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2021-04-09usb: Link the ports to the connectors they are attached toHeikki Krogerus1-0/+9
Creating link to the USB Type-C connector for every new port that is added when possible. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20210407065555.88110-3-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-09pwm: Clarify which state pwm_get_state() returnsUwe Kleine-König1-1/+5
Given that lowlevel drivers usually cannot implement exactly what a consumer requests with pwm_apply_state() there is some rounding involved. pwm_get_state() returns the setting that was requested most recently by the consumer (opposed to what was actually implemented in hardware in reply to the last request). Clarify this in the function kerneldoc. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-04-09habanalabs/gaudi: add debugfs to DMA from the deviceOded Gabbay1-15/+53
When trying to debug program, the user often needs to dump large parts of the device's DRAM, which can reach to tens of GBs. Because reading from the device's internal memory through the PCI BAR is extremely slow, the debug can take hours. Instead, we can provide the user to copy data through one of the DMA engines. This will make the operation much faster. Currently, only GAUDI is supported. In GAUDI, we need to find a PCI DMA engine that is IDLE and set the DMA as secured to be able to bypass our MMU as we currently don't map the temporary buffer to the MMU. Example bash one-line to dump entire HBM to file (~2 minutes): for (( i=0x0; i < 0x800000000; i+=0x8000000 )); do \ printf '0x%x\n' $i | sudo tee /sys/kernel/debug/habanalabs/hl0/addr ; \ echo 0x8000000 | sudo tee /sys/kernel/debug/habanalabs/hl0/dma_size ; \ sudo cat /sys/kernel/debug/habanalabs/hl0/data_dma >> hbm.txt ; done Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
2021-04-09habanalabs: support HW blocks vm showSagiv Ozeri1-1/+1
Improve "vm" debugfs node to print also the virtual addresses which are currently mapped to HW blocks in the device. Signed-off-by: Sagiv Ozeri <sozeri@habana.ai> Reviewed-by: Oded Gabbay <ogabbay@kernel.org> Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
2021-04-09media: dt-bindings: media: IR: Add H616 IR compatible stringAndre Przywara1-10/+6
Add the obvious compatible name to the existing IR binding, and pair it with the existing A31 fallback compatible string, as the devices are compatible. On the way use enums to group all compatible devices together. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-04-09media: rc: remove zte zx ir driverArnd Bergmann1-14/+0
The zte zx platform is getting removed, so this driver is no longer needed. Cc: Jun Nie <jun.nie@linaro.org> Cc: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-04-09media: rc: add keymaps for mecool-kii-pro/kiii-pro remotesChristian Hewitt1-0/+2
Add keymaps and bindings for the simple IR (NEC) remotes used with the MeCool KII-Pro and MeCool KIII-Pro Android STB devices. Tested-by: Drazen Spio <drazsp@gmail.com> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-04-09Merge tag 'aspeed-5.13-lpc' of ↵Arnd Bergmann1-75/+25
git://git.kernel.org/pub/scm/linux/kernel/git/joel/bmc into arm/drivers ASPEED LPC updates for 5.13 These patches fix the ASPEED LPC bindings and LPC-related device drivers so in the future the KCS driver can properly use the hardware. * tag 'aspeed-5.13-lpc' of git://git.kernel.org/pub/scm/linux/kernel/git/joel/bmc: soc: aspeed: Adapt to new LPC device tree layout pinctrl: aspeed-g5: Adapt to new LPC device tree layout ipmi: kcs: aspeed: Adapt to new LPC DTS layout ARM: dts: Remove LPC BMC and Host partitions dt-bindings: aspeed-lpc: Remove LPC partitioning Link: https://lore.kernel.org/r/CACPK8Xcb12LsVr7CUaXXjQskKbVjb7x+jgueG1Hik-kBPWtDSg@mail.gmail.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-04-09dt-bindings: watchdog: npcm: Add nuvoton,wpcm450-wdtJonathan Neuschäfer1-1/+2
Add a compatible string for the WPCM450 SoC, which has the same watchdog timer. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210406120921.2484986-5-j.neuschaefer@gmx.net Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-04-09dt-bindings: arm: npcm: Add nuvoton,wpcm450 compatible stringJonathan Neuschäfer1-0/+6
The WPCM450 is an older BMC SoC in the Nuvoton NPCM family, originally marketed as Winbond WPCM450. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210406120921.2484986-3-j.neuschaefer@gmx.net Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-04-09dt-bindings: vendor-prefixes: Add SupermicroJonathan Neuschäfer1-0/+2
Super Micro Computer, Inc. (https://www.supermicro.com/en/), commonly known as Supermicro, is a manufacturer of server hardware. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210406120921.2484986-2-j.neuschaefer@gmx.net Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-04-09dt-bindings: aspeed-lpc: Remove LPC partitioningChia-Wei, Wang1-75/+25
The LPC controller has no concept of the BMC and the Host partitions. This patch fixes the documentation by removing the description on LPC partitions. The register offsets illustrated in the DTS node examples are also fixed to adapt to the LPC DTS change. Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210319062752.145730-1-andrew@aj.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-04-09dt-bindings: pinctrl: qcom-pmic-gpio: Add pm8008 supportGuru Das Srinagesh1-0/+2
Add support for the 2 GPIOs present on Qualcomm Technologies, Inc. PM8008. Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org> Link: https://lore.kernel.org/r/2be34cc205ae96d40b04a9efdcf9287d5da9d1c0.1617901945.git.gurus@codeaurora.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-04-09Merge tag 'for-net-next-2021-04-08' of ↵David S. Miller3-57/+119
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next Luiz Augusto von Dentz says: ==================== bluetooth-next pull request for net-next: - Proper support for BCM4330 and BMC4334 - Various improvements for firmware download of Intel controllers - Update management interface revision to 20 - Support for AOSP HCI vendor commands - Initial Virtio support ==================== Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-08i2c: imx: mention Oleksij as maintainer of the binding docsWolfram Sang1-0/+3
When I removed myself as a maintainer of the yaml file, I missed that some maintainer is required. Oleksij is already listed in MAINTAINERS for this file, so add him here as well. Fixes: 1ae6b3780848 ("i2c: imx: drop me as maintainer of binding docs") Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-04-08arm64: Get rid of CONFIG_ARM64_VHEMarc Zyngier1-2/+1
CONFIG_ARM64_VHE was introduced with ARMv8.1 (some 7 years ago), and has been enabled by default for almost all that time. Given that newer systems that are VHE capable are finally becoming available, and that some systems are even incapable of not running VHE, drop the configuration altogether. Anyone willing to stick to non-VHE on VHE hardware for obscure reasons should use the 'kvm-arm.mode=nvhe' command-line option. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210408131010.1109027-4-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08docs/zh_CN: add riscv to zh_CN indexYanteng Si1-0/+1
All the files in the riscv directory have been translated into Chinese and it is time to add them to the zh_CN index. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-9-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add iio to zh_CN indexYanteng Si1-0/+1
All the files in the iio directory have been translated into Chinese and it is time to add them to the zh_CN index. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-8-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add mips to zh_CN indexYanteng Si1-0/+1
All the files in the mips directory have been translated into Chinese and it is time to add them to the zh_CN index. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-7-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add cpu-freq to zh_CN indexYanteng Si1-0/+1
All the files in the cpu-freq directory have been translated into Chinese and it is time to add them to the zh_CN index. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-6-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add cpu-freq index.rst translationYanteng Si1-0/+45
This patch translates Documention/cpu-freq/index.rst into Chinese. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-5-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add cpu-freq cpufreq-stats.rst translationYanteng Si1-0/+130
This patch translates Documention/cpu-freq/cpufreq-stats.rst into Chinese. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-4-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add cpu-freq cpu-drivers.rst translationYanteng Si1-0/+259
This patch translates Documention/cpu-freq/cpu-drivers.rst into Chinese. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-3-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/zh_CN: add cpu-freq core.rst translationYanteng Si1-0/+105
This patch translates Documention/cpu-freq/core.rst into Chinese. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20210406070239.19910-2-siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08arm64: Require that system registers at all visible ELs be initializedMark Brown1-3/+4
Currently we require that software at a higher exception level initialise all registers at the exception level the kernel will be entered prior to starting the kernel in order to ensure that there is nothing uninitialised which could result in an UNKNOWN state while running the kernel. The expectation is that the software running at the highest exception levels will be tightly coupled to the system and can ensure that all available features are appropriately initialised and that the kernel can initialise anything else. There is a gap here in the case where new registers are added to lower exception levels that require initialisation but the kernel does not yet understand them. Extend the requirement to also include exception levels below the one where the kernel is entered to cover this. Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210401180942.35815-4-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08arm64: Document requirements for fine grained traps at bootMark Brown1-0/+6
The arm64 FEAT_FGT extension introduces a set of traps to EL2 for accesses to small sets of registers and instructions from EL1 and EL0, access to which is controlled by EL3. Require access to it so that it is available to us in future and so that we can ensure these traps are disabled during boot. Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210401180942.35815-2-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08docs: Minor spelling fix in spi documentationStéphane Blondon1-1/+1
Signed-off-by: Stéphane Blondon <stephane.blondon@gmail.com> Link: https://lore.kernel.org/r/CAOy+up7EdTf4ouh5onVy_ZzXFWGBEP+P6CPqY-=E+1UFwCeq8w@mail.gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08docs/gcov: Convert two tags to ref in dev-tools/gov.rstWu XiangCheng1-2/+6
Htmldocs does not display the chapter number, convert the two manual chapter number tags to ref tags. Signed-off-by: Wu XiangCheng <bobwxc@email.cn> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Link: https://lore.kernel.org/r/20210403113752.GA32236@mipc Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08Merge tag 'memory-controller-drv-tegra-5.13' of ↵Arnd Bergmann5-48/+89
git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-mem-ctrl into arm/drivers Memory controller drivers for v5.13 - Tegra SoC 1. Few cleanups. 2. Add debug statistics to Tegra20 memory controller. 3. Update bindings and convert to dtschema. This update is not backwards compatible (ABI break) however the broken part was added recently (v5.11) and there are no users of it yet. * tag 'memory-controller-drv-tegra-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-mem-ctrl: dt-bindings: memory: tegra20: mc: Convert to schema dt-bindings: memory: tegra124: emc: Replace core regulator with power domain dt-bindings: memory: tegra30: emc: Replace core regulator with power domain dt-bindings: memory: tegra20: emc: Replace core regulator with power domain memory: tegra: Print out info-level once per driver probe memory: tegra20: Protect debug code with a lock memory: tegra20: Correct comment to MC_STAT registers writes memory: tegra20: Add debug statistics memory: tegra: replace DEFINE_SIMPLE_ATTRIBUTE with DEFINE_DEBUGFS_ATTRIBUTE Link: https://lore.kernel.org/r/20210407161333.73013-2-krzysztof.kozlowski@canonical.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-04-08Merge tag 'v5.12-next-soc.2' of ↵Arnd Bergmann1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/matthias.bgg/linux into arm/drivers MT8167: - add support for mmsys subsystem * tag 'v5.12-next-soc.2' of git://git.kernel.org/pub/scm/linux/kernel/git/matthias.bgg/linux: soc: mediatek: mmsys: Add support for MT8167 SoC dt-bindings: mediatek: mmsys: add mt8167 binding Link: https://lore.kernel.org/r/14104322-3a6c-e8eb-cd21-a5343a81aa0f@gmail.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-04-08Merge tag 'qcom-drivers-for-5.13' of ↵Arnd Bergmann4-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into arm/drivers Qualcomm driver updates for 5.13 This introduces SC7280 and SM8350 support in the RPMH power-domain driver, SC7280 support to the LLCC driver, SC7280 support tot he AOSS QMP driver, cleanups to the RPMH driver and a few smaller fixes to the SMEM, QMI and EBI2 drivers. * tag 'qcom-drivers-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux: bus: qcom: Put child node before return dt-bindings: firmware: scm: Add sc7280 support soc: qcom: rpmh-rsc: Fold WARN_ON() into if condition soc: qcom: rpmh-rsc: Loop over fewer bits in irq handler soc: qcom: rpmh-rsc: Remove tcs_is_free() API soc: qcom: smem: Update max processor count soc: qcom: aoss: Add AOSS QMP support for SC7280 dt-bindings: soc: qcom: aoss: Add SC7280 compatible soc: qcom: llcc: Add configuration data for SC7280 dt-bindings: arm: msm: Add LLCC for SC7280 soc: qcom: Fix typos in the file qmi_encdec.c soc: qcom: rpmhpd: Add sc7280 powerdomains dt-bindings: power: rpmpd: Add sc7280 to rpmpd binding soc: qcom: rpmhpd: Add SM8350 power domains dt-bindings: power: Add rpm power domain bindings for SM8350 Link: https://lore.kernel.org/r/20210404164951.713045-1-bjorn.andersson@linaro.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-04-08dt-bindings: timer: nuvoton,npcm7xx: Add wpcm450-timerJonathan Neuschäfer1-1/+2
Add a compatible string for WPCM450, which has essentially the same timer controller. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210320181610.680870-6-j.neuschaefer@gmx.net
2021-04-08ASoC: codecs: tlv320aic3x: add SPI to the DT bindingJiri Prchal1-2/+19
Added note and example of SPI support. Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz> Link: https://lore.kernel.org/r/20210408060741.6879-1-jiri.prchal@aksignal.cz Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-08docs: pin-control: Fix error path for control state exampleNiklas Söderlund1-1/+1
The error is constructed using the wrong variable. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Link: https://lore.kernel.org/r/20210328164222.720525-1-niklas.soderlund+renesas@ragnatech.se Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-04-08KVM: arm64: Fix table format for PTP documentationMarc Zyngier1-11/+11
The documentation build legitimately screams about the PTP documentation table being misformated. Fix it by adjusting the table width guides. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-08power: supply: Add battery driver for Surface Aggregator ModuleMaximilian Luz1-0/+15
On newer Microsoft Surface models (specifically 7th-generation, i.e. Surface Pro 7, Surface Book 3, Surface Laptop 3, and Surface Laptop Go), battery and AC status/information is no longer handled via standard ACPI devices, but instead directly via the Surface System Aggregator Module (SSAM), i.e. the embedded controller on those devices. While on previous generation models, battery status is also handled via SSAM, an ACPI shim was present to translate the standard ACPI battery interface to SSAM requests. The SSAM interface itself, which is modeled closely after the ACPI interface, has not changed. This commit introduces a new SSAM client device driver to support battery status/information via the aforementioned interface on said Surface models. It is in parts based on the standard ACPI battery driver. Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2021-04-08stack: Optionally randomize kernel stack offset each syscallKees Cook1-0/+11
This provides the ability for architectures to enable kernel stack base address offset randomization. This feature is controlled by the boot param "randomize_kstack_offset=on/off", with its default value set by CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT. This feature is based on the original idea from the last public release of PaX's RANDKSTACK feature: https://pax.grsecurity.net/docs/randkstack.txt All the credit for the original idea goes to the PaX team. Note that the design and implementation of this upstream randomize_kstack_offset feature differs greatly from the RANDKSTACK feature (see below). Reasoning for the feature: This feature aims to make harder the various stack-based attacks that rely on deterministic stack structure. We have had many such attacks in past (just to name few): https://jon.oberheide.org/files/infiltrate12-thestackisback.pdf https://jon.oberheide.org/files/stackjacking-infiltrate11.pdf https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html As Linux kernel stack protections have been constantly improving (vmap-based stack allocation with guard pages, removal of thread_info, STACKLEAK), attackers have had to find new ways for their exploits to work. They have done so, continuing to rely on the kernel's stack determinism, in situations where VMAP_STACK and THREAD_INFO_IN_TASK_STRUCT were not relevant. For example, the following recent attacks would have been hampered if the stack offset was non-deterministic between syscalls: https://repositorio-aberto.up.pt/bitstream/10216/125357/2/374717.pdf (page 70: targeting the pt_regs copy with linear stack overflow) https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html (leaked stack address from one syscall as a target during next syscall) The main idea is that since the stack offset is randomized on each system call, it is harder for an attack to reliably land in any particular place on the thread stack, even with address exposures, as the stack base will change on the next syscall. Also, since randomization is performed after placing pt_regs, the ptrace-based approach[1] to discover the randomized offset during a long-running syscall should not be possible. Design description: During most of the kernel's execution, it runs on the "thread stack", which is pretty deterministic in its structure: it is fixed in size, and on every entry from userspace to kernel on a syscall the thread stack starts construction from an address fetched from the per-cpu cpu_current_top_of_stack variable. The first element to be pushed to the thread stack is the pt_regs struct that stores all required CPU registers and syscall parameters. Finally the specific syscall function is called, with the stack being used as the kernel executes the resulting request. The goal of randomize_kstack_offset feature is to add a random offset after the pt_regs has been pushed to the stack and before the rest of the thread stack is used during the syscall processing, and to change it every time a process issues a syscall. The source of randomness is currently architecture-defined (but x86 is using the low byte of rdtsc()). Future improvements for different entropy sources is possible, but out of scope for this patch. Further more, to add more unpredictability, new offsets are chosen at the end of syscalls (the timing of which should be less easy to measure from userspace than at syscall entry time), and stored in a per-CPU variable, so that the life of the value does not stay explicitly tied to a single task. As suggested by Andy Lutomirski, the offset is added using alloca() and an empty asm() statement with an output constraint, since it avoids changes to assembly syscall entry code, to the unwinder, and provides correct stack alignment as defined by the compiler. In order to make this available by default with zero performance impact for those that don't want it, it is boot-time selectable with static branches. This way, if the overhead is not wanted, it can just be left turned off with no performance impact. The generated assembly for x86_64 with GCC looks like this: ... ffffffff81003977: 65 8b 05 02 ea 00 7f mov %gs:0x7f00ea02(%rip),%eax # 12380 <kstack_offset> ffffffff8100397e: 25 ff 03 00 00 and $0x3ff,%eax ffffffff81003983: 48 83 c0 0f add $0xf,%rax ffffffff81003987: 25 f8 07 00 00 and $0x7f8,%eax ffffffff8100398c: 48 29 c4 sub %rax,%rsp ffffffff8100398f: 48 8d 44 24 0f lea 0xf(%rsp),%rax ffffffff81003994: 48 83 e0 f0 and $0xfffffffffffffff0,%rax ... As a result of the above stack alignment, this patch introduces about 5 bits of randomness after pt_regs is spilled to the thread stack on x86_64, and 6 bits on x86_32 (since its has 1 fewer bit required for stack alignment). The amount of entropy could be adjusted based on how much of the stack space we wish to trade for security. My measure of syscall performance overhead (on x86_64): lmbench: /usr/lib/lmbench/bin/x86_64-linux-gnu/lat_syscall -N 10000 null randomize_kstack_offset=y Simple syscall: 0.7082 microseconds randomize_kstack_offset=n Simple syscall: 0.7016 microseconds So, roughly 0.9% overhead growth for a no-op syscall, which is very manageable. And for people that don't want this, it's off by default. There are two gotchas with using the alloca() trick. First, compilers that have Stack Clash protection (-fstack-clash-protection) enabled by default (e.g. Ubuntu[3]) add pagesize stack probes to any dynamic stack allocations. While the randomization offset is always less than a page, the resulting assembly would still contain (unreachable!) probing routines, bloating the resulting assembly. To avoid this, -fno-stack-clash-protection is unconditionally added to the kernel Makefile since this is the only dynamic stack allocation in the kernel (now that VLAs have been removed) and it is provably safe from Stack Clash style attacks. The second gotcha with alloca() is a negative interaction with -fstack-protector*, in that it sees the alloca() as an array allocation, which triggers the unconditional addition of the stack canary function pre/post-amble which slows down syscalls regardless of the static branch. In order to avoid adding this unneeded check and its associated performance impact, architectures need to carefully remove uses of -fstack-protector-strong (or -fstack-protector) in the compilation units that use the add_random_kstack() macro and to audit the resulting stack mitigation coverage (to make sure no desired coverage disappears). No change is visible for this on x86 because the stack protector is already unconditionally disabled for the compilation unit, but the change is required on arm64. There is, unfortunately, no attribute that can be used to disable stack protector for specific functions. Comparison to PaX RANDKSTACK feature: The RANDKSTACK feature randomizes the location of the stack start (cpu_current_top_of_stack), i.e. including the location of pt_regs structure itself on the stack. Initially this patch followed the same approach, but during the recent discussions[2], it has been determined to be of a little value since, if ptrace functionality is available for an attacker, they can use PTRACE_PEEKUSR/PTRACE_POKEUSR to read/write different offsets in the pt_regs struct, observe the cache behavior of the pt_regs accesses, and figure out the random stack offset. Another difference is that the random offset is stored in a per-cpu variable, rather than having it be per-thread. As a result, these implementations differ a fair bit in their implementation details and results, though obviously the intent is similar. [1] https://lore.kernel.org/kernel-hardening/2236FBA76BA1254E88B949DDB74E612BA4BC57C1@IRSMSX102.ger.corp.intel.com/ [2] https://lore.kernel.org/kernel-hardening/20190329081358.30497-1-elena.reshetova@intel.com/ [3] https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040741.html Co-developed-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210401232347.2791257-4-keescook@chromium.org
2021-04-08dt-bindings: timer: renesas,cmt: Document R8A77961Niklas Söderlund1-0/+2
Add missing bindings for M3-W+. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210211143344.352588-1-niklas.soderlund+renesas@ragnatech.se
2021-04-08dt-bindings: timer: renesas,cmt: Add r8a779a0 CMT supportWolfram Sang1-0/+2
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210311090918.2197-1-wsa+renesas@sang-engineering.com
2021-04-08dt-bindings: timer: ingenic: Add compatible strings for JZ4760(B)Paul Cercueil1-8/+22
Add compatible strings to support the system timer, clocksource, OST, watchdog and PWM blocks of the JZ4760 and JZ4760B SoCs. Newer SoCs which behave like the JZ4760 or JZ4760B now see their compatible string require a fallback compatible string that corresponds to one of these two SoCs. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210308212302.10288-1-paul@crapouillou.net
2021-04-08dt-bindings: timer: renesas,tmu: Document missing Gen3 SoCsNiklas Söderlund1-0/+6
Add missing bindings for Gen3 SoCs. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210211143102.350719-1-niklas.soderlund+renesas@ragnatech.se
2021-04-08dt-bindings: display: Add apple,simple-framebufferHector Martin1-0/+5
Apple SoCs run firmware that sets up a simplefb-compatible framebuffer for us. Add a compatible for it, and two missing supported formats. Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08dt-bindings: interrupt-controller: Add DT bindings for apple-aicHector Martin1-0/+88
AIC is the Apple Interrupt Controller found on Apple ARM SoCs, such as the M1. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08docs: driver-api: device-io: Document ioremap() variants & access funcsHector Martin1-0/+218
This documents the newly introduced ioremap_np() along with all the other common ioremap() variants, and some higher-level abstractions available. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08docs: driver-api: device-io: Document I/O access functionsArnd Bergmann1-0/+138
This adds more detailed descriptions of the various read/write primitives available for use with I/O memory/ports. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08asm-generic/io.h: Add a non-posted variant of ioremap()Hector Martin1-0/+1
ARM64 currently defaults to posted MMIO (nGnRE), but some devices require the use of non-posted MMIO (nGnRnE). Introduce a new ioremap() variant to handle this case. ioremap_np() returns NULL on arches that do not implement this variant. sparc64 is the only architecture that needs to be touched directly, because it includes neither of the generic io.h or iomap.h headers. This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this variant and marks a given resource as requiring non-posted mappings. This is implemented in the resource system because it is a SoC-level requirement, so existing drivers do not need special-case code to pick this ioremap variant. Then this is implemented in devres by introducing devm_ioremap_np(), and making devm_ioremap_resource() automatically select this variant when the resource has the IORESOURCE_MEM_NONPOSTED flag set. Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08dt-bindings: timer: arm,arch_timer: Add interrupt-names supportHector Martin1-0/+19
Not all platforms provide the same set of timers/interrupts, and Linux only needs one (plus kvm/guest ones); some platforms are working around this by using dummy fake interrupts. Implementing interrupt-names allows the devicetree to specify an arbitrary set of available interrupts, so the timer code can pick the right one. This also adds the hyp-virt timer/interrupt, which was previously not expressed in the fixed 4-interrupt form. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08dt-bindings: arm: cpus: Add apple,firestorm & icestorm compatiblesHector Martin1-0/+2
These are the CPU cores in the "Apple Silicon" M1 SoC. Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08dt-bindings: arm: apple: Add bindings for Apple ARM platformsHector Martin1-0/+64
This introduces bindings for all three 2020 Apple M1 devices: * apple,j274 - Mac mini (M1, 2020) * apple,j293 - MacBook Pro (13-inch, M1, 2020) * apple,j313 - MacBook Air (M1, 2020) Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08dt-bindings: vendor-prefixes: Add apple prefixHector Martin1-0/+2
This is different from the legacy AAPL prefix used on PPC, but consensus is that we prefer `apple` for these new platforms. Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Hector Martin <marcan@marcan.st>