IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull char/misc fixes/removals from Greg KH:
"Here's some small fixes for 5.10-rc2 and a big driver removal.
The fixes are for some reported issues in the interconnect and
coresight drivers, nothing major.
The "big" driver removal is the MIC drivers have been asked to be
removed as the hardware never shipped and Intel no longer wants to
maintain something that no one can use. This is welcomed by many as
the DMA usage of these drivers was "interesting" and the security
people were starting to question some issues that were starting to be
found in the codebase.
Note, one of the subsystems for this driver, the "VOP" code, will
probably come back in future kernel versions as it was looking to
potentially solve some PCIe virtualization issues that a number of
other vendors were wanting to solve. But as-is, this codebase didn't
work for anyone else so no actual functionality is being removed.
All of these have been in linux-next with no reported issues"
* tag 'char-misc-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
coresight: cti: Initialize dynamic sysfs attributes
coresight: Fix uninitialised pointer bug in etm_setup_aux()
coresight: add module license
misc: mic: remove the MIC drivers
interconnect: qcom: use icc_sync state for sm8[12]50
interconnect: qcom: Ensure that the floor bandwidth value is enforced
interconnect: qcom: sc7180: Init BCMs before creating the nodes
interconnect: qcom: sdm845: Init BCMs before creating the nodes
interconnect: Aggregate before setting initial bandwidth
interconnect: qcom: sdm845: Enable keepalive for the MM1 BCM
Pull driver core and documentation fixes from Greg KH:
"Here is one tiny debugfs change to fix up an API where the last user
was successfully fixed up in 5.10-rc1 (so it couldn't be merged
earlier), and a much larger Documentation/ABI/ update to the files so
they can be automatically parsed by our tools.
The Documentation/ABI/ updates are just formatting issues, small ones
to bring the files into parsable format, and have been acked by
numerous subsystem maintainers and the documentation maintainer. I
figured it was good to get this into 5.10-rc2 to help wih the merge
issues that would arise if these were to stick in linux-next until
5.11-rc1.
The debugfs change has been in linux-next for a long time, and the
Documentation updates only for the last linux-next release"
* tag 'driver-core-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (40 commits)
scripts: get_abi.pl: assume ReST format by default
docs: ABI: sysfs-class-led-trigger-pattern: remove hw_pattern duplication
docs: ABI: sysfs-class-backlight: unify ABI documentation
docs: ABI: sysfs-c2port: remove a duplicated entry
docs: ABI: sysfs-class-power: unify duplicated properties
docs: ABI: unify /sys/class/leds/<led>/brightness documentation
docs: ABI: stable: remove a duplicated documentation
docs: ABI: change read/write attributes
docs: ABI: cleanup several ABI documents
docs: ABI: sysfs-bus-nvdimm: use the right format for ABI
docs: ABI: vdso: use the right format for ABI
docs: ABI: fix syntax to be parsed using ReST notation
docs: ABI: convert testing/configfs-acpi to ReST
docs: Kconfig/Makefile: add a check for broken ABI files
docs: abi-testing.rst: enable --rst-sources when building docs
docs: ABI: don't escape ReST-incompatible chars from obsolete and removed
docs: ABI: create a 2-depth index for ABI
docs: ABI: make it parse ABI/stable as ReST-compatible files
docs: ABI: sysfs-uevent: make it compatible with ReST output
docs: ABI: testing: make the files compatible with ReST output
...
Pull kvm fixes from Paolo Bonzini:
"ARM:
- selftest fix
- force PTE mapping on device pages provided via VFIO
- fix detection of cacheable mapping at S2
- fallback to PMD/PTE mappings for composite huge pages
- fix accounting of Stage-2 PGD allocation
- fix AArch32 handling of some of the debug registers
- simplify host HYP entry
- fix stray pointer conversion on nVHE TLB invalidation
- fix initialization of the nVHE code
- simplify handling of capabilities exposed to HYP
- nuke VCPUs caught using a forbidden AArch32 EL0
x86:
- new nested virtualization selftest
- miscellaneous fixes
- make W=1 fixes
- reserve new CPUID bit in the KVM leaves"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: vmx: remove unused variable
KVM: selftests: Don't require THP to run tests
KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again
KVM: selftests: test behavior of unmapped L2 APIC-access address
KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()
KVM: x86: replace static const variables with macros
KVM: arm64: Handle Asymmetric AArch32 systems
arm64: cpufeature: upgrade hyp caps to final
arm64: cpufeature: reorder cpus_have_{const, final}_cap()
KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code()
KVM: arm64: Force PTE mapping on fault resulting in a device mapping
KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes
KVM: arm64: Fix masks in stage2_pte_cacheable()
KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR
KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT
KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition
KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation
KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call
x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
Pull arm64 fixes from Will Deacon:
"The diffstat is a bit spread out thanks to an invasive CPU erratum
workaround which missed the merge window and also a bunch of fixes to
the recently added MTE selftests.
- Fixes to MTE kselftests
- Fix return code from KVM Spectre-v2 hypercall
- Build fixes for ld.lld and Clang's infamous integrated assembler
- Ensure RCU is up and running before we use printk()
- Workaround for Cortex-A77 erratum 1508412
- Fix linker warnings from unexpected ELF sections
- Ensure PE/COFF sections are 64k aligned"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S
arm64/smp: Move rcu_cpu_starting() earlier
arm64: Add workaround for Arm Cortex-A77 erratum 1508412
arm64: Add part number for Arm Cortex-A77
arm64: mte: Document that user PSTATE.TCO is ignored by kernel uaccess
module: use hidden visibility for weak symbol references
arm64: efi: increase EFI PE/COFF header padding to 64 KB
arm64: vmlinux.lds: account for spurious empty .igot.plt sections
kselftest/arm64: Fix check_user_mem test
kselftest/arm64: Fix check_ksm_options test
kselftest/arm64: Fix check_mmap_options test
kselftest/arm64: Fix check_child_memory test
kselftest/arm64: Fix check_tags_inclusion test
kselftest/arm64: Fix check_buffer_fill test
arm64: avoid -Woverride-init warning
KVM: arm64: ARM_SMCCC_ARCH_WORKAROUND_1 doesn't return SMCCC_RET_NOT_REQUIRED
arm64: vdso32: Allow ld.lld to properly link the VDSO
Pull ARM SoC fixes from Arnd Bergmann:
"This is a fairly large set of bug fixes on top of -rc1, as most of
them were ready but didn't quite make it into the last-minute pull
requests for the merge window.
Allwinner:
- fix for incorrect CPU overtemperature limit
Amlogic:
- multiple smaller DT bugfixes, and missing device nodes
Marvell EBU:
- add missing aliases for ethernet switch ports on espressobin board
Marvell MMP:
- DTC warning fix
- bugfix for camera interface power-down
NXP i.MX:
- re-enable the GPIO driver on all defconfigs
ST STM32MP1:
- fix random crashes from incorrect voltage settings
Synaptics Berlin:
- enable the correct hardware timer driver
Texas Instruments K2G:
- fix a boot regression in the power domain code
TEE drivers:
- fix regression in TEE "login" method
SCMI drivers:
- multiple code fixes for corner cases in newly added code
MAINTAINERS file:
- move Kukjin Kim and Sangbeom Kim to credits (used to work on
Samsung Exynos)
- Masahiro Yamada is stepping down as Uniphier maintainer
I did not include a series of patches that work around a regression
caused by a bugfix in an ethernet phy driver that resulted in an
inadvertent DT binding change. This is still under discussion"
* tag 'arm-soc-fixes-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (31 commits)
soc: ti: ti_sci_pm_domains: check for proper args count in xlate
ARM: dts: stm32: Describe Vin power supply on stm32mp157c-edx board
ARM: dts: stm32: Describe Vin power supply on stm32mp15xx-dkx board
ARM: multi_v5_defconfig: Select CONFIG_GPIO_MXC
ARM: imx_v4_v5_defconfig: Select CONFIG_GPIO_MXC
ARM: dts: mmp2-olpc-xo-1-75: Use plural form of "-gpios"
ARM: dts: mmp3: Add power domain for the camera
arm64: berlin: Select DW_APB_TIMER_OF
dt-bindings: sram: sunxi-sram: add V3s compatible string
MAINTAINERS: Move Sangbeom Kim to credits
MAINTAINERS: Move Kukjin Kim to credits
MAINTAINERS: step down as maintainer of UniPhier SoCs and Denali driver
ARM: multi_v7_defconfig: Build in CONFIG_GPIO_MXC by default
ARM: imx_v6_v7_defconfig: Build in CONFIG_GPIO_MXC by default
arm64: defconfig: Build in CONFIG_GPIO_MXC by default
arm64: dts: meson: odroid-n2 plus: fix vddcpu_a pwm
ARM: dts: meson8: remove two invalid interrupt lines from the GPU node
arm64: dts: amlogic: add missing ethernet reset ID
firmware: arm_scmi: Fix duplicate workqueue name
firmware: arm_scmi: Fix locking in notifications
...
Pull drm fixes from Dave Airlie:
"A busier rc2 than normal, have larger sets of fixes for amdgpu +
nouveau, along with some i915, docs, core, panel, sun4i, v3d, vc4
fixes.
Nothing spooky though or pumpkin related.
docs:
- kernel doc fixes
core:
- fix shmem helpers dma-buf mmap bug
amdgpu:
- Add new navi1x PCI ID
- GPUVM reserved area fixes
- Misc display fixes
- Fix bad interactions between display code and CONFIG_KGDB
- Fixes for SMU manual fan control and i2c
nouveau:
- endian regression fix for old gpus
- buffer object refcount fix
- uapi start/end alignment fix
- display notifier fix
- display clock checking fixes
i915:
- Fix max memory region size calculation
- Restore ILK-M RPS support, restoring performance
- Reject 90/270 degreerotated initial fbs
panel:
- mantix reset fixes
sun4i:
- scalar fix
vc4:
- hdmi audio fixes
v3d:
- fix double free"
* tag 'drm-fixes-2020-10-30-1' of git://anongit.freedesktop.org/drm/drm: (42 commits)
drm/nouveau/kms/nv50-: Fix clock checking algorithm in nv50_dp_mode_valid()
drm/nouveau/kms/nv50-: Get rid of bogus nouveau_conn_mode_valid()
drm/nouveau/device: fix changing endianess code to work on older GPUs
drm/nouveau/gem: fix "refcount_t: underflow; use-after-free"
drm/nouveau/kms/nv50-: Program notifier offset before requesting disp caps
drm/nouveau/nouveau: fix the start/end range for migration
drm/i915: Reject 90/270 degree rotated initial fbs
drm/i915: Restore ILK-M RPS support
drm/i915/region: fix max size calculation
drm/vc4: Rework the structure conversion functions
drm/vc4: hdmi: Add a name to the codec DAI component
drm/shme-helpers: Fix dma_buf_mmap forwarding bug
drm/vc4: hdmi: Avoid sleeping in atomic context
drm/amdgpu/pm: fix the fan speed in fan1_input in manual mode for navi1x
drm/amd/pm: fix the wrong fan speed in fan1_input
drm/amdgpu/swsmu: drop smu i2c bus on navi1x
drm/vc4: drv: Add error handding for bind
drm: drm_print.h: fix kernel-doc markups
drm: kernel-doc: drm_dp_helper.h: fix a typo
drm: kernel-doc: add description for a new function parameter
...
The ABI files are supposed to be unique. Yet,
in the specific case of hw_pattern, there are some duplicated
entries as warned by scripts/get_abi.pl:
Warning: /sys/class/leds/<led>/hw_pattern is defined 3 times: Documentation/ABI/testing/sysfs-class-led-trigger-pattern:14 Documentation/ABI/testing/sysfs-class-led-driver-sc27xx:0 Documentation/ABI/testing/sysfs-class-led-driver-el15203000:0
Drop the duplication from the ABI files, moving the specific
definitions to files inside Documentation/leds.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/038e57881550550b298e598f8f9b7f20515cbe15.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both adp8860 and adp8870 define some extensions to the
backlight class. This causes warnings:
Warning: /sys/class/backlight/<backlight>/ambient_light_level is defined 2 times: /sys/class/backlight/<backlight>/ambient_light_level:8 /sys/class/backlight/<backlight>/ambient_light_level:30
Warning: /sys/class/backlight/<backlight>/ambient_light_zone is defined 2 times: /sys/class/backlight/<backlight>/ambient_light_zone:18 /sys/class/backlight/<backlight>/ambient_light_zone:40
As ABI definitions shouldn't be duplicated.
Unfortunately, the ABI is dependent on the specific device
features. As such, ambient_light_level range is somewhat
different among the supported devices.
The ambient_light_zone is even worse: the meanings of each
preset are different, and there's no ABI to retrieve
the supported types nor their meanins. Unfortunately,
it is too late to fix it without causing regressions,
as this has been used since Kernel v2.6.35.
Rewrite those ABI documentation using the current documentation
as a reference, and double-checking at the datasheets:
https://www.analog.com/media/en/technical-documentation/data-sheets/ADP8870.pdfhttps://www.analog.com/media/en/technical-documentation/data-sheets/ADP8860.pdf
in order to properly document the differences between those two
drivers.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/342195ad5a819d9bcfcebc133c77ab69b4211672.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ABI is not supposed to have duplicated entries, as warned
by get_abi.pl:
$ ./scripts/get_abi.pl validate 2>&1|grep sysfs-class-power
Warning: /sys/class/power_supply/<supply_name>/current_avg is defined 2 times: Documentation/ABI/testing/sysfs-class-power:108 Documentation/ABI/testing/sysfs-class-power:391
Warning: /sys/class/power_supply/<supply_name>/current_max is defined 2 times: Documentation/ABI/testing/sysfs-class-power:121 Documentation/ABI/testing/sysfs-class-power:404
Warning: /sys/class/power_supply/<supply_name>/current_now is defined 2 times: Documentation/ABI/testing/sysfs-class-power:130 Documentation/ABI/testing/sysfs-class-power:414
Warning: /sys/class/power_supply/<supply_name>/temp is defined 2 times: Documentation/ABI/testing/sysfs-class-power:281 Documentation/ABI/testing/sysfs-class-power:493
Warning: /sys/class/power_supply/<supply_name>/temp_alert_max is defined 2 times: Documentation/ABI/testing/sysfs-class-power:291 Documentation/ABI/testing/sysfs-class-power:505
Warning: /sys/class/power_supply/<supply_name>/temp_alert_min is defined 2 times: Documentation/ABI/testing/sysfs-class-power:306 Documentation/ABI/testing/sysfs-class-power:521
Warning: /sys/class/power_supply/<supply_name>/temp_max is defined 2 times: Documentation/ABI/testing/sysfs-class-power:322 Documentation/ABI/testing/sysfs-class-power:537
Warning: /sys/class/power_supply/<supply_name>/temp_min is defined 2 times: Documentation/ABI/testing/sysfs-class-power:333 Documentation/ABI/testing/sysfs-class-power:547
Warning: /sys/class/power_supply/<supply_name>/voltage_max is defined 2 times: Documentation/ABI/testing/sysfs-class-power:356 Documentation/ABI/testing/sysfs-class-power:571
Warning: /sys/class/power_supply/<supply_name>/voltage_min is defined 2 times: Documentation/ABI/testing/sysfs-class-power:367 Documentation/ABI/testing/sysfs-class-power:581
Warning: /sys/class/power_supply/<supply_name>/voltage_now is defined 2 times: Documentation/ABI/testing/sysfs-class-power:378 Documentation/ABI/testing/sysfs-class-power:591
Yet, both USB and Battery share a common set of charging-related
properties.
Unify the entries for such properties in order to avoid
duplication, while preserving the battery and USB-specific
data properly documented.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/bcdf5f76326ea48a990a7cac612af216c387537d.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The files under Documentation/ABI should follow the syntax
as defined at Documentation/ABI/README.
Allow checking if they're following the syntax by running
the ABI parser script on COMPILE_TEST.
With that, when there's a problem with a file under
Documentation/ABI, it would produce a warning like:
Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14:
What '/sys/bus/pci/devices/<dev>/aer_stats/aer_rootport_total_err_cor' doesn't have a description
Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21:
What '/sys/bus/pci/devices/<dev>/aer_stats/aer_rootport_total_err_fatal' doesn't have a description
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Just like kernel-doc extension, we need to be able to identify
what part of an imported document has issues, as reporting them
as:
get_abi.pl rest --dir $srctree/Documentation/ABI/obsolete --rst-source:1689: ERROR: Unexpected indentation.
Makes a lot harder for someone to fix.
It should be noticed that it the line which will be reported is
the line where the "What:" definition is, and not the line
with actually has an error.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/d6155ab16fb7631f2fa8e7a770eae72f24bf7cc5.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On exception entry, the kernel explicitly resets the PSTATE.TCO (tag
check override) so that any kernel memory accesses will be checked (the
bit is restored on exception return). This has the side-effect that the
uaccess routines will not honour the PSTATE.TCO that may have been set
by the user prior to a syscall.
There is no issue in practice since PSTATE.TCO is expected to be used
only for brief periods in specific routines (e.g. garbage collection).
To control the tag checking mode of the uaccess routines, the user will
have to invoke a corresponding prctl() call.
Document the kernel behaviour w.r.t. PSTATE.TCO accordingly.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: df9d7a22dd ("arm64: mte: Add Memory Tagging Extension documentation")
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Another round of wack-a-mole. The json-schema default is additional
unknown properties are allowed, but for DT all properties should be
defined.
Signed-off-by: Rob Herring <robh@kernel.org>
We have a few leftovers from the merge window period in
drm-misc-next-fixes, let's bring them into drm-misc-fixes
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
