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2020-10-22Merge tag 'kbuild-v5.10' of ↵Linus Torvalds1-3/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...
2020-10-22Merge tag 'pci-v5.10-changes' of ↵Linus Torvalds2-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Print IRQ number used by PCIe Link Bandwidth Notification (Dongdong Liu) - Add schedule point in pci_read_config() to reduce max latency (Jiang Biao) - Add Kconfig options for MPS/MRRS strategy (Jim Quinlan) Resource management: - Fix pci_iounmap() memory leak when !CONFIG_GENERIC_IOMAP (Lorenzo Pieralisi) PCIe native device hotplug: - Reduce noisiness on hot removal (Lukas Wunner) Power management: - Revert "PCI/PM: Apply D2 delay as milliseconds, not microseconds" that was done on the basis of spec typo (Bjorn Helgaas) - Rename pci_dev.d3_delay to d3hot_delay to remove D3hot/D3cold ambiguity (Krzysztof Wilczyński) - Remove unused pcibios_pm_ops (Vaibhav Gupta) IOMMU: - Enable Translation Blocking for external devices to harden against DMA attacks (Rajat Jain) Error handling: - Add an ACPI APEI notifier chain for vendor CPER records to enable device-specific error handling (Shiju Jose) ASPM: - Remove struct aspm_register_info to simplify code (Saheed O. Bolarinwa) Amlogic Meson PCIe controller driver: - Build as module by default (Kevin Hilman) Ampere Altra PCIe controller driver: - Add MCFG quirk to work around non-standard ECAM implementation (Tuan Phan) Broadcom iProc PCIe controller driver: - Set affinity mask on MSI interrupts (Mark Tomlinson) Broadcom STB PCIe controller driver: - Make PCIE_BRCMSTB depend on ARCH_BRCMSTB (Jim Quinlan) - Add DT bindings for more Brcmstb chips (Jim Quinlan) - Add bcm7278 register info (Jim Quinlan) - Add bcm7278 PERST# support (Jim Quinlan) - Add suspend and resume pm_ops (Jim Quinlan) - Add control of rescal reset (Jim Quinlan) - Set additional internal memory DMA viewport sizes (Jim Quinlan) - Accommodate MSI for older chips (Jim Quinlan) - Set bus max burst size by chip type (Jim Quinlan) - Add support for bcm7211, bcm7216, bcm7445, bcm7278 (Jim Quinlan) Freescale i.MX6 PCIe controller driver: - Use dev_err_probe() to reduce redundant messages (Anson Huang) Freescale Layerscape PCIe controller driver: - Enforce 4K DMA buffer alignment in endpoint test (Hou Zhiqiang) - Add DT compatible strings for ls1088a, ls2088a (Xiaowei Bao) - Add endpoint support for ls1088a, ls2088a (Xiaowei Bao) - Add endpoint test support for lS1088a (Xiaowei Bao) - Add MSI-X support for ls1088a (Xiaowei Bao) HiSilicon HIP PCIe controller driver: - Handle HIP-specific errors via ACPI APEI (Yicong Yang) HiSilicon Kirin PCIe controller driver: - Return -EPROBE_DEFER if the GPIO isn't ready (Bean Huo) Intel VMD host bridge driver: - Factor out physical offset, bus offset, IRQ domain, IRQ allocation (Jon Derrick) - Use generic PCI PM correctly (Jon Derrick) Marvell Aardvark PCIe controller driver: - Fix compilation on s390 (Pali Rohár) - Implement driver 'remove' function and allow to build it as module (Pali Rohár) - Move PCIe reset card code to advk_pcie_train_link() (Pali Rohár) - Convert mvebu a3700 internal SMCC firmware return codes to errno (Pali Rohár) - Fix initialization with old Marvell's Arm Trusted Firmware (Pali Rohár) Microsoft Hyper-V host bridge driver: - Fix hibernation in case interrupts are not re-created (Dexuan Cui) NVIDIA Tegra PCIe controller driver: - Stop checking return value of debugfs_create() functions (Greg Kroah-Hartman) - Convert to use DEFINE_SEQ_ATTRIBUTE macro (Liu Shixin) Qualcomm PCIe controller driver: - Reset PCIe to work around Qsdk U-Boot issue (Ansuel Smith) Renesas R-Car PCIe controller driver: - Add DT documentation for r8a774a1, r8a774b1, r8a774e1 endpoints (Lad Prabhakar) - Add RZ/G2M, RZ/G2N, RZ/G2H IDs to endpoint test (Lad Prabhakar) - Add DT support for r8a7742 (Lad Prabhakar) Socionext UniPhier Pro5 controller driver: - Add DT descriptions of iATU register (host and endpoint) (Kunihiko Hayashi) Synopsys DesignWare PCIe controller driver: - Add link up check in dw_child_pcie_ops.map_bus() (racy, but seems unavoidable) (Hou Zhiqiang) - Fix endpoint Header Type check so multi-function devices work (Hou Zhiqiang) - Skip PCIE_MSI_INTR0* programming if MSI is disabled (Jisheng Zhang) - Stop leaking MSI page in suspend/resume (Jisheng Zhang) - Add common iATU register support instead of keystone-specific code (Kunihiko Hayashi) - Major config space access and other cleanups in dwc core and drivers that use it (al, exynos, histb, imx6, intel-gw, keystone, kirin, meson, qcom, tegra) (Rob Herring) - Add multiple PFs support for endpoint (Xiaowei Bao) - Add MSI-X doorbell mode in endpoint mode (Xiaowei Bao) Miscellaneous: - Use fallthrough pseudo-keyword (Gustavo A. R. Silva) - Fix "0 used as NULL pointer" warnings (Gustavo Pimentel) - Fix "cast truncates bits from constant value" warnings (Gustavo Pimentel) - Remove redundant zeroing for sg_init_table() (Julia Lawall) - Use scnprintf(), not snprintf(), in sysfs "show" functions (Krzysztof Wilczyński) - Remove unused assignments (Krzysztof Wilczyński) - Fix "0 used as NULL pointer" warning (Krzysztof Wilczyński) - Simplify bool comparisons (Krzysztof Wilczyński) - Use for_each_child_of_node() and for_each_node_by_name() (Qinglang Miao) - Simplify return expressions (Qinglang Miao)" * tag 'pci-v5.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (147 commits) PCI: vmd: Update VMD PM to correctly use generic PCI PM PCI: vmd: Create IRQ allocation helper PCI: vmd: Create IRQ Domain configuration helper PCI: vmd: Create bus offset configuration helper PCI: vmd: Create physical offset helper PCI: v3-semi: Remove unneeded break PCI: dwc: Add link up check in dw_child_pcie_ops.map_bus() PCI/ASPM: Remove struct pcie_link_state.l1ss PCI/ASPM: Remove struct aspm_register_info.l1ss_cap PCI/ASPM: Pass L1SS Capabilities value, not struct aspm_register_info PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl1 PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl2 (unused) PCI/ASPM: Remove struct aspm_register_info.l1ss_cap_ptr PCI/ASPM: Remove struct aspm_register_info.latency_encoding PCI/ASPM: Remove struct aspm_register_info.enabled PCI/ASPM: Remove struct aspm_register_info.support PCI/ASPM: Use 'parent' and 'child' for readability PCI/ASPM: Move LTR path check to where it's used PCI/ASPM: Move pci_clear_and_set_dword() earlier PCI: dwc: Fix MSI page leakage in suspend/resume ...
2020-10-22Merge branch 'work.set_fs' of ↵Linus Torvalds9-125/+88
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull initial set_fs() removal from Al Viro: "Christoph's set_fs base series + fixups" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Allow a NULL pos pointer to __kernel_read fs: Allow a NULL pos pointer to __kernel_write powerpc: remove address space overrides using set_fs() powerpc: use non-set_fs based maccess routines x86: remove address space overrides using set_fs() x86: make TASK_SIZE_MAX usable from assembly code x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h lkdtm: remove set_fs-based tests test_bitmap: remove user bitmap tests uaccess: add infrastructure for kernel builds with set_fs() fs: don't allow splice read/write without explicit ops fs: don't allow kernel reads and writes without iter ops sysctl: Convert to iter interfaces proc: add a read_iter method to proc proc_ops proc: cleanup the compat vs no compat file ops proc: remove a level of indentation in proc_get_inode
2020-10-22x86/alternative: Don't call text_poke() in lazy TLB modeJuergen Gross1-0/+9
When running in lazy TLB mode the currently active page tables might be the ones of a previous process, e.g. when running a kernel thread. This can be problematic in case kernel code is being modified via text_poke() in a kernel thread, and on another processor exit_mmap() is active for the process which was running on the first cpu before the kernel thread. As text_poke() is using a temporary address space and the former address space (obtained via cpu_tlbstate.loaded_mm) is restored afterwards, there is a race possible in case the cpu on which exit_mmap() is running wants to make sure there are no stale references to that address space on any cpu active (this e.g. is required when running as a Xen PV guest, where this problem has been observed and analyzed). In order to avoid that, drop off TLB lazy mode before switching to the temporary address space. Fixes: cefa929c034eb5d ("x86/mm: Introduce temporary mm structs") Signed-off-by: Juergen Gross <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-21kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator argBen Gardon2-7/+9
In order to avoid creating executable hugepages in the TDP MMU PF handler, remove the dependency between disallowed_hugepage_adjust and the shadow_walk_iterator. This will open the function up to being used by the TDP MMU PF handler in a future patch. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Support zapping SPTEs in the TDP MMUBen Gardon5-0/+136
Add functions to zap SPTEs to the TDP MMU. These are needed to tear down TDP MMU roots properly and implement other MMU functions which require tearing down mappings. Future patches will add functions to populate the page tables, but as for this patch there will not be any work for these functions to do. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Add functions to handle changed TDP SPTEsBen Gardon3-1/+115
The existing bookkeeping done by KVM when a PTE is changed is spread around several functions. This makes it difficult to remember all the stats, bitmaps, and other subsystems that need to be updated whenever a PTE is modified. When a non-leaf PTE is marked non-present or becomes a leaf PTE, page table memory must also be freed. To simplify the MMU and facilitate the use of atomic operations on SPTEs in future patches, create functions to handle some of the bookkeeping required as a result of a change. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Allocate and free TDP MMU rootsBen Gardon5-6/+146
The TDP MMU must be able to allocate paging structure root pages and track the usage of those pages. Implement a similar, but separate system for root page allocation to that of the x86 shadow paging implementation. When future patches add synchronization model changes to allow for parallel page faults, these pages will need to be handled differently from the x86 shadow paging based MMU's root pages. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Init / Uninit the TDP MMUBen Gardon5-1/+55
The TDP MMU offers an alternative mode of operation to the x86 shadow paging based MMU, optimized for running an L1 guest with TDP. The TDP MMU will require new fields that need to be initialized and torn down. Add hooks into the existing KVM MMU initialization process to do that initialization / cleanup. Currently the initialization and cleanup fucntions do not do very much, however more operations will be added in future patches. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Introduce tdp_iterBen Gardon3-1/+234
The TDP iterator implements a pre-order traversal of a TDP paging structure. This iterator will be used in future patches to create an efficient implementation of the KVM MMU for the TDP case. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: mmu: extract spte.h and spte.cPaolo Bonzini5-548/+607
The SPTE format will be common to both the shadow and the TDP MMU. Extract code that implements the format to a separate module, as a first step towards adding the TDP MMU and putting mmu.c on a diet. Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: mmu: Separate updating a PTE from kvm_set_pte_rmappPaolo Bonzini1-7/+17
The TDP MMU's own function for the changed-PTE notifier will need to be update a PTE in the exact same way as the shadow MMU. Rather than re-implementing this logic, factor the SPTE creation out of kvm_set_pte_rmapp. Extracted out of a patch by Ben Gardon. <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86/mmu: Separate making SPTEs from set_spteBen Gardon1-16/+33
Separate the functions for generating leaf page table entries from the function that inserts them into the paging structure. This refactoring will facilitate changes to the MMU sychronization model to use atomic compare / exchanges (which are not guaranteed to succeed) instead of a monolithic MMU lock. No functional change expected. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This commit introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Reviewed-by: Peter Shier <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: mmu: Separate making non-leaf sptes from link_shadow_pageBen Gardon1-6/+15
The TDP MMU page fault handler will need to be able to create non-leaf SPTEs to build up the paging structures. Rather than re-implementing the function, factor the SPTE creation out of link_shadow_page. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21Merge branch 'kvm-fixes' into 'next'Paolo Bonzini4-22/+39
Pick up bugfixes from 5.9, otherwise various tests fail.
2020-10-21KVM: x86: Let the guest own CR4.FSGSBASELai Jiangshan1-1/+1
Add FSGSBASE to the set of possible guest-owned CR4 bits, i.e. let the guest own it on VMX. KVM never queries the guest's CR4.FSGSBASE value, thus there is no reason to force VM-Exit on FSGSBASE being toggled. Note, because FSGSBASE is conditionally available, this is dependent on recent changes to intercept reserved CR4 bits and to update the CR4 guest/host mask in response to guest CPUID changes. Cc: Paolo Bonzini <[email protected]> Signed-off-by: Lai Jiangshan <[email protected]> [sean: added justification in changelog] Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: VMX: Intercept guest reserved CR4 bits to inject #GP faultSean Christopherson1-5/+10
Intercept CR4 bits that are guest reserved so that KVM correctly injects a #GP fault if the guest attempts to set a reserved bit. If a feature is supported by the CPU but is not exposed to the guest, and its associated CR4 bit is not intercepted by KVM by default, then KVM will fail to inject a #GP if the guest sets the CR4 bit without triggering an exit, e.g. by toggling only the bit in question. Note, KVM doesn't give the guest direct access to any CR4 bits that are also dependent on guest CPUID. Yet. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: Move call to update_exception_bitmap() into VMX codeSean Christopherson2-1/+3
Now that vcpu_after_set_cpuid() and update_exception_bitmap() are called back-to-back, subsume the exception bitmap update into the common CPUID update. Drop the SVM invocation entirely as SVM's exception bitmap doesn't vary with respect to guest CPUID. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: Invoke vendor's vcpu_after_set_cpuid() after all common updatesSean Christopherson1-2/+3
Move the call to kvm_x86_ops.vcpu_after_set_cpuid() to the very end of kvm_vcpu_after_set_cpuid() to allow the vendor implementation to react to changes made by the common code. In the near future, this will be used by VMX to update its CR4 guest/host masks to account for reserved bits. In the long term, SGX support will update the allowed XCR0 mask for enclaves based on the vCPU's allowed XCR0. vcpu_after_set_cpuid() (nee kvm_update_cpuid()) was originally added by commit 2acf923e38fb ("KVM: VMX: Enable XSAVE/XRSTOR for guest"), and was called separately after kvm_x86_ops.vcpu_after_set_cpuid() (nee kvm_x86_ops->cpuid_update()). There is no indication that the placement of the common code updates after the vendor updates was anything more than a "new function at the end" decision. Inspection of the current code reveals no dependency on kvm_x86_ops' vcpu_after_set_cpuid() in kvm_vcpu_after_set_cpuid() or any of its helpers. The bulk of the common code depends only on the guest's CPUID configuration, kvm_mmu_reset_context() does not consume dynamic vendor state, and there are no collisions between kvm_pmu_refresh() and VMX's update of PT state. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: Intercept LA57 to inject #GP fault when it's reservedLai Jiangshan1-1/+1
Unconditionally intercept changes to CR4.LA57 so that KVM correctly injects a #GP fault if the guest attempts to set CR4.LA57 when it's supported in hardware but not exposed to the guest. Long term, KVM needs to properly handle CR4 bits that can be under guest control but also may be reserved from the guest's perspective. But, KVM currently sets the CR4 guest/host mask only during vCPU creation, and reworking flows to change that will take a bit of elbow grease. Even if/when generic support for intercepting reserved bits exists, it's probably not worth letting the guest set CR4.LA57 directly. LA57 can't be toggled while long mode is enabled, thus it's all but guaranteed to be set once (maybe twice, e.g. by BIOS and kernel) during boot and never touched again. On the flip side, letting the guest own CR4.LA57 may incur extra VMREADs. In other words, this temporary "hack" is probably also the right long term fix. Fixes: fd8cb433734e ("KVM: MMU: Expose the LA57 feature to VM.") Cc: [email protected] Cc: Lai Jiangshan <[email protected]> Signed-off-by: Lai Jiangshan <[email protected]> [sean: rewrote changelog] Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: SVM: Initialize prev_ga_tag before useSuravee Suthikulpanit1-0/+1
The function amd_ir_set_vcpu_affinity makes use of the parameter struct amd_iommu_pi_data.prev_ga_tag to determine if it should delete struct amd_iommu_pi_data from a list when not running in AVIC mode. However, prev_ga_tag is initialized only when AVIC is enabled. The non-zero uninitialized value can cause unintended code path, which ends up making use of the struct vcpu_svm.ir_list and ir_list_lock without being initialized (since they are intended only for the AVIC case). This triggers NULL pointer dereference bug in the function vm_ir_list_del with the following call trace: svm_update_pi_irte+0x3c2/0x550 [kvm_amd] ? proc_create_single_data+0x41/0x50 kvm_arch_irq_bypass_add_producer+0x40/0x60 [kvm] __connect+0x5f/0xb0 [irqbypass] irq_bypass_register_producer+0xf8/0x120 [irqbypass] vfio_msi_set_vector_signal+0x1de/0x2d0 [vfio_pci] vfio_msi_set_block+0x77/0xe0 [vfio_pci] vfio_pci_set_msi_trigger+0x25c/0x2f0 [vfio_pci] vfio_pci_set_irqs_ioctl+0x88/0xb0 [vfio_pci] vfio_pci_ioctl+0x2ea/0xed0 [vfio_pci] ? alloc_file_pseudo+0xa5/0x100 vfio_device_fops_unl_ioctl+0x26/0x30 [vfio] ? vfio_device_fops_unl_ioctl+0x26/0x30 [vfio] __x64_sys_ioctl+0x96/0xd0 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Therefore, initialize prev_ga_tag to zero before use. This should be safe because ga_tag value 0 is invalid (see function avic_vm_init). Fixes: dfa20099e26e ("KVM: SVM: Refactor AVIC vcpu initialization into avic_init_vcpu()") Signed-off-by: Suravee Suthikulpanit <[email protected]> Message-Id: <[email protected]> Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: nSVM: implement on demand allocation of the nested stateMaxim Levitsky3-28/+83
This way we don't waste memory on VMs which don't use nesting virtualization even when the host enabled it for them. Signed-off-by: Maxim Levitsky <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: allow kvm_x86_ops.set_efer to return an error valueMaxim Levitsky6-7/+15
This will be used to signal an error to the userspace, in case the vendor code failed during handling of this msr. (e.g -ENOMEM) Signed-off-by: Maxim Levitsky <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: report negative values from wrmsr emulation to userspaceMaxim Levitsky2-5/+8
This will allow the KVM to report such errors (e.g -ENOMEM) to the userspace. Signed-off-by: Maxim Levitsky <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: xen_hvm_config: cleanup return valuesMaxim Levitsky1-14/+9
Return 1 on errors that are caused by wrong guest behavior (which will inject #GP to the guest) And return a negative error value on issues that are the kernel's fault (e.g -ENOMEM) Signed-off-by: Maxim Levitsky <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm x86/mmu: Make struct kernel_param_ops definitions constJoe Perches1-2/+2
These should be const, so make it so. Signed-off-by: Joe Perches <[email protected]> Message-Id: <ed95eef4f10fc1317b66936c05bc7dd8f943a6d5.1601770305.git.joe@perches.com> Reviewed-by: Ben Gardon <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: bump KVM_MAX_CPUID_ENTRIESVitaly Kuznetsov1-1/+1
As vcpu->arch.cpuid_entries is now allocated dynamically, the only remaining use for KVM_MAX_CPUID_ENTRIES is to check KVM_SET_CPUID/ KVM_SET_CPUID2 input for sanity. Since it was reported that the current limit (80) is insufficient for some CPUs, bump KVM_MAX_CPUID_ENTRIES and use an arbitrary value '256' as the new limit. Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: x86: allocate vcpu->arch.cpuid_entries dynamicallyVitaly Kuznetsov3-39/+53
The current limit for guest CPUID leaves (KVM_MAX_CPUID_ENTRIES, 80) is reported to be insufficient but before we bump it let's switch to allocating vcpu->arch.cpuid_entries[] array dynamically. Currently, 'struct kvm_cpuid_entry2' is 40 bytes so vcpu->arch.cpuid_entries is 3200 bytes which accounts for 1/4 of the whole 'struct kvm_vcpu_arch' but having it pre-allocated (for all vCPUs which we also pre-allocate) gives us no real benefits. Another plus of the dynamic allocation is that we now do kvm_check_cpuid() check before we assign anything to vcpu->arch.cpuid_nent/cpuid_entries so no changes are made in case the check fails. Opportunistically remove unneeded 'out' labels from kvm_vcpu_ioctl_set_cpuid()/kvm_vcpu_ioctl_set_cpuid2() and return directly whenever possible. Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Reviewed-by: Maxim Levitsky <[email protected]>
2020-10-21KVM: x86: disconnect kvm_check_cpuid() from vcpu->arch.cpuid_entriesVitaly Kuznetsov1-15/+23
As a preparatory step to allocating vcpu->arch.cpuid_entries dynamically make kvm_check_cpuid() check work with an arbitrary 'struct kvm_cpuid_entry2' array. Currently, when kvm_check_cpuid() fails we reset vcpu->arch.cpuid_nent to 0 and this is kind of weird, i.e. one would expect CPUIDs to remain unchanged when KVM_SET_CPUID[2] call fails. No functional change intended. It would've been possible to move the updated kvm_check_cpuid() in kvm_vcpu_ioctl_set_cpuid2() and check the supplied input before we start updating vcpu->arch.cpuid_entries/nent but we can't do the same in kvm_vcpu_ioctl_set_cpuid() as we'll have to copy 'struct kvm_cpuid_entry' entries first. The change will be made when vcpu->arch.cpuid_entries[] array becomes allocated dynamically. Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86: only provide PV features if enabled in guest's CPUIDOliver Upton4-5/+94
KVM unconditionally provides PV features to the guest, regardless of the configured CPUID. An unwitting guest that doesn't check KVM_CPUID_FEATURES before use could access paravirt features that userspace did not intend to provide. Fix this by checking the guest's CPUID before performing any paravirtual operations. Introduce a capability, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, to gate the aforementioned enforcement. Migrating a VM from a host w/o this patch to a host with this patch could silently change the ABI exposed to the guest, warranting that we default to the old behavior and opt-in for the new one. Reviewed-by: Jim Mattson <[email protected]> Reviewed-by: Peter Shier <[email protected]> Signed-off-by: Oliver Upton <[email protected]> Change-Id: I202a0926f65035b872bfe8ad15307c026de59a98 Message-Id: <[email protected]> Reviewed-by: Wanpeng Li <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86: set wall_clock in kvm_write_wall_clock()Oliver Upton1-1/+2
Small change to avoid meaningless duplication in the subsequent patch. No functional change intended. Reviewed-by: Jim Mattson <[email protected]> Reviewed-by: Peter Shier <[email protected]> Signed-off-by: Oliver Upton <[email protected]> Change-Id: I77ab9cdad239790766b7a49d5cbae5e57a3005ea Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fnOliver Upton1-26/+32
No functional change intended. Reviewed-by: Jim Mattson <[email protected]> Reviewed-by: Peter Shier <[email protected]> Reviewed-by: Wanpeng Li <[email protected]> Signed-off-by: Oliver Upton <[email protected]> Change-Id: I7cbe71069db98d1ded612fd2ef088b70e7618426 Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21x86/kvm: Update the comment about asynchronous page fault in exc_page_fault()Vitaly Kuznetsov1-5/+8
KVM was switched to interrupt-based mechanism for 'page ready' event delivery in Linux-5.8 (see commit 2635b5c4a0e4 ("KVM: x86: interrupt based APF 'page ready' event delivery")) and #PF (ab)use for 'page ready' event delivery was removed. Linux guest switched to this new mechanism exclusively in 5.9 (see commit b1d405751cd5 ("KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery")) so it is not possible to get #PF for a 'page ready' event even when the guest is running on top of an older KVM (APF mechanism won't be enabled). Update the comment in exc_page_fault() to reflect the new reality. Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21x86/kvm: hide KVM options from menuconfig when KVM is not compiledMatteo Croce1-0/+1
Let KVM_WERROR depend on KVM, so it doesn't show in menuconfig alone. Signed-off-by: Matteo Croce <[email protected]> Message-Id: <[email protected]> Fixes: 4f337faf1c55e ("KVM: allow disabling -Werror") Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: VMX: Forbid userspace MSR filters for x2APICPaolo Bonzini1-1/+8
Allowing userspace to intercept reads to x2APIC MSRs when APICV is fully enabled for the guest simply can't work. But more in general, the LAPIC could be set to in-kernel after the MSR filter is setup and allowing accesses by userspace would be very confusing. We could in principle allow userspace to intercept reads and writes to TPR, and writes to EOI and SELF_IPI, but while that could be made it work, it would still be silly. Cc: Alexander Graf <[email protected]> Cc: Aaron Lewis <[email protected]> Cc: Peter Xu <[email protected]> Cc: Sean Christopherson <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21KVM: VMX: Ignore userspace MSR filters for x2APICSean Christopherson2-18/+31
Rework the resetting of the MSR bitmap for x2APIC MSRs to ignore userspace filtering. Allowing userspace to intercept reads to x2APIC MSRs when APICV is fully enabled for the guest simply can't work; the LAPIC and thus virtual APIC is in-kernel and cannot be directly accessed by userspace. To keep things simple we will in fact forbid intercepting x2APIC MSRs altogether, independent of the default_allow setting. Cc: Alexander Graf <[email protected]> Cc: Aaron Lewis <[email protected]> Cc: Peter Xu <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> [Modified to operate even if APICv is disabled, adjust documentation. - Paolo] Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-21Merge branch 'pci/misc'Bjorn Helgaas1-0/+1
- Remove unnecessary #includes (Gustavo Pimentel) - Fix intel_mid_pci.c build error when !CONFIG_ACPI (Randy Dunlap) - Use scnprintf(), not snprintf(), in sysfs "show" functions (Krzysztof Wilczyński) - Simplify pci-pf-stub by using module_pci_driver() (Liu Shixin) - Print IRQ used by Link Bandwidth Notification (Dongdong Liu) - Update sysfs mmap-related #ifdef comments (Clint Sbisa) - Simplify pci_dev_reset_slot_function() (Lukas Wunner) - Use "NULL" instead of "0" to fix sparse warnings (Gustavo Pimentel) - Simplify bool comparisons (Krzysztof Wilczyński) - Drop double zeroing for P2PDMA sg_init_table() (Julia Lawall) * pci/misc: PCI: v3-semi: Remove unneeded break PCI/P2PDMA: Drop double zeroing for sg_init_table() PCI: Simplify bool comparisons PCI: endpoint: Use "NULL" instead of "0" as a NULL pointer PCI: Simplify pci_dev_reset_slot_function() PCI: Update mmap-related #ifdef comments PCI/LINK: Print IRQ number used by port PCI/IOV: Simplify pci-pf-stub with module_pci_driver() PCI: Use scnprintf(), not snprintf(), in sysfs "show" functions x86/PCI: Fix intel_mid_pci.c build error when ACPI is not enabled PCI: Remove unnecessary header includes
2020-10-21treewide: remove DISABLE_LTOSami Tolvanen1-2/+0
This change removes all instances of DISABLE_LTO from Makefiles, as they are currently unused, and the preferred method of disabling LTO is to filter out the flags instead. Note added by Masahiro Yamada: DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272) Suggested-by: Kees Cook <[email protected]> Signed-off-by: Sami Tolvanen <[email protected]> Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Masahiro Yamada <[email protected]>
2020-10-19x86/boot/64: Explicitly map boot_params and command lineArvind Sankar2-3/+23
Commits ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") 8570978ea030 ("x86/boot/compressed/64: Don't pre-map memory in KASLR code") set up a new page table in the decompressor stub, but without explicit mappings for boot_params and the kernel command line, relying on the #PF handler instead. This is fragile, as boot_params and the command line mappings are required for the main kernel. If EARLY_PRINTK and RANDOMIZE_BASE are disabled, a QEMU/OVMF boot never accesses the command line in the decompressor stub, and so it never gets mapped. The main kernel accesses it from the identity mapping if AMD_MEM_ENCRYPT is enabled, and will crash. Fix this by adding back the explicit mapping of boot_params and the command line. Note: the changes also removed the explicit mapping of the main kernel, with the result that .bss and .brk may not be in the identity mapping, but those don't get accessed by the main kernel before it switches to its own page tables. [ bp: Pass boot_params with a MOV %rsp... instead of PUSH/POP. Use block formatting for the comment. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Joerg Roedel <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-19KVM: VMX: Fix x2APIC MSR intercept handling on !APICV platformsPeter Xu1-2/+3
Fix an inverted flag for intercepting x2APIC MSRs and intercept writes by default, even when APICV is enabled. Fixes: 3eb900173c71 ("KVM: x86: VMX: Prevent MSR passthrough when MSR access is denied") Co-developed-by: Peter Xu <[email protected]> [sean: added changelog] Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2020-10-19x86/head/64: Disable stack protection for head$(BITS).oArvind Sankar1-0/+2
On 64-bit, the startup_64_setup_env() function added in 866b556efa12 ("x86/head/64: Install startup GDT") has stack protection enabled because of set_bringup_idt_handler(). This happens when CONFIG_STACKPROTECTOR_STRONG is enabled. It also currently needs CONFIG_AMD_MEM_ENCRYPT enabled because then set_bringup_idt_handler() is not an empty stub but that might change in the future, when the other vendor adds their similar technology. At this point, %gs is not yet initialized, and this doesn't cause a crash only because the #PF handler from the decompressor stub is still installed and handles the page fault. Disable stack protection for the whole file, and do it on 32-bit as well to avoid surprises. [ bp: Extend commit message with the exact explanation how it happens. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Joerg Roedel <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-19x86/boot/64: Initialize 5-level paging variables earlierArvind Sankar3-14/+16
Commit ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") started using a new set of pagetables even without KASLR. After that commit, initialize_identity_maps() is called before the 5-level paging variables are setup in choose_random_location(), which will not work if 5-level paging is actually enabled. Fix this by moving the initialization of __pgtable_l5_enabled, pgdir_shift and ptrs_per_p4d into cleanup_trampoline(), which is called immediately after the finalization of whether the kernel is executing with 4- or 5-level paging. This will be earlier than anything that might require those variables, and keeps the 4- vs 5-level paging code all in one place. Fixes: ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Joerg Roedel <[email protected]> Tested-by: Joerg Roedel <[email protected]> Tested-by: Kirill A. Shutemov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-18Merge tag 'core-rcu-2020-10-12' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molnar: - Debugging for smp_call_function() - RT raw/non-raw lock ordering fixes - Strict grace periods for KASAN - New smp_call_function() torture test - Torture-test updates - Documentation updates - Miscellaneous fixes [ This doesn't actually pull the tag - I've dropped the last merge from the RCU branch due to questions about the series. - Linus ] * tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) smp: Make symbol 'csd_bug_count' static kernel/smp: Provide CSD lock timeout diagnostics smp: Add source and destination CPUs to __call_single_data rcu: Shrink each possible cpu krcp rcu/segcblist: Prevent useless GP start if no CBs to accelerate torture: Add gdb support rcutorture: Allow pointer leaks to test diagnostic code rcutorture: Hoist OOM registry up one level refperf: Avoid null pointer dereference when buf fails to allocate rcutorture: Properly synchronize with OOM notifier rcutorture: Properly set rcu_fwds for OOM handling torture: Add kvm.sh --help and update help message rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05 torture: Update initrd documentation rcutorture: Replace HTTP links with HTTPS ones locktorture: Make function torture_percpu_rwsem_init() static torture: document --allcpus argument added to the kvm.sh script rcutorture: Output number of elapsed grace periods rcutorture: Remove KCSAN stubs rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp() ...
2020-10-18Merge branch 'akpm' (patches from Andrew)Linus Torvalds3-7/+22
Merge yet more updates from Andrew Morton: "Subsystems affected by this patch series: mm (memcg, migration, pagemap, gup, madvise, vmalloc), ia64, and misc" * emailed patches from Andrew Morton <[email protected]>: (31 commits) mm: remove duplicate include statement in mmu.c mm: remove the filename in the top of file comment in vmalloc.c mm: cleanup the gfp_mask handling in __vmalloc_area_node mm: remove alloc_vm_area x86/xen: open code alloc_vm_area in arch_gnttab_valloc xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv drm/i915: use vmap in i915_gem_object_map drm/i915: stop using kmap in i915_gem_object_map drm/i915: use vmap in shmem_pin_map zsmalloc: switch from alloc_vm_area to get_vm_area mm: allow a NULL fn callback in apply_to_page_range mm: add a vmap_pfn function mm: add a VM_MAP_PUT_PAGES flag for vmap mm: update the documentation for vfree mm/madvise: introduce process_madvise() syscall: an external memory hinting API pid: move pidfd_get_pid() to pid.c mm/madvise: pass mm to do_madvise selftests/vm: 10x speedup for hmm-tests binfmt_elf: take the mmap lock around find_extend_vma() mm/gup_benchmark: take the mmap lock around GUP ...
2020-10-18Merge tag 'for-linus-5.10-rc1' of ↵Linus Torvalds2-13/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - Improve support for non-glibc systems - Vector: Add support for scripting and dynamic tap devices - Various fixes for the vector networking driver - Various fixes for time travel mode * tag 'for-linus-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: vector: Add dynamic tap interfaces and scripting um: Clean up stacktrace dump um: Fix incorrect assumptions about max pid length um: Remove dead usage of TIF_IA32 um: Remove redundant NULL check um: change sigio_spinlock to a mutex um: time-travel: Return the sequence number in ACK messages um: time-travel: Fix IRQ handling in time_travel_handle_message() um: Allow static linking for non-glibc implementations um: Some fixes to build UML with musl um: vector: Use GFP_ATOMIC under spin lock um: Fix null pointer dereference in vector_user_bpf
2020-10-18x86/xen: open code alloc_vm_area in arch_gnttab_vallocChristoph Hellwig1-7/+20
Replace the last call to alloc_vm_area with an open coded version using an iterator in struct gnttab_vm_area instead of the triple indirection magic in alloc_vm_area. Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Boris Ostrovsky <[email protected]> Cc: Chris Wilson <[email protected]> Cc: Jani Nikula <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Matthew Auld <[email protected]> Cc: "Matthew Wilcox (Oracle)" <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Nitin Gupta <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rodrigo Vivi <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-10-18mm/madvise: introduce process_madvise() syscall: an external memory hinting APIMinchan Kim2-0/+2
There is usecase that System Management Software(SMS) want to give a memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the case of Android, it is the ActivityManagerService. The information required to make the reclaim decision is not known to the app. Instead, it is known to the centralized userspace daemon(ActivityManagerService), and that daemon must be able to initiate reclaim on its own without any app involvement. To solve the issue, this patch introduces a new syscall process_madvise(2). It uses pidfd of an external process to give the hint. It also supports vector address range because Android app has thousands of vmas due to zygote so it's totally waste of CPU and power if we should call the syscall one by one for each vma.(With testing 2000-vma syscall vs 1-vector syscall, it showed 15% performance improvement. I think it would be bigger in real practice because the testing ran very cache friendly environment). Another potential use case for the vector range is to amortize the cost ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could benefit users like TCP receive zerocopy and malloc implementations. In future, we could find more usecases for other advises so let's make it happens as API since we introduce a new syscall at this moment. With that, existing madvise(2) user could replace it with process_madvise(2) with their own pid if they want to have batch address ranges support feature. ince it could affect other process's address range, only privileged process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same UID) gives it the right to ptrace the process could use it successfully. The flag argument is reserved for future use if we need to extend the API. I think supporting all hints madvise has/will supported/support to process_madvise is rather risky. Because we are not sure all hints make sense from external process and implementation for the hint may rely on the caller being in the current context so it could be error-prone. Thus, I just limited hints as MADV_[COLD|PAGEOUT] in this patch. If someone want to add other hints, we could hear the usecase and review it for each hint. It's safer for maintenance rather than introducing a buggy syscall but hard to fix it later. So finally, the API is as follows, ssize_t process_madvise(int pidfd, const struct iovec *iovec, unsigned long vlen, int advice, unsigned int flags); DESCRIPTION The process_madvise() system call is used to give advice or directions to the kernel about the address ranges from external process as well as local process. It provides the advice to address ranges of process described by iovec and vlen. The goal of such advice is to improve system or application performance. The pidfd selects the process referred to by the PID file descriptor specified in pidfd. (See pidofd_open(2) for further information) The pointer iovec points to an array of iovec structures, defined in <sys/uio.h> as: struct iovec { void *iov_base; /* starting address */ size_t iov_len; /* number of bytes to be advised */ }; The iovec describes address ranges beginning at address(iov_base) and with size length of bytes(iov_len). The vlen represents the number of elements in iovec. The advice is indicated in the advice argument, which is one of the following at this moment if the target process specified by pidfd is external. MADV_COLD MADV_PAGEOUT Permission to provide a hint to external process is governed by a ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2). The process_madvise supports every advice madvise(2) has if target process is in same thread group with calling process so user could use process_madvise(2) to extend existing madvise(2) to support vector address ranges. RETURN VALUE On success, process_madvise() returns the number of bytes advised. This return value may be less than the total number of requested bytes, if an error occurred. The caller should check return value to determine whether a partial advice occurred. FAQ: Q.1 - Why does any external entity have better knowledge? Quote from Sandeep "For Android, every application (including the special SystemServer) are forked from Zygote. The reason of course is to share as many libraries and classes between the two as possible to benefit from the preloading during boot. After applications start, (almost) all of the APIs end up calling into this SystemServer process over IPC (binder) and back to the application. In a fully running system, the SystemServer monitors every single process periodically to calculate their PSS / RSS and also decides which process is "important" to the user for interactivity. So, because of how these processes start _and_ the fact that the SystemServer is looping to monitor each process, it does tend to *know* which address range of the application is not used / useful. Besides, we can never rely on applications to clean things up themselves. We've had the "hey app1, the system is low on memory, please trim your memory usage down" notifications for a long time[1]. They rely on applications honoring the broadcasts and very few do. So, if we want to avoid the inevitable killing of the application and restarting it, some way to be able to tell the OS about unimportant memory in these applications will be useful. - ssp Q.2 - How to guarantee the race(i.e., object validation) between when giving a hint from an external process and get the hint from the target process? process_madvise operates on the target process's address space as it exists at the instant that process_madvise is called. If the space target process can run between the time the process_madvise process inspects the target process address space and the time that process_madvise is actually called, process_madvise may operate on memory regions that the calling process does not expect. It's the responsibility of the process calling process_madvise to close this race condition. For example, the calling process can suspend the target process with ptrace, SIGSTOP, or the freezer cgroup so that it doesn't have an opportunity to change its own address space before process_madvise is called. Another option is to operate on memory regions that the caller knows a priori will be unchanged in the target process. Yet another option is to accept the race for certain process_madvise calls after reasoning that mistargeting will do no harm. The suggested API itself does not provide synchronization. It also apply other APIs like move_pages, process_vm_write. The race isn't really a problem though. Why is it so wrong to require that callers do their own synchronization in some manner? Nobody objects to write(2) merely because it's possible for two processes to open the same file and clobber each other's writes --- instead, we tell people to use flock or something. Think about mmap. It never guarantees newly allocated address space is still valid when the user tries to access it because other threads could unmap the memory right before. That's where we need synchronization by using other API or design from userside. It shouldn't be part of API itself. If someone needs more fine-grained synchronization rather than process level, there were two ideas suggested - cookie[2] and anon-fd[3]. Both are applicable via using last reserved argument of the API but I don't think it's necessary right now since we have already ways to prevent the race so don't want to add additional complexity with more fine-grained optimization model. To make the API extend, it reserved an unsigned long as last argument so we could support it in future if someone really needs it. Q.3 - Why doesn't ptrace work? Injecting an madvise in the target process using ptrace would not work for us because such injected madvise would have to be executed by the target process, which means that process would have to be runnable and that creates the risk of the abovementioned race and hinting a wrong VMA. Furthermore, we want to act the hint in caller's context, not the callee's, because the callee is usually limited in cpuset/cgroups or even freezed state so they can't act by themselves quick enough, which causes more thrashing/kill. It doesn't work if the target process are ptraced(e.g., strace, debugger, minidump) because a process can have at most one ptracer. [1] https://developer.android.com/topic/performance/memory" [2] process_getinfo for getting the cookie which is updated whenever vma of process address layout are changed - Daniel Colascione - https://lore.kernel.org/lkml/[email protected]/T/#m7694416fd179b2066a2c62b5b139b14e3894e224 [3] anonymous fd which is used for the object(i.e., address range) validation - Michal Hocko - https://lore.kernel.org/lkml/[email protected]/ [[email protected]: fix process_madvise build break for arm64] Link: http://lkml.kernel.org/r/[email protected] [[email protected]: fix build error for mips of process_madvise] Link: http://lkml.kernel.org/r/[email protected] [[email protected]: fix patch ordering issue] [[email protected]: fix arm64 whoops] [[email protected]: make process_madvise() vlen arg have type size_t, per Florian] [[email protected]: fix i386 build] [[email protected]: fix syscall numbering] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: madvise.c needs compat.h] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: fix mips build] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: remove duplicate header which is included twice] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: do not use helper functions for process_madvise] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: pidfd_get_pid() gained an argument] [[email protected]: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Minchan Kim <[email protected]> Signed-off-by: YueHaibing <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Suren Baghdasaryan <[email protected]> Reviewed-by: Vlastimil Babka <[email protected]> Acked-by: David Rientjes <[email protected]> Cc: Alexander Duyck <[email protected]> Cc: Brian Geffon <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Daniel Colascione <[email protected]> Cc: Jann Horn <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: John Dias <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oleksandr Natalenko <[email protected]> Cc: Sandeep Patil <[email protected]> Cc: SeongJae Park <[email protected]> Cc: SeongJae Park <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Sonny Rao <[email protected]> Cc: Tim Murray <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Florian Weimer <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-10-17task_work: cleanup notification modesJens Axboe2-2/+2
A previous commit changed the notification mode from true/false to an int, allowing notify-no, notify-yes, or signal-notify. This was backwards compatible in the sense that any existing true/false user would translate to either 0 (on notification sent) or 1, the latter which mapped to TWA_RESUME. TWA_SIGNAL was assigned a value of 2. Clean this up properly, and define a proper enum for the notification mode. Now we have: - TWA_NONE. This is 0, same as before the original change, meaning no notification requested. - TWA_RESUME. This is 1, same as before the original change, meaning that we use TIF_NOTIFY_RESUME. - TWA_SIGNAL. This uses TIF_SIGPENDING/JOBCTL_TASK_WORK for the notification. Clean up all the callers, switching their 0/1/false/true to using the appropriate TWA_* mode for notifications. Fixes: e91b48162332 ("task_work: teach task_work_add() to do signal_wake_up()") Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2020-10-15Merge tag 'net-next-5.10' of ↵Linus Torvalds2-81/+245
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: - Add redirect_neigh() BPF packet redirect helper, allowing to limit stack traversal in common container configs and improving TCP back-pressure. Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain. - Expand netlink policy support and improve policy export to user space. (Ge)netlink core performs request validation according to declared policies. Expand the expressiveness of those policies (min/max length and bitmasks). Allow dumping policies for particular commands. This is used for feature discovery by user space (instead of kernel version parsing or trial and error). - Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge. - Allow more than 255 IPv4 multicast interfaces. - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK packets of TCPv6. - In Multi-patch TCP (MPTCP) support concurrent transmission of data on multiple subflows in a load balancing scenario. Enhance advertising addresses via the RM_ADDR/ADD_ADDR options. - Support SMC-Dv2 version of SMC, which enables multi-subnet deployments. - Allow more calls to same peer in RxRPC. - Support two new Controller Area Network (CAN) protocols - CAN-FD and ISO 15765-2:2016. - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit kernel problem. - Add TC actions for implementing MPLS L2 VPNs. - Improve nexthop code - e.g. handle various corner cases when nexthop objects are removed from groups better, skip unnecessary notifications and make it easier to offload nexthops into HW by converting to a blocking notifier. - Support adding and consuming TCP header options by BPF programs, opening the doors for easy experimental and deployment-specific TCP option use. - Reorganize TCP congestion control (CC) initialization to simplify life of TCP CC implemented in BPF. - Add support for shipping BPF programs with the kernel and loading them early on boot via the User Mode Driver mechanism, hence reusing all the user space infra we have. - Support sleepable BPF programs, initially targeting LSM and tracing. - Add bpf_d_path() helper for returning full path for given 'struct path'. - Make bpf_tail_call compatible with bpf-to-bpf calls. - Allow BPF programs to call map_update_elem on sockmaps. - Add BPF Type Format (BTF) support for type and enum discovery, as well as support for using BTF within the kernel itself (current use is for pretty printing structures). - Support listing and getting information about bpf_links via the bpf syscall. - Enhance kernel interfaces around NIC firmware update. Allow specifying overwrite mask to control if settings etc. are reset during update; report expected max time operation may take to users; support firmware activation without machine reboot incl. limits of how much impact reset may have (e.g. dropping link or not). - Extend ethtool configuration interface to report IEEE-standard counters, to limit the need for per-vendor logic in user space. - Adopt or extend devlink use for debug, monitoring, fw update in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx, dpaa2-eth). - In mlxsw expose critical and emergency SFP module temperature alarms. Refactor port buffer handling to make the defaults more suitable and support setting these values explicitly via the DCBNL interface. - Add XDP support for Intel's igb driver. - Support offloading TC flower classification and filtering rules to mscc_ocelot switches. - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as fixed interval period pulse generator and one-step timestamping in dpaa-eth. - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3) offload. - Add Lynx PHY/PCS MDIO module, and convert various drivers which have this HW to use it. Convert mvpp2 to split PCS. - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as 7-port Mediatek MT7531 IP. - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver, and wcn3680 support in wcn36xx. - Improve performance for packets which don't require much offloads on recent Mellanox NICs by 20% by making multiple packets share a descriptor entry. - Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto subtree to drivers/net. Move MDIO drivers out of the phy directory. - Clean up a lot of W=1 warnings, reportedly the actively developed subsections of networking drivers should now build W=1 warning free. - Make sure drivers don't use in_interrupt() to dynamically adapt their code. Convert tasklets to use new tasklet_setup API (sadly this conversion is not yet complete). * tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits) Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH" net, sockmap: Don't call bpf_prog_put() on NULL pointer bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo bpf, sockmap: Add locking annotations to iterator netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements net: fix pos incrementment in ipv6_route_seq_next net/smc: fix invalid return code in smcd_new_buf_create() net/smc: fix valid DMBE buffer sizes net/smc: fix use-after-free of delayed events bpfilter: Fix build error with CONFIG_BPFILTER_UMH cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info bpf: Fix register equivalence tracking. rxrpc: Fix loss of final ack on shutdown rxrpc: Fix bundle counting for exclusive connections netfilter: restore NF_INET_NUMHOOKS ibmveth: Identify ingress large send packets. ibmveth: Switch order of ibmveth_helper calls. cxgb4: handle 4-tuple PEDIT to NAT mode translation selftests: Add VRF route leaking tests ...
2020-10-15Merge tag 'trace-v5.10' of ↵Linus Torvalds1-11/+9
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Updates for tracing and bootconfig: - Add support for "bool" type in synthetic events - Add per instance tracing for bootconfig - Support perf-style return probe ("SYMBOL%return") in kprobes and uprobes - Allow for kprobes to be enabled earlier in boot up - Added tracepoint helper function to allow testing if tracepoints are enabled in headers - Synthetic events can now have dynamic strings (variable length) - Various fixes and cleanups" * tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (58 commits) tracing: support "bool" type in synthetic trace events selftests/ftrace: Add test case for synthetic event syntax errors tracing: Handle synthetic event array field type checking correctly selftests/ftrace: Change synthetic event name for inter-event-combined test tracing: Add synthetic event error logging tracing: Check that the synthetic event and field names are legal tracing: Move is_good_name() from trace_probe.h to trace.h tracing: Don't show dynamic string internals in synthetic event description tracing: Fix some typos in comments tracing/boot: Add ftrace.instance.*.alloc_snapshot option tracing: Fix race in trace_open and buffer resize call tracing: Check return value of __create_val_fields() before using its result tracing: Fix synthetic print fmt check for use of __get_str() tracing: Remove a pointless assignment ftrace: ftrace_global_list is renamed to ftrace_ops_list ftrace: Format variable declarations of ftrace_allocate_records ftrace: Simplify the calculation of page number for ftrace_page->records ftrace: Simplify the dyn_ftrace->flags macro ftrace: Simplify the hash calculation ftrace: Use fls() to get the bits for dup_hash() ...