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2021-08-20Merge branch kvm-arm64/generic-entry into kvmarm-master/nextMarc Zyngier5-28/+52
Switch KVM/arm64 to the generic entry code, courtesy of Oliver Upton * kvm-arm64/generic-entry: KVM: arm64: Use generic KVM xfer to guest work function entry: KVM: Allow use of generic KVM entry w/o full generic support KVM: arm64: Record number of signal exits as a vCPU stat Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch kvm-arm64/psci/cpu_on into kvmarm-master/nextMarc Zyngier7-9/+156
PSCI fixes from Oliver Upton: - Plug race on reset - Ensure that a pending reset is applied before userspace accesses - Reject PSCI requests with illegal affinity bits * kvm-arm64/psci/cpu_on: selftests: KVM: Introduce psci_cpu_on_test KVM: arm64: Enforce reserved bits for PSCI target affinities KVM: arm64: Handle PSCI resets before userspace touches vCPU state KVM: arm64: Fix read-side race on updates to vcpu reset state Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch kvm-arm64/mmu/el2-tracking into kvmarm-master/nextMarc Zyngier15-306/+618
* kvm-arm64/mmu/el2-tracking: (25 commits) : Enable tracking of page sharing between host EL1 and EL2 KVM: arm64: Minor optimization of range_is_memory KVM: arm64: Make hyp_panic() more robust when protected mode is enabled KVM: arm64: Return -EPERM from __pkvm_host_share_hyp() KVM: arm64: Make __pkvm_create_mappings static KVM: arm64: Restrict EL2 stage-1 changes in protected mode KVM: arm64: Refactor protected nVHE stage-1 locking KVM: arm64: Remove __pkvm_mark_hyp KVM: arm64: Mark host bss and rodata section as shared KVM: arm64: Enable retrieving protections attributes of PTEs KVM: arm64: Introduce addr_is_memory() KVM: arm64: Expose pkvm_hyp_id KVM: arm64: Expose host stage-2 manipulation helpers KVM: arm64: Add helpers to tag shared pages in SW bits KVM: arm64: Allow populating software bits KVM: arm64: Enable forcing page-level stage-2 mappings KVM: arm64: Tolerate re-creating hyp mappings to set software bits KVM: arm64: Don't overwrite software bits with owner id KVM: arm64: Rename KVM_PTE_LEAF_ATTR_S2_IGNORED KVM: arm64: Optimize host memory aborts KVM: arm64: Expose page-table helpers ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge tag 'for-net-next-2021-08-19' of ↵David S. Miller21-1489/+2015
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next Luiz Augusto von Dentz says: ==================== bluetooth-next pull request for net-next: - Add support for Foxconn Mediatek Chip - Add support for LG LGSBWAC92/TWCM-K505D - hci_h5 flow control fixes and suspend support - Switch to use lock_sock for SCO and RFCOMM - Various fixes for extended advertising - Reword Intel's setup on btusb unifying the supported generations ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-20Merge branch kvm-arm64/mmu/kmemleak-pkvm into kvmarm-master/nextMarc Zyngier2-2/+9
Prevent kmemleak from peeking into the HYP data, which is fatal in protected mode. * kvm-arm64/mmu/kmemleak-pkvm: KVM: arm64: Unregister HYP sections from kmemleak in protected mode arm64: Move .hyp.rodata outside of the _sdata.._edata range Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch kvm-arm64/misc-5.15 into kvmarm-master/nextMarc Zyngier14-135/+112
* kvm-arm64/misc-5.15: : Misc improvements for 5.15: : : - Account the number of VMID-wide TLB invalidations as : remote TLB flushes : - Fix comments in the VGIC code : - Cleanup the PMU IMPDEF identification : - Streamline the TGRAN2 usage : - Avoid advertising a 52bit IPA range for non-64KB configs : - Avoid spurious signalling when a HW-mapped interrupt is in the : A+P state on entry, and in the P state on exit, but that the : physical line is not pending anymore. : - Bunch of minor cleanups KVM: arm64: vgic: Resample HW pending state on deactivation KVM: arm64: vgic: Drop WARN from vgic_get_irq KVM: arm64: Drop unused REQUIRES_VIRT KVM: arm64: Drop check_kvm_target_cpu() based percpu probe KVM: arm64: Drop init_common_resources() KVM: arm64: Use ARM64_MIN_PARANGE_BITS as the minimum supported IPA arm64/mm: Add remaining ID_AA64MMFR0_PARANGE_ macros KVM: arm64: Restrict IPA size to maximum 48 bits on 4K and 16K page size arm64/mm: Define ID_AA64MMFR0_TGRAN_2_SHIFT KVM: arm64: perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF KVM: arm64: Fix comments related to GICv2 PMR reporting KVM: arm64: Count VMID-wide TLB invalidations arm64/kexec: Test page size support with new TGRAN range values Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch kvm-arm64/mmu/mapping-levels into kvmarm-master/nextMarc Zyngier6-63/+98
Revamp the KVM/arm64 THP code by parsing the userspace page tables instead of relying on an infrastructure that is about to disappear (we are the last user). * kvm-arm64/mmu/mapping-levels: KVM: Get rid of kvm_get_pfn() KVM: arm64: Use get_page() instead of kvm_get_pfn() KVM: Remove kvm_is_transparent_hugepage() and PageTransCompoundMap() KVM: arm64: Avoid mapping size adjustment on permission fault KVM: arm64: Walk userspace page tables to compute the THP mapping size KVM: arm64: Introduce helper to retrieve a PTE and its level Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch kvm-arm64/pmu/reset-values into kvmarm-master/nextMarc Zyngier3-12/+67
Fix the reset values for our PMU emulation. As a side effect, it allows a nice optimisation by only tracking the in-use counters when flipping them on and off, now that we are guaranteed not to have any spurious bit set. * kvm-arm64/pmu/reset-values: KVM: arm64: Remove PMSWINC_EL0 shadow register KVM: arm64: Disabling disabled PMU counters wastes a lot of time KVM: arm64: Drop unnecessary masking of PMU registers KVM: arm64: Narrow PMU sysreg reset values to architectural requirements Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20kselftest/arm64: pac: Fix skipping of tests on systems without PACMark Brown1-4/+6
The PAC tests check to see if the system supports the relevant PAC features but instead of skipping the tests if they can't be executed they fail the tests which makes things look like they're not working when they are. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210819165723.43903-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-20Merge tag 'batadv-next-pullrequest-20210819' of ↵David S. Miller28-456/+364
git://git.open-mesh.org/linux-merge Simon Wunderlich says: ==================== This cleanup patchset includes the following patches: - bump version strings, by Simon Wunderlich - update docs about move IRC channel away from freenode, by Sven Eckelmann - Switch to kstrtox.h for kstrtou64, by Sven Eckelmann - Update NULL checks, by Sven Eckelmann (2 patches) - remove remaining skb-copy calls for broadcast packets, by Linus Lüssing ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-20KVM: arm64: Minor optimization of range_is_memoryDavid Brazdil1-5/+8
Currently range_is_memory finds the corresponding struct memblock_region for both the lower and upper bounds of the given address range with two rounds of binary search, and then checks that the two memblocks are the same. Simplify this by only doing binary search on the lower bound and then checking that the upper bound is in the same memblock. Signed-off-by: David Brazdil <dbrazdil@google.com> Reviewed-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210728153232.1018911-3-dbrazdil@google.com
2021-08-20Merge tag 'kvmarm-fixes-5.14-2' into kvm-arm64/mmu/el2-trackingMarc Zyngier2-5/+9
KVM/arm64 fixes for 5.14, take #2 - Plug race between enabling MTE and creating vcpus - Fix off-by-one bug when checking whether an address range is RAM Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20Merge branch arm64/for-next/sysreg into kvm-arm64/misc-5.15Marc Zyngier2-15/+22
Merge the arm64/for-next/sysreg branch to avoid merge conflicts in -next and upstream. * arm64/for-next/sysreg: arm64/kexec: Test page size support with new TGRAN range values Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20ARM: 9118/1: div64: Remove always-true __div64_const32_is_OK() duplicateGeert Uytterhoeven1-11/+0
Since commit cafa0010cd51fb71 ("Raise the minimum required gcc version to 4.6"), the kernel can no longer be compiled using gcc-3. Hence __div64_const32_is_OK() is always true. Moreover, __div64_const32_is_OK() is defined in the same way in include/asm-generic/div64.h, so the ARM-specific definition can be removed regardless. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9117/1: asm-generic: div64: Remove always-true __div64_const32_is_OK()Geert Uytterhoeven1-10/+4
Since commit cafa0010cd51fb71 ("Raise the minimum required gcc version to 4.6"), the kernel can no longer be compiled using gcc-3. Hence __div64_const32_is_OK() is always true, and the corresponding check can thus be removed. While at it, remove the whitespace error that hurts my eyes, and add the missing curly braces for the final else statement, as per coding style. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9116/1: unified: Remove check for gcc < 4Geert Uytterhoeven1-4/+0
Since commit cafa0010cd51fb71 ("Raise the minimum required gcc version to 4.6"), the kernel can no longer be compiled using gcc-3. Hence this condition is never true, and the check can thus be removed. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9110/1: oabi-compat: fix oabi epoll sparse warningArnd Bergmann1-1/+1
As my patches change the oabi epoll definition, I received a report from the kernel test robot about a pre-existing issue with a mismatched __poll_t type. The OABI code was correct when it was initially added in linux-2.16, but a later (also correct) change to the generic __poll_t triggered a type mismatch warning from sparse. As __poll_t is always 32-bit bits wide and otherwise compatible, using this instead of __u32 in the oabi_epoll_event definition is a valid workaround. Reported-by: kernel test robot <lkp@intel.com> Fixes: 8ced390c2b18 ("define __poll_t, annotate constants") Fixes: ee219b946e4b ("uapi: turn __poll_t sparse checks on by default") Fixes: 687ad0191488 ("[ARM] 3109/1: old ABI compat: syscall wrappers for ABI impedance matching") Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9113/1: uaccess: remove set_fs() implementationArnd Bergmann11-86/+7
There are no remaining callers of set_fs(), so just remove it along with all associated code that operates on thread_info->addr_limit. There are still further optimizations that can be done: - In get_user(), the address check could be moved entirely into the out of line code, rather than passing a constant as an argument, - I assume the DACR handling can be simplified as we now only change it during user access when CONFIG_CPU_SW_DOMAIN_PAN is set, but not during set_fs(). Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9112/1: uaccess: add __{get,put}_kernel_nofaultArnd Bergmann1-40/+83
These mimic the behavior of get_user and put_user, except for domain switching, address limit checking and handling of mismatched sizes, none of which are relevant here. To work with pre-Armv6 kernels, this has to avoid TUSER() inside of the new macros, the new approach passes the "t" string along with the opcode, which is a bit uglier but avoids duplicating more code. As there is no __get_user_asm_dword(), I work around it by copying 32 bit at a time, which is possible because the output size is known. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9111/1: oabi-compat: rework fcntl64() emulationArnd Bergmann1-33/+60
This is one of the last users of get_fs(), and this is fairly easy to change, since the infrastructure for it is already there. The replacement here is essentially a copy of the existing fcntl64() syscall entry function. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9114/1: oabi-compat: rework sys_semtimedop emulationArnd Bergmann3-48/+99
sys_oabi_semtimedop() is one of the last users of set_fs() on Arm. To remove this one, expose the internal code of the actual implementation that operates on a kernel pointer and call it directly after copying. There should be no measurable impact on the normal execution of this function, and it makes the overly long function a little shorter, which may help readability. While reworking the oabi version, make it behave a little more like the native one, using kvmalloc_array() and restructure the code flow in a similar way. The naming of __do_semtimedop() is not very good, I hope someone can come up with a better name. One regression was spotted by kernel test robot <rong.a.chen@intel.com> and fixed before the first mailing list submission. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9108/1: oabi-compat: rework epoll_wait/epoll_pwait emulationArnd Bergmann5-72/+49
The epoll_wait() system call wrapper is one of the remaining users of the set_fs() infrasturcture for Arm. Changing it to not require set_fs() is rather complex unfortunately. The approach I'm taking here is to allow architectures to override the code that copies the output to user space, and let the oabi-compat implementation check whether it is getting called from an EABI or OABI system call based on the thread_info->syscall value. The in_oabi_syscall() check here mirrors the in_compat_syscall() and in_x32_syscall() helpers for 32-bit compat implementations on other architectures. Overall, the amount of code goes down, at least with the newly added sys_oabi_epoll_pwait() helper getting removed again. The downside is added complexity in the source code for the native implementation. There should be no difference in runtime performance except for Arm kernels with CONFIG_OABI_COMPAT enabled that now have to go through an external function call to check which of the two variants to use. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9107/1: syscall: always store thread_info->abi_syscallArnd Bergmann6-10/+21
The system call number is used in a a couple of places, in particular ptrace, seccomp and /proc/<pid>/syscall. The last one apparently never worked reliably on ARM for tasks that are not currently getting traced. Storing the syscall number in the normal entry path makes it work, as well as allowing us to see if the current system call is for OABI compat mode, which is the next thing I want to hook into. Since the thread_info->syscall field is not just the number any more, it is now renamed to abi_syscall. In kernels that enable both OABI and EABI, the upper bits of this field encode 0x900000 (__NR_OABI_SYSCALL_BASE) for OABI tasks, while normal EABI tasks do not set the upper bits. This makes it possible to implement the in_oabi_syscall() helper later. All other users of thread_info->syscall go through the syscall_get_nr() helper, which in turn filters out the ABI bits. Note that the ABI information is lost with PTRACE_SET_SYSCALL, so one cannot set the internal number to a particular version, but this was already the case. We could change it to let gdb encode the ABI type along with the syscall in a CONFIG_OABI_COMPAT-enabled kernel, but that itself would be a (backwards-compatible) ABI change, so I don't do it here. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9109/1: oabi-compat: add epoll_pwait handlerArnd Bergmann2-4/+36
The epoll_wait() syscall has a special version for OABI compat mode to convert the arguments to the EABI structure layout of the kernel. However, the later epoll_pwait() syscall was added in arch/arm in linux-2.6.32 without this conversion. Use the same kind of handler for both. Fixes: 369842658a36 ("ARM: 5677/1: ARM support for TIF_RESTORE_SIGMASK/pselect6/ppoll/epoll_pwait") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9106/1: traps: use get_kernel_nofault instead of set_fs()Arnd Bergmann1-31/+16
ARM uses set_fs() and __get_user() to allow the stack dumping code to access possibly invalid pointers carefully. These can be changed to the simpler get_kernel_nofault(), and allow the eventual removal of set_fs(). dump_instr() will print either kernel or user space pointers, depending on how it was called. For dump_mem(), I assume we are only interested in kernel pointers, and the only time that this is called with user_mode(regs)==true is when the regs themselves are unreliable as a result of the condition that caused the trap. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9115/1: mm/maccess: fix unaligned copy_{from,to}_kernel_nofaultArnd Bergmann1-6/+22
On machines such as ARMv5 that trap unaligned accesses, these two functions can be slow when each access needs to be emulated, or they might not work at all. Change them so that each loop is only used when both the src and dst pointers are naturally aligned. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20locking/semaphore: Add might_sleep() to down_*() familyXiaoming Ni1-0/+4
Semaphore is sleeping lock. Add might_sleep() to down*() family (with exception of down_trylock()) to detect atomic context sleep. Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210809021215.19991-1-nixiaoming@huawei.com
2021-08-20Documentation: arm64: describe asymmetric 32-bit supportWill Deacon3-0/+159
Document support for running 32-bit tasks on asymmetric 32-bit systems and its impact on the user ABI when enabled. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210730112443.23245-17-will@kernel.org
2021-08-20arm64: Remove logic to kill 32-bit tasks on 64-bit-only coresWill Deacon2-39/+1
The scheduler now knows enough about these braindead systems to place 32-bit tasks accordingly, so throw out the safety checks and allow the ret-to-user path to avoid do_notify_resume() if there is nothing to do. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-16-will@kernel.org
2021-08-20arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0Will Deacon2-0/+15
Allow systems with mismatched 32-bit support at EL0 to run 32-bit applications based on a new kernel parameter. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-15-will@kernel.org
2021-08-20arm64: Advertise CPUs capable of running 32-bit applications in sysfsWill Deacon2-0/+28
Since 32-bit applications will be killed if they are caught trying to execute on a 64-bit-only CPU in a mismatched system, advertise the set of 32-bit capable CPUs to userspace in sysfs. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-14-will@kernel.org
2021-08-20arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched systemWill Deacon1-1/+24
If we want to support 32-bit applications, then when we identify a CPU with mismatched 32-bit EL0 support we must ensure that we will always have an active 32-bit CPU available to us from then on. This is important for the scheduler, because is_cpu_allowed() will be constrained to 32-bit CPUs for compat tasks and forced migration due to a hotplug event will hang if no 32-bit CPUs are available. On detecting a mismatch, prevent offlining of either the mismatching CPU if it is 32-bit capable, or find the first active 32-bit capable CPU otherwise. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-13-will@kernel.org
2021-08-20arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0Will Deacon2-5/+40
When exec'ing a 32-bit task on a system with mismatched support for 32-bit EL0, try to ensure that it starts life on a CPU that can actually run it. Similarly, when exec'ing a 64-bit task on such a system, try to restore the old affinity mask if it was previously restricted. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Reviewed-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20210730112443.23245-12-will@kernel.org
2021-08-20arm64: Implement task_cpu_possible_mask()Will Deacon1-0/+13
Provide an implementation of task_cpu_possible_mask() so that we can prevent 64-bit-only cores being added to the 'cpus_mask' for compat tasks on systems with mismatched 32-bit support at EL0, Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-11-will@kernel.org
2021-08-20Merge branch 'sched/core'Peter Zijlstra14-171/+714
2021-08-20sched: Introduce dl_task_check_affinity() to check proposed affinityWill Deacon2-17/+35
In preparation for restricting the affinity of a task during execve() on arm64, introduce a new dl_task_check_affinity() helper function to give an indication as to whether the restricted mask is admissible for a deadline task. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Link: https://lore.kernel.org/r/20210730112443.23245-10-will@kernel.org
2021-08-20sched: Allow task CPU affinity to be restricted on asymmetric systemsWill Deacon3-18/+183
Asymmetric systems may not offer the same level of userspace ISA support across all CPUs, meaning that some applications cannot be executed by some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do not feature support for 32-bit applications on both clusters. Although userspace can carefully manage the affinity masks for such tasks, one place where it is particularly problematic is execve() because the CPU on which the execve() is occurring may be incompatible with the new application image. In such a situation, it is desirable to restrict the affinity mask of the task and ensure that the new image is entered on a compatible CPU. From userspace's point of view, this looks the same as if the incompatible CPUs have been hotplugged off in the task's affinity mask. Similarly, if a subsequent execve() reverts to a compatible image, then the old affinity is restored if it is still valid. In preparation for restricting the affinity mask for compat tasks on arm64 systems without uniform support for 32-bit applications, introduce {force,relax}_compatible_cpus_allowed_ptr(), which respectively restrict and restore the affinity mask for a task based on the compatible CPUs. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20210730112443.23245-9-will@kernel.org
2021-08-20sched: Split the guts of sched_setaffinity() into a helper functionWill Deacon1-48/+57
In preparation for replaying user affinity requests using a saved mask, split sched_setaffinity() up so that the initial task lookup and security checks are only performed when the request is coming directly from userspace. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-8-will@kernel.org
2021-08-20sched: Introduce task_struct::user_cpus_ptr to track requested affinityWill Deacon4-0/+36
In preparation for saving and restoring the user-requested CPU affinity mask of a task, add a new cpumask_t pointer to 'struct task_struct'. If the pointer is non-NULL, then the mask is copied across fork() and freed on task exit. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-7-will@kernel.org
2021-08-20sched: Reject CPU affinity changes based on task_cpu_possible_mask()Will Deacon1-1/+8
Reject explicit requests to change the affinity mask of a task via set_cpus_allowed_ptr() if the requested mask is not a subset of the mask returned by task_cpu_possible_mask(). This ensures that the 'cpus_mask' for a given task cannot contain CPUs which are incapable of executing it, except in cases where the affinity is forced. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20210730112443.23245-6-will@kernel.org
2021-08-20cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq()Will Deacon3-6/+12
select_fallback_rq() only needs to recheck for an allowed CPU if the affinity mask of the task has changed since the last check. Return a 'bool' from cpuset_cpus_allowed_fallback() to indicate whether the affinity mask was updated, and use this to elide the allowed check when the mask has been left alone. No functional change. Suggested-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-5-will@kernel.org
2021-08-20cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()Will Deacon2-18/+27
Asymmetric systems may not offer the same level of userspace ISA support across all CPUs, meaning that some applications cannot be executed by some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do not feature support for 32-bit applications on both clusters. Modify guarantee_online_cpus() to take task_cpu_possible_mask() into account when trying to find a suitable set of online CPUs for a given task. This will avoid passing an invalid mask to set_cpus_allowed_ptr() during ->attach() and will subsequently allow the cpuset hierarchy to be taken into account when forcefully overriding the affinity mask for a task which requires migration to a compatible CPU. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Link: https://lkml.kernel.org/r/20210730112443.23245-4-will@kernel.org
2021-08-20cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1Will Deacon2-2/+7
If the scheduler cannot find an allowed CPU for a task, cpuset_cpus_allowed_fallback() will widen the affinity to cpu_possible_mask if cgroup v1 is in use. In preparation for allowing architectures to provide their own fallback mask, just return early if we're either using cgroup v1 or we're using cgroup v2 with a mask that contains invalid CPUs. This will allow select_fallback_rq() to figure out the mask by itself. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Link: https://lkml.kernel.org/r/20210730112443.23245-3-will@kernel.org
2021-08-20sched: Introduce task_cpu_possible_mask() to limit fallback rq selectionWill Deacon2-6/+17
Asymmetric systems may not offer the same level of userspace ISA support across all CPUs, meaning that some applications cannot be executed by some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do not feature support for 32-bit applications on both clusters. On such a system, we must take care not to migrate a task to an unsupported CPU when forcefully moving tasks in select_fallback_rq() in response to a CPU hot-unplug operation. Introduce a task_cpu_possible_mask() hook which, given a task argument, allows an architecture to return a cpumask of CPUs that are capable of executing that task. The default implementation returns the cpu_possible_mask, since sane machines do not suffer from per-cpu ISA limitations that affect scheduling. The new mask is used when selecting the fallback runqueue as a last resort before forcing a migration to the first active CPU. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20210730112443.23245-2-will@kernel.org
2021-08-20sched: Cgroup SCHED_IDLE supportJosh Don4-25/+208
This extends SCHED_IDLE to cgroups. Interface: cgroup/cpu.idle. 0: default behavior 1: SCHED_IDLE Extending SCHED_IDLE to cgroups means that we incorporate the existing aspects of SCHED_IDLE; a SCHED_IDLE cgroup will count all of its descendant threads towards the idle_h_nr_running count of all of its ancestor cgroups. Thus, sched_idle_rq() will work properly. Additionally, SCHED_IDLE cgroups are configured with minimum weight. There are two key differences between the per-task and per-cgroup SCHED_IDLE interface: - The cgroup interface allows tasks within a SCHED_IDLE hierarchy to maintain their relative weights. The entity that is "idle" is the cgroup, not the tasks themselves. - Since the idle entity is the cgroup, our SCHED_IDLE wakeup preemption decision is not made by comparing the current task with the woken task, but rather by comparing their matching sched_entity. A typical use-case for this is a user that creates an idle and a non-idle subtree. The non-idle subtree will dominate competition vs the idle subtree, but the idle subtree will still be high priority vs other users on the system. The latter is accomplished via comparing matching sched_entity in the waken preemption path (this could also be improved by making the sched_idle_rq() decision dependent on the perspective of a specific task). For now, we maintain the existing SCHED_IDLE semantics. Future patches may make improvements that extend how we treat SCHED_IDLE entities. The per-task_group idle field is an integer that currently only holds either a 0 or a 1. This is explicitly typed as an integer to allow for further extensions to this API. For example, a negative value may indicate a highly latency-sensitive cgroup that should be preferred for preemption/placement/etc. Signed-off-by: Josh Don <joshdon@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20210730020019.1487127-2-joshdon@google.com
2021-08-20sched/topology: Skip updating masks for non-online nodesValentin Schneider1-0/+65
The scheduler currently expects NUMA node distances to be stable from init onwards, and as a consequence builds the related data structures once-and-for-all at init (see sched_init_numa()). Unfortunately, on some architectures node distance is unreliable for offline nodes and may very well change upon onlining. Skip over offline nodes during sched_init_numa(). Track nodes that have been onlined at least once, and trigger a build of a node's NUMA masks when it is first onlined post-init. Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210818074333.48645-1-srikar@linux.vnet.ibm.com
2021-08-20sched: Fix Core-wide rq->lock for uninitialized CPUsPeter Zijlstra2-27/+118
Eugene tripped over the case where rq_lock(), as called in a for_each_possible_cpu() loop came apart because rq->core hadn't been setup yet. This is a somewhat unusual, but valid case. Rework things such that rq->core is initialized to point at itself. IOW initialize each CPU as a single threaded Core. CPU online will then join the new CPU (thread) to an existing Core where needed. For completeness sake, have CPU offline fully undo the state so as to not presume the topology will match the next time it comes online. Fixes: 9edeaea1bc45 ("sched: Core-wide rq->lock") Reported-by: Eugene Syromiatnikov <esyr@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Don <joshdon@google.com> Tested-by: Eugene Syromiatnikov <esyr@redhat.com> Link: https://lkml.kernel.org/r/YR473ZGeKqMs6kw+@hirez.programming.kicks-ass.net
2021-08-20locking/ww_mutex: Initialize waiter.ww_ctx properlySebastian Andrzej Siewior1-1/+1
The consolidation of the debug code for mutex waiter intialization sets waiter::ww_ctx to a poison value unconditionally. For regular mutexes this is intended to catch the case where waiter_ww_ctx is dereferenced accidentally. For ww_mutex the poison value has to be overwritten either with a context pointer or NULL for ww_mutexes without context. The rework broke this as it made the store conditional on the context pointer instead of the argument which signals whether ww_mutex code should be compiled in or optiized out. As a result waiter::ww_ctx ends up with the poison pointer for contextless ww_mutexes which causes a later dereference of the poison pointer because it is != NULL. Use the build argument instead so for ww_mutex the poison value is always overwritten. Fixes: c0afb0ffc06e6 ("locking/ww_mutex: Gather mutex_waiter initialization") Reported-by: Guenter Roeck <linux@roeck-us.net> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210819193030.zpwrpvvrmy7xxxiy@linutronix.de
2021-08-20KVM: arm64: Upgrade trace_kvm_arm_set_dreg32() to 64bitMarc Zyngier1-3/+7
A number of registers pased to trace_kvm_arm_set_dreg32() are actually 64bit. Upgrade the tracepoint to take a 64bit value, despite the name... Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20KVM: arm64: Add config register bit definitionsFuad Tabba1-0/+22
Add hardware configuration register bit definitions for HCR_EL2 and MDCR_EL2. Future patches toggle these hyp configuration register bits to trap on certain accesses. No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-11-tabba@google.com