lwn.git/arch/s390/kernel/Makefile, branch v5.14-rc2

s390/vdso: add minimal compat vdso

2021-07-08T13:37:28+00:00

Add a small vdso for 31 bit compat application that provides trampolines for calls to sigreturn,rt_sigreturn,syscall_restart. This is requird for moving these syscalls away from the signal frame to the vdso. Note that this patch effectively disables CONFIG_COMPAT when using clang to compile the kernel. clang doesn't support 31 bit mode. We want to redirect sigreturn and restart_syscall to the vdso. However, the kernel cannot parse the ELF vdso file, so we need to generate header files which contain the offsets of the syscall instructions in the vdso page. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility

2021-07-05T10:44:23+00:00

Commit cf6acb8bdb1d ("s390/cpumf: Add support for complete counter set extraction") allows access to the CPU Measurement Counter Facility via character device /dev/hwctr. The access was exclusive via this device or via perf_event_open() system call. Only one path at a time was permitted. The CPU Measurement Counter Facility device driver blocked access to other processes. This patch removes this restriction and allows concurrent access to the CPU Measurement Counter Facility from multiple processes at the same time via perf_event_open() SVC and via /dev/hwctr device. The access via /dev/hwctr device is still exclusive, only one process is allowed to access this device. This patch - moves the /dev/hwctr device access from file perf_cpum_cf_diag.c. to file perf_cpum_cf.c. - use only one trace buffer .../s390dbf/cpum_cf. - remove cfset_csd structure and includes its members it into the structure cpu_cf_events. This results in one data structure and simplifies the access. - rework function familiy ctr_set_enable, ctr_set_disable, ctr_set_start and ctr_set_stop which operate on a counter set number. Now they operate on a counter set bit mask. - move CF_DIAG event functionality to file perf_cpum_cf.c. It now contains the complete functionality of the CPU Measurement Counter Facility: - Performance measurement support for counters using perf stat. - Support for complete counter set extraction with device /dev/hwctr. - Support for counter set extraction event CF_DIAG attached to samples using perf record. - removes file perf_cpum_cf_diag.c Signed-off-by: Thomas Richter Reviewed-by: Sumanth Korikkar Signed-off-by: Vasily Gorbik

s390/traps: convert pgm_check.S to C

2021-04-12T10:46:41+00:00

Convert the program check table to C. Which allows to get rid of yet another assembler file, and also enables proper type checking for the table. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390: convert to generic entry

2021-01-19T11:29:26+00:00

This patch converts s390 to use the generic entry infrastructure from kernel/entry/*. There are a few special things on s390: - PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't know about our PIF flags in exit_to_user_mode_loop(). - The old code had several ways to restart syscalls: a) PIF_SYSCALL_RESTART, which was only set during execve to force a restart after upgrading a process (usually qemu-kvm) to pgste page table extensions. b) PIF_SYSCALL, which is set by do_signal() to indicate that the current syscall should be restarted. This is changed so that do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use PIF_SYSCALL doesn't work with the generic code, and changing it to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART more unique. - On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by executing a svc instruction on the process stack which causes a fault. While handling that fault the fault code sets PIF_SYSCALL to hand over processing to the syscall code on exit to usermode. The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets a return value for a syscall. The s390x ptrace ABI uses r2 both for the syscall number and return value, so ptrace cannot set the syscall number + return value at the same time. The flag makes handling that a bit easier. do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET is set. CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY. CR1/7/13 will be checked both on kernel entry and exit to contain the correct asces. Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik

s390/kprobes: move insn_page to text segment

2020-10-09T21:45:30+00:00

Move the in-kernel kprobes insn page to text segment. Rationale: having that page in rw data segment is suboptimal, since as soon as a kprobe is set, this will split the 1:1 kernel mapping for a single page which get new permissions. Note: there is always at least one kprobe present for the kretprobe trampoline; so the mapping will always be split into smaller 4k mappings because of this. Moving the kprobes insn page into text segment makes sure that the page is mapped RO/X in any case, and avoids that the 1:1 mapping is split. The kprobe insn_page is defined as a dummy function which is filled with "br %r14" instructions. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/numa: move code to arch/s390/kernel

2020-08-11T16:16:55+00:00

Move all code from arch/s390/numa/ to arch/s390/kernel/ since numa.c is the only source file and all others were deleted with the fake NUMA support removal. Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390: ptrace: hard-code "s390x" instead of UTS_MACHINE

2020-05-06T12:59:20+00:00

s390 uses the UTS_MACHINE defined arch/s390/Makefile as follows: UTS_MACHINE := s390x We do not need to pass the fixed string from the command line. Hard-code user_regset_view::name, like many other architectures do. Link: https://lkml.kernel.org/r/20200413013113.8529-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Signed-off-by: Vasily Gorbik

Merge tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2020-04-04T16:45:50+00:00

Pull s390 updates from Vasily Gorbik: - Update maintainers. Niklas Schnelle takes over zpci and Vineeth Vijayan common io code. - Extend cpuinfo to include topology information. - Add new extended counters for IBM z15 and sampling buffer allocation rework in perf code. - Add control over zeroing out memory during system restart. - CCA protected key block version 2 support and other fixes/improvements in crypto code. - Convert to new fallthrough; annotations. - Replace zero-length arrays with flexible-arrays. - QDIO debugfs and other small improvements. - Drop 2-level paging support optimization for compat tasks. Varios mm cleanups. - Remove broken and unused hibernate / power management support. - Remove fake numa support which does not bring any benefits. - Exclude offline CPUs from CPU topology masks to be more consistent with other architectures. - Prevent last branching instruction address leaking to userspace. - Other small various fixes and improvements all over the code. * tag 's390-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (57 commits) s390/mm: cleanup init_new_context() callback s390/mm: cleanup virtual memory constants usage s390/mm: remove page table downgrade support s390/qdio: set qdio_irq->cdev at allocation time s390/qdio: remove unused function declarations s390/ccwgroup: remove pm support s390/ap: remove power management code from ap bus and drivers s390/zcrypt: use kvmalloc instead of kmalloc for 256k alloc s390/mm: cleanup arch_get_unmapped_area() and friends s390/ism: remove pm support s390/cio: use fallthrough; s390/vfio: use fallthrough; s390/zcrypt: use fallthrough; s390: use fallthrough; s390/cpum_sf: Fix wrong page count in error message s390/diag: fix display of diagnose call statistics s390/ap: Remove ap device suspend and resume callbacks s390/pci: Improve handling of unset UID s390/pci: Fix zpci_alloc_domain() over allocation s390/qdio: pass ISC as parameter to chsc_sadc() ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-04-02T22:13:15+00:00

Pull kvm updates from Paolo Bonzini: "ARM: - GICv4.1 support - 32bit host removal PPC: - secure (encrypted) using under the Protected Execution Framework ultravisor s390: - allow disabling GISA (hardware interrupt injection) and protected VMs/ultravisor support. x86: - New dirty bitmap flag that sets all bits in the bitmap when dirty page logging is enabled; this is faster because it doesn't require bulk modification of the page tables. - Initial work on making nested SVM event injection more similar to VMX, and less buggy. - Various cleanups to MMU code (though the big ones and related optimizations were delayed to 5.8). Instead of using cr3 in function names which occasionally means eptp, KVM too has standardized on "pgd". - A large refactoring of CPUID features, which now use an array that parallels the core x86_features. - Some removal of pointer chasing from kvm_x86_ops, which will also be switched to static calls as soon as they are available. - New Tigerlake CPUID features. - More bugfixes, optimizations and cleanups. Generic: - selftests: cleanups, new MMU notifier stress test, steal-time test - CSV output for kvm_stat" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (277 commits) x86/kvm: fix a missing-prototypes "vmread_error" KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=y KVM: VMX: Add a trampoline to fix VMREAD error handling KVM: SVM: Annotate svm_x86_ops as __initdata KVM: VMX: Annotate vmx_x86_ops as __initdata KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup() KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes KVM: VMX: Configure runtime hooks using vmx_x86_ops KVM: VMX: Move hardware_setup() definition below vmx_x86_ops KVM: x86: Move init-only kvm_x86_ops to separate struct KVM: Pass kvm_init()'s opaque param to additional arch funcs s390/gmap: return proper error code on ksm unsharing KVM: selftests: Fix cosmetic copy-paste error in vm_mem_region_move() KVM: Fix out of range accesses to memslots KVM: X86: Micro-optimize IPI fastpath delay KVM: X86: Delay read msr data iff writes ICR MSR KVM: PPC: Book3S HV: Add a capability for enabling secure guests KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs ...

s390: remove broken hibernate / power management support

2020-03-23T12:41:55+00:00

Hibernation is known to be broken for many years on s390. Given that there aren't any real use cases, remove the code instead of spending time to fix and maintain it. Without hibernate support it doesn't make too much sense to keep power management support; therefore remove it completely. Acked-by: Christian Borntraeger Acked-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik