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2019-05-06Merge branch 'x86-topology-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 topology updates from Ingo Molnar: "Two main changes: preparatory changes for Intel multi-die topology support, plus a syslog message tweak" * 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/topology: Make DEBUG_HOTPLUG_CPU0 pr_info() more descriptive x86/smpboot: Rename match_die() to match_pkg() topology: Simplify cputopology.txt formatting and wording x86/topology: Fix documentation typo
2019-05-06Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "The changes in here are: - text_poke() fixes and an extensive set of executability lockdowns, to (hopefully) eliminate the last residual circumstances under which we are using W|X mappings even temporarily on x86 kernels. This required a broad range of surgery in text patching facilities, module loading, trampoline handling and other bits. - tweak page fault messages to be more informative and more structured. - remove DISCONTIGMEM support on x86-32 and make SPARSEMEM the default. - reduce KASLR granularity on 5-level paging kernels from 512 GB to 1 GB. - misc other changes and updates" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/mm: Initialize PGD cache during mm initialization x86/alternatives: Add comment about module removal races x86/kprobes: Use vmalloc special flag x86/ftrace: Use vmalloc special flag bpf: Use vmalloc special flag modules: Use vmalloc special flag mm/vmalloc: Add flag for freeing of special permsissions mm/hibernation: Make hibernation handle unmapped pages x86/mm/cpa: Add set_direct_map_*() functions x86/alternatives: Remove the return value of text_poke_*() x86/jump-label: Remove support for custom text poker x86/modules: Avoid breaking W^X while loading modules x86/kprobes: Set instruction page as executable x86/ftrace: Set trampoline pages as executable x86/kgdb: Avoid redundant comparison of patched code x86/alternatives: Use temporary mm for text poking x86/alternatives: Initialize temporary mm for patching fork: Provide a function for copying init_mm uprobes: Initialize uprobes earlier x86/mm: Save debug registers when loading a temporary mm ...
2019-04-19x86/topology: Fix documentation typoLen Brown1-1/+1
Syntax only, no functional or semantic change. reflect actual cpuinfo_x86 field name: s/logical_id/logical_proc_id/ Signed-off-by: Len Brown <len.brown@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/e2810a5317d3a109a98204e883fd1461f77b9339.1551160674.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-17x86/exceptions: Split debug IST stackThomas Gleixner1-1/+6
The debug IST stack is actually two separate debug stacks to handle #DB recursion. This is required because the CPU starts always at top of stack on exception entry, which means on #DB recursion the second #DB would overwrite the stack of the first. The low level entry code therefore adjusts the top of stack on entry so a secondary #DB starts from a different stack page. But the stack pages are adjacent without a guard page between them. Split the debug stack into 3 stacks which are separated by guard pages. The 3rd stack is never mapped into the cpu_entry_area and is only there to catch triple #DB nesting: --- top of DB_stack <- Initial stack --- end of DB_stack guard page --- top of DB1_stack <- Top of stack after entering first #DB --- end of DB1_stack guard page --- top of DB2_stack <- Top of stack after entering second #DB --- end of DB2_stack guard page If DB2 would not act as the final guard hole, a second #DB would point the top of #DB stack to the stack below #DB1 which would be valid and not catch the not so desired triple nesting. The backing store does not allocate any memory for DB2 and its guard page as it is not going to be mapped into the cpu_entry_area. - Adjust the low level entry code so it adjusts top of #DB with the offset between the stacks instead of exception stack size. - Make the dumpstack code aware of the new stacks. - Adjust the in_debug_stack() implementation and move it into the NMI code where it belongs. As this is NMI hotpath code, it just checks the full area between top of DB_stack and bottom of DB1_stack without checking for the guard page. That's correct because the NMI cannot hit a stackpointer pointing to the guard page between DB and DB1 stack. Even if it would, then the NMI operation still is unaffected, but the resume of the debug exception on the topmost DB stack will crash by touching the guard page. [ bp: Make exception_stack_names static const char * const ] Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: linux-doc@vger.kernel.org Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190414160145.439944544@linutronix.de
2019-04-17x86/exceptions: Make IST index zero basedThomas Gleixner1-4/+4
The defines for the exception stack (IST) array in the TSS are using the SDM convention IST1 - IST7. That causes all sorts of code to subtract 1 for array indices related to IST. That's confusing at best and does not provide any value. Make the indices zero based and fixup the usage sites. The only code which needs to adjust the 0 based index is the interrupt descriptor setup which needs to add 1 now. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: linux-doc@vger.kernel.org Cc: Nicolai Stange <nstange@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190414160144.331772825@linutronix.de
2019-04-16x86/mm: Fix the 56-bit addresses memory map in Documentation/x86/x86_64/mm.txtStephen Kitt1-3/+3
This fixes a PT typo, and the following 56-bit address-space addresses: * the hole extends from 0100000000000000 to feffffffffffffff * the KASAN shadow memory area stops at fffffbffffffffff (see kasan.h) Signed-off-by: Stephen Kitt <steve@sk2.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alex.popov@linux.com Cc: bhe@redhat.com Cc: corbet@lwn.net Cc: kirill.shutemov@linux.intel.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20190415150853.10354-1-steve@sk2.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-18doc: add boot protocol 2.13 description to Documentation/x86/boot.txtJuergen Gross1-0/+4
Documentation/x86/boot.txt is missing protocol 2.13 description. Reported-by: Ross Philipson <ross.philipson@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-03-06x86/speculation/mds: Add mitigation mode VMWERVThomas Gleixner1-0/+27
In virtualized environments it can happen that the host has the microcode update which utilizes the VERW instruction to clear CPU buffers, but the hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit to guests. Introduce an internal mitigation mode VMWERV which enables the invocation of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the system has no updated microcode this results in a pointless execution of the VERW instruction wasting a few CPU cycles. If the microcode is updated, but not exposed to a guest then the CPU buffers will be cleared. That said: Virtual Machines Will Eventually Receive Vaccine Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Conditionally clear CPU buffers on idle entryThomas Gleixner1-0/+42
Add a static key which controls the invocation of the CPU buffer clear mechanism on idle entry. This is independent of other MDS mitigations because the idle entry invocation to mitigate the potential leakage due to store buffer repartitioning is only necessary on SMT systems. Add the actual invocations to the different halt/mwait variants which covers all usage sites. mwaitx is not patched as it's not available on Intel CPUs. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU is spilled to the Hyper-Thread sibling after the Store buffer got repartitioned and all entries are available to the non idle sibling. When coming out of idle the store buffer is partitioned again so each sibling has half of it available. Now CPU which returned from idle could be speculatively exposed to contents of the sibling, but the buffers are flushed either on exit to user space or on VMENTER. When later on conditional buffer clearing is implemented on top of this, then there is no action required either because before returning to user space the context switch will set the condition flag which causes a flush on the return to user path. Note, that the buffer clearing on idle is only sensible on CPUs which are solely affected by MSBDS and not any other variant of MDS because the other MDS variants cannot be mitigated when SMT is enabled, so the buffer clearing on idle would be a window dressing exercise. This intentionally does not handle the case in the acpi/processor_idle driver which uses the legacy IO port interface for C-State transitions for two reasons: - The acpi/processor_idle driver was replaced by the intel_idle driver almost a decade ago. Anything Nehalem upwards supports it and defaults to that new driver. - The legacy IO port interface is likely to be used on older and therefore unaffected CPUs or on systems which do not receive microcode updates anymore, so there is no point in adding that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Clear CPU buffers on exit to userThomas Gleixner1-0/+52
Add a static key which controls the invocation of the CPU buffer clear mechanism on exit to user space and add the call into prepare_exit_to_usermode() and do_nmi() right before actually returning. Add documentation which kernel to user space transition this covers and explain why some corner cases are not mitigated. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add mds_clear_cpu_buffers()Thomas Gleixner3-0/+117
The Microarchitectural Data Sampling (MDS) vulernabilities are mitigated by clearing the affected CPU buffers. The mechanism for clearing the buffers uses the unused and obsolete VERW instruction in combination with a microcode update which triggers a CPU buffer clear when VERW is executed. Provide a inline function with the assembly magic. The argument of the VERW instruction must be a memory operand as documented: "MD_CLEAR enumerates that the memory-operand variant of VERW (for example, VERW m16) has been extended to also overwrite buffers affected by MDS. This buffer overwriting functionality is not guaranteed for the register operand variant of VERW." Documentation also recommends to use a writable data segment selector: "The buffer overwriting occurs regardless of the result of the VERW permission check, as well as when the selector is null or causes a descriptor load segment violation. However, for lowest latency we recommend using a selector that indicates a valid writable data segment." Add x86 specific documentation about MDS and the internal workings of the mitigation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-02-02x86/resctrl: Avoid confusion over the new X86_RESCTRL configJohannes Weiner1-1/+1
"Resource Control" is a very broad term for this CPU feature, and a term that is also associated with containers, cgroups etc. This can easily cause confusion. Make the user prompt more specific. Match the config symbol name. [ bp: In the future, the corresponding ARM arch-specific code will be under ARM_CPU_RESCTRL and the arch-agnostic bits will be carved out under the CPU_RESCTRL umbrella symbol. ] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Babu Moger <Babu.Moger@amd.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-doc@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pu Wen <puwen@hygon.cn> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190130195621.GA30653@cmpxchg.org
2019-01-09x86/cache: Rename config option to CONFIG_X86_RESCTRLBorislav Petkov1-1/+1
CONFIG_RESCTRL is too generic. The final goal is to have a generic option called like this which is selected by the arch-specific ones CONFIG_X86_RESCTRL and CONFIG_ARM64_RESCTRL. The generic one will cover the resctrl filesystem and other generic and shared bits of functionality. Signed-off-by: Borislav Petkov <bp@suse.de> Suggested-by: Ingo Molnar <mingo@kernel.org> Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Babu Moger <babu.moger@amd.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Morse <james.morse@arm.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20190108171401.GC12235@zn.tnic
2018-12-29Merge tag 'docs-5.0' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation update from Jonathan Corbet: "A fairly normal cycle for documentation stuff. We have a new document on perf security, more Italian translations, more improvements to the memory-management docs, improvements to the pathname lookup documentation, and the usual array of smaller fixes. As is often the case, there are a few reaches outside of Documentation/ to adjust kerneldoc comments" * tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits) docs: improve pathname-lookup document structure configfs: fix wrong name of struct in documentation docs/mm-api: link slab_common.c to "The Slab Cache" section slab: make kmem_cache_create{_usercopy} description proper kernel-doc doc:process: add links where missing docs/core-api: make mm-api.rst more structured x86, boot: documentation whitespace fixup Documentation: devres: note checking needs when converting doc:it: add some process/* translations doc:it: fixes in process/1.Intro Documentation: convert path-lookup from markdown to resturctured text Documentation/admin-guide: update admin-guide index.rst Documentation/admin-guide: introduce perf-security.rst file scripts/kernel-doc: Fix struct and struct field attribute processing Documentation: dev-tools: Fix typos in index.rst Correct gen_init_cpio tool's documentation Document /proc/pid PID reuse behavior Documentation: update path-lookup.md for parallel lookups Documentation: Use "while" instead of "whilst" dmaengine: Add mailing list address to the documentation ...
2018-12-28Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-4/+1
Pull DMA mapping updates from Christoph Hellwig: "A huge update this time, but a lot of that is just consolidating or removing code: - provide a common DMA_MAPPING_ERROR definition and avoid indirect calls for dma_map_* error checking - use direct calls for the DMA direct mapping case, avoiding huge retpoline overhead for high performance workloads - merge the swiotlb dma_map_ops into dma-direct - provide a generic remapping DMA consistent allocator for architectures that have devices that perform DMA that is not cache coherent. Based on the existing arm64 implementation and also used for csky now. - improve the dma-debug infrastructure, including dynamic allocation of entries (Robin Murphy) - default to providing chaining scatterlist everywhere, with opt-outs for the few architectures (alpha, parisc, most arm32 variants) that can't cope with it - misc sparc32 dma-related cleanups - remove the dma_mark_clean arch hook used by swiotlb on ia64 and replace it with the generic noncoherent infrastructure - fix the return type of dma_set_max_seg_size (Niklas Söderlund) - move the dummy dma ops for not DMA capable devices from arm64 to common code (Robin Murphy) - ensure dma_alloc_coherent returns zeroed memory to avoid kernel data leaks through userspace. We already did this for most common architectures, but this ensures we do it everywhere. dma_zalloc_coherent has been deprecated and can hopefully be removed after -rc1 with a coccinelle script" * tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping: (73 commits) dma-mapping: fix inverted logic in dma_supported dma-mapping: deprecate dma_zalloc_coherent dma-mapping: zero memory returned from dma_alloc_* sparc/iommu: fix ->map_sg return value sparc/io-unit: fix ->map_sg return value arm64: default to the direct mapping in get_arch_dma_ops PCI: Remove unused attr variable in pci_dma_configure ia64: only select ARCH_HAS_DMA_COHERENT_TO_PFN if swiotlb is enabled dma-mapping: bypass indirect calls for dma-direct vmd: use the proper dma_* APIs instead of direct methods calls dma-direct: merge swiotlb_dma_ops into the dma_direct code dma-direct: use dma_direct_map_page to implement dma_direct_map_sg dma-direct: improve addressability error reporting swiotlb: remove dma_mark_clean swiotlb: remove SWIOTLB_MAP_ERROR ACPI / scan: Refactor _CCA enforcement dma-mapping: factor out dummy DMA ops dma-mapping: always build the direct mapping code dma-mapping: move dma_cache_sync out of line dma-mapping: move various slow path functions out of line ...
2018-12-26Merge branch 'x86-cache-for-linus' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache control updates from Borislav Petkov: - The generalization of the RDT code to accommodate the addition of AMD's very similar implementation of the cache monitoring feature. This entails a subsystem move into a separate and generic arch/x86/kernel/cpu/resctrl/ directory along with adding vendor-specific initialization and feature detection helpers. Ontop of that is the unification of user-visible strings, both in the resctrl filesystem error handling and Kconfig. Provided by Babu Moger and Sherry Hurwitz. - Code simplifications and error handling improvements by Reinette Chatre. * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Fix rdt_find_domain() return value and checks x86/resctrl: Remove unnecessary check for cbm_validate() x86/resctrl: Use rdt_last_cmd_puts() where possible MAINTAINERS: Update resctrl filename patterns Documentation: Rename and update intel_rdt_ui.txt to resctrl_ui.txt x86/resctrl: Introduce AMD QOS feature x86/resctrl: Fixup the user-visible strings x86/resctrl: Add AMD's X86_FEATURE_MBA to the scattered CPUID features x86/resctrl: Rename the config option INTEL_RDT to RESCTRL x86/resctrl: Add vendor check for the MBA software controller x86/resctrl: Bring cbm_validate() into the resource structure x86/resctrl: Initialize the vendor-specific resource functions x86/resctrl: Move all the macros to resctrl/internal.h x86/resctrl: Re-arrange the RDT init code x86/resctrl: Rename the RDT functions and definitions x86/resctrl: Rename and move rdt files to a separate directory
2018-12-11x86/dma/amd-gart: Stop resizing dma_debug_entry poolRobin Murphy1-4/+1
dma-debug is now capable of adding new entries to its pool on-demand if the initial preallocation was insufficient, so the IOMMU_LEAK logic no longer needs to explicitly change the pool size. This does lose it the ability to save a couple of megabytes of RAM by reducing the pool size below its default, but it seems unlikely that that is a realistic concern these days (or indeed that anyone is actively debugging AGP drivers' DMA usage any more). Getting rid of dma_debug_resize_entries() will make room for further streamlining in the dma-debug code itself. Removing the call reveals quite a lot of cruft which has been useless for nearly a decade since commit 19c1a6f5764d ("x86 gart: reimplement IOMMU_LEAK feature by using DMA_API_DEBUG"), including the entire 'iommu=leak' parameter, which controlled nothing except whether dma_debug_resize_entries() was called or not. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-06x86, boot: documentation whitespace fixupMichael S. Tsirkin1-1/+1
Fix an extra space that sneaked in with commit 09c205afd "(x86, boot: Define the 2.12 bzImage boot protocol"). Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-11-22Documentation: Rename and update intel_rdt_ui.txt to resctrl_ui.txtBabu Moger1-3/+6
Rename intel_rdt_ui.txt to generic resctrl_ui.txt and update the documentation for AMD. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: David Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Safonov <dima@arista.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <linux-doc@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Pu Wen <puwen@hygon.cn> Cc: <qianyue.zj@alibaba-inc.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Rian Hunter <rian@alum.mit.edu> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: <xiaochen.shen@intel.com> Link: https://lkml.kernel.org/r/20181121202811.4492-13-babu.moger@amd.com
2018-11-20x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to ↵Juergen Gross1-31/+1
setup_header") Peter Anvin pointed out that commit: ae7e1238e68f2a ("x86/boot: Add ACPI RSDP address to setup_header") should be reverted as setup_header should only contain items set by the legacy BIOS. So revert said commit. Instead of fully reverting the dependent commit of: e7b66d16fe4172 ("x86/acpi, x86/boot: Take RSDP address for boot params if available") just remove the setup_header reference in order to replace it by a boot_params in a followup patch. Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: daniel.kiper@oracle.com Cc: sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181120072529.5489-2-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-06x86/mm: Move LDT remap out of KASLR region on 5-level pagingKirill A. Shutemov1-16/+18
On 5-level paging the LDT remap area is placed in the middle of the KASLR randomization region and it can overlap with the direct mapping, the vmalloc or the vmap area. The LDT mapping is per mm, so it cannot be moved into the P4D page table next to the CPU_ENTRY_AREA without complicating PGD table allocation for 5-level paging. The 4 PGD slot gap just before the direct mapping is reserved for hypervisors, so it cannot be used. Move the direct mapping one slot deeper and use the resulting gap for the LDT remap area. The resulting layout is the same for 4 and 5 level paging. [ tglx: Massaged changelog ] Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: peterz@infradead.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: bhe@redhat.com Cc: willy@infradead.org Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181026122856.66224-2-kirill.shutemov@linux.intel.com
2018-11-05Documentation/x86: Fix typo in zero-page.txtRandy Dunlap1-1/+1
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/f259b21b-1f2b-f215-00d2-23388bed2530@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-01Merge tag 'stackleak-v4.20-rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull stackleak gcc plugin from Kees Cook: "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin was ported from grsecurity by Alexander Popov. It provides efficient stack content poisoning at syscall exit. This creates a defense against at least two classes of flaws: - Uninitialized stack usage. (We continue to work on improving the compiler to do this in other ways: e.g. unconditional zero init was proposed to GCC and Clang, and more plugin work has started too). - Stack content exposure. By greatly reducing the lifetime of valid stack contents, exposures via either direct read bugs or unknown cache side-channels become much more difficult to exploit. This complements the existing buddy and heap poisoning options, but provides the coverage for stacks. The x86 hooks are included in this series (which have been reviewed by Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already been merged through the arm64 tree (written by Laura Abbott and reviewed by Mark Rutland and Will Deacon). With VLAs having been removed this release, there is no need for alloca() protection, so it has been removed from the plugin" * tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: Drop unneeded stackleak_check_alloca() stackleak: Allow runtime disabling of kernel stack erasing doc: self-protection: Add information about STACKLEAK feature fs/proc: Show STACKLEAK metrics in the /proc file system lkdtm: Add a test for STACKLEAK gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
2018-10-26mm: remove references to vm_insert_pfn()Matthew Wilcox1-2/+2
Documentation and comments. Link: http://lkml.kernel.org/r/20180828145728.11873-7-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-24Merge tag 'docs-4.20' of git://git.lwn.net/linuxLinus Torvalds2-36/+0
Pull documentation updates from Jonathan Corbet: "This is a fairly typical cycle for documentation. There's some welcome readability improvements for the formatted output, some LICENSES updates including the addition of the ISC license, the removal of the unloved and unmaintained 00-INDEX files, the deprecated APIs document from Kees, more MM docs from Mike Rapoport, and the usual pile of typo fixes and corrections" * tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits) docs: Fix typos in histogram.rst docs: Introduce deprecated APIs list kernel-doc: fix declaration type determination doc: fix a typo in adding-syscalls.rst docs/admin-guide: memory-hotplug: remove table of contents doc: printk-formats: Remove bogus kobject references for device nodes Documentation: preempt-locking: Use better example dm flakey: Document "error_writes" feature docs/completion.txt: Fix a couple of punctuation nits LICENSES: Add ISC license text LICENSES: Add note to CDDL-1.0 license that it should not be used docs/core-api: memory-hotplug: add some details about locking internals docs/core-api: rename memory-hotplug-notifier to memory-hotplug docs: improve readability for people with poorer eyesight yama: clarify ptrace_scope=2 in Yama documentation docs/vm: split memory hotplug notifier description to Documentation/core-api docs: move memory hotplug description into admin-guide/mm doc: Fix acronym "FEKEK" in ecryptfs docs: fix some broken documentation references iommu: Fix passthrough option documentation ...
2018-10-23Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-51/+120
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "Lots of changes in this cycle: - Lots of CPA (change page attribute) optimizations and related cleanups (Thomas Gleixner, Peter Zijstra) - Make lazy TLB mode even lazier (Rik van Riel) - Fault handler cleanups and improvements (Dave Hansen) - kdump, vmcore: Enable kdumping encrypted memory with AMD SME enabled (Lianbo Jiang) - Clean up VM layout documentation (Baoquan He, Ingo Molnar) - ... plus misc other fixes and enhancements" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) x86/stackprotector: Remove the call to boot_init_stack_canary() from cpu_startup_entry() x86/mm: Kill stray kernel fault handling comment x86/mm: Do not warn about PCI BIOS W+X mappings resource: Clean it up a bit resource: Fix find_next_iomem_res() iteration issue resource: Include resource end in walk_*() interfaces x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error x86/mm: Remove spurious fault pkey check x86/mm/vsyscall: Consider vsyscall page part of user address space x86/mm: Add vsyscall address helper x86/mm: Fix exception table comments x86/mm: Add clarifying comments for user addr space x86/mm: Break out user address space handling x86/mm: Break out kernel address space handling x86/mm: Clarify hardware vs. software "error_code" x86/mm/tlb: Make lazy TLB mode lazier x86/mm/tlb: Add freed_tables element to flush_tlb_info x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range smp,cpumask: introduce on_each_cpu_cond_mask smp: use __cpumask_set_cpu in on_each_cpu_cond ...
2018-10-23Merge branch 'x86-grub2-for-linus' of ↵Linus Torvalds1-1/+31
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 grub2 updates from Ingo Molnar: "This extends the x86 boot protocol to include an address for the RSDP table - utilized by Xen currently. Matching Grub2 patches are pending as well. (Juergen Gross)" * 'x86-grub2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/acpi, x86/boot: Take RSDP address for boot params if available x86/boot: Add ACPI RSDP address to setup_header x86/xen: Fix boot loader version reported for PVH guests
2018-10-10x86/boot: Add ACPI RSDP address to setup_headerJuergen Gross1-1/+31
Xen PVH guests receive the address of the RSDP table from Xen. In order to support booting a Xen PVH guest via Grub2 using the standard x86 boot entry we need a way for Grub2 to pass the RSDP address to the kernel. For this purpose expand the struct setup_header to hold the physical address of the RSDP address. Being zero means it isn't specified and has to be located the legacy way (searching through low memory or EBDA). While documenting the new setup_header layout and protocol version 2.14 add the missing documentation of protocol version 2.13. There are Grub2 versions in several distros with a downstream patch violating the boot protocol by writing past the end of setup_header. This requires another update of the boot protocol to enable the kernel to distinguish between a specified RSDP address and one filled with garbage by such a broken Grub2. From protocol 2.14 on Grub2 will write the version it is supporting (but never a higher value than found to be supported by the kernel) ored with 0x8000 to the version field of setup_header. This enables the kernel to know up to which field Grub2 has written information to. All fields after that are supposed to be clobbered. Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-06x86/mm/doc: Enhance the x86-64 virtual memory layout descriptionsIngo Molnar1-51/+120
After the cleanups from Baoquan He, make it even more readable: - Remove the 'bits' area size column: it's pretty pointless and was even wrong for some of the entries. Given that MB, GB, TB, PT are 10, 20, 30 and 40 bits, a "8 TB" size description makes it obvious that it's 43 bits. - Introduce an "offset" column: -------------------------------------------------------------------------------- start addr | offset | end addr | size | VM area description -----------------|------------|------------------|---------|-------------------- ... ffff880000000000 | -120 TB | ffffc7ffffffffff | 64 TB | direct mapping of all physical memory (page_offset_base), this is what limits max physical memory supported. The -120 TB notation makes it obvious where this particular virtual memory region starts: 120 TB down from the top of the 64-bit virtual memory space. Especially the layout of the kernel mappings is a *lot* more obvious when written this way, plus it's much easier to compare it with the size column and understand/check/validate and modify the kernel's layout in the future. - Mark the part from where the 47-bit and 56-bit kernel layouts are 100% identical, this starts at the -512 GB offset and the EFI region. - Re-shuffle the size desciptions to be continous blocks of sizes, instead of the often mixed size. I.e. write "0.5 TB" instead of "512 GB" if we are still in the TB-granular region of the map. - Make the 47-bit and 56-bit descriptions use the *exact* same layout and wording, and only differ where there's a material difference. This makes it easy to compare the two tables side by side by switching between two terminal tabs. - Plus enhance a lot of other stylistic/typographical details: make the tables explicitly tabular, add headers, enhance certain entries, etc. etc. Note that there are some apparent errors in the tables as well, but I'll fix them in a separate patch to make it easier to review/validate. Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.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: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-06x86/mm/doc: Clean up the x86-64 virtual memory layout descriptionsBaoquan He1-42/+42
In Documentation/x86/x86_64/mm.txt, the description of the x86-64 virtual memory layout has become a confusing hodgepodge of inconsistencies: - there's a hard to read mixture of 'TB' and 'bits' notation - the entries sometimes mention a size in the description and sometimes not - sometimes they list holes by address, sometimes only as an 'unused hole' line So make it all a coherent, readable, well organized description. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.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: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/20181006084327.27467-3-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-28x86/intel_rdt: Use perf infrastructure for measurementsReinette Chatre1-8/+14
The success of a cache pseudo-locked region is measured using performance monitoring events that are programmed directly at the time the user requests a measurement. Modifying the performance event registers directly is not appropriate since it circumvents the in-kernel perf infrastructure that exists to manage these resources and provide resource arbitration to the performance monitoring hardware. The cache pseudo-locking measurements are modified to use the in-kernel perf infrastructure. Performance events are created and validated with the appropriate perf API. The performance counters are still read as directly as possible to avoid the additional cache hits. This is done safely by first ensuring with the perf API that the counters have been programmed correctly and only accessing the counters in an interrupt disabled section where they are not able to be moved. As part of the transition to the in-kernel perf infrastructure the L2 and L3 measurements are split into two separate measurements that can be triggered independently. This separation prevents additional cache misses incurred during the extra testing code used to decide if a L2 and/or L3 measurement should be made. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: peterz@infradead.org Cc: acme@kernel.org Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/fc24e728b446404f42c78573c506e98cd0599873.1537468643.git.reinette.chatre@intel.com
2018-09-10x86/doc: Fix Documentation/x86/earlyprintk.txtRandy Dunlap1-10/+15
Fix a few issues in Documentation/x86/earlyprintk.txt: - correct typos, punctuation, missing word, wrong word - change product name from Netchip to NetChip - expand where to add "earlyprintk=dbg" Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-doc@vger.kernel.org Cc: linux-usb@vger.kernel.org Link: http://lkml.kernel.org/r/d0c40ac3-7659-6374-dbda-23d3d2577f30@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-09Drop all 00-INDEX files from Documentation/Henrik Austad2-36/+0
This is a respin with a wider audience (all that get_maintainer returned) and I know this spams a *lot* of people. Not sure what would be the correct way, so my apologies for ruining your inbox. The 00-INDEX files are supposed to give a summary of all files present in a directory, but these files are horribly out of date and their usefulness is brought into question. Often a simple "ls" would reveal the same information as the filenames are generally quite descriptive as a short introduction to what the file covers (it should not surprise anyone what Documentation/sched/sched-design-CFS.txt covers) A few years back it was mentioned that these files were no longer really needed, and they have since then grown further out of date, so perhaps it is time to just throw them out. A short status yields the following _outdated_ 00-INDEX files, first counter is files listed in 00-INDEX but missing in the directory, last is files present but not listed in 00-INDEX. List of outdated 00-INDEX: Documentation: (4/10) Documentation/sysctl: (0/1) Documentation/timers: (1/0) Documentation/blockdev: (3/1) Documentation/w1/slaves: (0/1) Documentation/locking: (0/1) Documentation/devicetree: (0/5) Documentation/power: (1/1) Documentation/powerpc: (0/5) Documentation/arm: (1/0) Documentation/x86: (0/9) Documentation/x86/x86_64: (1/1) Documentation/scsi: (4/4) Documentation/filesystems: (2/9) Documentation/filesystems/nfs: (0/2) Documentation/cgroup-v1: (0/2) Documentation/kbuild: (0/4) Documentation/spi: (1/0) Documentation/virtual/kvm: (1/0) Documentation/scheduler: (0/2) Documentation/fb: (0/1) Documentation/block: (0/1) Documentation/networking: (6/37) Documentation/vm: (1/3) Then there are 364 subdirectories in Documentation/ with several files that are missing 00-INDEX alltogether (and another 120 with a single file and no 00-INDEX). I don't really have an opinion to whether or not we /should/ have 00-INDEX, but the above 00-INDEX should either be removed or be kept up to date. If we should keep the files, I can try to keep them updated, but I rather not if we just want to delete them anyway. As a starting point, remove all index-files and references to 00-INDEX and see where the discussion is going. Signed-off-by: Henrik Austad <henrik@austad.us> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Just-do-it-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: [Almost everybody else] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-04x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscallsAlexander Popov1-0/+2
The STACKLEAK feature (initially developed by PaX Team) has the following benefits: 1. Reduces the information that can be revealed through kernel stack leak bugs. The idea of erasing the thread stack at the end of syscalls is similar to CONFIG_PAGE_POISONING and memzero_explicit() in kernel crypto, which all comply with FDP_RIP.2 (Full Residual Information Protection) of the Common Criteria standard. 2. Blocks some uninitialized stack variable attacks (e.g. CVE-2017-17712, CVE-2010-2963). That kind of bugs should be killed by improving C compilers in future, which might take a long time. This commit introduces the code filling the used part of the kernel stack with a poison value before returning to userspace. Full STACKLEAK feature also contains the gcc plugin which comes in a separate commit. The STACKLEAK feature is ported from grsecurity/PaX. More information at: https://grsecurity.net/ https://pax.grsecurity.net/ This code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on our understanding of the code. Changes or omissions from the original code are ours and don't reflect the original grsecurity/PaX code. Performance impact: Hardware: Intel Core i7-4770, 16 GB RAM Test #1: building the Linux kernel on a single core 0.91% slowdown Test #2: hackbench -s 4096 -l 2000 -g 15 -f 25 -P 4.2% slowdown So the STACKLEAK description in Kconfig includes: "The tradeoff is the performance impact: on a single CPU system kernel compilation sees a 1% slowdown, other systems and workloads may vary and you are advised to test this feature on your expected workload before deploying it". Signed-off-by: Alexander Popov <alex.popov@linux.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-08-13Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds1-3/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Thomas Gleixner: "Early TSC based time stamping to allow better boot time analysis. This comes with a general cleanup of the TSC calibration code which grew warts and duct taping over the years and removes 250 lines of code. Initiated and mostly implemented by Pavel with help from various folks" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/kvmclock: Mark kvm_get_preset_lpj() as __init x86/tsc: Consolidate init code sched/clock: Disable interrupts when calling generic_sched_clock_init() timekeeping: Prevent false warning when persistent clock is not available sched/clock: Close a hole in sched_clock_init() x86/tsc: Make use of tsc_calibrate_cpu_early() x86/tsc: Split native_calibrate_cpu() into early and late parts sched/clock: Use static key for sched_clock_running sched/clock: Enable sched clock early sched/clock: Move sched clock initialization and merge with generic clock x86/tsc: Use TSC as sched clock early x86/tsc: Initialize cyc2ns when tsc frequency is determined x86/tsc: Calibrate tsc only once ARM/time: Remove read_boot_clock64() s390/time: Remove read_boot_clock64() timekeeping: Default boot time offset to local_clock() timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() s390/time: Add read_persistent_wall_and_boot_offset() x86/xen/time: Output xen sched_clock time from 0 x86/xen/time: Initialize pv xen time in init_hypervisor_platform() ...
2018-08-13Merge branch 'x86-cache-for-linus' of ↵Linus Torvalds1-3/+377
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache QoS (RDT/CAR) updates from Thomas Gleixner: "Add support for pseudo-locked cache regions. Cache Allocation Technology (CAT) allows on certain CPUs to isolate a region of cache and 'lock' it. Cache pseudo-locking builds on the fact that a CPU can still read and write data pre-allocated outside its current allocated area on cache hit. With cache pseudo-locking data can be preloaded into a reserved portion of cache that no application can fill, and from that point on will only serve cache hits. The cache pseudo-locked memory is made accessible to user space where an application can map it into its virtual address space and thus have a region of memory with reduced average read latency. The locking is not perfect and gets totally screwed by WBINDV and similar mechanisms, but it provides a reasonable enhancement for certain types of latency sensitive applications. The implementation extends the current CAT mechanism and provides a generally useful exclusive CAT mode on which it builds the extra pseude-locked regions" * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) x86/intel_rdt: Disable PMU access x86/intel_rdt: Fix possible circular lock dependency x86/intel_rdt: Make CPU information accessible for pseudo-locked regions x86/intel_rdt: Support restoration of subset of permissions x86/intel_rdt: Fix cleanup of plr structure on error x86/intel_rdt: Move pseudo_lock_region_clear() x86/intel_rdt: Limit C-states dynamically when pseudo-locking active x86/intel_rdt: Support L3 cache performance event of Broadwell x86/intel_rdt: More precise L2 hit/miss measurements x86/intel_rdt: Create character device exposing pseudo-locked region x86/intel_rdt: Create debugfs files for pseudo-locking testing x86/intel_rdt: Create resctrl debug area x86/intel_rdt: Ensure RDT cleanup on exit x86/intel_rdt: Resctrl files reflect pseudo-locked information x86/intel_rdt: Support creation/removal of pseudo-locked region x86/intel_rdt: Pseudo-lock region creation/removal core x86/intel_rdt: Discover supported platforms via prefetch disable bits x86/intel_rdt: Add utilities to test pseudo-locked region possibility x86/intel_rdt: Split resource group removal in two x86/intel_rdt: Enable entering of pseudo-locksetup mode ...
2018-07-20x86/tsc: Redefine notsc to behave as tsc=unstablePavel Tatashin1-3/+1
Currently, the notsc kernel parameter disables the use of the TSC by sched_clock(). However, this parameter does not prevent the kernel from accessing tsc in other places. The only rationale to boot with notsc is to avoid timing discrepancies on multi-socket systems where TSC are not properly synchronized, and thus exclude TSC from being used for time keeping. But that prevents using TSC as sched_clock() as well, which is not necessary as the core sched_clock() implementation can handle non synchronized TSC based sched clocks just fine. However, there is another method to solve the above problem: booting with tsc=unstable parameter. This parameter allows sched_clock() to use TSC and just excludes it from timekeeping. So there is no real reason to keep notsc, but for compatibility reasons the parameter has to stay. Make it behave like 'tsc=unstable' instead. [ tglx: Massaged changelog ] Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-12-pasha.tatashin@oracle.com
2018-07-06x86/numa_emulation: Introduce uniform split capabilityDan Williams1-0/+4
The current NUMA emulation capabilities for splitting System RAM by a fixed size or by a set number of nodes may result in some nodes being larger than others. The implementation prioritizes establishing a minimum usable memory size over satisfying the requested number of NUMA nodes. Introduce a uniform split capability that evenly partitions each physical NUMA node into N emulated nodes. For example numa=fake=3U creates 6 emulated nodes total on a system that has 2 physical nodes. This capability is useful for debugging and evaluating platform memory-side-cache capabilities as described by the ACPI HMAT (see 5.2.27.5 Memory Side Cache Information Structure in ACPI 6.2a) Compare numa=fake=6 that results in only 5 nodes being created against numa=fake=3U which takes the 2 physical nodes and evenly divides them. numa=fake=6 available: 5 nodes (0-4) node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 0 size: 2648 MB node 0 free: 2443 MB node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 1 size: 2672 MB node 1 free: 2442 MB node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 2 size: 5291 MB node 2 free: 5278 MB node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 3 size: 2677 MB node 3 free: 2665 MB node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 4 size: 2676 MB node 4 free: 2663 MB node distances: node 0 1 2 3 4 0: 10 20 10 20 20 1: 20 10 20 10 10 2: 10 20 10 20 20 3: 20 10 20 10 10 4: 20 10 20 10 10 numa=fake=3U available: 6 nodes (0-5) node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 0 size: 2900 MB node 0 free: 2637 MB node 1 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 1 size: 3023 MB node 1 free: 3012 MB node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 node 2 size: 2015 MB node 2 free: 2004 MB node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 3 size: 2704 MB node 3 free: 2522 MB node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 4 size: 2709 MB node 4 free: 2698 MB node 5 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 node 5 size: 2612 MB node 5 free: 2601 MB node distances: node 0 1 2 3 4 5 0: 10 10 10 20 20 20 1: 10 10 10 20 20 20 2: 10 10 10 20 20 20 3: 20 20 20 10 10 10 4: 20 20 20 10 10 10 5: 20 20 20 10 10 10 Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/153089328617.27680.14930758266174305832.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03x86/intel_rdt: Make CPU information accessible for pseudo-locked regionsReinette Chatre1-0/+3
When a resource group enters pseudo-locksetup mode it reflects that the platform supports cache pseudo-locking and the resource group is unused, ready to be used for a pseudo-locked region. Until it is set up as a pseudo-locked region the resource group is "locked down" such that no new tasks or cpus can be assigned to it. This is accomplished in a user visible way by making the cpus, cpus_list, and tasks resctrl files inaccassible (user cannot read from or write to these files). When the resource group changes to pseudo-locked mode it represents a cache pseudo-locked region. While not appropriate to make any changes to the cpus assigned to this region it is useful to make it easy for the user to see which cpus are associated with the pseudo-locked region. Modify the permissions of the cpus/cpus_list file when the resource group changes to pseudo-locked mode to support reading (not writing). The information presented to the user when reading the file are the cpus associated with the pseudo-locked region. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/12756b7963b6abc1bffe8fb560b87b75da827bd1.1530421961.git.reinette.chatre@intel.com
2018-06-24x86/intel_rdt: Limit C-states dynamically when pseudo-locking activeReinette Chatre1-2/+2
Deeper C-states impact cache content through shrinking of the cache or flushing entire cache to memory before reducing power to the cache. Deeper C-states will thus negatively impact the pseudo-locked regions. To avoid impacting pseudo-locked regions C-states are limited on pseudo-locked region creation so that cores associated with the pseudo-locked region are prevented from entering deeper C-states. This is accomplished by requesting a CPU latency target which will prevent the core from entering C6 across all supported platforms. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1ef4f99dd6ba12fa6fb44c5a1141e75f952b9cd9.1529706536.git.reinette.chatre@intel.com
2018-06-23x86/intel_rdt: Documentation for Cache Pseudo-LockingReinette Chatre1-2/+278
Add description of Cache Pseudo-Locking feature, its interface, as well as an example of its usage. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/6e118c15d2c254a27b8891783505cd1bb94a2b10.1529706536.git.reinette.chatre@intel.com
2018-06-23x86/intel_rdt: Document new mode, size, and bit_usageReinette Chatre1-2/+97
By default resource groups allow sharing of their cache allocations. There is nothing that prevents a resource group from configuring a cache allocation that overlaps with that of an existing resource group. To enable resource groups to specify that their cache allocations cannot be shared a resource group "mode" is introduced to support two possible modes: "shareable" and "exclusive". A "shareable" resource group allows sharing of its cache allocations, an "exclusive" resource group does not. A new resctrl file "mode" associated with each resource group is used to communicate its (the associated resource group's) mode setting and allow the mode to be changed. The new "mode" file as well as two other resctrl files, "bit_usage" and "size", are introduced in this series. Add documentation for the three new resctrl files as well as one example demonstrating their use. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/f03a3059ec40ae719be6f3fba9f446bb055e0064.1529706536.git.reinette.chatre@intel.com
2018-06-04Merge branch 'x86-cache-for-linus' of ↵Linus Torvalds1-8/+67
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache resource controller updates from Thomas Gleixner: "An update for the Intel Resource Director Technolgy (RDT) which adds a feedback driven software controller to runtime adjust the bandwidth allocation MSRs. This makes the allocations more accurate and allows to use bandwidth values in understandable units (MB/s) instead of using percentage based allocations as the original, still available, interface. The software controller can be enabled with a new mount option for the resctrl filesystem" * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth x86/intel_rdt/mba_sc: Prepare for feedback loop x86/intel_rdt/mba_sc: Add schemata support x86/intel_rdt/mba_sc: Add initialization support x86/intel_rdt/mba_sc: Enable/disable MBA software controller x86/intel_rdt/mba_sc: Documentation for MBA software controller(mba_sc)
2018-05-28x86/pci-dma: remove the explicit nodac and allowdac optionChristoph Hellwig1-5/+0
This is something drivers should decide (modulo chipset quirks like for VIA), which as far as I can tell is how things have been handled for the last 15 years. Note that we keep the usedac option for now, as it is used in the wild to override the too generic VIA quirk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-28x86/pci-dma: remove the experimental forcesac boot optionChristoph Hellwig1-3/+1
Limiting the dma mask to avoid PCI (pre-PCIe) DAC cycles while paying the huge overhead of an IOMMU is rather pointless, and this seriously gets in the way of dma mapping work. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-28Documentation/x86: remove a stray reference to pci-nommu.cChristoph Hellwig1-2/+2
This is just the minimal workaround. The file is mostly either stale and/or duplicative of Documentation/admin-guide/kernel-parameters.txt, but that is much more work than I'm willing to do right now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-19x86/intel_rdt/mba_sc: Documentation for MBA software controller(mba_sc)Vikas Shivappa1-8/+67
Add documentation about the feedback loop mechanism (MBA software controller) which lets the user specify the memory bandwidth allocation in MBps. This includes some changes to "schemata" formati with examples. Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1524263781-14267-2-git-send-email-vikas.shivappa@linux.intel.com
2018-04-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-1/+1
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
2018-04-12Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is readyIngo Molnar1-6/+3
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05Merge branch 'for-linus' of ↵Linus Torvalds1-2/+2
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