (u32)<op> S32_MIN
- reg_bounds_crafted/(s32)S32_MIN (u32)<op> [S32_MIN; 0]
- reg_bounds_crafted/(s64)[0; 0x1f] (u32)<op> [0xffffffff80000000; 0x7fffffff]
- reg_bounds_crafted/(s64)[0xffffffff80000000; 0x7fffffff] (u32)<op> [0; 0x1f]
- reg_bounds_crafted/(s64)[0; 0x1f] (u32)<op> [0xffffffffffff8000; 0x7fff]
As well as some reg_bounds_roand_{consts,ranges}_A_B, where A and B
differ in sign domain.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260424-cnums-everywhere-rfc-v1-v3-3-ca434b39a486@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Replace direct access to bpf_reg_state->{smin,smax,umin,umax,
s32_min,s32_max,u32_min,u32_max}_value with getter/setter inline
functions, preparing for future switch to cnum-based internal
representation.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260424-cnums-everywhere-rfc-v1-v3-2-ca434b39a486@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds basic definitions for cnum32/cnum64.
This is a unified numeric range representation for signed and unsigned
domains. Inspired by an old post from Shung-Hsi Yu [1] and paper [2].
Operations correctness is verified using cbmc model checker,
tests source code can be found in a separate repo [3].
The cnum64_cnum32_intersect() function is notable, because it handled
several cases verifier.c:deduce_bounds_64_from_32() does not.
Given:
- a is a 64-bit range
- b is a 32-bit range
- t is a refined 64-bit range, such that ∀ v ∈ a, (u32)v ∈ b: v ∈ t.
cnum64_cnum32_intersect() makes the following deductions:
(A): 'b' is a sub-range of the first or the last 32-bit
sub-range of 'a':
64-bit number axis --->
N*2^32 (N+1)*2^32 (N+2)*2^32 (N+3)*2^32
||------|---|=====|-------||----------|=====|-------||----------|=====|----|--||
| |< b >| |< b >| |< b >| |
| | | |
|<--+--------------------------- a ---------------------------+--->|
| |
|<-------------------------- t -------------------------->|
(B) 'b' does not intersect with the first of the last 32-bit
sub-range of 'a':
N*2^32 (N+1)*2^32 (N+2)*2^32 (N+3)*2^32
||--|=====|----|----------||--|=====|---------------||--|=====|------------|--||
|< b >| | |< b >| |< b >| |
| | | |
|<-------------+--------- a -------------------|----------->|
| |
|<-------- t ------------------>|
(C) 'b' crosses 0/U32_MAX boundary:
N*2^32 (N+1)*2^32 (N+2)*2^32 (N+3)*2^32
||===|---------|------|===||===|----------------|===||===|---------|------|===||
|b >| | |< b||b >| |< b||b >| | |< b|
| | | |
|<-----+----------------- a --------------+-------->|
| |
|<---------------- t ------------->|
Current implementation of deduce_bounds_64_from_32() only handles
case (A).
[1] https://lore.kernel.org/all/ZTZxoDJJbX9mrQ9w@u94a/
[2] https://jorgenavas.github.io/papers/ACM-TOPLAS-wrapped.pdf
[3] https://github.com/eddyz87/cnum-verif/tree/master
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260424-cnums-everywhere-rfc-v1-v3-1-ca434b39a486@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull to receive:
c0e8ddc76d ("sched_ext: Align cgroup #ifdef guards with SUB_SCHED vs GROUP_SCHED")
which conflicts with:
41e3312861 ("sched_ext: add p->scx.tid and SCX_OPS_TID_TO_TASK lookup")
It's a simple context conflict. Take changes from both.
Signed-off-by: Tejun Heo <tj@kernel.org>
scx_root_enable_workfn() takes cpus_read_lock() before
scx_link_sched(sch), but the `if (ret) goto err_disable` on failure
skips the matching cpus_read_unlock() - all other err_disable gotos
along this path drop the lock first.
scx_link_sched() only returns non-zero on the sub-sched path
(parent != NULL), so the leak path is unreachable via the root
caller today. Still, the unwind is out of line with the surrounding
paths.
Drop cpus_read_lock() before goto err_disable.
v2: Correct Fixes: tag (Andrea Righi).
Fixes: 25037af712 ("sched_ext: Add rhashtable lookup for sub-schedulers")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
scx_prog_sched(aux) returns NULL for TRACING / SYSCALL BPF progs that
have no struct_ops association when the root scheduler has sub_attach
set. scx_bpf_task_set_slice() and scx_bpf_task_set_dsq_vtime() pass
that NULL into scx_task_on_sched(sch, p), which under
CONFIG_EXT_SUB_SCHED is rcu_access_pointer(p->scx.sched) == sch. For
any non-scx task p->scx.sched is NULL, so NULL == NULL returns true
and the authority gate is bypassed - a privileged but
non-struct_ops-associated prog can poke p->scx.slice /
p->scx.dsq_vtime on arbitrary tasks.
Reject !sch up front so the gate only admits callers with a resolved
scheduler.
Fixes: 245d09c594 ("sched_ext: Enforce scheduler ownership when updating slice and dsq_vtime")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
select_cpu_from_kfunc() skipped pi_lock for @p when called from
ops.select_cpu() or another rq-locked SCX op, assuming the held lock
protects @p. scx_bpf_select_cpu_dfl() / __scx_bpf_select_cpu_and() accept an
arbitrary KF_RCU task_struct, so a caller in e.g. ops.select_cpu(p1) or
ops.enqueue(p1) can pass some other p2 - the held pi_lock / rq lock is p1's,
not p2's - and reading p2->cpus_ptr / nr_cpus_allowed races with
set_cpus_allowed_ptr() and migrate_disable_switch() on another CPU.
Abort the scheduler on cross-task calls in both branches: for
ops.select_cpu() use scx_kf_arg_task_ok() to verify @p is the wake-up
task recorded in current->scx.kf_tasks[] by SCX_CALL_OP_TASK_RET();
for other rq-locked SCX ops compare task_rq(p) against scx_locked_rq().
v2: Switch the in_select_cpu cross-task check from direct_dispatch_task
comparison to scx_kf_arg_task_ok(). The former spuriously rejects when
ops.select_cpu() calls scx_bpf_dsq_insert() first, then calls
scx_bpf_select_cpu_*() on the same task. (Andrea Righi)
Fixes: 0022b32850 ("sched_ext: Decouple kfunc unlocked-context check from kf_mask")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrea Righi <arighi@nvidia.com>
Two EXT_GROUP_SCHED/SUB_SCHED guards are misclassified:
- scx_root_enable_workfn()'s cgroup_get(cgrp) and the err_put_cgrp unwind
in scx_alloc_and_add_sched() are under `#if GROUP || SUB`, but the
matching cgroup_put() in scx_sched_free_rcu_work() is inside `#ifdef SUB`
only (via sch->cgrp, stored only under SUB). GROUP-only would leak a
reference on every root-sched enable.
- sch_cgroup() / set_cgroup_sched() live under `#if GROUP || SUB` but touch
SUB-only fields (sch->cgrp, cgroup->scx_sched). GROUP-only wouldn't
compile.
GROUP needs CGROUP_SCHED; SUB needs only CGROUPS. CGROUPS=y/CGROUP_SCHED=n
gives the reachable GROUP=n, SUB=y combination; GROUP=y, SUB=n isn't
reachable today (SUB is def_bool y under CGROUPS). Neither miscategorization
triggers a real bug in any reachable config, but keep the guards honest:
- Narrow cgroup_get and err_put_cgrp to `#ifdef SUB` (matches the free-side
put).
- Move sch_cgroup() and set_cgroup_sched() to a separate `#ifdef SUB` block
with no-op stubs for the !SUB case; keep root_cgroup() and scx_cgroup_{
lock,unlock}() under `#if GROUP || SUB` since those only need cgroup core.
Fixes: ebeca1f930 ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
scx_bypass_lb_{donee,resched}_cpumask were file-scope statics shared by all
scheduler instances. With CONFIG_EXT_SUB_SCHED, multiple sched instances
each arm their own bypass_lb_timer; concurrent bypass_lb_node() calls RMW
the global cpumasks with no lock, corrupting donee/resched decisions.
Move the cpumasks into struct scx_sched, allocate them alongside the timer
in scx_alloc_and_add_sched(), free them in scx_sched_free_rcu_work().
Fixes: 95d1df610c ("sched_ext: Implement load balancer for bypass mode")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
scx_prio_less() runs from core-sched's pick_next_task() path with rq
locked but invokes ops.core_sched_before() with NULL locked_rq, leaving
scx_locked_rq_state NULL. If the BPF callback calls a kfunc that
re-acquires rq based on scx_locked_rq() - e.g. scx_bpf_cpuperf_set(cpu)
- it re-acquires the already-held rq.
Pass task_rq(a).
Fixes: 7b0888b7cc ("sched_ext: Implement core-sched support")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
scx_dump_state() walks CPUs with rq_lock_irqsave() held and invokes
ops.dump_cpu / ops.dump_task with NULL locked_rq, leaving
scx_locked_rq_state NULL. If the BPF callback calls a kfunc that
re-acquires rq based on scx_locked_rq() - e.g. scx_bpf_cpuperf_set(cpu)
- it re-acquires the already-held rq.
Pass the held rq to SCX_CALL_OP(). Thread it into scx_dump_task() too.
The pre-loop ops.dump call runs before rq_lock_irqsave() so keeps
rq=NULL.
Fixes: 07814a9439 ("sched_ext: Print debug dump after an error exit")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
SCX_CALL_OP{,_RET}() unconditionally clears scx_locked_rq_state to NULL on
exit. Correct at the top level, but ops can recurse via
scx_bpf_sub_dispatch(): a parent's ops.dispatch calls the helper, which
invokes the child's ops.dispatch under another SCX_CALL_OP. When the inner
call returns, the NULL clobbers the outer's state. The parent's BPF then
calls kfuncs like scx_bpf_cpuperf_set() which read scx_locked_rq()==NULL and
re-acquire the already-held rq.
Snapshot scx_locked_rq_state on entry and restore on exit. Rename the rq
parameter to locked_rq across all SCX_CALL_OP* macros so the snapshot local
can be typed as 'struct rq *' without colliding with the parameter token in
the expansion. SCX_CALL_OP_TASK{,_RET}() and SCX_CALL_OP_2TASKS_RET() funnel
through the two base macros and inherit the fix.
Fixes: 4f8b122848 ("sched_ext: Add basic building blocks for nested sub-scheduler dispatching")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
dispatch_enqueue()'s FIFO-tail path used list_empty(&dsq->list) to decide
whether to set dsq->first_task on enqueue. dsq->list can contain parked BPF
iterator cursors (SCX_DSQ_LNODE_ITER_CURSOR), so list_empty() is not a
reliable "no real task" check. If the last real task is unlinked while a
cursor is parked, first_task becomes NULL; the next FIFO-tail enqueue then
sees list_empty() == false and skips the first_task update, leaving
scx_bpf_dsq_peek() returning NULL for a non-empty DSQ.
Test dsq->first_task directly, which already tracks only real tasks and is
maintained under dsq->lock.
Fixes: 44f5c8ec5b ("sched_ext: Add lockless peek operation for DSQs")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Cc: Ryan Newton <newton@meta.com>
scx_bpf_create_dsq() resolves the calling scheduler via scx_prog_sched(aux)
and inserts the new DSQ into that scheduler's dsq_hash. Its inverse
scx_bpf_destroy_dsq() and the query helper scx_bpf_dsq_nr_queued() were
hard-coded to rcu_dereference(scx_root), so a sub-scheduler could only
destroy or query DSQs in the root scheduler's hash - never its own. If the
root had a DSQ with the same id, the sub-sched silently destroyed it and the
root aborted on the next dispatch ("invalid DSQ ID 0x0..").
Take a const struct bpf_prog_aux *aux via KF_IMPLICIT_ARGS and resolve the
scheduler with scx_prog_sched(aux), matching scx_bpf_create_dsq().
Fixes: ebeca1f930 ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
scx_group_set_{weight,idle,bandwidth}() cache scx_root before acquiring
scx_cgroup_ops_rwsem, so the pointer can be stale by the time the op runs.
If the loaded scheduler is disabled and freed (via RCU work) and another is
enabled between the naked load and the rwsem acquire, the reader sees
scx_cgroup_enabled=true (the new scheduler's) but dereferences the freed one
- UAF on SCX_HAS_OP(sch, ...) / SCX_CALL_OP(sch, ...).
scx_cgroup_enabled is toggled only under scx_cgroup_ops_rwsem write
(scx_cgroup_{init,exit}), so reading scx_root inside the rwsem read section
correlates @sch with the enabled snapshot.
Fixes: a5bd6ba30b ("sched_ext: Use cgroup_lock/unlock() to synchronize against cgroup operations")
Cc: stable@vger.kernel.org # v6.18+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
scx_sub_enable_workfn()'s prep loop calls __scx_init_task(sch, p, false)
without transitioning task state, then sets SCX_TASK_SUB_INIT. If prep fails
partway, the abort path runs __scx_disable_and_exit_task(sch, p) on the
marked tasks. Task state is still the parent's ENABLED, so that dispatches
to the SCX_TASK_ENABLED arm and calls scx_disable_task(sch, p) - i.e.
child->ops.disable() - for tasks on which child->ops.enable() never ran. A
BPF sub-scheduler allocating per-task state in enable/freeing in disable
would operate on uninitialized state.
The dying-task branch in scx_disable_and_exit_task() has the same problem,
and scx_enabling_sub_sched was cleared before the abort cleanup loop - a
task exiting during cleanup tripped the WARN and skipped both ops.exit_task
and the SCX_TASK_SUB_INIT clear, leaking per-task resources and leaving the
task stuck.
Introduce scx_sub_init_cancel_task() that calls ops.exit_task with
cancelled=true - matching what the top-level init path does when init_task
itself returns -errno. Use it in the abort loop and in the dying-task
branch. scx_enabling_sub_sched now stays set until the abort loop finishes
clearing SUB_INIT, so concurrent exits hitting the dying-task branch can
still find @sch. That branch also clears SCX_TASK_SUB_INIT unconditionally
when seen, leaving the task unmarked even if the WARN fires.
Fixes: 337ec00b1d ("sched_ext: Implement cgroup sub-sched enabling and disabling")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
bypass_lb_cpu() transfers tasks between per-CPU bypass DSQs without
migrating them - task_cpu() only updates when the donee later consumes the
task via move_remote_task_to_local_dsq(). If the LB timer fires again before
consumption and the new DSQ becomes a donor, @p is still on the previous CPU
and task_rq(@p) != donor_rq. @p can't be moved without its own rq locked.
Skip such tasks.
Fixes: 95d1df610c ("sched_ext: Implement load balancer for bypass mode")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
bpf_iter_scx_dsq_new() clears kit->dsq on failure and
bpf_iter_scx_dsq_{next,destroy}() guard against that. scx_dsq_move() doesn't -
it dereferences kit->dsq immediately, so a BPF program that calls
scx_bpf_dsq_move[_vtime]() after a failed iter_new oopses the kernel.
Return false if kit->dsq is NULL.
Fixes: 4c30f5ce4f ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
