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2018-08-27x86/Kconfig: Fix trivial typoNikolas Nyby
Fix a typo in the Kconfig help text: adverticed -> advertised. Signed-off-by: Nikolas Nyby <nikolas@gnu.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Cc: tglx@linutronix.de Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20180825231054.23813-1-nikolas@gnu.org
2018-08-23x86/mm: Only use tlb_remove_table() for paravirtPeter Zijlstra
If we don't use paravirt; don't play unnecessary and complicated games to free page-tables. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREEPeter Zijlstra
Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes: 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22arch: enable relative relocations for arm64, power and x86Ard Biesheuvel
Patch series "add support for relative references in special sections", v10. This adds support for emitting special sections such as initcall arrays, PCI fixups and tracepoints as relative references rather than absolute references. This reduces the size by 50% on 64-bit architectures, but more importantly, it removes the need for carrying relocation metadata for these sections in relocatable kernels (e.g., for KASLR) that needs to be fixed up at boot time. On arm64, this reduces the vmlinux footprint of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs 4 byte relative reference) Patch #3 was sent out before as a single patch. This series supersedes the previous submission. This version makes relative ksymtab entries dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather than trying to infer from kbuild test robot replies for which architectures it should be blacklisted. Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS, and sets it for the main architectures that are expected to benefit the most from this feature, i.e., 64-bit architectures or ones that use runtime relocations. Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of ksymtab/kcrctab sections in decompressor and EFI stub objects when rebuilding existing C files to run in a different context. Patches #4 - #6 implement relative references for initcalls, PCI fixups and tracepoints, respectively, all of which produce sections with order ~1000 entries on an arm64 defconfig kernel with tracing enabled. This means we save about 28 KB of vmlinux space for each of these patches. [From the v7 series blurb, which included the jump_label patches as well]: For the arm64 kernel, all patches combined reduce the memory footprint of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has KASLR enabled), of which ~1 MB is the size reduction of the RELA section in .init, and the remaining 300 KB is reduction of .text/.data. This patch (of 6): Before updating certain subsystems to use place relative 32-bit relocations in special sections, to save space and reduce the number of absolute relocations that need to be processed at runtime by relocatable kernels, introduce the Kconfig symbol and define it for some architectures that should be able to support and benefit from it. Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Morris <jmorris@namei.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Cc: James Morris <james.morris@microsoft.com> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-15Merge tag 'kconfig-v4.19-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig consolidation from Masahiro Yamada: "Consolidation of Kconfig files by Christoph Hellwig. Move the source statements of arch-independent Kconfig files instead of duplicating the includes in every arch/$(SRCARCH)/Kconfig" * tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: add a Memory Management options" menu kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt kconfig: use a menu in arch/Kconfig to reduce clutter kconfig: include kernel/Kconfig.preempt from init/Kconfig Kconfig: consolidate the "Kernel hacking" menu kconfig: include common Kconfig files from top-level Kconfig kconfig: remove duplicate SWAP symbol defintions um: create a proper drivers Kconfig um: cleanup Kconfig files um: stop abusing KBUILD_KCONFIG
2018-08-14Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "A bunch of good stuff in here. Worth noting is that we've pulled in the x86/mm branch from -tip so that we can make use of the core ioremap changes which allow us to put down huge mappings in the vmalloc area without screwing up the TLB. Much of the positive diffstat is because of the rseq selftest for arm64. Summary: - Wire up support for qspinlock, replacing our trusty ticket lock code - Add an IPI to flush_icache_range() to ensure that stale instructions fetched into the pipeline are discarded along with the I-cache lines - Support for the GCC "stackleak" plugin - Support for restartable sequences, plus an arm64 port for the selftest - Kexec/kdump support on systems booting with ACPI - Rewrite of our syscall entry code in C, which allows us to zero the GPRs on entry from userspace - Support for chained PMU counters, allowing 64-bit event counters to be constructed on current CPUs - Ensure scheduler topology information is kept up-to-date with CPU hotplug events - Re-enable support for huge vmalloc/IO mappings now that the core code has the correct hooks to use break-before-make sequences - Miscellaneous, non-critical fixes and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (90 commits) arm64: alternative: Use true and false for boolean values arm64: kexec: Add comment to explain use of __flush_icache_range() arm64: sdei: Mark sdei stack helper functions as static arm64, kaslr: export offset in VMCOREINFO ELF notes arm64: perf: Add cap_user_time aarch64 efi/libstub: Only disable stackleak plugin for arm64 arm64: drop unused kernel_neon_begin_partial() macro arm64: kexec: machine_kexec should call __flush_icache_range arm64: svc: Ensure hardirq tracing is updated before return arm64: mm: Export __sync_icache_dcache() for xen-privcmd drivers/perf: arm-ccn: Use devm_ioremap_resource() to map memory arm64: Add support for STACKLEAK gcc plugin arm64: Add stack information to on_accessible_stack drivers/perf: hisi: update the sccl_id/ccl_id when MT is supported arm64: fix ACPI dependencies rseq/selftests: Add support for arm64 arm64: acpi: fix alignment fault in accessing ACPI efi/arm: map UEFI memory map even w/o runtime services enabled efi/arm: preserve early mapping of UEFI memory map longer for BGRT drivers: acpi: add dependency of EFI for arm64 ...
2018-08-14Merge branch 'l1tf-final' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Merge L1 Terminal Fault fixes from Thomas Gleixner: "L1TF, aka L1 Terminal Fault, is yet another speculative hardware engineering trainwreck. It's a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Cache when the page table entry controlling the virtual address, which is used for the access, has the Present bit cleared or other reserved bits set. If an instruction accesses a virtual address for which the relevant page table entry (PTE) has the Present bit cleared or other reserved bits set, then speculative execution ignores the invalid PTE and loads the referenced data if it is present in the Level 1 Data Cache, as if the page referenced by the address bits in the PTE was still present and accessible. While this is a purely speculative mechanism and the instruction will raise a page fault when it is retired eventually, the pure act of loading the data and making it available to other speculative instructions opens up the opportunity for side channel attacks to unprivileged malicious code, similar to the Meltdown attack. While Meltdown breaks the user space to kernel space protection, L1TF allows to attack any physical memory address in the system and the attack works across all protection domains. It allows an attack of SGX and also works from inside virtual machines because the speculation bypasses the extended page table (EPT) protection mechanism. The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646 The mitigations provided by this pull request include: - Host side protection by inverting the upper address bits of a non present page table entry so the entry points to uncacheable memory. - Hypervisor protection by flushing L1 Data Cache on VMENTER. - SMT (HyperThreading) control knobs, which allow to 'turn off' SMT by offlining the sibling CPU threads. The knobs are available on the kernel command line and at runtime via sysfs - Control knobs for the hypervisor mitigation, related to L1D flush and SMT control. The knobs are available on the kernel command line and at runtime via sysfs - Extensive documentation about L1TF including various degrees of mitigations. Thanks to all people who have contributed to this in various ways - patches, review, testing, backporting - and the fruitful, sometimes heated, but at the end constructive discussions. There is work in progress to provide other forms of mitigations, which might be less horrible performance wise for a particular kind of workloads, but this is not yet ready for consumption due to their complexity and limitations" * 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) x86/microcode: Allow late microcode loading with SMT disabled tools headers: Synchronise x86 cpufeatures.h for L1TF additions x86/mm/kmmio: Make the tracer robust against L1TF x86/mm/pat: Make set_memory_np() L1TF safe x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert x86/speculation/l1tf: Invert all not present mappings cpu/hotplug: Fix SMT supported evaluation KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Documentation/l1tf: Remove Yonah processors from not vulnerable list x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr() x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d x86: Don't include linux/irq.h from asm/hardirq.h x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond' x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush() cpu/hotplug: detect SMT disabled by BIOS ...
2018-08-13Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Thomas Gleixner: "The lowlevel and ASM code updates for x86: - Make stack trace unwinding more reliable - ASM instruction updates for better code generation - Various cleanups" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry/64: Add two more instruction suffixes x86/asm/64: Use 32-bit XOR to zero registers x86/build/vdso: Simplify 'cmd_vdso2c' x86/build/vdso: Remove unused vdso-syms.lds x86/stacktrace: Enable HAVE_RELIABLE_STACKTRACE for the ORC unwinder x86/unwind/orc: Detect the end of the stack x86/stacktrace: Do not fail for ORC with regs on stack x86/stacktrace: Clarify the reliable success paths x86/stacktrace: Remove STACKTRACE_DUMP_ONCE x86/stacktrace: Do not unwind after user regs x86/asm: Use CC_SET/CC_OUT in percpu_cmpxchg8b_double() to micro-optimize code generation
2018-08-05Merge 4.18-rc7 into master to pick up the KVM dependcyThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-08-02kconfig: include kernel/Kconfig.preempt from init/KconfigChristoph Hellwig
Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to disable preempt support for alpha, hexagon, non-coldfire m68k and user mode Linux. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02Kconfig: consolidate the "Kernel hacking" menuChristoph Hellwig
Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to the top-level Kconfig. For two architectures that means moving their arch-specific symbols in that menu into a new arch Kconfig.debug file, and for a few more creating a dummy file so that we can include it unconditionally. Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where it belongs. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02kconfig: include common Kconfig files from top-level KconfigChristoph Hellwig
Instead of duplicating the source statements in every architecture just do it once in the toplevel Kconfig file. Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of the top-level Kconfig into arch/Kconfig so that don't violate ordering constraits while keeping a sensible menu structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-24arm64: fix ACPI dependenciesArnd Bergmann
Kconfig reports a warning on x86 builds after the ARM64 dependency was added. drivers/acpi/Kconfig:6:error: recursive dependency detected! drivers/acpi/Kconfig:6: symbol ACPI depends on EFI This rephrases the dependency to keep the ARM64 details out of the shared Kconfig file, so Kconfig no longer gets confused by it. For consistency, all three architectures that support ACPI now select ARCH_SUPPORTS_ACPI in exactly the configuration in which they allow it. We still need the 'default x86', as each one wants a different default: default-y on x86, default-n on arm64, and always-y on ia64. Fixes: 5bcd44083a08 ("drivers: acpi: add dependency of EFI for arm64") Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-16x86/asm/memcpy_mcsafe: Fix copy_to_user_mcsafe() exception handlingDan Williams
All copy_to_user() implementations need to be prepared to handle faults accessing userspace. The __memcpy_mcsafe() implementation handles both mmu-faults on the user destination and machine-check-exceptions on the source buffer. However, the memcpy_mcsafe() wrapper may silently fallback to memcpy() depending on build options and cpu-capabilities. Force copy_to_user_mcsafe() to always use __memcpy_mcsafe() when available, and otherwise disable all of the copy_to_user_mcsafe() infrastructure when __memcpy_mcsafe() is not available, i.e. CONFIG_X86_MCE=n. This fixes crashes of the form: run fstests generic/323 at 2018-07-02 12:46:23 BUG: unable to handle kernel paging request at 00007f0d50001000 RIP: 0010:__memcpy+0x12/0x20 [..] Call Trace: copyout_mcsafe+0x3a/0x50 _copy_to_iter_mcsafe+0xa1/0x4a0 ? dax_alive+0x30/0x50 dax_iomap_actor+0x1f9/0x280 ? dax_iomap_rw+0x100/0x100 iomap_apply+0xba/0x130 ? dax_iomap_rw+0x100/0x100 dax_iomap_rw+0x95/0x100 ? dax_iomap_rw+0x100/0x100 xfs_file_dax_read+0x7b/0x1d0 [xfs] xfs_file_read_iter+0xa7/0xc0 [xfs] aio_read+0x11c/0x1a0 Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Fixes: 8780356ef630 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()") Link: http://lkml.kernel.org/r/153108277790.37979.1486841789275803399.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21x86/stacktrace: Enable HAVE_RELIABLE_STACKTRACE for the ORC unwinderJiri Slaby
In SUSE, we need a reliable stack unwinder for kernel live patching, but we do not want to enable frame pointers for performance reasons. So after the previous patches to make the ORC reliable, mark ORC as a reliable stack unwinder on x86. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/lkml/20180518064713.26440-6-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21cpu/hotplug: Provide knobs to control SMTThomas Gleixner
Provide a command line and a sysfs knob to control SMT. The command line options are: 'nosmt': Enumerate secondary threads, but do not online them 'nosmt=force': Ignore secondary threads completely during enumeration via MP table and ACPI/MADT. The sysfs control file has the following states (read/write): 'on': SMT is enabled. Secondary threads can be freely onlined 'off': SMT is disabled. Secondary threads, even if enumerated cannot be onlined 'forceoff': SMT is permanentely disabled. Writes to the control file are rejected. 'notsupported': SMT is not supported by the CPU The command line option 'nosmt' sets the sysfs control to 'off'. This can be changed to 'on' to reenable SMT during runtime. The command line option 'nosmt=force' sets the sysfs control to 'forceoff'. This cannot be changed during runtime. When SMT is 'on' and the control file is changed to 'off' then all online secondary threads are offlined and attempts to online a secondary thread later on are rejected. When SMT is 'off' and the control file is changed to 'on' then secondary threads can be onlined again. The 'off' -> 'on' transition does not automatically online the secondary threads. When the control file is set to 'forceoff', the behaviour is the same as setting it to 'off', but the operation is irreversible and later writes to the control file are rejected. When the control status is 'notsupported' then writes to the control file are rejected. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-06-15Kbuild: rename HAVE_CC_STACKPROTECTOR config variableMasahiro Yamada
HAVE_CC_STACKPROTECTOR should be selected by architectures with stack canary implementation. It is not about the compiler support. For the consistency with commit 050e9baa9dc9 ("Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables"), remove 'CC_' from the config symbol. I moved the 'select' lines to keep the alphabetical sorting. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15x86: fix dependency of X86_32_LAZY_GSMasahiro Yamada
Commit 2a61f4747eea ("stack-protector: test compiler capability in Kconfig and drop AUTO mode") replaced the 'choice' with two boolean symbols, so CC_STACKPROTECTOR_NONE no longer exists. Prior to commit 2bc2f688fdf8 ("Makefile: move stack-protector availability out of Kconfig"), this line was like this: depends on X86_32 && !CC_STACKPROTECTOR The CC_ prefix was dropped by commit 050e9baa9dc9 ("Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables"), so the dependency now should be: depends on X86_32 && !STACKPROTECTOR Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-13Merge tag 'kbuild-v4.18-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix some bugs introduced by the recent Kconfig syntax extension - add some symbols about compiler information in Kconfig, such as CC_IS_GCC, CC_IS_CLANG, GCC_VERSION, etc. - test compiler capability for the stack protector in Kconfig, and clean-up Makefile - test compiler capability for GCC-plugins in Kconfig, and clean-up Makefile - allow to enable GCC-plugins for COMPILE_TEST - test compiler capability for KCOV in Kconfig and correct dependency - remove auto-detect mode of the GCOV format, which is now more nicely handled in Kconfig - test compiler capability for mprofile-kernel on PowerPC, and clean-up Makefile - misc cleanups * tag 'kbuild-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: linux/linkage.h: replace VMLINUX_SYMBOL_STR() with __stringify() kconfig: fix localmodconfig sh: remove no-op macro VMLINUX_SYMBOL() powerpc/kbuild: move -mprofile-kernel check to Kconfig Documentation: kconfig: add recommended way to describe compiler support gcc-plugins: disable GCC_PLUGIN_STRUCTLEAK_BYREF_ALL for COMPILE_TEST gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST gcc-plugins: test plugin support in Kconfig and clean up Makefile gcc-plugins: move GCC version check for PowerPC to Kconfig kcov: test compiler capability in Kconfig and correct dependency gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig kconfig: add CC_IS_CLANG and CLANG_VERSION kconfig: add CC_IS_GCC and GCC_VERSION stack-protector: test compiler capability in Kconfig and drop AUTO mode kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
2018-06-10Merge branch 'core-rseq-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull restartable sequence support from Thomas Gleixner: "The restartable sequences syscall (finally): After a lot of back and forth discussion and massive delays caused by the speculative distraction of maintainers, the core set of restartable sequences has finally reached a consensus. It comes with the basic non disputed core implementation along with support for arm, powerpc and x86 and a full set of selftests It was exposed to linux-next earlier this week, so it does not fully comply with the merge window requirements, but there is really no point to drag it out for yet another cycle" * 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rseq/selftests: Provide Makefile, scripts, gitignore rseq/selftests: Provide parametrized tests rseq/selftests: Provide basic percpu ops test rseq/selftests: Provide basic test rseq/selftests: Provide rseq library selftests/lib.mk: Introduce OVERRIDE_TARGETS powerpc: Wire up restartable sequences system call powerpc: Add syscall detection for restartable sequences powerpc: Add support for restartable sequences x86: Wire up restartable sequence system call x86: Add support for restartable sequences arm: Wire up restartable sequences system call arm: Add syscall detection for restartable sequences arm: Add restartable sequences support rseq: Introduce restartable sequences system call uapi/headers: Provide types_32_64.h
2018-06-10Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates and fixes from Thomas Gleixner: - Fix the (late) fallout from the vector management rework causing hlist corruption and irq descriptor reference leaks caused by a missing sanity check. The straight forward fix triggered another long standing issue to surface. The pre rework code hid the issue due to being way slower, but now the chance that user space sees an EBUSY error return when updating irq affinities is way higher, though quite a bunch of userspace tools do not handle it properly despite the fact that EBUSY could be returned for at least 10 years. It turned out that the EBUSY return can be avoided completely by utilizing the existing delayed affinity update mechanism for irq remapped scenarios as well. That's a bit more error handling in the kernel, but avoids fruitless fingerpointing discussions with tool developers. - Decouple PHYSICAL_MASK from AMD SME as its going to be required for the upcoming Intel memory encryption support as well. - Handle legacy device ACPI detection properly for newer platforms - Fix the wrong argument ordering in the vector allocation tracepoint - Simplify the IDT setup code for the APIC=n case - Use the proper string helpers in the MTRR code - Remove a stale unused VDSO source file - Convert the microcode update lock to a raw spinlock as its used in atomic context. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel_rdt: Enable CMT and MBM on new Skylake stepping x86/apic/vector: Print APIC control bits in debugfs genirq/affinity: Defer affinity setting if irq chip is busy x86/platform/uv: Use apic_ack_irq() x86/ioapic: Use apic_ack_irq() irq_remapping: Use apic_ack_irq() x86/apic: Provide apic_ack_irq() genirq/migration: Avoid out of line call if pending is not set genirq/generic_pending: Do not lose pending affinity update x86/apic/vector: Prevent hlist corruption and leaks x86/vector: Fix the args of vector_alloc tracepoint x86/idt: Simplify the idt_setup_apic_and_irq_gates() x86/platform/uv: Remove extra parentheses x86/mm: Decouple dynamic __PHYSICAL_MASK from AMD SME x86: Mark native_set_p4d() as __always_inline x86/microcode: Make the late update update_lock a raw lock for RT x86/mtrr: Convert to use strncpy_from_user() helper x86/mtrr: Convert to use match_string() helper x86/vdso: Remove unused file x86/i8237: Register device based on FADT legacy boot flag
2018-06-08stack-protector: test compiler capability in Kconfig and drop AUTO modeMasahiro Yamada
Move the test for -fstack-protector(-strong) option to Kconfig. If the compiler does not support the option, the corresponding menu is automatically hidden. If STRONG is not supported, it will fall back to REGULAR. If REGULAR is not supported, it will be disabled. This means, AUTO is implicitly handled by the dependency solver of Kconfig, hence removed. I also turned the 'choice' into only two boolean symbols. The use of 'choice' is not a good idea here, because all of all{yes,mod,no}config would choose the first visible value, while we want allnoconfig to disable as many features as possible. X86 has additional shell scripts in case the compiler supports those options, but generates broken code. I added CC_HAS_SANE_STACKPROTECTOR to test this. I had to add -m32 to gcc-x86_32-has-stack-protector.sh to make it work correctly. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org>
2018-06-07mm: introduce ARCH_HAS_PTE_SPECIALLaurent Dufour
Currently the PTE special supports is turned on in per architecture header files. Most of the time, it is defined in arch/*/include/asm/pgtable.h depending or not on some other per architecture static definition. This patch introduce a new configuration variable to manage this directly in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL. Here notes for some architecture where the definition of __HAVE_ARCH_PTE_SPECIAL is not obvious: arm __HAVE_ARCH_PTE_SPECIAL which is currently defined in arch/arm/include/asm/pgtable-3level.h which is included by arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set. So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE. powerpc __HAVE_ARCH_PTE_SPECIAL is defined in 2 files: - arch/powerpc/include/asm/book3s/64/pgtable.h - arch/powerpc/include/asm/pte-common.h The first one is included if (PPC_BOOK3S & PPC64) while the second is included in all the other cases. So select ARCH_HAS_PTE_SPECIAL all the time. sparc: __HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) && defined(__arch64__) which are defined through the compiler in sparc/Makefile if !SPARC32 which I assume to be if SPARC64. So select ARCH_HAS_PTE_SPECIAL if SPARC64 There is no functional change introduced by this patch. Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Add Maglev hashing scheduler to IPVS, from Inju Song. 2) Lots of new TC subsystem tests from Roman Mashak. 3) Add TCP zero copy receive and fix delayed acks and autotuning with SO_RCVLOWAT, from Eric Dumazet. 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard Brouer. 5) Add ttl inherit support to vxlan, from Hangbin Liu. 6) Properly separate ipv6 routes into their logically independant components. fib6_info for the routing table, and fib6_nh for sets of nexthops, which thus can be shared. From David Ahern. 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP messages from XDP programs. From Nikita V. Shirokov. 8) Lots of long overdue cleanups to the r8169 driver, from Heiner Kallweit. 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau. 10) Add traffic condition monitoring to iwlwifi, from Luca Coelho. 11) Plumb extack down into fib_rules, from Roopa Prabhu. 12) Add Flower classifier offload support to igb, from Vinicius Costa Gomes. 13) Add UDP GSO support, from Willem de Bruijn. 14) Add documentation for eBPF helpers, from Quentin Monnet. 15) Add TLS tx offload to mlx5, from Ilya Lesokhin. 16) Allow applications to be given the number of bytes available to read on a socket via a control message returned from recvmsg(), from Soheil Hassas Yeganeh. 17) Add x86_32 eBPF JIT compiler, from Wang YanQing. 18) Add AF_XDP sockets, with zerocopy support infrastructure as well. From Björn Töpel. 19) Remove indirect load support from all of the BPF JITs and handle these operations in the verifier by translating them into native BPF instead. From Daniel Borkmann. 20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha. 21) Allow XDP programs to do lookups in the main kernel routing tables for forwarding. From David Ahern. 22) Allow drivers to store hardware state into an ELF section of kernel dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy. 23) Various RACK and loss detection improvements in TCP, from Yuchung Cheng. 24) Add TCP SACK compression, from Eric Dumazet. 25) Add User Mode Helper support and basic bpfilter infrastructure, from Alexei Starovoitov. 26) Support ports and protocol values in RTM_GETROUTE, from Roopa Prabhu. 27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard Brouer. 28) Add lots of forwarding selftests, from Petr Machata. 29) Add generic network device failover driver, from Sridhar Samudrala. * ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits) strparser: Add __strp_unpause and use it in ktls. rxrpc: Fix terminal retransmission connection ID to include the channel net: hns3: Optimize PF CMDQ interrupt switching process net: hns3: Fix for VF mailbox receiving unknown message net: hns3: Fix for VF mailbox cannot receiving PF response bnx2x: use the right constant Revert "net: sched: cls: Fix offloading when ingress dev is vxlan" net: dsa: b53: Fix for brcm tag issue in Cygnus SoC enic: fix UDP rss bits netdev-FAQ: clarify DaveM's position for stable backports rtnetlink: validate attributes in do_setlink() mlxsw: Add extack messages for port_{un, }split failures netdevsim: Add extack error message for devlink reload devlink: Add extack to reload and port_{un, }split operations net: metrics: add proper netlink validation ipmr: fix error path when ipmr_new_table fails ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds net: hns3: remove unused hclgevf_cfg_func_mta_filter netfilter: provide udp*_lib_lookup for nf_tproxy qed*: Utilize FW 8.37.2.0 ...
2018-06-06Merge tag 'kconfig-v4.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: "Kconfig now supports new functionality to perform textual substitution. It has been a while since Linus suggested to move compiler option tests from makefiles to Kconfig. Finally, here it is. The implementation has been generalized into a Make-like macro language. Some built-in functions such as 'shell' are provided. Variables and user-defined functions are also supported so that 'cc-option', 'ld-option', etc. are implemented as macros. Summary: - refactor package checks for building {m,n,q,g}conf - remove unused/unmaintained localization support - remove Kbuild cache - drop CONFIG_CROSS_COMPILE support - replace 'option env=' with direct variable expansion - add built-in functions such as 'shell' - support variables and user-defined functions - add helper macros as as 'cc-option' - add unit tests and a document of the new macro language - add 'testconfig' to help - fix warnings from GCC 8.1" * tag 'kconfig-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) kconfig: Avoid format overflow warning from GCC 8.1 kbuild: Move last word of nconfig help to the previous line kconfig: Add testconfig into make help output kconfig: add basic helper macros to scripts/Kconfig.include kconfig: show compiler version text in the top comment kconfig: test: add Kconfig macro language tests Documentation: kconfig: document a new Kconfig macro language kconfig: error out if a recursive variable references itself kconfig: add 'filename' and 'lineno' built-in variables kconfig: add 'info', 'warning-if', and 'error-if' built-in functions kconfig: expand lefthand side of assignment statement kconfig: support append assignment operator kconfig: support simply expanded variable kconfig: support user-defined function and recursively expanded variable kconfig: begin PARAM state only when seeing a command keyword kconfig: replace $(UNAME_RELEASE) with function call kconfig: add 'shell' built-in function kconfig: add built-in function support kconfig: make default prompt of mainmenu less specific kconfig: remove sym_expand_string_value() ...
2018-06-06x86/mm: Decouple dynamic __PHYSICAL_MASK from AMD SMEKirill A. Shutemov
AMD SME claims one bit from physical address to indicate whether the page is encrypted or not. To achieve that we clear out the bit from __PHYSICAL_MASK. The capability to adjust __PHYSICAL_MASK is required beyond AMD SME. For instance for upcoming Intel Multi-Key Total Memory Encryption. Factor it out into a separate feature with own Kconfig handle. It also helps with overhead of AMD SME. It saves more than 3k in .text on defconfig + AMD_MEM_ENCRYPT: add/remove: 3/2 grow/shrink: 5/110 up/down: 189/-3753 (-3564) We would need to return to this once we have infrastructure to patch constants in code. That's good candidate for it. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: linux-mm@kvack.org Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20180518113028.79825-1-kirill.shutemov@linux.intel.com
2018-06-06x86: Add support for restartable sequencesMathieu Desnoyers
Call the rseq_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. Perform fixup on the pre-signal frame when a signal is delivered on top of a restartable sequence critical section. Check that system calls are not invoked from within rseq critical sections by invoking rseq_signal() from syscall_return_slowpath(). With CONFIG_DEBUG_RSEQ, such behavior results in termination of the process with SIGSEGV. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-7-mathieu.desnoyers@efficios.com
2018-06-04Merge branch 'x86-dax-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 dax updates from Ingo Molnar: "This contains x86 memcpy_mcsafe() fault handling improvements the nvdimm tree would like to make more use of" * 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe() x86/asm/memcpy_mcsafe: Add write-protection-fault handling x86/asm/memcpy_mcsafe: Return bytes remaining x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling x86/asm/memcpy_mcsafe: Remove loop unrolling
2018-05-29kconfig: reference environment variables directly and remove 'option env='Masahiro Yamada
To get access to environment variables, Kconfig needs to define a symbol using "option env=" syntax. It is tedious to add a symbol entry for each environment variable given that we need to define much more such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability in Kconfig. Adding '$' for symbol references is grammatically inconsistent. Looking at the code, the symbols prefixed with 'S' are expanded by: - conf_expand_value() This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list' - sym_expand_string_value() This is used to expand strings in 'source' and 'mainmenu' All of them are fixed values independent of user configuration. So, they can be changed into the direct expansion instead of symbols. This change makes the code much cleaner. The bounce symbols 'SRCARCH', 'ARCH', 'SUBARCH', 'KERNELVERSION' are gone. sym_init() hard-coding 'UNAME_RELEASE' is also gone. 'UNAME_RELEASE' should be replaced with an environment variable. ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced without '$' prefix. The new syntax is addicted by Make. The variable reference needs parentheses, like $(FOO), but you can omit them for single-letter variables, like $F. Yet, in Makefiles, people tend to use the parenthetical form for consistency / clarification. At this moment, only the environment variable is supported, but I will extend the concept of 'variable' later on. The variables are expanded in the lexer so we can simplify the token handling on the parser side. For example, the following code works. [Example code] config MY_TOOLCHAIN_LIST string default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)" [Result] $ make -s alldefconfig && tail -n 1 .config CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E" Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-15x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()Dan Williams
Use the updated memcpy_mcsafe() implementation to define copy_user_mcsafe() and copy_to_iter_mcsafe(). The most significant difference from typical copy_to_iter() is that the ITER_KVEC and ITER_BVEC iterator types can fail to complete a full transfer. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539239150.31796.9189779163576449784.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-09swiotlb: move the SWIOTLB config symbol to lib/KconfigChristoph Hellwig
This way we have one central definition of it, and user can select it as needed. The new option is not user visible, which is the behavior it had in most architectures, with a few notable exceptions: - On x86_64 and mips/loongson3 it used to be user selectable, but defaulted to y. It now is unconditional, which seems like the right thing for 64-bit architectures without guaranteed availablity of IOMMUs. - on powerpc the symbol is user selectable and defaults to n, but many boards select it. This change assumes no working setup required a manual selection, but if that turned out to be wrong we'll have to add another select statement or two for the respective boards. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-09arch: define the ARCH_DMA_ADDR_T_64BIT config symbol in lib/KconfigChristoph Hellwig
Define this symbol if the architecture either uses 64-bit pointers or the PHYS_ADDR_T_64BIT is set. This covers 95% of the old arch magic. We only need an additional select for Xen on ARM (why anyway?), and we now always set ARCH_DMA_ADDR_T_64BIT on mips boards with 64-bit physical addressing instead of only doing it when highmem is set. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: James Hogan <jhogan@kernel.org>
2018-05-09arch: remove the ARCH_PHYS_ADDR_T_64BIT config symbolChristoph Hellwig
Instead select the PHYS_ADDR_T_64BIT for 32-bit architectures that need a 64-bit phys_addr_t type directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: James Hogan <jhogan@kernel.org>
2018-05-09dma-mapping: move the NEED_DMA_MAP_STATE config symbol to lib/KconfigChristoph Hellwig
This way we have one central definition of it, and user can select it as needed. Note that we now also always select it when CONFIG_DMA_API_DEBUG is select, which fixes some incorrect checks in a few network drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2018-05-09scatterlist: move the NEED_SG_DMA_LENGTH config symbol to lib/KconfigChristoph Hellwig
This way we have one central definition of it, and user can select it as needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2018-05-09iommu-helper: move the IOMMU_HELPER config symbol to lib/Christoph Hellwig
This way we have one central definition of it, and user can select it as needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2018-05-09iommu-helper: mark iommu_is_span_boundary as inlineChristoph Hellwig
This avoids selecting IOMMU_HELPER just for this function. And we only use it once or twice in normal builds so this often even is a size reduction. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-08dma-debug: remove CONFIG_HAVE_DMA_API_DEBUGChristoph Hellwig
There is no arch specific code required for dma-debug, so there is no need to opt into the support either. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-05-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Minor conflict, a CHECK was placed into an if() statement in net-next, whilst a newline was added to that CHECK call in 'net'. Thanks to Daniel for the merge resolution. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-03bpf, x86_32: add eBPF JIT compiler for ia32Wang YanQing
The JIT compiler emits ia32 bit instructions. Currently, It supports eBPF only. Classic BPF is supported because of the conversion by BPF core. Almost all instructions from eBPF ISA supported except the following: BPF_ALU64 | BPF_DIV | BPF_K BPF_ALU64 | BPF_DIV | BPF_X BPF_ALU64 | BPF_MOD | BPF_K BPF_ALU64 | BPF_MOD | BPF_X BPF_STX | BPF_XADD | BPF_W BPF_STX | BPF_XADD | BPF_DW It doesn't support BPF_JMP|BPF_CALL with BPF_PSEUDO_CALL at the moment. IA32 has few general purpose registers, EAX|EDX|ECX|EBX|ESI|EDI. I use EAX|EDX|ECX|EBX as temporary registers to simulate instructions in eBPF ISA, and allocate ESI|EDI to BPF_REG_AX for constant blinding, all others eBPF registers, R0-R10, are simulated through scratch space on stack. The reasons behind the hardware registers allocation policy are: 1:MUL need EAX:EDX, shift operation need ECX, so they aren't fit for general eBPF 64bit register simulation. 2:We need at least 4 registers to simulate most eBPF ISA operations on registers operands instead of on register&memory operands. 3:We need to put BPF_REG_AX on hardware registers, or constant blinding will degrade jit performance heavily. Tested on PC (Intel(R) Core(TM) i5-5200U CPU). Testing results on i5-5200U: 1) test_bpf: Summary: 349 PASSED, 0 FAILED, [319/341 JIT'ed] 2) test_progs: Summary: 83 PASSED, 0 FAILED. 3) test_lpm: OK 4) test_lru_map: OK 5) test_verifier: Summary: 828 PASSED, 0 FAILED. Above tests are all done in following two conditions separately: 1:bpf_jit_enable=1 and bpf_jit_harden=0 2:bpf_jit_enable=1 and bpf_jit_harden=2 Below are some numbers for this jit implementation: Note: I run test_progs in kselftest 100 times continuously for every condition, the numbers are in format: total/times=avg. The numbers that test_bpf reports show almost the same relation. a:jit_enable=0 and jit_harden=0 b:jit_enable=1 and jit_harden=0 test_pkt_access:PASS:ipv4:15622/100=156 test_pkt_access:PASS:ipv4:10674/100=106 test_pkt_access:PASS:ipv6:9130/100=91 test_pkt_access:PASS:ipv6:4855/100=48 test_xdp:PASS:ipv4:240198/100=2401 test_xdp:PASS:ipv4:138912/100=1389 test_xdp:PASS:ipv6:137326/100=1373 test_xdp:PASS:ipv6:68542/100=685 test_l4lb:PASS:ipv4:61100/100=611 test_l4lb:PASS:ipv4:37302/100=373 test_l4lb:PASS:ipv6:101000/100=1010 test_l4lb:PASS:ipv6:55030/100=550 c:jit_enable=1 and jit_harden=2 test_pkt_access:PASS:ipv4:10558/100=105 test_pkt_access:PASS:ipv6:5092/100=50 test_xdp:PASS:ipv4:131902/100=1319 test_xdp:PASS:ipv6:77932/100=779 test_l4lb:PASS:ipv4:38924/100=389 test_l4lb:PASS:ipv6:57520/100=575 The numbers show we get 30%~50% improvement. See Documentation/networking/filter.txt for more information. Changelog: Changes v5-v6: 1:Add do {} while (0) to RETPOLINE_RAX_BPF_JIT for consistence reason. 2:Clean up non-standard comments, reported by Daniel Borkmann. 3:Fix a memory leak issue, repoted by Daniel Borkmann. Changes v4-v5: 1:Delete is_on_stack, BPF_REG_AX is the only one on real hardware registers, so just check with it. 2:Apply commit 1612a981b766 ("bpf, x64: fix JIT emission for dead code"), suggested by Daniel Borkmann. Changes v3-v4: 1:Fix changelog in commit. I install llvm-6.0, then test_progs willn't report errors. I submit another patch: "bpf: fix misaligned access for BPF_PROG_TYPE_PERF_EVENT program type on x86_32 platform" to fix another problem, after that patch, test_verifier willn't report errors too. 2:Fix clear r0[1] twice unnecessarily in *BPF_IND|BPF_ABS* simulation. Changes v2-v3: 1:Move BPF_REG_AX to real hardware registers for performance reason. 3:Using bpf_load_pointer instead of bpf_jit32.S, suggested by Daniel Borkmann. 4:Delete partial codes in 1c2a088a6626, suggested by Daniel Borkmann. 5:Some bug fixes and comments improvement. Changes v1-v2: 1:Fix bug in emit_ia32_neg64. 2:Fix bug in emit_ia32_arsh_r64. 3:Delete filename in top level comment, suggested by Thomas Gleixner. 4:Delete unnecessary boiler plate text, suggested by Thomas Gleixner. 5:Rewrite some words in changelog. 6:CodingSytle improvement and a little more comments. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-25x86/pti: Filter at vma->vm_page_prot populationDave Hansen
commit ce9962bf7e22bb3891655c349faff618922d4a73 0day reported warnings at boot on 32-bit systems without NX support: attempted to set unsupported pgprot: 8000000000000025 bits: 8000000000000000 supported: 7fffffffffffffff WARNING: CPU: 0 PID: 1 at arch/x86/include/asm/pgtable.h:540 handle_mm_fault+0xfc1/0xfe0: check_pgprot at arch/x86/include/asm/pgtable.h:535 (inlined by) pfn_pte at arch/x86/include/asm/pgtable.h:549 (inlined by) do_anonymous_page at mm/memory.c:3169 (inlined by) handle_pte_fault at mm/memory.c:3961 (inlined by) __handle_mm_fault at mm/memory.c:4087 (inlined by) handle_mm_fault at mm/memory.c:4124 The problem is that due to the recent commit which removed auto-massaging of page protections, filtering page permissions at PTE creation time is not longer done, so vma->vm_page_prot is passed unfiltered to PTE creation. Filter the page protections before they are installed in vma->vm_page_prot. Fixes: fb43d6cb91 ("x86/mm: Do not auto-massage page protections") Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Link: https://lkml.kernel.org/r/20180420222028.99D72858@viggo.jf.intel.com
2018-04-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of fixes and updates for x86: - Address a swiotlb regression which was caused by the recent DMA rework and made driver fail because dma_direct_supported() returned false - Fix a signedness bug in the APIC ID validation which caused invalid APIC IDs to be detected as valid thereby bloating the CPU possible space. - Fix inconsisten config dependcy/select magic for the MFD_CS5535 driver. - Fix a corruption of the physical address space bits when encryption has reduced the address space and late cpuinfo updates overwrite the reduced bit information with the original value. - Dominiks syscall rework which consolidates the architecture specific syscall functions so all syscalls can be wrapped with the same macros. This allows to switch x86/64 to struct pt_regs based syscalls. Extend the clearing of user space controlled registers in the entry patch to the lower registers" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Fix signedness bug in APIC ID validity checks x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption x86/olpc: Fix inconsistent MFD_CS5535 configuration swiotlb: Use dma_direct_supported() for swiotlb_ops syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming convention syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*() syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention syscalls/core, syscalls/x86: Clean up syscall stub naming convention syscalls/x86: Extend register clearing on syscall entry to lower registers syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64 syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32 syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y x86/syscalls: Don't pointlessly reload the system call number x86/mm: Fix documentation of module mapping range with 4-level paging x86/cpuid: Switch to 'static const' specifier
2018-04-13kexec_file: make use of purgatory optionalAKASHI Takahiro
Patch series "kexec_file, x86, powerpc: refactoring for other architecutres", v2. This is a preparatory patchset for adding kexec_file support on arm64. It was originally included in a arm64 patch set[1], but Philipp is also working on their kexec_file support on s390[2] and some changes are now conflicting. So these common parts were extracted and put into a separate patch set for better integration. What's more, my original patch#4 was split into a few small chunks for easier review after Dave's comment. As such, the resulting code is basically identical with my original, and the only *visible* differences are: - renaming of _kexec_kernel_image_probe() and _kimage_file_post_load_cleanup() - change one of types of arguments at prepare_elf64_headers() Those, unfortunately, require a couple of trivial changes on the rest (#1, #6 to #13) of my arm64 kexec_file patch set[1]. Patch #1 allows making a use of purgatory optional, particularly useful for arm64. Patch #2 commonalizes arch_kexec_kernel_{image_probe, image_load, verify_sig}() and arch_kimage_file_post_load_cleanup() across architectures. Patches #3-#7 are also intended to generalize parse_elf64_headers(), along with exclude_mem_range(), to be made best re-use of. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2018-February/561182.html [2] http://lkml.iu.edu//hypermail/linux/kernel/1802.1/02596.html This patch (of 7): On arm64, crash dump kernel's usable memory is protected by *unmapping* it from kernel virtual space unlike other architectures where the region is just made read-only. It is highly unlikely that the region is accidentally corrupted and this observation rationalizes that digest check code can also be dropped from purgatory. The resulting code is so simple as it doesn't require a bit ugly re-linking/relocation stuff, i.e. arch_kexec_apply_relocations_add(). Please see: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-December/545428.html All that the purgatory does is to shuffle arguments and jump into a new kernel, while we still need to have some space for a hash value (purgatory_sha256_digest) which is never checked against. As such, it doesn't make sense to have trampline code between old kernel and new kernel on arm64. This patch introduces a new configuration, ARCH_HAS_KEXEC_PURGATORY, and allows related code to be compiled in only if necessary. [takahiro.akashi@linaro.org: fix trivial screwup] Link: http://lkml.kernel.org/r/20180309093346.GF25863@linaro.org Link: http://lkml.kernel.org/r/20180306102303.9063-2-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Dave Young <dyoung@redhat.com> Tested-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-12Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is readyIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-09x86/olpc: Fix inconsistent MFD_CS5535 configurationArnd Bergmann
This Kconfig warning appeared after a fix to the Kconfig validation. The GPIO_CS5535 driver depends on the MFD_CS5535 driver, but the former is selected in places where the latter is not: WARNING: unmet direct dependencies detected for GPIO_CS5535 Depends on [m]: GPIOLIB [=y] && (X86 [=y] || MIPS || COMPILE_TEST [=y]) && MFD_CS5535 [=m] Selected by [y]: - OLPC_XO1_SCI [=y] && X86_32 [=y] && OLPC [=y] && OLPC_XO1_PM [=y] && INPUT [=y]=y The warning does seem appropriate, since the GPIO_CS5535 driver won't work unless MFD_CS5535 is also present. However, there is no link time dependency between the two, so this caused no problems during randconfig testing before. This changes the 'select GPIO_CS5535' to 'depends on GPIO_CS5535' to avoid the issue, at the expense of making it harder to configure the driver (one now has to select the dependencies first). The 'select MFD_CORE' part is completely redundant, since we already depend on MFD_CS5535 here, so I'm removing that as well. Ideally, the private symbols exported by that cs5535 gpio driver would just be converted to gpiolib interfaces so we could expletely avoid this dependency. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kbuild@vger.kernel.org Fixes: f622f8279581 ("kconfig: warn unmet direct dependency of tristate symbols selected by y") Link: http://lkml.kernel.org/r/20180404124539.3817101-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: kfifo: fix inaccurate comment tools/thermal: tmon: fix for segfault net: Spelling s/stucture/structure/ edd: don't spam log if no EDD information is present Documentation: Fix early-microcode.txt references after file rename tracing: Block comments should align the * on each line treewide: Fix typos in printk GenWQE: Fix a typo in two comments treewide: Align function definition open/close braces
2018-04-05Merge tag 'gpio-v4.17-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.17 kernel cycle: New drivers: - Nintendo Wii GameCube GPIO, known as "Hollywood" - Raspberry Pi mailbox service GPIO expander - Spreadtrum main SC9860 SoC and IEC GPIO controllers. Improvements: - Implemented .get_multiple() callback for most of the high-performance industrial GPIO cards for the ISA bus. - ISA GPIO drivers now select the ISA_BUS_API instead of depending on it. This is merged with the same pattern for all the ISA drivers and some other Kconfig cleanups related to this. Cleanup: - Delete the TZ1090 GPIO drivers following the deletion of this SoC from the ARM tree. - Move the documentation over to driver-api to conform with the rest of the kernel documentation build. - Continue to make the GPIO drivers include only <linux/gpio/driver.h> and not the too broad <linux/gpio.h> that we want to get rid of. - Managed to remove VLA allocation from two drivers pending more fixes in this area for the next merge window. - Misc janitorial fixes" * tag 'gpio-v4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (77 commits) gpio: Add Spreadtrum PMIC EIC driver support gpio: Add Spreadtrum EIC driver support dt-bindings: gpio: Add Spreadtrum EIC controller documentation gpio: ath79: Fix potential NULL dereference in ath79_gpio_probe() pinctrl: qcom: Don't allow protected pins to be requested gpiolib: Support 'gpio-reserved-ranges' property gpiolib: Change bitmap allocation to kmalloc_array gpiolib: Extract mask allocation into subroutine dt-bindings: gpio: Add a gpio-reserved-ranges property gpio: mockup: fix a potential crash when creating debugfs entries gpio: pca953x: add compatibility for pcal6524 and pcal9555a gpio: dwapb: Add support for a bus clock gpio: Remove VLA from xra1403 driver gpio: Remove VLA from MAX3191X driver gpio: ws16c48: Implement get_multiple callback gpio: gpio-mm: Implement get_multiple callback gpio: 104-idi-48: Implement get_multiple callback gpio: 104-dio-48e: Implement get_multiple callback gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks gpio: pci-idio-16: Implement get_multiple callback ...
2018-04-05syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64Dominik Brodowski
Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify several codepaths. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION ↵Dominik Brodowski
and x32 Extend ARCH_HAS_SYSCALL_WRAPPER for i386 emulation and for x32 on 64-bit x86. For x32, all we need to do is to create an additional stub for each compat syscall which decodes the parameters in x86-64 ordering, e.g.: asmlinkage long __compat_sys_x32_xyzzy(struct pt_regs *regs) { return c_SyS_xyzzy(regs->di, regs->si, regs->dx); } For i386 emulation, we need to teach compat_sys_*() to take struct pt_regs as its only argument, e.g.: asmlinkage long __compat_sys_ia32_xyzzy(struct pt_regs *regs) { return c_SyS_xyzzy(regs->bx, regs->cx, regs->dx); } In addition, we need to create additional stubs for common syscalls (that is, for syscalls which have the same parameters on 32-bit and 64-bit), e.g.: asmlinkage long __sys_ia32_xyzzy(struct pt_regs *regs) { return c_sys_xyzzy(regs->bx, regs->cx, regs->dx); } This approach avoids leaking random user-provided register content down the call chain. This patch is based on an original proof-of-concept | From: Linus Torvalds <torvalds@linux-foundation.org> | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> and was split up and heavily modified by me, in particular to base it on ARCH_HAS_SYSCALL_WRAPPER. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-6-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05syscalls/x86: Use 'struct pt_regs' based syscall calling convention for ↵Dominik Brodowski
64-bit syscalls Let's make use of ARCH_HAS_SYSCALL_WRAPPER=y on pure 64-bit x86-64 systems: Each syscall defines a stub which takes struct pt_regs as its only argument. It decodes just those parameters it needs, e.g: asmlinkage long sys_xyzzy(const struct pt_regs *regs) { return SyS_xyzzy(regs->di, regs->si, regs->dx); } This approach avoids leaking random user-provided register content down the call chain. For example, for sys_recv() which is a 4-parameter syscall, the assembly now is (in slightly reordered fashion): <sys_recv>: callq <__fentry__> /* decode regs->di, ->si, ->dx and ->r10 */ mov 0x70(%rdi),%rdi mov 0x68(%rdi),%rsi mov 0x60(%rdi),%rdx mov 0x38(%rdi),%rcx [ SyS_recv() is automatically inlined by the compiler, as it is not [yet] used anywhere else ] /* clear %r9 and %r8, the 5th and 6th args */ xor %r9d,%r9d xor %r8d,%r8d /* do the actual work */ callq __sys_recvfrom /* cleanup and return */ cltq retq The only valid place in an x86-64 kernel which rightfully calls a syscall function on its own -- vsyscall -- needs to be modified to pass struct pt_regs onwards as well. To keep the syscall table generation working independent of SYSCALL_PTREGS being enabled, the stubs are named the same as the "original" syscall stubs, i.e. sys_*(). This patch is based on an original proof-of-concept | From: Linus Torvalds <torvalds@linux-foundation.org> | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> and was split up and heavily modified by me, in particular to base it on ARCH_HAS_SYSCALL_WRAPPER, to limit it to 64-bit-only for the time being, and to update the vsyscall to the new calling convention. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-4-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>