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2021-02-27Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull io_uring thread rewrite from Jens Axboe: "This converts the io-wq workers to be forked off the tasks in question instead of being kernel threads that assume various bits of the original task identity. This kills > 400 lines of code from io_uring/io-wq, and it's the worst part of the code. We've had several bugs in this area, and the worry is always that we could be missing some pieces for file types doing unusual things (recent /dev/tty example comes to mind, userfaultfd reads installing file descriptors is another fun one... - both of which need special handling, and I bet it's not the last weird oddity we'll find). With these identical workers, we can have full confidence that we're never missing anything. That, in itself, is a huge win. Outside of that, it's also more efficient since we're not wasting space and code on tracking state, or switching between different states. I'm sure we're going to find little things to patch up after this series, but testing has been pretty thorough, from the usual regression suite to production. Any issue that may crop up should be manageable. There's also a nice series of further reductions we can do on top of this, but I wanted to get the meat of it out sooner rather than later. The general worry here isn't that it's fundamentally broken. Most of the little issues we've found over the last week have been related to just changes in how thread startup/exit is done, since that's the main difference between using kthreads and these kinds of threads. In fact, if all goes according to plan, I want to get this into the 5.10 and 5.11 stable branches as well. That said, the changes outside of io_uring/io-wq are: - arch setup, simple one-liner to each arch copy_thread() implementation. - Removal of net and proc restrictions for io_uring, they are no longer needed or useful" * tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits) io-wq: remove now unused IO_WQ_BIT_ERROR io_uring: fix SQPOLL thread handling over exec io-wq: improve manager/worker handling over exec io_uring: ensure SQPOLL startup is triggered before error shutdown io-wq: make buffered file write hashed work map per-ctx io-wq: fix race around io_worker grabbing io-wq: fix races around manager/worker creation and task exit io_uring: ensure io-wq context is always destroyed for tasks arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread() io_uring: cleanup ->user usage io-wq: remove nr_process accounting io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS net: remove cmsg restriction from io_uring based send/recvmsg calls Revert "proc: don't allow async path resolution of /proc/self components" Revert "proc: don't allow async path resolution of /proc/thread-self components" io_uring: move SQPOLL thread io-wq forked worker io-wq: make io_wq_fork_thread() available to other users io-wq: only remove worker from free_list, if it was there io_uring: remove io_identity io_uring: remove any grabbing of context ...
2021-02-26Merge tag 's390-5.12-2' of ↵Linus Torvalds10-79/+657
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Fix physical vs virtual confusion in some basic mm macros and routines. Caused by __pa == __va on s390 currently. - Get rid of on-stack cpu masks. - Add support for complete CPU counter set extraction. - Add arch_irq_work_raise implementation. - virtio-ccw revision and opcode fixes. * tag 's390-5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/cpumf: Add support for complete counter set extraction virtio/s390: implement virtio-ccw revision 2 correctly s390/smp: implement arch_irq_work_raise() s390/topology: move cpumasks away from stack s390/smp: smp_emergency_stop() - move cpumask away from stack s390/smp: __smp_rescan_cpus() - move cpumask away from stack s390/smp: consolidate locking for smp_rescan() s390/mm: fix phys vs virt confusion in vmem_*() functions family s390/mm: fix phys vs virt confusion in pgtable allocation routines s390/mm: fix invalid __pa() usage in pfn_pXd() macros s390/mm: make pXd_deref() macros return a pointer s390/opcodes: rename selhhhr to selfhr
2021-02-26s390/mm: define arch_get_mappable_range()Anshuman Khandual2-1/+14
This overrides arch_get_mappabble_range() on s390 platform which will be used with recently added generic framework. It modifies the existing range check in vmem_add_mapping() using arch_get_mappable_range(). It also adds a VM_BUG_ON() check that would ensure that mhp_range_allowed() has already been called on the hotplug path. Link: https://lkml.kernel.org/r/1612149902-7867-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-25Merge tag 'pci-v5.12-changes' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "Enumeration: - Remove unnecessary locking around _OSC (Bjorn Helgaas) - Clarify message about _OSC failure (Bjorn Helgaas) - Remove notification of PCIe bandwidth changes (Bjorn Helgaas) - Tidy checking of syscall user config accessors (Heiner Kallweit) Resource management: - Decline to resize resources if boot config must be preserved (Ard Biesheuvel) - Fix pci_register_io_range() memory leak (Geert Uytterhoeven) Error handling (Keith Busch): - Clear error status from the correct device - Retain error recovery status so drivers can use it after reset - Log the type of Port (Root or Switch Downstream) that we reset - Always request a reset for Downstream Ports in frozen state Endpoint framework and NTB (Kishon Vijay Abraham I): - Make *_get_first_free_bar() take into account 64 bit BAR - Add helper API to get the 'next' unreserved BAR - Make *_free_bar() return error codes on failure - Remove unused pci_epf_match_device() - Add support to associate secondary EPC with EPF - Add support in configfs to associate two EPCs with EPF - Add pci_epc_ops to map MSI IRQ - Add pci_epf_ops to expose function-specific attrs - Allow user to create sub-directory of 'EPF Device' directory - Implement ->msi_map_irq() ops for cadence - Configure LM_EP_FUNC_CFG based on epc->function_num_map for cadence - Add EP function driver to provide NTB functionality - Add support for EPF PCI Non-Transparent Bridge - Add specification for PCI NTB function device - Add PCI endpoint NTB function user guide - Add configfs binding documentation for pci-ntb endpoint function Broadcom STB PCIe controller driver: - Add support for BCM4908 and external PERST# signal controller (Rafał Miłecki) Cadence PCIe controller driver: - Retrain Link to work around Gen2 training defect (Nadeem Athani) - Fix merge botch in cdns_pcie_host_map_dma_ranges() (Krzysztof Wilczyński) Freescale Layerscape PCIe controller driver: - Add LX2160A rev2 EP mode support (Hou Zhiqiang) - Convert to builtin_platform_driver() (Michael Walle) MediaTek PCIe controller driver: - Fix OF node reference leak (Krzysztof Wilczyński) Microchip PolarFlare PCIe controller driver: - Add Microchip PolarFire PCIe controller driver (Daire McNamara) Qualcomm PCIe controller driver: - Use PHY_REFCLK_USE_PAD only for ipq8064 (Ansuel Smith) - Add support for ddrss_sf_tbu clock for sm8250 (Dmitry Baryshkov) Renesas R-Car PCIe controller driver: - Drop PCIE_RCAR config option (Lad Prabhakar) - Always allocate MSI addresses in 32bit space (Marek Vasut) Rockchip PCIe controller driver: - Add FriendlyARM NanoPi M4B DT binding (Chen-Yu Tsai) - Make 'ep-gpios' DT property optional (Chen-Yu Tsai) Synopsys DesignWare PCIe controller driver: - Work around ECRC configuration hardware defect (Vidya Sagar) - Drop support for config space in DT 'ranges' (Rob Herring) - Change size to u64 for EP outbound iATU (Shradha Todi) - Add upper limit address for outbound iATU (Shradha Todi) - Make dw_pcie ops optional (Jisheng Zhang) - Remove unnecessary dw_pcie_ops from al driver (Jisheng Zhang) Xilinx Versal CPM PCIe controller driver: - Fix OF node reference leak (Pan Bian) Miscellaneous: - Remove tango host controller driver (Arnd Bergmann) - Remove IRQ handler & data together (altera-msi, brcmstb, dwc) (Martin Kaiser) - Fix xgene-msi race in installing chained IRQ handler (Martin Kaiser) - Apply CONFIG_PCI_DEBUG to entire drivers/pci hierarchy (Junhao He) - Fix pci-bridge-emul array overruns (Russell King) - Remove obsolete uses of WARN_ON(in_interrupt()) (Sebastian Andrzej Siewior)" * tag 'pci-v5.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (69 commits) PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064 PCI: qcom: Add support for ddrss_sf_tbu clock dt-bindings: PCI: qcom: Document ddrss_sf_tbu clock for sm8250 PCI: al: Remove useless dw_pcie_ops PCI: dwc: Don't assume the ops in dw_pcie always exist PCI: dwc: Add upper limit address for outbound iATU PCI: dwc: Change size to u64 for EP outbound iATU PCI: dwc: Drop support for config space in 'ranges' PCI: layerscape: Convert to builtin_platform_driver() PCI: layerscape: Add LX2160A rev2 EP mode support dt-bindings: PCI: layerscape: Add LX2160A rev2 compatible strings PCI: dwc: Work around ECRC configuration issue PCI/portdrv: Report reset for frozen channel PCI/AER: Specify the type of Port that was reset PCI/ERR: Retain status from error notification PCI/AER: Clear AER status from Root Port when resetting Downstream Port PCI/ERR: Clear status of the reporting device dt-bindings: arm: rockchip: Add FriendlyARM NanoPi M4B PCI: rockchip: Make 'ep-gpios' DT property optional Documentation: PCI: Add PCI endpoint NTB function user guide ...
2021-02-24Merge tag 'x86-entry-2021-02-24' of ↵Linus Torvalds3-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation
2021-02-24s390/cpumf: Add support for complete counter set extractionThomas Richter2-23/+576
Add support to the CPU Measurement counter facility device driver to extract complete counter sets per CPU and per counter set from user space. This includes a new device named /dev/hwctr and support for the device driver functions open, close and ioctl. Other functions are not supported. The ioctl command supports 3 subcommands: S390_HWCTR_START: enables counter sets on a list of CPUs. S390_HWCTR_STOP: disables counter sets on a list of CPUs. S390_HWCTR_READ: reads counter sets on a list of CPUs. The ioctl(..., S390_HWCTR_READ, ...) is the only subcommand which returns data. It requires member data_bytes to be positive and indicates the maximum amount of data available to store counter set data. The other ioctl() subcommands do not use this member and it should be set to zero. The S390_HWCTR_READ subcommand returns the following data: The cpuset data is flattened using the following scheme, stored in member data: 0x0 0x8 0xc 0x10 0x10 0x18 0x20 0x28 0xU-1 +---------+-----+---------+-----+---------+-----+-----+------+------+ | no_cpus | cpu | no_sets | set | no_cnts | cv1 | cv2 | .... | cv_n | +---------+-----+---------+-----+---------+-----+-----+------+------+ 0xU 0xU+4 0xU+8 0xU+10 0xV-1 +-----+---------+-----+-----+------+------+ | set | no_cnts | cv1 | cv2 | .... | cv_n | +-----+---------+-----+-----+------+------+ 0xV 0xV+4 0xV+8 0xV+c +-----+---------+-----+---------+-----+-----+------+------+ | cpu | no_sets | set | no_cnts | cv1 | cv2 | .... | cv_n | +-----+---------+-----+---------+-----+-----+------+------+ U and V denote arbitrary hexadezimal addresses. The first integer represents the number of CPUs data was extracted from. This is followed by CPU number and number of counter sets extracted. Both are two integer values. This is followed by the set identifer and number of counters extracted. Both are two integer values. This is followed by the counter values, each element is eight bytes in size. The S390_HWCTR_READ ioctl subcommand is also limited to one call per minute. This ensures that an application does not read out the counter sets too often and reduces the overall CPU performance. The complete counter set extraction is an expensive operation. Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/smp: implement arch_irq_work_raise()Ilya Leoshkevich2-0/+23
The immediate need to have this is to have bpf_send_signal() send the signal ASAP instead of during the next hrtimer interrupt. However, it should also improve irq_work_queue() latencies in general, as well as get s390 out of the lame architectures list [1]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/irq_work.c?h=v5.11#n45 Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/topology: move cpumasks away from stackHeiko Carstens1-12/+13
Make cpumasks static variables to avoid potential large stack frames. There shouldn't be any concurrent callers since all current callers are serialized with the cpu hotplug lock. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/smp: smp_emergency_stop() - move cpumask away from stackHeiko Carstens1-1/+4
Make "cpumask_t cpumask" a static variable to avoid a potential large stack frame. Also protect against potential concurrent callers by introducing a local lock. Note: smp_emergency_stop() gets only called with irqs and machine checks disabled, therefore a cpu local deadlock is not possible. For concurrent callers the first cpu which enters the critical section wins and will stop all other cpus. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/smp: __smp_rescan_cpus() - move cpumask away from stackHeiko Carstens1-1/+1
Avoid a potentially large stack frame and overflow by making "cpumask_t avail" a static variable. There is no concurrent access due to the existing locking. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/smp: consolidate locking for smp_rescan()Heiko Carstens1-6/+4
Move locking to __smp_rescan() instead of duplicating it to all call sites. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/mm: fix phys vs virt confusion in vmem_*() functions familyAlexander Gordeev1-15/+15
Due to historical reasons vmem_*() functions misuse or ignore the notion of physical vs virtual addresses difference. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/mm: fix phys vs virt confusion in pgtable allocation routinesAlexander Gordeev2-12/+12
The physical address of page tables is passed around and used as virtual address in various locations. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/mm: fix invalid __pa() usage in pfn_pXd() macrosAlexander Gordeev1-2/+2
There is little sense in applying __pa() to a physical address, but that what pfn_pXd() macros do. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/mm: make pXd_deref() macros return a pointerAlexander Gordeev1-6/+6
This update fixes semantics of pXd_deref macros which are expected to return a CPU-addressable pointer. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-24s390/opcodes: rename selhhhr to selfhrHeiko Carstens1-1/+1
Provide correct mnemonic for selfhr. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-23Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull idmapped mounts from Christian Brauner: "This introduces idmapped mounts which has been in the making for some time. Simply put, different mounts can expose the same file or directory with different ownership. This initial implementation comes with ports for fat, ext4 and with Christoph's port for xfs with more filesystems being actively worked on by independent people and maintainers. Idmapping mounts handle a wide range of long standing use-cases. Here are just a few: - Idmapped mounts make it possible to easily share files between multiple users or multiple machines especially in complex scenarios. For example, idmapped mounts will be used in the implementation of portable home directories in systemd-homed.service(8) where they allow users to move their home directory to an external storage device and use it on multiple computers where they are assigned different uids and gids. This effectively makes it possible to assign random uids and gids at login time. - It is possible to share files from the host with unprivileged containers without having to change ownership permanently through chown(2). - It is possible to idmap a container's rootfs and without having to mangle every file. For example, Chromebooks use it to share the user's Download folder with their unprivileged containers in their Linux subsystem. - It is possible to share files between containers with non-overlapping idmappings. - Filesystem that lack a proper concept of ownership such as fat can use idmapped mounts to implement discretionary access (DAC) permission checking. - They allow users to efficiently changing ownership on a per-mount basis without having to (recursively) chown(2) all files. In contrast to chown (2) changing ownership of large sets of files is instantenous with idmapped mounts. This is especially useful when ownership of a whole root filesystem of a virtual machine or container is changed. With idmapped mounts a single syscall mount_setattr syscall will be sufficient to change the ownership of all files. - Idmapped mounts always take the current ownership into account as idmappings specify what a given uid or gid is supposed to be mapped to. This contrasts with the chown(2) syscall which cannot by itself take the current ownership of the files it changes into account. It simply changes the ownership to the specified uid and gid. This is especially problematic when recursively chown(2)ing a large set of files which is commong with the aforementioned portable home directory and container and vm scenario. - Idmapped mounts allow to change ownership locally, restricting it to specific mounts, and temporarily as the ownership changes only apply as long as the mount exists. Several userspace projects have either already put up patches and pull-requests for this feature or will do so should you decide to pull this: - systemd: In a wide variety of scenarios but especially right away in their implementation of portable home directories. https://systemd.io/HOME_DIRECTORY/ - container runtimes: containerd, runC, LXD:To share data between host and unprivileged containers, unprivileged and privileged containers, etc. The pull request for idmapped mounts support in containerd, the default Kubernetes runtime is already up for quite a while now: https://github.com/containerd/containerd/pull/4734 - The virtio-fs developers and several users have expressed interest in using this feature with virtual machines once virtio-fs is ported. - ChromeOS: Sharing host-directories with unprivileged containers. I've tightly synced with all those projects and all of those listed here have also expressed their need/desire for this feature on the mailing list. For more info on how people use this there's a bunch of talks about this too. Here's just two recent ones: https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf https://fosdem.org/2021/schedule/event/containers_idmap/ This comes with an extensive xfstests suite covering both ext4 and xfs: https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts It covers truncation, creation, opening, xattrs, vfscaps, setid execution, setgid inheritance and more both with idmapped and non-idmapped mounts. It already helped to discover an unrelated xfs setgid inheritance bug which has since been fixed in mainline. It will be sent for inclusion with the xfstests project should you decide to merge this. In order to support per-mount idmappings vfsmounts are marked with user namespaces. The idmapping of the user namespace will be used to map the ids of vfs objects when they are accessed through that mount. By default all vfsmounts are marked with the initial user namespace. The initial user namespace is used to indicate that a mount is not idmapped. All operations behave as before and this is verified in the testsuite. Based on prior discussions we want to attach the whole user namespace and not just a dedicated idmapping struct. This allows us to reuse all the helpers that already exist for dealing with idmappings instead of introducing a whole new range of helpers. In addition, if we decide in the future that we are confident enough to enable unprivileged users to setup idmapped mounts the permission checking can take into account whether the caller is privileged in the user namespace the mount is currently marked with. The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern of extensibility. The following conditions must be met in order to create an idmapped mount: - The caller must currently have the CAP_SYS_ADMIN capability in the user namespace the underlying filesystem has been mounted in. - The underlying filesystem must support idmapped mounts. - The mount must not already be idmapped. This also implies that the idmapping of a mount cannot be altered once it has been idmapped. - The mount must be a detached/anonymous mount, i.e. it must have been created by calling open_tree() with the OPEN_TREE_CLONE flag and it must not already have been visible in the filesystem. The last two points guarantee easier semantics for userspace and the kernel and make the implementation significantly simpler. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes are observed. The manpage with a detailed description can be found here: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The patches to convert individual filesystem are not very large or complicated overall as can be seen from the included fat, ext4, and xfs ports. Patches for other filesystems are actively worked on and will be sent out separately. The xfstestsuite can be used to verify that port has been done correctly. The mount_setattr() syscall is motivated independent of the idmapped mounts patches and it's been around since July 2019. One of the most valuable features of the new mount api is the ability to perform mounts based on file descriptors only. Together with the lookup restrictions available in the openat2() RESOLVE_* flag namespace which we added in v5.6 this is the first time we are close to hardened and race-free (e.g. symlinks) mounting and path resolution. While userspace has started porting to the new mount api to mount proper filesystems and create new bind-mounts it is currently not possible to change mount options of an already existing bind mount in the new mount api since the mount_setattr() syscall is missing. With the addition of the mount_setattr() syscall we remove this last restriction and userspace can now fully port to the new mount api, covering every use-case the old mount api could. We also add the crucial ability to recursively change mount options for a whole mount tree, both removing and adding mount options at the same time. This syscall has been requested multiple times by various people and projects. There is a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. I'll add support for the regular mount binary should you decide to pull this in the following weeks: Here's an example to a simple idmapped mount of another user's home directory: u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r--" * tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits) xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl xfs: support idmapped mounts ext4: support idmapped mounts fat: handle idmapped mounts tests: add mount_setattr() selftests fs: introduce MOUNT_ATTR_IDMAP fs: add mount_setattr() fs: add attr_flags_to_mnt_flags helper fs: split out functions to hold writers namespace: only take read lock in do_reconfigure_mnt() mount: make {lock,unlock}_mount_hash() static namespace: take lock_mount_hash() directly when changing flags nfs: do not export idmapped mounts overlayfs: do not mount on top of idmapped mounts ecryptfs: do not mount on top of idmapped mounts ima: handle idmapped mounts apparmor: handle idmapped mounts fs: make helpers idmap mount aware exec: handle idmapped mounts would_dump: handle idmapped mounts ...
2021-02-23Merge tag 'modules-for-v5.12' of ↵Linus Torvalds2-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: - Retire EXPORT_UNUSED_SYMBOL() and EXPORT_SYMBOL_GPL_FUTURE(). These export types were introduced between 2006 - 2008. All the of the unused symbols have been long removed and gpl future symbols were converted to gpl quite a long time ago, and I don't believe these export types have been used ever since. So, I think it should be safe to retire those export types now (Christoph Hellwig) - Refactor and clean up some aged code cruft in the module loader (Christoph Hellwig) - Build {,module_}kallsyms_on_each_symbol only when livepatching is enabled, as it is the only caller (Christoph Hellwig) - Unexport find_module() and module_mutex and fix the last module callers to not rely on these anymore. Make module_mutex internal to the module loader (Christoph Hellwig) - Harden ELF checks on module load and validate ELF structures before checking the module signature (Frank van der Linden) - Fix undefined symbol warning for clang (Fangrui Song) - Fix smatch warning (Dan Carpenter) * tag 'modules-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: potential uninitialized return in module_kallsyms_on_each_symbol() module: remove EXPORT_UNUSED_SYMBOL* module: remove EXPORT_SYMBOL_GPL_FUTURE module: move struct symsearch to module.c module: pass struct find_symbol_args to find_symbol module: merge each_symbol_section into find_symbol module: remove each_symbol_in_section module: mark module_mutex static kallsyms: only build {,module_}kallsyms_on_each_symbol when required kallsyms: refactor {,module_}kallsyms_on_each_symbol module: use RCU to synchronize find_module module: unexport find_module and module_mutex drm: remove drm_fb_helper_modinit powerpc/powernv: remove get_cxl_module module: harden ELF info handling module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
2021-02-21Merge branch 'linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "API: - Restrict crypto_cipher to internal API users only. Algorithms: - Add x86 aesni acceleration for cts. - Improve x86 aesni acceleration for xts. - Remove x86 acceleration of some uncommon algorithms. - Remove RIPE-MD, Tiger and Salsa20. - Remove tnepres. - Add ARM acceleration for BLAKE2s and BLAKE2b. Drivers: - Add Keem Bay OCS HCU driver. - Add Marvell OcteonTX2 CPT PF driver. - Remove PicoXcell driver. - Remove mediatek driver" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (154 commits) hwrng: timeriomem - Use device-managed registration API crypto: hisilicon/qm - fix printing format issue crypto: hisilicon/qm - do not reset hardware when CE happens crypto: hisilicon/qm - update irqflag crypto: hisilicon/qm - fix the value of 'QM_SQC_VFT_BASE_MASK_V2' crypto: hisilicon/qm - fix request missing error crypto: hisilicon/qm - removing driver after reset crypto: octeontx2 - fix -Wpointer-bool-conversion warning crypto: hisilicon/hpre - enable Elliptic curve cryptography crypto: hisilicon - PASID fixed on Kunpeng 930 crypto: hisilicon/qm - fix use of 'dma_map_single' crypto: hisilicon/hpre - tiny fix crypto: hisilicon/hpre - adapt the number of clusters crypto: cpt - remove casting dma_alloc_coherent crypto: keembay-ocs-aes - Fix 'q' assignment during CCM B0 generation crypto: xor - Fix typo of optimization hwrng: optee - Use device-managed registration API crypto: arm64/crc-t10dif - move NEON yield to C code crypto: arm64/aes-ce-mac - simplify NEON yield crypto: arm64/aes-neonbs - remove NEON yield calls ...
2021-02-21arch: setup PF_IO_WORKER threads like PF_KTHREADJens Axboe1-1/+1
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-21Merge tag 's390-5.12-1' of ↵Linus Torvalds69-1379/+1182
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Convert to using the generic entry infrastructure. - Add vdso time namespace support. - Switch s390 and alpha to 64-bit ino_t. As discussed at https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/ - Get rid of expensive stck (store clock) usages where possible. Utilize cpu alternatives to patch stckf when supported. - Make tod_clock usage less error prone by converting it to a union and rework code which is using it. - Machine check handler fixes and cleanups. - Drop couple of minor inline asm optimizations to fix clang build. - Default configs changes notably to make libvirt happy. - Various changes to rework and improve qdio code. - Other small various fixes and improvements all over the code. * tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits) s390/qdio: remove 'merge_pending' mechanism s390/qdio: improve handling of PENDING buffers for QEBSM devices s390/qdio: rework q->qdio_error indication s390/qdio: inline qdio_kick_handler() s390/time: remove get_tod_clock_ext() s390/crypto: use store_tod_clock_ext() s390/hypfs: use store_tod_clock_ext() s390/debug: use union tod_clock s390/kvm: use union tod_clock s390/vdso: use union tod_clock s390/time: convert tod_clock_base to union s390/time: introduce new store_tod_clock_ext() s390/time: rename store_tod_clock_ext() and use union tod_clock s390/time: introduce union tod_clock s390,alpha: switch to 64-bit ino_t s390: split cleanup_sie s390: use r13 in cleanup_sie as temp register s390: fix kernel asce loading when sie is interrupted s390: add stack for machine check handler s390: use WRITE_ONCE when re-allocating async stack ...
2021-02-21Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-3/+2
Pull KVM updates from Paolo Bonzini: "x86: - Support for userspace to emulate Xen hypercalls - Raise the maximum number of user memslots - Scalability improvements for the new MMU. Instead of the complex "fast page fault" logic that is used in mmu.c, tdp_mmu.c uses an rwlock so that page faults are concurrent, but the code that can run against page faults is limited. Right now only page faults take the lock for reading; in the future this will be extended to some cases of page table destruction. I hope to switch the default MMU around 5.12-rc3 (some testing was delayed due to Chinese New Year). - Cleanups for MAXPHYADDR checks - Use static calls for vendor-specific callbacks - On AMD, use VMLOAD/VMSAVE to save and restore host state - Stop using deprecated jump label APIs - Workaround for AMD erratum that made nested virtualization unreliable - Support for LBR emulation in the guest - Support for communicating bus lock vmexits to userspace - Add support for SEV attestation command - Miscellaneous cleanups PPC: - Support for second data watchpoint on POWER10 - Remove some complex workarounds for buggy early versions of POWER9 - Guest entry/exit fixes ARM64: - Make the nVHE EL2 object relocatable - Cleanups for concurrent translation faults hitting the same page - Support for the standard TRNG hypervisor call - A bunch of small PMU/Debug fixes - Simplification of the early init hypercall handling Non-KVM changes (with acks): - Detection of contended rwlocks (implemented only for qrwlocks, because KVM only needs it for x86) - Allow __DISABLE_EXPORTS from assembly code - Provide a saner follow_pfn replacements for modules" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (192 commits) KVM: x86/xen: Explicitly pad struct compat_vcpu_info to 64 bytes KVM: selftests: Don't bother mapping GVA for Xen shinfo test KVM: selftests: Fix hex vs. decimal snafu in Xen test KVM: selftests: Fix size of memslots created by Xen tests KVM: selftests: Ignore recently added Xen tests' build output KVM: selftests: Add missing header file needed by xAPIC IPI tests KVM: selftests: Add operand to vmsave/vmload/vmrun in svm.c KVM: SVM: Make symbol 'svm_gp_erratum_intercept' static locking/arch: Move qrwlock.h include after qspinlock.h KVM: PPC: Book3S HV: Fix host radix SLB optimisation with hash guests KVM: PPC: Book3S HV: Ensure radix guest has no SLB entries KVM: PPC: Don't always report hash MMU capability for P9 < DD2.2 KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path KVM: PPC: remove unneeded semicolon KVM: PPC: Book3S HV: Use POWER9 SLBIA IH=6 variant to clear SLB KVM: PPC: Book3S HV: No need to clear radix host SLB before loading HPT guest KVM: PPC: Book3S HV: Fix radix guest SLB side channel KVM: PPC: Book3S HV: Remove support for running HPT guest on RPT host without mixed mode support KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWR KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR ...
2021-02-21Merge tag 'oprofile-removal-5.12' of ↵Linus Torvalds6-53/+0
git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux Pull oprofile and dcookies removal from Viresh Kumar: "Remove oprofile and dcookies support The 'oprofile' user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. The dcookies stuff is only used by the oprofile code. Now that oprofile's support is getting removed from the kernel, there is no need for dcookies as well. Remove kernel's old oprofile and dcookies support" * tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux: fs: Remove dcookies support drivers: Remove CONFIG_OPROFILE support arch: xtensa: Remove CONFIG_OPROFILE support arch: x86: Remove CONFIG_OPROFILE support arch: sparc: Remove CONFIG_OPROFILE support arch: sh: Remove CONFIG_OPROFILE support arch: s390: Remove CONFIG_OPROFILE support arch: powerpc: Remove oprofile arch: powerpc: Stop building and using oprofile arch: parisc: Remove CONFIG_OPROFILE support arch: mips: Remove CONFIG_OPROFILE support arch: microblaze: Remove CONFIG_OPROFILE support arch: ia64: Remove rest of perfmon support arch: ia64: Remove CONFIG_OPROFILE support arch: hexagon: Don't select HAVE_OPROFILE arch: arc: Remove CONFIG_OPROFILE support arch: arm: Remove CONFIG_OPROFILE support arch: alpha: Remove CONFIG_OPROFILE support
2021-02-21Merge branch 'work.elf-compat' of ↵Linus Torvalds2-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ELF compat updates from Al Viro: "Sanitizing ELF compat support, especially for triarch architectures: - X32 handling cleaned up - MIPS64 uses compat_binfmt_elf.c both for O32 and N32 now - Kconfig side of things regularized Eventually I hope to have compat_binfmt_elf.c killed, with both native and compat built from fs/binfmt_elf.c, with -DELF_BITS={64,32} passed by kbuild, but that's a separate story - not included here" * 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: get rid of COMPAT_ELF_EXEC_PAGESIZE compat_binfmt_elf: don't bother with undef of ELF_ARCH Kconfig: regularize selection of CONFIG_BINFMT_ELF mips compat: switch to compat_binfmt_elf.c mips: don't bother with ELF_CORE_EFLAGS mips compat: don't bother with ELF_ET_DYN_BASE mips: KVM_GUEST makes no sense for 64bit builds... mips: kill unused definitions in binfmt_elf[on]32.c mips binfmt_elf*32.c: use elfcore-compat.h x32: make X32, !IA32_EMULATION setups able to execute x32 binaries [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly elf_prstatus: collect the common part (everything before pr_reg) into a struct binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALID
2021-02-13s390/qdio: remove 'merge_pending' mechanismJulian Wiedmann1-4/+0
For non-QEBSM devices, get_buf_states() merges PENDING and EMPTY buffers into a single group of finished buffers. To allow the upper-layer driver to differentiate between the two states, qdio_check_pending() looks at each buffer's state again and sets the sbal_state flag to QDIO_OUTBUF_STATE_FLAG_PENDING accordingly. So effectively we're spending overhead on _every_ Output Queue inspection, just to avoid some additional TX completion calls in case a group of buffers has completed with mixed EMPTY / PENDING state. Given that PENDING buffers should rarely occur, this is a bad trade-off. In particular so as the additional checks in get_buf_states() affect _all_ device types (even those that don't use the PENDING state). Rip it all out, and just report the PENDING completions separately as we already do for QEBSM devices. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/qdio: improve handling of PENDING buffers for QEBSM devicesJulian Wiedmann1-0/+1
For QEBSM devices the 'merge_pending' mechanism in get_buf_states() doesn't apply, and we can actually get SLSB_P_OUTPUT_PENDING returned. So for this case propagating the PENDING state to the driver via the queue's sbal_state doesn't make sense and creates unnecessary overhead. Instead introduce a new QDIO_ERROR_* flag that gets passed to the driver, and triggers the same processing as if the buffers were flagged as QDIO_OUTBUF_STATE_FLAG_PENDING. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/time: remove get_tod_clock_ext()Heiko Carstens1-12/+3
Remove get_tod_clock_ext() and the STORE_CLOCK_EXT_SIZE define. This enforces all users of the existing low level functions to use a union tod_clock. This way there is now a compile time check for the correct time and therefore also if the size of the argument matches what will be written to by the STORE CLOCK EXTENDED instruction. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/crypto: use store_tod_clock_ext()Heiko Carstens1-1/+1
Use store_tod_clock_ext() in order to be able to get rid get_tod_clock_ext(). Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/hypfs: use store_tod_clock_ext()Heiko Carstens2-3/+3
Use store_tod_clock_ext() instead of get_tod_clock_ext(). Unfortunately one usage has to be converted to a cast, since otherwise a uapi header file would have to be changed. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/debug: use union tod_clockHeiko Carstens1-3/+3
Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/kvm: use union tod_clockHeiko Carstens1-15/+9
Use union tod_clock and get rid of the kvm specific struct kvm_s390_tod_clock_ext which apparently was introduced for the same purpose. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/vdso: use union tod_clockHeiko Carstens1-3/+3
Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/time: convert tod_clock_base to unionHeiko Carstens5-40/+24
Convert tod_clock_base to union tod_clock. This simplifies quite a bit of code and also fixes a bug in read_persistent_clock64(); void read_persistent_clock64(struct timespec64 *ts) { __u64 delta; delta = initial_leap_seconds + TOD_UNIX_EPOCH; get_tod_clock_ext(clk); *(__u64 *) &clk[1] -= delta; if (*(__u64 *) &clk[1] > delta) clk[0]--; ext_to_timespec64(clk, ts); } Assume &clk[1] == 3 and delta == 2; then after the substraction the if condition becomes true and the epoch part of the clock is decremented by one because of an assumed overflow, even though there is none. Fix this by using 128 bit arithmetics and let the compiler do the right thing: void read_persistent_clock64(struct timespec64 *ts) { union tod_clock clk; u64 delta; delta = initial_leap_seconds + TOD_UNIX_EPOCH; store_tod_clock_ext(&clk); clk.eitod -= delta; ext_to_timespec64(&clk, ts); } Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/time: introduce new store_tod_clock_ext()Heiko Carstens1-0/+5
Introduce new store_tod_clock_ext() function, which is the same like store_tod_clock_ext_cc() except that it doesn't return a condition code. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/time: rename store_tod_clock_ext() and use union tod_clockHeiko Carstens2-6/+5
Rename store_tod_clock_ext() to store_tod_clock_ext_cc() to reflect that it returns a condition code and also use union tod_clock as parameter. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/time: introduce union tod_clockHeiko Carstens1-0/+19
Introduce union tod_clock which is supposed to be used to decode and access various fields of the result of STORE CLOCK EXTENDED. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390,alpha: switch to 64-bit ino_tHeiko Carstens1-0/+1
s390 and alpha are the only 64 bit architectures with a 32-bit ino_t. Since this is quite unusual this causes bugs from time to time. See e.g. commit ebce3eb2f7ef ("ceph: fix inode number handling on arches with 32-bit ino_t") for an example. This (obviously) also prevents s390 and alpha to use 64-bit ino_t for tmpfs. See commit b85a7a8bb573 ("tmpfs: disallow CONFIG_TMPFS_INODE64 on s390"). Therefore switch both s390 and alpha to 64-bit ino_t. This should only have an effect on the ustat system call. To prevent ABI breakage define struct ustat compatible to the old layout and change sys_ustat() accordingly. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: split cleanup_sieSven Schnelle1-10/+7
The current code uses the address in %r11 to figure out whether it was called from the machine check handler or from a normal interrupt handler. Instead of doing this implicit logic (which is mostly a leftover from the old critical cleanup approach) just add a second label and use that. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: use r13 in cleanup_sie as temp registerSven Schnelle1-2/+2
Instead of thrashing r11 which is normally our pointer to struct pt_regs on the stack, use r13 as temporary register in the BR_EX macro. r13 is already used in cleanup_sie, so no need to thrash another register. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: fix kernel asce loading when sie is interruptedSven Schnelle1-2/+1
If a machine check is coming in during sie, the PU saves the control registers to the machine check save area. Afterwards mcck_int_handler is called, which loads __LC_KERNEL_ASCE into %cr1. Later the code restores %cr1 from the machine check area, but that is wrong when SIE was interrupted because the machine check area still contains the gmap asce. Instead it should return with either __KERNEL_ASCE in %cr1 when interrupted in SIE or the previous %cr1 content saved in the machine check save area. Fixes: 87d598634521 ("s390/mm: remove set_fs / rework address space handling") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Cc: <stable@kernel.org> # v5.8+ Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: add stack for machine check handlerSven Schnelle5-25/+41
The previous code used the normal kernel stack for machine checks. This is problematic when a machine check interrupts a system call or interrupt handler right at the beginning where registers are set up. Assume system_call is interrupted at the first instruction and a machine check is triggered. The machine check handler is called, checks the PSW to see whether it is coming from user space, notices that it is already in kernel mode but %r15 still contains the user space stack. This would lead to a kernel crash. There are basically two ways of fixing that: Either using the 'critical cleanup' approach which compares the address in the PSW to see whether it is already at a point where the stack has been set up, or use an extra stack for the machine check handler. For simplicity, we will go with the second approach and allocate an extra stack. This adds some memory overhead for large systems, but usually large system have plenty of memory so this isn't really a concern. But it keeps the mchk stack setup simple and less error prone. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Cc: <stable@kernel.org> # v5.8+ Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: use WRITE_ONCE when re-allocating async stackSven Schnelle1-1/+1
The code does: S390_lowcore.async_stack = new + STACK_INIT_OFFSET; But the compiler is free to first assign one value and add the other value later. If a IRQ would be coming in between these two operations, it would run with an invalid stack. Prevent this by using WRITE_ONCE. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390: open code SWITCH_KERNEL macroSven Schnelle1-28/+46
This is a preparation patch for two later bugfixes. In the past both int_handler and machine check handler used SWITCH_KERNEL to switch to the kernel stack. However, SWITCH_KERNEL doesn't work properly in machine check context. So instead of adding more complexity to this macro, just remove it. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Cc: <stable@kernel.org> # v5.8+ Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-12Merge branch 'x86/paravirt' into x86/entryIngo Molnar3-4/+4
Merge in the recent paravirt changes to resolve conflicts caused by objtool annotations. Conflicts: arch/x86/xen/xen-asm.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-02-10softirq: Move do_softirq_own_stack() to generic asm headerThomas Gleixner1-0/+1
To avoid include recursion hell move the do_softirq_own_stack() related content into a generic asm header and include it from all places in arch/ which need the prototype. This allows architectures to provide an inline implementation of do_softirq_own_stack() without introducing a lot of #ifdeffery all over the place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de
2021-02-10softirq: Move __ARCH_HAS_DO_SOFTIRQ to KconfigThomas Gleixner2-1/+1
To prepare for inlining do_softirq_own_stack() replace __ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected architectures. This allows in the next step to move the function prototype and the inline stub into a seperate asm-generic header file which is required to avoid include recursion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
2021-02-09s390/vtime: use cpu alternative for stck/stckfHeiko Carstens1-11/+8
Use a cpu alternative to switch between stck and stckf instead of making it compile time dependent. This will also make kernels compiled for old machines, but running on newer machines, use stckf. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/alternatives: add alternative_input() / alternative_io()Heiko Carstens1-0/+16
Add support for alternative inline assemblies with input and output arguments. This is consistent to x86. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/entry: use cpu alternative for stck/stckfHeiko Carstens1-5/+3
Use a cpu alternative to switch between stck and stckf instead of making it compile time dependent. This will also make kernels compiled for old machines, but running on newer machines, use stckf. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/time: use stcke instead of stckHeiko Carstens2-7/+9
Use STORE CLOCK EXTENDED instead of STORE CLOCK in early tod clock setup. This is just to remove another usage of stck, trying to remove all usages of STORE CLOCK. This doesn't fix anything. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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