linux/include/asm-generic/pgtable.h, branch v5.0

lib/ioremap: ensure break-before-make is used for huge p4d mappings

2018-12-28T20:11:50Z

Whilst no architectures actually enable support for huge p4d mappings in the vmap area, the code that is implemented should be using break-before-make, as we do for pud and pmd huge entries. Link: http://lkml.kernel.org/r/1544120495-17438-6-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon Reviewed-by: Toshi Kani Cc: Chintan Pandya Cc: Toshi Kani Cc: Thomas Gleixner Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Sean Christopherson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

generic/pgtable: Introduce set_pte_safe()

2018-12-05T08:03:06Z

Commit: f77084d96355 "x86/mm/pat: Disable preemption around __flush_tlb_all()" introduced a warning to capture cases __flush_tlb_all() is called without pre-emption disabled. It triggers a false positive warning in the memory hotplug path. On investigation it was found that the __flush_tlb_all() calls are not necessary. However, they are only "not necessary" in practice provided the ptes are being initially populated from the !present state. Introduce set_pte_safe() as a sanity check that the pte is being updated in a way that does not require a TLB flush. Forgive the macro, the availability of the various of set_pte() levels is hit and miss across architectures. [ mingo: Minor readability edits. ] Suggested-by: Peter Zijlstra Suggested-by: Dave Hansen Signed-off-by: Dan Williams Acked-by: Peter Zijlstra (Intel) Acked-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Rik van Riel Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/279dadae-9148-465c-7ec6-3f37e026c6c9@intel.com Signed-off-by: Ingo Molnar

generic/pgtable: Introduce {p4d,pgd}_same()

2018-12-05T08:03:06Z

In preparation for introducing '_safe' versions of page table entry 'set' helpers, introduce generic versions of p4d_same() and pgd_same(). Signed-off-by: Dan Williams Acked-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/154395943153.32119.1733586547359626311.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

generic/pgtable: Make {pmd, pud}_same() unconditionally available

2018-12-05T08:03:05Z

In preparation for {pmd,pud}_same() to be used outside of transparent huge page code paths, make them unconditionally available. This enables them to be used in the definition of a new family of set_{pte,pmd,pud,p4d,pgd}_safe() helpers. Signed-off-by: Dan Williams Acked-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/154395942644.32119.10238934183949418128.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

Merge tag 's390-4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2018-11-09T12:30:44Z

Pull s390 fixes from Martin Schwidefsky: - A fix for the pgtable_bytes misaccounting on s390. The patch changes common code part in regard to page table folding and adds extra checks to mm_[inc|dec]_nr_[pmds|puds]. - Add FORCE for all build targets using if_changed - Use non-loadable phdr for the .vmlinux.info section to avoid a segment overlap that confuses kexec - Cleanup the attribute definition for the diagnostic sampling - Increase stack size for CONFIG_KASAN=y builds - Export __node_distance to fix a build error - Correct return code of a PMU event init function - An update for the default configs * tag 's390-4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/perf: Change CPUM_CF return code in event init function s390: update defconfigs s390/mm: Fix ERROR: "__node_distance" undefined! s390/kasan: increase instrumented stack size to 64k s390/cpum_sf: Rework attribute definition for diagnostic sampling s390/mm: fix mis-accounting of pgtable_bytes mm: add mm_pxd_folded checks to pgtable_bytes accounting functions mm: introduce mm_[p4d|pud|pmd]_folded mm: make the __PAGETABLE_PxD_FOLDED defines non-empty s390: avoid vmlinux segments overlap s390/vdso: add missing FORCE to build targets s390/decompressor: add missing FORCE to build targets

mm: introduce mm_[p4d|pud|pmd]_folded

2018-11-02T07:31:53Z

Add three architecture overrideable functions to test if the p4d, pud, or pmd layer of a page table is folded or not. Acked-by: Kirill A. Shutemov Signed-off-by: Martin Schwidefsky

mm: remove references to vm_insert_pfn()

2018-10-26T23:25:20Z

Documentation and comments. Link: http://lkml.kernel.org/r/20180828145728.11873-7-willy@infradead.org Signed-off-by: Matthew Wilcox Reviewed-by: Andrew Morton Cc: Nicolas Pitre Cc: Souptick Joarder Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: provide a fallback for PAGE_KERNEL_EXEC for architectures

2018-08-17T23:20:29Z

Some architectures just don't have PAGE_KERNEL_EXEC. The mm/nommu.c and mm/vmalloc.c code have been using PAGE_KERNEL as a fallback for years. Move this fallback to asm-generic. Link: http://lkml.kernel.org/r/20180510185507.2439-3-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Suggested-by: Matthew Wilcox Reviewed-by: Andrew Morton Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: provide a fallback for PAGE_KERNEL_RO for architectures

2018-08-17T23:20:29Z

Some architectures do not define certain PAGE_KERNEL_* flags, this is either because: a) The way to implement some of these flags is *not yet ported*, or b) The architecture *has no way* to describe them Over time we have accumulated a few PAGE_KERNEL_* fallback workarounds for architectures in the kernel which do not define them using *relatively safe* equivalents. Move these scattered fallback hacks into asm-generic. We start off with PAGE_KERNEL_RO using PAGE_KERNEL as a fallback. This has been in place on the firmware loader for years. Move the fallback into the respective asm-generic header. Link: http://lkml.kernel.org/r/20180510185507.2439-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Reviewed-by: Andrew Morton Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Matthew Wilcox Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-08-14T16:46:06Z

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 ...