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* x86/mm: Sync also unmappings in vmalloc_sync_all()Joerg Roedel2019-07-221-8/+5Star
| | | | | | | | | | | | | | | | | With huge-page ioremap areas the unmappings also need to be synced between all page-tables. Otherwise it can cause data corruption when a region is unmapped and later re-used. Make the vmalloc_sync_one() function ready to sync unmappings and make sure vmalloc_sync_all() iterates over all page-tables even when an unmapped PMD is found. Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20190719184652.11391-3-joro@8bytes.org
* x86/mm: Check for pfn instead of page in vmalloc_sync_one()Joerg Roedel2019-07-221-1/+1
| | | | | | | | | | | | | Do not require a struct page for the mapped memory location because it might not exist. This can happen when an ioremapped region is mapped with 2MB pages. Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20190719184652.11391-2-joro@8bytes.org
* Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2019-07-201-0/+30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull dma-mapping fixes from Christoph Hellwig: "Fix various regressions: - force unencrypted dma-coherent buffers if encryption bit can't fit into the dma coherent mask (Tom Lendacky) - avoid limiting request size if swiotlb is not used (me) - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang Duan)" * tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device dma-direct: only limit the mapping size if swiotlb could be used dma-mapping: add a dma_addressing_limited helper dma-direct: Force unencrypted DMA under SME for certain DMA masks
| * dma-direct: Force unencrypted DMA under SME for certain DMA masksTom Lendacky2019-07-161-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a device doesn't support DMA to a physical address that includes the encryption bit (currently bit 47, so 48-bit DMA), then the DMA must occur to unencrypted memory. SWIOTLB is used to satisfy that requirement if an IOMMU is not active (enabled or configured in passthrough mode). However, commit fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") modified the coherent allocation support in SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU is not active, this resulted in dma_alloc_coherent() failing for devices that didn't support DMA addresses that included the encryption bit. Addressing this requires changes to the force_dma_unencrypted() function in kernel/dma/direct.c. Since the function is now non-trivial and SME/SEV specific, update the DMA direct support to add an arch override for the force_dma_unencrypted() function. The arch override is selected when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either SEV is active or SME is active and the device does not support DMA to physical addresses that include the encryption bit. Fixes: fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> [hch: moved the force_dma_unencrypted declaration to dma-mapping.h, fold the s390 fix from Halil Pasic] Signed-off-by: Christoph Hellwig <hch@lst.de>
* | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2019-07-202-20/+12Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of x86 specific fixes and updates: - The CR2 corruption fixes which store CR2 early in the entry code and hand the stored address to the fault handlers. - Revert a forgotten leftover of the dropped FSGSBASE series. - Plug a memory leak in the boot code. - Make the Hyper-V assist functionality robust by zeroing the shadow page. - Remove a useless check for dead processes with LDT - Update paravirt and VMware maintainers entries. - A few cleanup patches addressing various compiler warnings" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry/64: Prevent clobbering of saved CR2 value x86/hyper-v: Zero out the VP ASSIST PAGE on allocation x86, boot: Remove multiple copy of static function sanitize_boot_params() x86/boot/compressed/64: Remove unused variable x86/boot/efi: Remove unused variables x86/mm, tracing: Fix CR2 corruption x86/entry/64: Update comments and sanity tests for create_gap x86/entry/64: Simplify idtentry a little x86/entry/32: Simplify common_exception x86/paravirt: Make read_cr2() CALLEE_SAVE MAINTAINERS: Update PARAVIRT_OPS_INTERFACE and VMWARE_HYPERVISOR_INTERFACE x86/process: Delete useless check for dead process with LDT x86: math-emu: Hide clang warnings for 16-bit overflow x86/e820: Use proper booleans instead of 0/1 x86/apic: Silence -Wtype-limits compiler warnings x86/mm: Free sme_early_buffer after init x86/boot: Fix memory leak in default_get_smp_config() Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test
| * | x86/mm, tracing: Fix CR2 corruptionPeter Zijlstra2019-07-171-19/+11Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Despite the current efforts to read CR2 before tracing happens there still exist a number of possible holes: idtentry page_fault do_page_fault has_error_code=1 call error_entry TRACE_IRQS_OFF call trace_hardirqs_off* #PF // modifies CR2 CALL_enter_from_user_mode __context_tracking_exit() trace_user_exit(0) #PF // modifies CR2 call do_page_fault address = read_cr2(); /* whoopsie */ And similar for i386. Fix it by pulling the CR2 read into the entry code, before any of that stuff gets a chance to run and ruin things. Reported-by: He Zhe <zhe.he@windriver.com> Reported-by: Eiichi Tsukata <devel@etsukata.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: bp@alien8.de Cc: rostedt@goodmis.org Cc: torvalds@linux-foundation.org Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: jgross@suse.com Cc: joel@joelfernandes.org Link: https://lkml.kernel.org/r/20190711114336.116812491@infradead.org Debugged-by: Steven Rostedt <rostedt@goodmis.org>
| * | x86/mm: Free sme_early_buffer after initDavid Rientjes2019-07-161-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | The contents of sme_early_buffer should be cleared after __sme_early_enc_dec() because it is used to move encrypted and decrypted data, but since __sme_early_enc_dec() is __init this buffer simply can be freed after init. This saves a page that is otherwise unreferenced after init. Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907101318170.197432@chino.kir.corp.google.com
* | mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()Dan Williams2019-07-191-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow sub-section sized ranges to be added to the memmap. populate_section_memmap() takes an explict pfn range rather than assuming a full section, and those parameters are plumbed all the way through to vmmemap_populate(). There should be no sub-section usage in current deployments. New warnings are added to clarify which memmap allocation paths are sub-section capable. Link: http://lkml.kernel.org/r/156092352058.979959.6551283472062305149.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVEDavid Hildenbrand2019-07-192-4/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to improve error handling while adding memory by allowing to use arch_remove_memory() and __remove_pages() even if CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like: arch_add_memory() rc = do_something(); if (rc) { arch_remove_memory(); } We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require quite some dependencies for memory offlining. Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Mark Brown <broonie@kernel.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Rob Herring <robh@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Baoquan He <bhe@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault()Anshuman Khandual2019-07-171-19/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architectures which support kprobes have very similar boilerplate around calling kprobe_fault_handler(). Use a helper function in kprobes.h to unify them, based on the x86 code. This changes the behaviour for other architectures when preemption is enabled. Previously, they would have disabled preemption while calling the kprobe handler. However, preemption would be disabled if this fault was due to a kprobe, so we know the fault was not due to a kprobe handler and can simply return failure. This behaviour was introduced in commit a980c0ef9f6d ("x86/kprobes: Refactor kprobes_fault() like kprobe_exceptions_notify()") [anshuman.khandual@arm.com: export kprobe_fault_handler()] Link: http://lkml.kernel.org/r/1561133358-8876-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r/1560420444-25737-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: James Hogan <jhogan@kernel.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/ioremap: probe platform for p4d huge map supportAnshuman Khandual2019-07-171-0/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | Finish up what commit c2febafc6773 ("mm: convert generic code to 5-level paging") started while levelling up P4D huge mapping support at par with PUD and PMD. A new arch call back arch_ioremap_p4d_supported() is added which just maintains status quo (P4D huge map not supported) on x86, arm64 and powerpc. When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the arch about the support, hence runtime effects are minimal. Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'for-linus-hmm' of ↵Linus Torvalds2019-07-151-6/+2Star
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma Pull HMM updates from Jason Gunthorpe: "Improvements and bug fixes for the hmm interface in the kernel: - Improve clarity, locking and APIs related to the 'hmm mirror' feature merged last cycle. In linux-next we now see AMDGPU and nouveau to be using this API. - Remove old or transitional hmm APIs. These are hold overs from the past with no users, or APIs that existed only to manage cross tree conflicts. There are still a few more of these cleanups that didn't make the merge window cut off. - Improve some core mm APIs: - export alloc_pages_vma() for driver use - refactor into devm_request_free_mem_region() to manage DEVICE_PRIVATE resource reservations - refactor duplicative driver code into the core dev_pagemap struct - Remove hmm wrappers of improved core mm APIs, instead have drivers use the simplified API directly - Remove DEVICE_PUBLIC - Simplify the kconfig flow for the hmm users and core code" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits) mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR mm: remove the HMM config option mm: sort out the DEVICE_PRIVATE Kconfig mess mm: simplify ZONE_DEVICE page private data mm: remove hmm_devmem_add mm: remove hmm_vma_alloc_locked_page nouveau: use devm_memremap_pages directly nouveau: use alloc_page_vma directly PCI/P2PDMA: use the dev_pagemap internal refcount device-dax: use the dev_pagemap internal refcount memremap: provide an optional internal refcount in struct dev_pagemap memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag memremap: remove the data field in struct dev_pagemap memremap: add a migrate_to_ram method to struct dev_pagemap_ops memremap: lift the devmap_enable manipulation into devm_memremap_pages memremap: pass a struct dev_pagemap to ->kill and ->cleanup memremap: move dev_pagemap callbacks into a separate structure memremap: validate the pagemap type passed to devm_memremap_pages mm: factor out a devm_request_free_mem_region helper mm: export alloc_pages_vma ...
| * memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flagChristoph Hellwig2019-07-021-6/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a flags field to struct dev_pagemap to replace the altmap_valid boolean to be a little more extensible. Also add a pgmap_altmap() helper to find the optional altmap and clean up the code using the altmap using it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
* | Merge tag 'driver-core-5.3-rc1' of ↵Linus Torvalds2019-07-121-28/+7Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the "big" driver core and debugfs changes for 5.3-rc1 It's a lot of different patches, all across the tree due to some api changes and lots of debugfs cleanups. Other than the debugfs cleanups, in this set of changes we have: - bus iteration function cleanups - scripts/get_abi.pl tool to display and parse Documentation/ABI entries in a simple way - cleanups to Documenatation/ABI/ entries to make them parse easier due to typos and other minor things - default_attrs use for some ktype users - driver model documentation file conversions to .rst - compressed firmware file loading - deferred probe fixes All of these have been in linux-next for a while, with a bunch of merge issues that Stephen has been patient with me for" * tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits) debugfs: make error message a bit more verbose orangefs: fix build warning from debugfs cleanup patch ubifs: fix build warning after debugfs cleanup patch driver: core: Allow subsystems to continue deferring probe drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT arch_topology: Remove error messages on out-of-memory conditions lib: notifier-error-inject: no need to check return value of debugfs_create functions swiotlb: no need to check return value of debugfs_create functions ceph: no need to check return value of debugfs_create functions sunrpc: no need to check return value of debugfs_create functions ubifs: no need to check return value of debugfs_create functions orangefs: no need to check return value of debugfs_create functions nfsd: no need to check return value of debugfs_create functions lib: 842: no need to check return value of debugfs_create functions debugfs: provide pr_fmt() macro debugfs: log errors when something goes wrong drivers: s390/cio: Fix compilation warning about const qualifiers drivers: Add generic helper to match by of_node driver_find_device: Unify the match function with class_find_device() bus_find_device: Unify the match callback with class_find_device ...
| * | x86: mm: no need to check return value of debugfs_create functionsGreg Kroah-Hartman2019-06-031-28/+7Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]Mike Rapoport2019-07-121-24/+9Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most architectures have identical or very similar implementation of pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and pte_free(). Add a generic implementation that can be reused across architectures and enable its use on x86. The generic implementation uses GFP_KERNEL | __GFP_ZERO for the kernel page tables and GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT for the user page tables. The "base" functions for PTE allocation, namely __pte_alloc_one_kernel() and __pte_alloc_one() are intended for the architectures that require additional actions after actual memory allocation or must use non-default GFP flags. x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and pte_free(). x86 still implements pte_alloc_one() to allow run-time control of GFP flags required for "userpte" command line option. Link: http://lkml.kernel.org/r/1557296232-15361-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds2019-07-091-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
| * \ \ Merge tag 'v5.2-rc4' into mauroJonathan Corbet2019-06-1419-96/+19Star
| |\ \ \ | | | | | | | | | | | | | | | | | | | | We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
| * | | | docs: fix broken documentation linksMauro Carvalho Chehab2019-06-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | | | | Merge branch 'x86-kdump-for-linus' of ↵Linus Torvalds2019-07-092-28/+65
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x865 kdump updates from Thomas Gleixner: "Yet more kexec/kdump updates: - Properly support kexec when AMD's memory encryption (SME) is enabled - Pass reserved e820 ranges to the kexec kernel so both PCI and SME can work" * 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fs/proc/vmcore: Enable dumping of encrypted memory when SEV was active x86/kexec: Set the C-bit in the identity map page table when SEV is active x86/kexec: Do not map kexec area as decrypted when SEV is active x86/crash: Add e820 reserved ranges to kdump kernel's e820 table x86/mm: Rework ioremap resource mapping determination x86/e820, ioport: Add a new I/O resource descriptor IORES_DESC_RESERVED x86/mm: Create a workarea in the kernel for SME early encryption x86/mm: Identify the end of the kernel area to be reserved
| * | | | | x86/mm: Rework ioremap resource mapping determinationLianbo Jiang2019-06-201-26/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On ioremap(), __ioremap_check_mem() does a couple of checks on the supplied memory range to determine how the range should be mapped and in particular what protection flags should be used. Generalize the procedure by introducing IORES_MAP_* flags which control different aspects of the ioremapping and use them in the respective helpers which determine which descriptor flags should be set per range. [ bp: - Rewrite commit message. - Add/improve comments. - Reflow __ioremap_caller()'s args. - s/__ioremap_check_desc/__ioremap_check_encrypted/g; - s/__ioremap_res_check/__ioremap_collect_map_flags/g; - clarify __ioremap_check_ram()'s purpose. ] Signed-off-by: Lianbo Jiang <lijiang@redhat.com> Co-developed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: bhe@redhat.com Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: dyoung@redhat.com Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: kexec@lists.infradead.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190423013007.17838-3-lijiang@redhat.com
| * | | | | x86/mm: Create a workarea in the kernel for SME early encryptionThomas Lendacky2019-06-201-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order for the kernel to be encrypted "in place" during boot, a workarea outside of the kernel must be used. This SME workarea used during early encryption of the kernel is situated on a 2MB boundary after the end of the kernel text, data, etc. sections (_end). This works well during initial boot of a compressed kernel because of the relocation used for decompression of the kernel. But when performing a kexec boot, there's a chance that the SME workarea may not be mapped by the kexec pagetables or that some of the other data used by kexec could exist in this range. Create a section for SME in vmlinux.lds.S. Position it after "_end", which is after "__end_of_kernel_reserve", so that the memory will be reclaimed during boot and since this area is all zeroes, it compresses well. This new section will be part of the kernel image, so kexec will account for it in pagetable mappings and placement of data after the kernel. Here's an example of a kernel size without and with the SME section: without: vmlinux: 36,501,616 bzImage: 6,497,344 100000000-47f37ffff : System RAM 1e4000000-1e47677d4 : Kernel code (0x7677d4) 1e47677d5-1e4e2e0bf : Kernel data (0x6c68ea) 1e5074000-1e5372fff : Kernel bss (0x2fefff) with: vmlinux: 44,419,408 bzImage: 6,503,136 880000000-c7ff7ffff : System RAM 8cf000000-8cf7677d4 : Kernel code (0x7677d4) 8cf7677d5-8cfe2e0bf : Kernel data (0x6c68ea) 8d0074000-8d0372fff : Kernel bss (0x2fefff) Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Tested-by: Lianbo Jiang <lijiang@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael Ávila de Espíndola" <rafael@espindo.la> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/3c483262eb4077b1654b2052bd14a8d011bffde3.1560969363.git.thomas.lendacky@amd.com
* | | | | | Merge branch 'siginfo-linus' of ↵Linus Torvalds2019-07-092-8/+6Star
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...
| * | | | | | signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbusEric W. Biederman2019-06-031-2/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stephen Rothwell <sfr@canb.auug.org.au> reported: > After merging the userns tree, today's linux-next build (i386 defconfig) > produced this warning: > > arch/x86/mm/fault.c: In function 'do_sigbus': > arch/x86/mm/fault.c:1017:22: warning: unused variable 'tsk' [-Wunused-variable] > struct task_struct *tsk = current; > ^~~ > > Introduced by commit > > 351b6825b3a9 ("signal: Explicitly call force_sig_fault on current") > > The remaining used of "tsk" are protected by CONFIG_MEMORY_FAILURE. So do the obvious thing and move tsk inside of CONFIG_MEMORY_FAILURE to prevent introducing new warnings into the build. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | | | | signal: Remove the task parameter from force_sig_faultEric W. Biederman2019-05-291-4/+3Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As synchronous exceptions really only make sense against the current task (otherwise how are you synchronous) remove the task parameter from from force_sig_fault to make it explicit that is what is going on. The two known exceptions that deliver a synchronous exception to a stopped ptraced task have already been changed to force_sig_fault_to_task. The callers have been changed with the following emacs regular expression (with obvious variations on the architectures that take more arguments) to avoid typos: force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)] -> force_sig_fault(\1,\2,\3) Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | | | | signal: Explicitly call force_sig_fault on currentEric W. Biederman2019-05-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the calls of force_sig_fault that pass in a variable that is set to current earlier to explicitly use current. This is to make the next change that removes the task parameter from force_sig_fault easier to verify. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | | | | signal: Remove task parameter from force_sig_mceerrEric W. Biederman2019-05-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All of the callers pass current into force_sig_mceer so remove the task parameter to make this obvious. This also makes it clear that force_sig_mceerr passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * | | | | | signal: Remove task parameter from force_sigEric W. Biederman2019-05-271-1/+1
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | | | | Merge branch 'x86-entry-for-linus' of ↵Linus Torvalds2019-07-081-6/+12
|\ \ \ \ \ \ | |_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vsyscall updates from Thomas Gleixner: "Further hardening of the legacy vsyscall by providing support for execute only mode and switching the default to it. This prevents a certain class of attacks which rely on the vsyscall page being accessible at a fixed address in the canonical kernel address space" * 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86: Add a test for process_vm_readv() on the vsyscall page x86/vsyscall: Add __ro_after_init to global variables x86/vsyscall: Change the default vsyscall mode to xonly selftests/x86/vsyscall: Verify that vsyscall=none blocks execution x86/vsyscall: Document odd SIGSEGV error code for vsyscalls x86/vsyscall: Show something useful on a read fault x86/vsyscall: Add a new vsyscall=xonly mode Documentation/admin: Remove the vsyscall=native documentation
| * | | | | x86/vsyscall: Document odd SIGSEGV error code for vsyscallsAndy Lutomirski2019-06-281-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even if vsyscall=none, user page faults on the vsyscall page are reported as though the PROT bit in the error code was set. Add a comment explaining why this is probably okay and display the value in the test case. While at it, explain why the behavior is correct with respect to PKRU. Modify also the selftest to print the odd error code so that there is a way to demonstrate the odd behaviour. If anyone really cares about more accurate emulation, the behaviour could be changed. But that needs a real good justification. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/75c91855fd850649ace162eec5495a1354221aaa.1561610354.git.luto@kernel.org
| * | | | | x86/vsyscall: Show something useful on a read faultAndy Lutomirski2019-06-281-6/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just segfaulting the application when it tries to read the vsyscall page in xonly mode is not helpful for those who need to debug it. Emit a hint. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jann Horn <jannh@google.com> Link: https://lkml.kernel.org/r/8016afffe0eab497be32017ad7f6f7030dc3ba66.1561610354.git.luto@kernel.org
* | | | | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2019-06-291-11/+13
|\ \ \ \ \ \ | |/ / / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes all over the place: - might_sleep() atomicity fix in the microcode loader - resctrl boundary condition fix - APIC arithmethics bug fix for frequencies >= 4.2 GHz - three 5-level paging crash fixes - two speculation fixes - a perf/stacktrace fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/unwind/orc: Fall back to using frame pointers for generated code perf/x86: Always store regs->ip in perf_callchain_kernel() x86/speculation: Allow guests to use SSBD even if host does not x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init() x86/boot/64: Add missing fixup_pointer() for next_early_pgt access x86/boot/64: Fix crash if kernel image crosses page table boundary x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz x86/resctrl: Prevent possible overrun during bitmap operations x86/microcode: Fix the microcode load on CPU hotplug for real
| * | | | | x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init()Kirill A. Shutemov2019-06-261-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kyle has reported occasional crashes when booting a kernel in 5-level paging mode with KASLR enabled: WARNING: CPU: 0 PID: 0 at arch/x86/mm/init_64.c:87 phys_p4d_init+0x1d4/0x1ea RIP: 0010:phys_p4d_init+0x1d4/0x1ea Call Trace: __kernel_physical_mapping_init+0x10a/0x35c kernel_physical_mapping_init+0xe/0x10 init_memory_mapping+0x1aa/0x3b0 init_range_memory_mapping+0xc8/0x116 init_mem_mapping+0x225/0x2eb setup_arch+0x6ff/0xcf5 start_kernel+0x64/0x53b ? copy_bootdata+0x1f/0xce x86_64_start_reservations+0x24/0x26 x86_64_start_kernel+0x8a/0x8d secondary_startup_64+0xb6/0xc0 which causes later: BUG: unable to handle page fault for address: ff484d019580eff8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page BAD Oops: 0000 [#1] SMP NOPTI RIP: 0010:fill_pud+0x13/0x130 Call Trace: set_pte_vaddr_p4d+0x2e/0x50 set_pte_vaddr+0x6f/0xb0 __native_set_fixmap+0x28/0x40 native_set_fixmap+0x39/0x70 register_lapic_address+0x49/0xb6 early_acpi_boot_init+0xa5/0xde setup_arch+0x944/0xcf5 start_kernel+0x64/0x53b Kyle bisected the issue to commit b569c1843498 ("x86/mm/KASLR: Reduce randomization granularity for 5-level paging to 1GB") Before this commit PAGE_OFFSET was always aligned to P4D_SIZE when booting 5-level paging mode. But now only PUD_SIZE alignment is guaranteed. In the case I was able to reproduce the following vaddr/paddr values were observed in phys_p4d_init(): Iteration vaddr paddr 1 0xff4228027fe00000 0x033fe00000 2 0xff42287f40000000 0x8000000000 'vaddr' in both cases belongs to the same p4d entry. But due to the original assumption that PAGE_OFFSET is aligned to P4D_SIZE this overlap cannot be handled correctly. The code assumes strictly aligned entries and unconditionally increments the index into the P4D table, which creates false duplicate entries. Once the index reaches the end, the last entry in the page table is missing. Aside of that the 'paddr >= paddr_end' condition can evaluate wrong which causes an P4D entry to be cleared incorrectly. Change the loop in phys_p4d_init() to walk purely based on virtual addresses like __kernel_physical_mapping_init() does. This makes it work correctly with unaligned virtual addresses. Fixes: b569c1843498 ("x86/mm/KASLR: Reduce randomization granularity for 5-level paging to 1GB") Reported-by: Kyle Pelton <kyle.d.pelton@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Pelton <kyle.d.pelton@intel.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190624123150.920-1-kirill.shutemov@linux.intel.com
* | | | | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-193-12/+3Star
| |_|/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2019-06-162-2/+11
|\| | | | | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "The accumulated fixes from this and last week: - Fix vmalloc TLB flush and map range calculations which lead to stale TLBs, spurious faults and other hard to diagnose issues. - Use fault_in_pages_writable() for prefaulting the user stack in the FPU code as it's less fragile than the current solution - Use the PF_KTHREAD flag when checking for a kernel thread instead of current->mm as the latter can give the wrong answer due to use_mm() - Compute the vmemmap size correctly for KASLR and 5-Level paging. Otherwise this can end up with a way too small vmemmap area. - Make KASAN and 5-level paging work again by making sure that all invalid bits are masked out when computing the P4D offset. This worked before but got broken recently when the LDT remap area was moved. - Prevent a NULL pointer dereference in the resource control code which can be triggered with certain mount options when the requested resource is not available. - Enforce ordering of microcode loading vs. perf initialization on secondary CPUs. Otherwise perf tries to access a non-existing MSR as the boot CPU marked it as available. - Don't stop the resource control group walk early otherwise the control bitmaps are not updated correctly and become inconsistent. - Unbreak kgdb by returning 0 on success from kgdb_arch_set_breakpoint() instead of an error code. - Add more Icelake CPU model defines so depending changes can be queued in other trees" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback x86/kasan: Fix boot with 5-level paging and KASAN x86/fpu: Don't use current->mm to check for a kthread x86/kgdb: Return 0 from kgdb_arch_set_breakpoint() x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled x86/resctrl: Don't stop walking closids when a locksetup group is found x86/fpu: Update kernel's FPU state before using for the fsave header x86/mm/KASLR: Compute the size of the vmemmap section properly x86/fpu: Use fault_in_pages_writeable() for pre-faulting x86/CPU: Add more Icelake model numbers mm/vmalloc: Avoid rare case of flushing TLB with weird arguments mm/vmalloc: Fix calculation of direct map addr range
| * | | x86/kasan: Fix boot with 5-level paging and KASANAndrey Ryabinin2019-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit d52888aa2753 ("x86/mm: Move LDT remap out of KASLR region on 5-level paging") kernel doesn't boot with KASAN on 5-level paging machines. The bug is actually in early_p4d_offset() and introduced by commit 12a8cc7fcf54 ("x86/kasan: Use the same shadow offset for 4- and 5-level paging") early_p4d_offset() tries to convert pgd_val(*pgd) value to a physical address. This doesn't make sense because pgd_val() already contains the physical address. It did work prior to commit d52888aa2753 because the result of "__pa_nodebug(pgd_val(*pgd)) & PTE_PFN_MASK" was the same as "pgd_val(*pgd) & PTE_PFN_MASK". __pa_nodebug() just set some high bits which were masked out by applying PTE_PFN_MASK. After the change of the PAGE_OFFSET offset in commit d52888aa2753 __pa_nodebug(pgd_val(*pgd)) started to return a value with more high bits set and PTE_PFN_MASK wasn't enough to mask out all of them. So it returns a wrong not even canonical address and crashes on the attempt to dereference it. Switch back to pgd_val() & PTE_PFN_MASK to cure the issue. Fixes: 12a8cc7fcf54 ("x86/kasan: Use the same shadow offset for 4- and 5-level paging") Reported-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: kasan-dev@googlegroups.com Cc: stable@vger.kernel.org Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20190614143149.2227-1-aryabinin@virtuozzo.com
| * | | x86/mm/KASLR: Compute the size of the vmemmap section properlyBaoquan He2019-06-071-1/+10
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The size of the vmemmap section is hardcoded to 1 TB to support the maximum amount of system RAM in 4-level paging mode - 64 TB. However, 1 TB is not enough for vmemmap in 5-level paging mode. Assuming the size of struct page is 64 Bytes, to support 4 PB system RAM in 5-level, 64 TB of vmemmap area is needed: 4 * 1000^5 PB / 4096 bytes page size * 64 bytes per page struct / 1000^4 TB = 62.5 TB. This hardcoding may cause vmemmap to corrupt the following cpu_entry_area section, if KASLR puts vmemmap very close to it and the actual vmemmap size is bigger than 1 TB. So calculate the actual size of the vmemmap region needed and then align it up to 1 TB boundary. In 4-level paging mode it is always 1 TB. In 5-level it's adjusted on demand. The current code reserves 0.5 PB for vmemmap on 5-level. With this change, the space can be saved and thus used to increase entropy for the randomization. [ bp: Spell out how the 64 TB needed for vmemmap is computed and massage commit message. ] Fixes: eedb92abb9bb ("x86/mm: Make virtual memory layout dynamic for CONFIG_X86_5LEVEL=y") Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Kirill A. Shutemov <kirill@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: kirill.shutemov@linux.intel.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190523025744.3756-1-bhe@redhat.com
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner2019-06-051-5/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295Thomas Gleixner2019-06-051-9/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 64 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288Thomas Gleixner2019-06-051-9/+1Star
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner2019-05-305-73/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | treewide: Add SPDX license identifier for more missed filesThomas Gleixner2019-05-212-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-219-0/+9
|/ | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'kbuild-v5.2-2' of ↵Linus Torvalds2019-05-191-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - remove unneeded use of cc-option, cc-disable-warning, cc-ldoption - exclude tracked files from .gitignore - re-enable -Wint-in-bool-context warning - refactor samples/Makefile - stop building immediately if syncconfig fails - do not sprinkle error messages when $(CC) does not exist - move arch/alpha/defconfig to the configs subdirectory - remove crappy header search path manipulation - add comment lines to .config to clarify the end of menu blocks - check uniqueness of module names (adding new warnings intentionally) * tag 'kbuild-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (24 commits) kconfig: use 'else ifneq' for Makefile to improve readability kbuild: check uniqueness of module names kconfig: Terminate menu blocks with a comment in the generated config kbuild: add LICENSES to KBUILD_ALLDIRS kbuild: remove 'addtree' and 'flags' magic for header search paths treewide: prefix header search paths with $(srctree)/ media: prefix header search paths with $(srctree)/ media: remove unneeded header search paths alpha: move arch/alpha/defconfig to arch/alpha/configs/defconfig kbuild: terminate Kconfig when $(CC) or $(LD) is missing kbuild: turn auto.conf.cmd into a mandatory include file .gitignore: exclude .get_maintainer.ignore and .gitattributes kbuild: add all Clang-specific flags unconditionally kbuild: Don't try to add '-fcatch-undefined-behavior' flag kbuild: add some extra warning flags unconditionally kbuild: add -Wvla flag unconditionally arch: remove dangling asm-generic wrappers samples: guard sub-directories with CONFIG options kbuild: re-enable int-in-bool-context warning MAINTAINERS: kbuild: Add pattern for scripts/*vmlinux* ...
| * treewide: prefix header search paths with $(srctree)/Masahiro Yamada2019-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the Kbuild core manipulates header search paths in a crazy way [1]. To fix this mess, I want all Makefiles to add explicit $(srctree)/ to the search paths in the srctree. Some Makefiles are already written in that way, but not all. The goal of this work is to make the notation consistent, and finally get rid of the gross hacks. Having whitespaces after -I does not matter since commit 48f6e3cf5bc6 ("kbuild: do not drop -I without parameter"). [1]: https://patchwork.kernel.org/patch/9632347/ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* | Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2019-05-191-4/+6
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core fixes from Ingo Molnar: "This fixes a particularly thorny munmap() bug with MPX, plus fixes a host build environment assumption in objtool" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Allow AR to be overridden with HOSTAR x86/mpx, mm/core: Fix recursive munmap() corruption
| * x86/mpx, mm/core: Fix recursive munmap() corruptionDave Hansen2019-05-091-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a bit of a mess, to put it mildly. But, it's a bug that only seems to have showed up in 4.20 but wasn't noticed until now, because nobody uses MPX. MPX has the arch_unmap() hook inside of munmap() because MPX uses bounds tables that protect other areas of memory. When memory is unmapped, there is also a need to unmap the MPX bounds tables. Barring this, unused bounds tables can eat 80% of the address space. But, the recursive do_munmap() that gets called vi arch_unmap() wreaks havoc with __do_munmap()'s state. It can result in freeing populated page tables, accessing bogus VMA state, double-freed VMAs and more. See the "long story" further below for the gory details. To fix this, call arch_unmap() before __do_unmap() has a chance to do anything meaningful. Also, remove the 'vma' argument and force the MPX code to do its own, independent VMA lookup. == UML / unicore32 impact == Remove unused 'vma' argument to arch_unmap(). No functional change. I compile tested this on UML but not unicore32. == powerpc impact == powerpc uses arch_unmap() well to watch for munmap() on the VDSO and zeroes out 'current->mm->context.vdso_base'. Moving arch_unmap() makes this happen earlier in __do_munmap(). But, 'vdso_base' seems to only be used in perf and in the signal delivery that happens near the return to userspace. I can not find any likely impact to powerpc, other than the zeroing happening a little earlier. powerpc does not use the 'vma' argument and is unaffected by its removal. I compile-tested a 64-bit powerpc defconfig. == x86 impact == For the common success case this is functionally identical to what was there before. For the munmap() failure case, it's possible that some MPX tables will be zapped for memory that continues to be in use. But, this is an extraordinarily unlikely scenario and the harm would be that MPX provides no protection since the bounds table got reset (zeroed). I can't imagine anyone doing this: ptr = mmap(); // use ptr ret = munmap(ptr); if (ret) // oh, there was an error, I'll // keep using ptr. Because if you're doing munmap(), you are *done* with the memory. There's probably no good data in there _anyway_. This passes the original reproducer from Richard Biener as well as the existing mpx selftests/. The long story: munmap() has a couple of pieces: 1. Find the affected VMA(s) 2. Split the start/end one(s) if neceesary 3. Pull the VMAs out of the rbtree 4. Actually zap the memory via unmap_region(), including freeing page tables (or queueing them to be freed). 5. Fix up some of the accounting (like fput()) and actually free the VMA itself. This specific ordering was actually introduced by: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") during the 4.20 merge window. The previous __do_munmap() code was actually safe because the only thing after arch_unmap() was remove_vma_list(). arch_unmap() could not see 'vma' in the rbtree because it was detached, so it is not even capable of doing operations unsafe for remove_vma_list()'s use of 'vma'. Richard Biener reported a test that shows this in dmesg: [1216548.787498] BUG: Bad rss-counter state mm:0000000017ce560b idx:1 val:551 [1216548.787500] BUG: non-zero pgtables_bytes on freeing mm: 24576 What triggered this was the recursive do_munmap() called via arch_unmap(). It was freeing page tables that has not been properly zapped. But, the problem was bigger than this. For one, arch_unmap() can free VMAs. But, the calling __do_munmap() has variables that *point* to VMAs and obviously can't handle them just getting freed while the pointer is still in use. I tried a couple of things here. First, I tried to fix the page table freeing problem in isolation, but I then found the VMA issue. I also tried having the MPX code return a flag if it modified the rbtree which would force __do_munmap() to re-walk to restart. That spiralled out of control in complexity pretty fast. Just moving arch_unmap() and accepting that the bonkers failure case might eat some bounds tables seems like the simplest viable fix. This was also reported in the following kernel bugzilla entry: https://bugzilla.kernel.org/show_bug.cgi?id=203123 There are some reports that this commit triggered this bug: dd2283f2605 ("mm: mmap: zap pages with read mmap_sem in munmap") While that commit certainly made the issues easier to hit, I believe the fundamental issue has been with us as long as MPX itself, thus the Fixes: tag below is for one of the original MPX commits. [ mingo: Minor edits to the changelog and the patch. ] Reported-by: Richard Biener <rguenther@suse.de> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-um@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: stable@vger.kernel.org Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Link: http://lkml.kernel.org/r/20190419194747.5E1AD6DC@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'linus' into x86/urgent, to pick up dependent changesIngo Molnar2019-05-166-37/+27Star
|\ \ | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never failDavid Hildenbrand2019-05-142-9/+6Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All callers of arch_remove_memory() ignore errors. And we should really try to remove any errors from the memory removal path. No more errors are reported from __remove_pages(). BUG() in s390x code in case arch_remove_memory() is triggered. We may implement that properly later. WARN in case powerpc code failed to remove the section mapping, which is better than ignoring the error completely right now. Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stefan Agner <stefan@agner.ch> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Rob Herring <robh@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mike Travis <mike.travis@hpe.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | mm, memory_hotplug: provide a more generic restrictions for memory hotplugMichal Hocko2019-05-142-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_add_memory, __add_pages take a want_memblock which controls whether the newly added memory should get the sysfs memblock user API (e.g. ZONE_DEVICE users do not want/need this interface). Some callers even want to control where do we allocate the memmap from by configuring altmap. Add a more generic hotplug context for arch_add_memory and __add_pages. struct mhp_restrictions contains flags which contains additional features to be enabled by the memory hotplug (MHP_MEMBLOCK_API currently) and altmap for alternative memmap allocator. This patch shouldn't introduce any functional change. [akpm@linux-foundation.org: build fix] Link: http://lkml.kernel.org/r/20190408082633.2864-3-osalvador@suse.de Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>