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2021-07-21Revert "mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge"Jonathan Marek
This reverts commit c742199a014de23ee92055c2473d91fe5561ffdf. c742199a014d ("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") breaks arm64 in at least two ways for configurations where PUD or PMD folding occur: 1. We no longer install huge-vmap mappings and silently fall back to page-granular entries, despite being able to install block entries at what is effectively the PGD level. 2. If the linear map is backed with block mappings, these will now silently fail to be created in alloc_init_pud(), causing a panic early during boot. The pgtable selftests caught this, although a fix has not been forthcoming and Christophe is AWOL at the moment, so just revert the change for now to get a working -rc3 on which we can queue patches for 5.15. A simple revert breaks the build for 32-bit PowerPC 8xx machines, which rely on the default function definitions when the corresponding page-table levels are folded, since commit a6a8f7c4aa7e ("powerpc/8xx: add support for huge pages on VMAP and VMALLOC"), eg: powerpc64-linux-ld: mm/vmalloc.o: in function `vunmap_pud_range': linux/mm/vmalloc.c:362: undefined reference to `pud_clear_huge' To avoid that, add stubs for pud_clear_huge() and pmd_clear_huge() in arch/powerpc/mm/nohash/8xx.c as suggested by Christophe. Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: c742199a014d ("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge") Signed-off-by: Jonathan Marek <jonathan@marek.ca> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> [mpe: Fold in 8xx.c changes from Christophe and mention in change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/linux-arm-kernel/CAMuHMdXShORDox-xxaeUfDW3wx2PeggFSqhVSHVZNKCGK-y_vQ@mail.gmail.com/ Link: https://lore.kernel.org/r/20210717160118.9855-1-jonathan@marek.ca Link: https://lore.kernel.org/r/87r1fs1762.fsf@mpe.ellerman.id.au Signed-off-by: Will Deacon <will@kernel.org>
2021-07-08mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t *Aneesh Kumar K.V
No functional change in this patch. [aneesh.kumar@linux.ibm.com: m68k build error reported by kernel robot] Link: https://lkml.kernel.org/r/87tulxnb2v.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20210615110859.320299-2-aneesh.kumar@linux.ibm.com Link: https://lore.kernel.org/linuxppc-dev/CAHk-=wi+J+iodze9FtjM3Zi4j4OeS+qqbKxME9QN4roxPEXH9Q@mail.gmail.com/ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Hugh Dickins <hughd@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> 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>
2021-07-08mm: rename pud_page_vaddr to pud_pgtable and make it return pmd_t *Aneesh Kumar K.V
No functional change in this patch. [aneesh.kumar@linux.ibm.com: fix] Link: https://lkml.kernel.org/r/87wnqtnb60.fsf@linux.ibm.com [sfr@canb.auug.org.au: another fix] Link: https://lkml.kernel.org/r/20210619134410.89559-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20210615110859.320299-1-aneesh.kumar@linux.ibm.com Link: https://lore.kernel.org/linuxppc-dev/CAHk-=wi+J+iodze9FtjM3Zi4j4OeS+qqbKxME9QN4roxPEXH9Q@mail.gmail.com/ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Hugh Dickins <hughd@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> 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>
2021-07-07Merge tag 'x86-fpu-2021-07-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Thomas Gleixner: "Fixes and improvements for FPU handling on x86: - Prevent sigaltstack out of bounds writes. The kernel unconditionally writes the FPU state to the alternate stack without checking whether the stack is large enough to accomodate it. Check the alternate stack size before doing so and in case it's too small force a SIGSEGV instead of silently corrupting user space data. - MINSIGSTKZ and SIGSTKSZ are constants in signal.h and have never been updated despite the fact that the FPU state which is stored on the signal stack has grown over time which causes trouble in the field when AVX512 is available on a CPU. The kernel does not expose the minimum requirements for the alternate stack size depending on the available and enabled CPU features. ARM already added an aux vector AT_MINSIGSTKSZ for the same reason. Add it to x86 as well. - A major cleanup of the x86 FPU code. The recent discoveries of XSTATE related issues unearthed quite some inconsistencies, duplicated code and other issues. The fine granular overhaul addresses this, makes the code more robust and maintainable, which allows to integrate upcoming XSTATE related features in sane ways" * tag 'x86-fpu-2021-07-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits) x86/fpu/xstate: Clear xstate header in copy_xstate_to_uabi_buf() again x86/fpu/signal: Let xrstor handle the features to init x86/fpu/signal: Handle #PF in the direct restore path x86/fpu: Return proper error codes from user access functions x86/fpu/signal: Split out the direct restore code x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing() x86/fpu/signal: Sanitize the xstate check on sigframe x86/fpu/signal: Remove the legacy alignment check x86/fpu/signal: Move initial checks into fpu__restore_sig() x86/fpu: Mark init_fpstate __ro_after_init x86/pkru: Remove xstate fiddling from write_pkru() x86/fpu: Don't store PKRU in xstate in fpu_reset_fpstate() x86/fpu: Remove PKRU handling from switch_fpu_finish() x86/fpu: Mask PKRU from kernel XRSTOR[S] operations x86/fpu: Hook up PKRU into ptrace() x86/fpu: Add PKRU storage outside of task XSAVE buffer x86/fpu: Dont restore PKRU in fpregs_restore_userspace() x86/fpu: Rename xfeatures_mask_user() to xfeatures_mask_uabi() x86/fpu: Move FXSAVE_LEAK quirk info __copy_kernel_to_fpregs() x86/fpu: Rename __fpregs_load_activate() to fpregs_restore_userregs() ...
2021-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...
2021-06-30mm: sparsemem: use huge PMD mapping for vmemmap pagesMuchun Song
The preparation of splitting huge PMD mapping of vmemmap pages is ready, so switch the mapping from PTE to PMD. Link: https://lkml.kernel.org/r/20210616094915.34432-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm/pgtable: add stubs for {pmd/pub}_{set/clear}_hugeChristophe Leroy
For architectures with no PMD and/or no PUD, add stubs similar to what we have for architectures without P4D. [christophe.leroy@csgroup.eu: arm64: define only {pud/pmd}_{set/clear}_huge when useful] Link: https://lkml.kernel.org/r/73ec95f40cafbbb69bdfb43a7f53876fd845b0ce.1620990479.git.christophe.leroy@csgroup.eu [christophe.leroy@csgroup.eu: x86: define only {pud/pmd}_{set/clear}_huge when useful] Link: https://lkml.kernel.org/r/7fbf1b6bc3e15c07c24fa45278d57064f14c896b.1620930415.git.christophe.leroy@csgroup.eu Link: https://lkml.kernel.org/r/5ac5976419350e8e048d463a64cae449eb3ba4b0.1620795204.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm: hugetlb: add a kernel parameter hugetlb_free_vmemmapMuchun Song
Add a kernel parameter hugetlb_free_vmemmap to enable the feature of freeing unused vmemmap pages associated with each hugetlb page on boot. We disable PMD mapping of vmemmap pages for x86-64 arch when this feature is enabled. Because vmemmap_remap_free() depends on vmemmap being base page mapped. Link: https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAPMuchun Song
The option HUGETLB_PAGE_FREE_VMEMMAP allows for the freeing of some vmemmap pages associated with pre-allocated HugeTLB pages. For example, on X86_64 6 vmemmap pages of size 4KB each can be saved for each 2MB HugeTLB page. 4094 vmemmap pages of size 4KB each can be saved for each 1GB HugeTLB page. When a HugeTLB page is allocated or freed, the vmemmap array representing the range associated with the page will need to be remapped. When a page is allocated, vmemmap pages are freed after remapping. When a page is freed, previously discarded vmemmap pages must be allocated before remapping. The config option is introduced early so that supporting code can be written to depend on the option. The initial version of the code only provides support for x86-64. If config HAVE_BOOTMEM_INFO_NODE is enabled, the freeing vmemmap page code denpend on it to free vmemmap pages. Otherwise, just use free_reserved_page() to free vmemmmap pages. The routine register_page_bootmem_info() is used to register bootmem info. Therefore, make sure register_page_bootmem_info is enabled if HUGETLB_PAGE_FREE_VMEMMAP is defined. Link: https://lkml.kernel.org/r/20210510030027.56044-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm: memory_hotplug: factor out bootmem core functions to bootmem_info.cMuchun Song
Patch series "Free some vmemmap pages of HugeTLB page", v23. This patch series will free some vmemmap pages(struct page structures) associated with each HugeTLB page when preallocated to save memory. In order to reduce the difficulty of the first version of code review. In this version, we disable PMD/huge page mapping of vmemmap if this feature was enabled. This acutely eliminates a bunch of the complex code doing page table manipulation. When this patch series is solid, we cam add the code of vmemmap page table manipulation in the future. The struct page structures (page structs) are used to describe a physical page frame. By default, there is an one-to-one mapping from a page frame to it's corresponding page struct. The HugeTLB pages consist of multiple base page size pages and is supported by many architectures. See hugetlbpage.rst in the Documentation directory for more details. On the x86 architecture, HugeTLB pages of size 2MB and 1GB are currently supported. Since the base page size on x86 is 4KB, a 2MB HugeTLB page consists of 512 base pages and a 1GB HugeTLB page consists of 4096 base pages. For each base page, there is a corresponding page struct. Within the HugeTLB subsystem, only the first 4 page structs are used to contain unique information about a HugeTLB page. HUGETLB_CGROUP_MIN_ORDER provides this upper limit. The only 'useful' information in the remaining page structs is the compound_head field, and this field is the same for all tail pages. By removing redundant page structs for HugeTLB pages, memory can returned to the buddy allocator for other uses. When the system boot up, every 2M HugeTLB has 512 struct page structs which size is 8 pages(sizeof(struct page) * 512 / PAGE_SIZE). HugeTLB struct pages(8 pages) page frame(8 pages) +-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+ | | | 0 | -------------> | 0 | | | +-----------+ +-----------+ | | | 1 | -------------> | 1 | | | +-----------+ +-----------+ | | | 2 | -------------> | 2 | | | +-----------+ +-----------+ | | | 3 | -------------> | 3 | | | +-----------+ +-----------+ | | | 4 | -------------> | 4 | | 2MB | +-----------+ +-----------+ | | | 5 | -------------> | 5 | | | +-----------+ +-----------+ | | | 6 | -------------> | 6 | | | +-----------+ +-----------+ | | | 7 | -------------> | 7 | | | +-----------+ +-----------+ | | | | | | +-----------+ The value of page->compound_head is the same for all tail pages. The first page of page structs (page 0) associated with the HugeTLB page contains the 4 page structs necessary to describe the HugeTLB. The only use of the remaining pages of page structs (page 1 to page 7) is to point to page->compound_head. Therefore, we can remap pages 2 to 7 to page 1. Only 2 pages of page structs will be used for each HugeTLB page. This will allow us to free the remaining 6 pages to the buddy allocator. Here is how things look after remapping. HugeTLB struct pages(8 pages) page frame(8 pages) +-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+ | | | 0 | -------------> | 0 | | | +-----------+ +-----------+ | | | 1 | -------------> | 1 | | | +-----------+ +-----------+ | | | 2 | ----------------^ ^ ^ ^ ^ ^ | | +-----------+ | | | | | | | | 3 | ------------------+ | | | | | | +-----------+ | | | | | | | 4 | --------------------+ | | | | 2MB | +-----------+ | | | | | | 5 | ----------------------+ | | | | +-----------+ | | | | | 6 | ------------------------+ | | | +-----------+ | | | | 7 | --------------------------+ | | +-----------+ | | | | | | +-----------+ When a HugeTLB is freed to the buddy system, we should allocate 6 pages for vmemmap pages and restore the previous mapping relationship. Apart from 2MB HugeTLB page, we also have 1GB HugeTLB page. It is similar to the 2MB HugeTLB page. We also can use this approach to free the vmemmap pages. In this case, for the 1GB HugeTLB page, we can save 4094 pages. This is a very substantial gain. On our server, run some SPDK/QEMU applications which will use 1024GB HugeTLB page. With this feature enabled, we can save ~16GB (1G hugepage)/~12GB (2MB hugepage) memory. Because there are vmemmap page tables reconstruction on the freeing/allocating path, it increases some overhead. Here are some overhead analysis. 1) Allocating 10240 2MB HugeTLB pages. a) With this patch series applied: # time echo 10240 > /proc/sys/vm/nr_hugepages real 0m0.166s user 0m0.000s sys 0m0.166s # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; } kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs - @start[tid]); delete(@start[tid]); }' Attaching 2 probes... @latency: [8K, 16K) 5476 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [16K, 32K) 4760 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [32K, 64K) 4 | | b) Without this patch series: # time echo 10240 > /proc/sys/vm/nr_hugepages real 0m0.067s user 0m0.000s sys 0m0.067s # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; } kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs - @start[tid]); delete(@start[tid]); }' Attaching 2 probes... @latency: [4K, 8K) 10147 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [8K, 16K) 93 | | Summarize: this feature is about ~2x slower than before. 2) Freeing 10240 2MB HugeTLB pages. a) With this patch series applied: # time echo 0 > /proc/sys/vm/nr_hugepages real 0m0.213s user 0m0.000s sys 0m0.213s # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; } kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs - @start[tid]); delete(@start[tid]); }' Attaching 2 probes... @latency: [8K, 16K) 6 | | [16K, 32K) 10227 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [32K, 64K) 7 | | b) Without this patch series: # time echo 0 > /proc/sys/vm/nr_hugepages real 0m0.081s user 0m0.000s sys 0m0.081s # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; } kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs - @start[tid]); delete(@start[tid]); }' Attaching 2 probes... @latency: [4K, 8K) 6805 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [8K, 16K) 3427 |@@@@@@@@@@@@@@@@@@@@@@@@@@ | [16K, 32K) 8 | | Summary: The overhead of __free_hugepage is about ~2-3x slower than before. Although the overhead has increased, the overhead is not significant. Like Mike said, "However, remember that the majority of use cases create HugeTLB pages at or shortly after boot time and add them to the pool. So, additional overhead is at pool creation time. There is no change to 'normal run time' operations of getting a page from or returning a page to the pool (think page fault/unmap)". Despite the overhead and in addition to the memory gains from this series. The following data is obtained by Joao Martins. Very thanks to his effort. There's an additional benefit which is page (un)pinners will see an improvement and Joao presumes because there are fewer memmap pages and thus the tail/head pages are staying in cache more often. Out of the box Joao saw (when comparing linux-next against linux-next + this series) with gup_test and pinning a 16G HugeTLB file (with 1G pages): get_user_pages(): ~32k -> ~9k unpin_user_pages(): ~75k -> ~70k Usually any tight loop fetching compound_head(), or reading tail pages data (e.g. compound_head) benefit a lot. There's some unpinning inefficiencies Joao was fixing[2], but with that in added it shows even more: unpin_user_pages(): ~27k -> ~3.8k [1] https://lore.kernel.org/linux-mm/20210409205254.242291-1-mike.kravetz@oracle.com/ [2] https://lore.kernel.org/linux-mm/20210204202500.26474-1-joao.m.martins@oracle.com/ This patch (of 9): Move bootmem info registration common API to individual bootmem_info.c. And we will use {get,put}_page_bootmem() to initialize the page for the vmemmap pages or free the vmemmap pages to buddy in the later patch. So move them out of CONFIG_MEMORY_HOTPLUG_SPARSE. This is just code movement without any functional change. Link: https://lkml.kernel.org/r/20210510030027.56044-1-songmuchun@bytedance.com Link: https://lkml.kernel.org/r/20210510030027.56044-2-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Chen Huang <chenhuang5@huawei.com> Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org 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> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Oliver Neukum <oneukum@suse.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Mina Almasry <almasrymina@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMAMike Rapoport
After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA configuration options are equivalent. Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead. Done with $ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \ $(git grep -wl CONFIG_NEED_MULTIPLE_NODES) $ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \ $(git grep -wl NEED_MULTIPLE_NODES) with manual tweaks afterwards. [rppt@linux.ibm.com: fix arm boot crash] Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-28Merge tag 'x86-mm-2021-06-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm update from Ingo Molnar: "Do not create the x86/init_pkru debugfs file if the CPU doesn't support PKRU" * tag 'x86-mm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pkeys: Skip 'init_pkru' debugfs file creation when pkeys not supported
2021-06-28Merge tag 'perf-core-2021-06-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: - Platform PMU driver updates: - x86 Intel uncore driver updates for Skylake (SNR) and Icelake (ICX) servers - Fix RDPMC support - Fix [extended-]PEBS-via-PT support - Fix Sapphire Rapids event constraints - Fix :ppp support on Sapphire Rapids - Fix fixed counter sanity check on Alder Lake & X86_FEATURE_HYBRID_CPU - Other heterogenous-PMU fixes - Kprobes: - Remove the unused and misguided kprobe::fault_handler callbacks. - Warn about kprobes taking a page fault. - Fix the 'nmissed' stat counter. - Misc cleanups and fixes. * tag 'perf-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix task context PMU for Hetero perf/x86/intel: Fix instructions:ppp support in Sapphire Rapids perf/x86/intel: Add more events requires FRONTEND MSR on Sapphire Rapids perf/x86/intel: Fix fixed counter check warning for some Alder Lake perf/x86/intel: Fix PEBS-via-PT reload base value for Extended PEBS perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task kprobes: Do not increment probe miss count in the fault handler x86,kprobes: WARN if kprobes tries to handle a fault kprobes: Remove kprobe::fault_handler uprobes: Update uprobe_write_opcode() kernel-doc comment perf/hw_breakpoint: Fix DocBook warnings in perf hw_breakpoint perf/core: Fix DocBook warnings perf/core: Make local function perf_pmu_snapshot_aux() static perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on ICX perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on SNR perf/x86/intel/uncore: Generalize I/O stacks to PMON mapping procedure perf/x86/intel/uncore: Drop unnecessary NULL checks after container_of()
2021-06-23x86/fpu: Mask PKRU from kernel XRSTOR[S] operationsThomas Gleixner
As the PKRU state is managed separately restoring it from the xstate buffer would be counterproductive as it might either restore a stale value or reinit the PKRU state to 0. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121456.606745195@linutronix.de
2021-06-23x86/fpu: Use pkru_write_default() in copy_init_fpstate_to_fpregs()Thomas Gleixner
There is no point in using copy_init_pkru_to_fpregs() which in turn calls write_pkru(). write_pkru() tries to fiddle with the task's xstate buffer for nothing because the XRSTOR[S](init_fpstate) just cleared the xfeature flag in the xstate header which makes get_xsave_addr() fail. It's a useless exercise anyway because the reinitialization activates the FPU so before the task's xstate buffer can be used again a XRSTOR[S] must happen which in turn dumps the PKRU value. Get rid of the now unused copy_init_pkru_to_fpregs(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121455.732508792@linutronix.de
2021-06-23x86/cpu: Sanitize X86_FEATURE_OSPKEThomas Gleixner
X86_FEATURE_OSPKE is enabled first on the boot CPU and the feature flag is set. Secondary CPUs have to enable CR4.PKE as well and set their per CPU feature flag. That's ineffective because all call sites have checks for boot_cpu_data. Make it smarter and force the feature flag when PKU is enabled on the boot cpu which allows then to use cpu_feature_enabled(X86_FEATURE_OSPKE) all over the place. That either compiles the code out when PKEY support is disabled in Kconfig or uses a static_cpu_has() for the feature check which makes a significant difference in hotpaths, e.g. context switch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121455.305113644@linutronix.de
2021-06-23x86/pkeys: Move read_pkru() and write_pkru()Dave Hansen
write_pkru() was originally used just to write to the PKRU register. It was mercifully short and sweet and was not out of place in pgtable.h with some other pkey-related code. But, later work included a requirement to also modify the task XSAVE buffer when updating the register. This really is more related to the XSAVE architecture than to paging. Move the read/write_pkru() to asm/pkru.h. pgtable.h won't miss them. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121455.102647114@linutronix.de
2021-06-23x86/fpu: Rename copy_kernel_to_fpregs() to restore_fpregs_from_fpstate()Thomas Gleixner
This is not a copy functionality. It restores the register state from the supplied kernel buffer. No functional changes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.716058365@linutronix.de
2021-06-23x86/pkeys: Revert a5eff7259790 ("x86/pkeys: Add PKRU value to init_fpstate")Thomas Gleixner
This cannot work and it's unclear how that ever made a difference. init_fpstate.xsave.header.xfeatures is always 0 so get_xsave_addr() will always return a NULL pointer, which will prevent storing the default PKRU value in init_fpstate. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.451391598@linutronix.de
2021-06-18x86/mm: Avoid truncating memblocks for SGX memoryFan Du
tl;dr: Several SGX users reported seeing the following message on NUMA systems: sgx: [Firmware Bug]: Unable to map EPC section to online node. Fallback to the NUMA node 0. This turned out to be the memblock code mistakenly throwing away SGX memory. === Full Changelog === The 'max_pfn' variable represents the highest known RAM address. It can be used, for instance, to quickly determine for which physical addresses there is mem_map[] space allocated. The numa_meminfo code makes an effort to throw out ("trim") all memory blocks which are above 'max_pfn'. SGX memory is not considered RAM (it is marked as "Reserved" in the e820) and is not taken into account by max_pfn. Despite this, SGX memory areas have NUMA affinity and are enumerated in the ACPI SRAT table. The existing SGX code uses the numa_meminfo mechanism to look up the NUMA affinity for its memory areas. In cases where SGX memory was above max_pfn (usually just the one EPC section in the last highest NUMA node), the numa_memblock is truncated at 'max_pfn', which is below the SGX memory. When the SGX code tries to look up the affinity of this memory, it fails and produces an error message: sgx: [Firmware Bug]: Unable to map EPC section to online node. Fallback to the NUMA node 0. and assigns the memory to NUMA node 0. Instead of silently truncating the memory block at 'max_pfn' and dropping the SGX memory, add the truncated portion to 'numa_reserved_meminfo'. This allows the SGX code to later determine the NUMA affinity of its 'Reserved' area. Before, numa_meminfo looked like this (from 'crash'): blk = { start = 0x0, end = 0x2080000000, nid = 0x0 } { start = 0x2080000000, end = 0x4000000000, nid = 0x1 } numa_reserved_meminfo is empty. With this, numa_meminfo looks like this: blk = { start = 0x0, end = 0x2080000000, nid = 0x0 } { start = 0x2080000000, end = 0x4000000000, nid = 0x1 } and numa_reserved_meminfo has an entry for node 1's SGX memory: blk = { start = 0x4000000000, end = 0x4080000000, nid = 0x1 } [ daveh: completely rewrote/reworked changelog ] Fixes: 5d30f92e7631 ("x86/NUMA: Provide a range-to-target_node lookup facility") Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Fan Du <fan.du@intel.com> Signed-off-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20210617194657.0A99CB22@viggo.jf.intel.com
2021-06-17perf/x86: Reset the dirty counter to prevent the leak for an RDPMC taskKan Liang
The counter value of a perf task may leak to another RDPMC task. For example, a perf stat task as below is running on CPU 0. perf stat -e 'branches,cycles' -- taskset -c 0 ./workload In the meantime, an RDPMC task, which is also running on CPU 0, may read the GP counters periodically. (The RDPMC task creates a fixed event, but read four GP counters.) $./rdpmc_read_all_counters index 0x0 value 0x8001e5970f99 index 0x1 value 0x8005d750edb6 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x8002358e48a5 index 0x1 value 0x8006bd1e3bc9 index 0x2 value 0x0 index 0x3 value 0x0 It is a potential security issue. Once the attacker knows what the other thread is counting. The PerfMon counter can be used as a side-channel to attack cryptosystems. The counter value of the perf stat task leaks to the RDPMC task because perf never clears the counter when it's stopped. Three methods were considered to address the issue. - Unconditionally reset the counter in x86_pmu_del(). It can bring extra overhead even when there is no RDPMC task running. - Only reset the un-assigned dirty counters when the RDPMC task is scheduled in via sched_task(). It fails for the below case. Thread A Thread B clone(CLONE_THREAD) ---> set_affine(0) set_affine(1) while (!event-enabled) ; event = perf_event_open() mmap(event) ioctl(event, IOC_ENABLE); ---> RDPMC Counters are still leaked to the thread B. - Only reset the un-assigned dirty counters before updating the CR4.PCE bit. The method is implemented here. The dirty counter is a counter, on which the assigned event has been deleted, but the counter is not reset. To track the dirty counters, add a 'dirty' variable in the struct cpu_hw_events. The security issue can only be found with an RDPMC task. To enable the RDMPC, the CR4.PCE bit has to be updated. Add a perf_clear_dirty_counters() right before updating the CR4.PCE bit to clear the existing dirty counters. Only the current un-assigned dirty counters are reset, because the RDPMC assigned dirty counters will be updated soon. After applying the patch, $ ./rdpmc_read_all_counters index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 Performance The performance of a context switch only be impacted when there are two or more perf users and one of the users must be an RDPMC user. In other cases, there is no performance impact. The worst-case occurs when there are two users: the RDPMC user only uses one counter; while the other user uses all available counters. When the RDPMC task is scheduled in, all the counters, other than the RDPMC assigned one, have to be reset. Test results for the worst-case, using a modified lat_ctx as measured on an Ice Lake platform, which has 8 GP and 3 FP counters (ignoring SLOTS). lat_ctx -s 128K -N 1000 processes 2 Without the patch: The context switch time is 4.97 us With the patch: The context switch time is 5.16 us There is ~4% performance drop for the context switching time in the worst-case. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1623693582-187370-1-git-send-email-kan.liang@linux.intel.com
2021-06-08x86/ioremap: Map EFI-reserved memory as encrypted for SEVTom Lendacky
Some drivers require memory that is marked as EFI boot services data. In order for this memory to not be re-used by the kernel after ExitBootServices(), efi_mem_reserve() is used to preserve it by inserting a new EFI memory descriptor and marking it with the EFI_MEMORY_RUNTIME attribute. Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to be mapped encrypted by Linux, otherwise the kernel might crash at boot like below: EFI Variables Facility v0.08 2004-May-17 general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:efi_mokvar_entry_next [...] Call Trace: efi_mokvar_sysfs_init ? efi_mokvar_table_init do_one_initcall ? __kmalloc kernel_init_freeable ? rest_init kernel_init ret_from_fork Expand the __ioremap_check_other() function to additionally check for this other type of boot data reserved at runtime and indicate that it should be mapped encrypted for an SEV guest. [ bp: Massage commit message. ] Fixes: 58c909022a5a ("efi: Support for MOK variable config table") Reported-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Joerg Roedel <jroedel@suse.de> Cc: <stable@vger.kernel.org> # 5.10+ Link: https://lkml.kernel.org/r/20210608095439.12668-2-joro@8bytes.org
2021-06-04x86/sev: Check SME/SEV support in CPUID firstPu Wen
The first two bits of the CPUID leaf 0x8000001F EAX indicate whether SEV or SME is supported, respectively. It's better to check whether SEV or SME is actually supported before accessing the MSR_AMD64_SEV to check whether SEV or SME is enabled. This is both a bare-metal issue and a guest/VM issue. Since the first generation Hygon Dhyana CPU doesn't support the MSR_AMD64_SEV, reading that MSR results in a #GP - either directly from hardware in the bare-metal case or via the hypervisor (because the RDMSR is actually intercepted) in the guest/VM case, resulting in a failed boot. And since this is very early in the boot phase, rdmsrl_safe()/native_read_msr_safe() can't be used. So check the CPUID bits first, before accessing the MSR. [ tlendacky: Expand and improve commit message. ] [ bp: Massage commit message. ] Fixes: eab696d8e8b9 ("x86/sev: Do not require Hypervisor CPUID bit for SEV guests") Signed-off-by: Pu Wen <puwen@hygon.cn> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@vger.kernel.org> # v5.10+ Link: https://lkml.kernel.org/r/20210602070207.2480-1-puwen@hygon.cn
2021-06-04x86/pkeys: Skip 'init_pkru' debugfs file creation when pkeys not supportedDave Hansen
The PKRU hardware is permissive by default: all reads and writes are allowed. The in-kernel policy is restrictive by default: deny all unnecessary access until explicitly requested. That policy can be modified with a debugfs file: "x86/init_pkru". This file is created unconditionally, regardless of PKRU support in the hardware, which is a little silly. Avoid creating the file when pkeys are not available. This also removes the need to check for pkey support at runtime, which would be required once the new pkey modification infrastructure is put in place later in this series. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210603230810.113FF3F2@viggo.jf.intel.com
2021-06-04x86/fault: Don't send SIGSEGV twice on SEGV_PKUERRJiashuo Liang
__bad_area_nosemaphore() calls both force_sig_pkuerr() and force_sig_fault() when handling SEGV_PKUERR. This does not cause problems because the second signal is filtered by the legacy_queue() check in __send_signal() because in both cases, the signal is SIGSEGV, the second one seeing that the first one is already pending. This causes the kernel to do unnecessary work so send the signal only once for SEGV_PKUERR. [ bp: Massage commit message. ] Fixes: 9db812dbb29d ("signal/x86: Call force_sig_pkuerr from __bad_area_nosemaphore") Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Jiashuo Liang <liangjs@pku.edu.cn> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Link: https://lkml.kernel.org/r/20210601085203.40214-1-liangjs@pku.edu.cn
2021-06-01x86,kprobes: WARN if kprobes tries to handle a faultPeter Zijlstra
With the removal of kprobe::handle_fault there is no reason left that kprobe_page_fault() would ever return true on x86, make sure it doesn't happen by accident. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20210525073213.660594073@infradead.org
2021-05-10x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFGBrijesh Singh
The SYSCFG MSR continued being updated beyond the K8 family; drop the K8 name from it. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20210427111636.1207-4-brijesh.singh@amd.com
2021-05-10x86/sev-es: Rename sev-es.{ch} to sev.{ch}Brijesh Singh
SEV-SNP builds upon the SEV-ES functionality while adding new hardware protection. Version 2 of the GHCB specification adds new NAE events that are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all SEV* functionality can be consolidated in one place. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com
2021-05-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "The remainder of the main mm/ queue. 143 patches. Subsystems affected by this patch series (all mm): pagecache, hugetlb, userfaultfd, vmscan, compaction, migration, cma, ksm, vmstat, mmap, kconfig, util, memory-hotplug, zswap, zsmalloc, highmem, cleanups, and kfence" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (143 commits) kfence: use power-efficient work queue to run delayed work kfence: maximize allocation wait timeout duration kfence: await for allocation using wait_event kfence: zero guard page after out-of-bounds access mm/process_vm_access.c: remove duplicate include mm/mempool: minor coding style tweaks mm/highmem.c: fix coding style issue btrfs: use memzero_page() instead of open coded kmap pattern iov_iter: lift memzero_page() to highmem.h mm/zsmalloc: use BUG_ON instead of if condition followed by BUG. mm/zswap.c: switch from strlcpy to strscpy arm64/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE x86/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE mm,memory_hotplug: add kernel boot option to enable memmap_on_memory acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported mm,memory_hotplug: allocate memmap from the added memory range mm,memory_hotplug: factor out adjusting present pages into adjust_present_page_count() mm,memory_hotplug: relax fully spanned sections check drivers/base/memory: introduce memory_block_{online,offline} mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove ...
2021-05-05x86/mm: track linear mapping split eventsSaravanan D
To help with debugging the sluggishness caused by TLB miss/reload, we introduce monotonic hugepage [direct mapped] split event counts since system state: SYSTEM_RUNNING to be displayed as part of /proc/vmstat in x86 servers The lifetime split event information will be displayed at the bottom of /proc/vmstat .... swap_ra 0 swap_ra_hit 0 direct_map_level2_splits 94 direct_map_level3_splits 4 nr_unstable 0 .... One of the many lasting sources of direct hugepage splits is kernel tracing (kprobes, tracepoints). Note that the kernel's code segment [512 MB] points to the same physical addresses that have been already mapped in the kernel's direct mapping range. Source : Documentation/x86/x86_64/mm.rst When we enable kernel tracing, the kernel has to modify attributes/permissions of the text segment hugepages that are direct mapped causing them to split. Kernel's direct mapped hugepages do not coalesce back after split and remain in place for the remainder of the lifetime. An instance of direct page splits when we turn on dynamic kernel tracing .... cat /proc/vmstat | grep -i direct_map_level direct_map_level2_splits 784 direct_map_level3_splits 12 bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @ [pid, comm] = count(); }' cat /proc/vmstat | grep -i direct_map_level direct_map_level2_splits 789 direct_map_level3_splits 12 .... Link: https://lkml.kernel.org/r/20210218235744.1040634-1-saravanand@fb.com Signed-off-by: Saravanan D <saravanand@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
2021-04-30mm: move mem_init_print_info() into mm_init()Kefeng Wang
mem_init_print_info() is called in mem_init() on each architecture, and pass NULL argument, so using void argument and move it into mm_init(). Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> [powerpc] Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Anatoly Pugachev <matorola@gmail.com> [sparc64] Acked-by: Russell King <rmk+kernel@armlinux.org.uk> [arm] Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Guo Ren <guoren@kernel.org> Cc: Yoshinori Sato <ysato@users.osdn.me> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86: inline huge vmap supported functionsNicholas Piggin
This allows unsupported levels to be constant folded away, and so p4d_free_pud_page can be removed because it's no longer linked to. Link: https://lkml.kernel.org/r/20210317062402.533919-10-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> 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: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: HUGE_VMAP arch support cleanupNicholas Piggin
This changes the awkward approach where architectures provide init functions to determine which levels they can provide large mappings for, to one where the arch is queried for each call. This removes code and indirection, and allows constant-folding of dead code for unsupported levels. This also adds a prot argument to the arch query. This is unused currently but could help with some architectures (e.g., some powerpc processors can't map uncacheable memory with large pages). Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Will Deacon <will@kernel.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: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: optimize for consecutive sections in partial populated PMDsOscar Salvador
We can optimize in the case we are adding consecutive sections, so no memset(PAGE_UNUSED) is needed. In that case, let us keep track where the unused range of the previous memory range begins, so we can compare it with start of the range to be added. If they are equal, we know sections are added consecutively. For that purpose, let us introduce 'unused_pmd_start', which always holds the beginning of the unused memory range. In the case a section does not contiguously follow the previous one, we know we can memset [unused_pmd_start, PMD_BOUNDARY) with PAGE_UNUSE. This patch is based on a similar patch by David Hildenbrand: https://lore.kernel.org/linux-mm/20200722094558.9828-10-david@redhat.com/ Link: https://lkml.kernel.org/r/20210309214050.4674-5-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: handle unpopulated sub-pmd rangesOscar Salvador
When sizeof(struct page) is not a power of 2, sections do not span a PMD anymore and so when populating them some parts of the PMD will remain unused. Because of this, PMDs will be left behind when depopulating sections since remove_pmd_table() thinks that those unused parts are still in use. Fix this by marking the unused parts with PAGE_UNUSED, so memchr_inv() will do the right thing and will let us free the PMD when the last user of it is gone. This patch is based on a similar patch by David Hildenbrand: https://lore.kernel.org/linux-mm/20200722094558.9828-9-david@redhat.com/ [osalvador@suse.de: go back to the ifdef version] Link: https://lkml.kernel.org/r/YGy++mSft7K4u+88@localhost.localdomain Link: https://lkml.kernel.org/r/20210309214050.4674-4-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: drop handling of 1GB vmemmap rangesOscar Salvador
There is no code to allocate 1GB pages when mapping the vmemmap range as this might waste some memory and requires more complexity which is not really worth. Drop the dead code both for the aligned and unaligned cases and leave only the direct map handling. Link: https://lkml.kernel.org/r/20210309214050.4674-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: drop handling of 4K unaligned vmemmap rangeOscar Salvador
Patch series "Cleanup and fixups for vmemmap handling", v6. This series contains cleanups to remove dead code that handles unaligned cases for 4K and 1GB pages (patch#1 and patch#2) when removing the vemmmap range, and a fix (patch#3) to handle the case when two vmemmap ranges intersect the same PMD. This patch (of 4): remove_pte_table() is prepared to handle the case where either the start or the end of the range is not PAGE aligned. This cannot actually happen: __populate_section_memmap enforces the range to be PMD aligned, so as long as the size of the struct page remains multiple of 8, the vmemmap range will be aligned to PAGE_SIZE. Drop the dead code and place a VM_BUG_ON in vmemmap_{populate,free} to catch nasty cases. Note that the VM_BUG_ON is placed in there because vmemmap_{populate,free= } is the gate of all removing and freeing page tables logic. Link: https://lkml.kernel.org/r/20210309214050.4674-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20210309214050.4674-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: 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@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-29Merge tag 'x86-mm-2021-04-29' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 tlb updates from Ingo Molnar: "The x86 MM changes in this cycle were: - Implement concurrent TLB flushes, which overlaps the local TLB flush with the remote TLB flush. In testing this improved sysbench performance measurably by a couple of percentage points, especially if TLB-heavy security mitigations are active. - Further micro-optimizations to improve the performance of TLB flushes" * tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp: Micro-optimize smp_call_function_many_cond() smp: Inline on_each_cpu_cond() and on_each_cpu() x86/mm/tlb: Remove unnecessary uses of the inline keyword cpumask: Mark functions as pure x86/mm/tlb: Do not make is_lazy dirty for no reason x86/mm/tlb: Privatize cpu_tlbstate x86/mm/tlb: Flush remote and local TLBs concurrently x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy() x86/mm/tlb: Unify flush_tlb_func_local() and flush_tlb_func_remote() smp: Run functions concurrently in smp_call_function_many_cond()
2021-04-26Merge tag 'x86_cleanups_for_v5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 cleanups from Borislav Petkov: "Trivial cleanups and fixes all over the place" * tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Remove me from IDE/ATAPI section x86/pat: Do not compile stubbed functions when X86_PAT is off x86/asm: Ensure asm/proto.h can be included stand-alone x86/platform/intel/quark: Fix incorrect kernel-doc comment syntax in files x86/msr: Make locally used functions static x86/cacheinfo: Remove unneeded dead-store initialization x86/process/64: Move cpu_current_top_of_stack out of TSS tools/turbostat: Unmark non-kernel-doc comment x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL() x86/fpu/math-emu: Fix function cast warning x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes x86: Fix various typos in comments, take #2 x86: Remove unusual Unicode characters from comments x86/kaslr: Return boolean values from a function returning bool x86: Fix various typos in comments x86/setup: Remove unused RESERVE_BRK_ARRAY() stacktrace: Move documentation for arch_stack_walk_reliable() to header x86: Remove duplicate TSC DEADLINE MSR definitions
2021-04-26Merge tag 'x86_seves_for_v5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 AMD secure virtualization (SEV-ES) updates from Borislav Petkov: "Add support for SEV-ES guests booting through the 32-bit boot path, along with cleanups, fixes and improvements" * tag 'x86_seves_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Optimize __sev_es_ist_enter() for better readability x86/sev-es: Replace open-coded hlt-loops with sev_es_terminate() x86/boot/compressed/64: Check SEV encryption in the 32-bit boot-path x86/boot/compressed/64: Add CPUID sanity check to 32-bit boot-path x86/boot/compressed/64: Add 32-bit boot #VC handler x86/boot/compressed/64: Setup IDT in startup_32 boot path x86/boot/compressed/64: Reload CS in startup_32 x86/sev: Do not require Hypervisor CPUID bit for SEV guests x86/boot/compressed/64: Cleanup exception handling before booting kernel x86/virtio: Have SEV guests enforce restricted virtio memory access x86/sev-es: Remove subtraction of res variable
2021-04-26x86/sev: Drop redundant and potentially misleading 'sev_enabled'Sean Christopherson
Drop the sev_enabled flag and switch its one user over to sev_active(). sev_enabled was made redundant with the introduction of sev_status in commit b57de6cd1639 ("x86/sev-es: Add SEV-ES Feature Detection"). sev_enabled and sev_active() are guaranteed to be equivalent, as each is true iff 'sev_status & MSR_AMD64_SEV_ENABLED' is true, and are only ever written in tandem (ignoring compressed boot's version of sev_status). Removing sev_enabled avoids confusion over whether it refers to the guest or the host, and will also allow KVM to usurp "sev_enabled" for its own purposes. No functional change intended. Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210422021125.3417167-7-seanjc@google.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-14x86/pat: Do not compile stubbed functions when X86_PAT is offJan Kiszka
Those are already provided by linux/io.h as stubs. The conflict remains invisible until someone would pull linux/io.h into memtype.c. This fixes a build error when this file is used outside of the kernel tree. [ bp: Massage commit message. ] Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/a9351615-7a0d-9d47-af65-d9e2fffe8192@siemens.com
2021-03-28x86/process/64: Move cpu_current_top_of_stack out of TSSLai Jiangshan
cpu_current_top_of_stack is currently stored in TSS.sp1. TSS is exposed through the cpu_entry_area which is visible with user CR3 when PTI is enabled and active. This makes it a coveted fruit for attackers. An attacker can fetch the kernel stack top from it and continue next steps of actions based on the kernel stack. But it is actualy not necessary to be stored in the TSS. It is only accessed after the entry code switched to kernel CR3 and kernel GS_BASE which means it can be in any regular percpu variable. The reason why it is in TSS is historical (pre PTI) because TSS is also used as scratch space in SYSCALL_64 and therefore cache hot. A syscall also needs the per CPU variable current_task and eventually __preempt_count, so placing cpu_current_top_of_stack next to them makes it likely that they end up in the same cache line which should avoid performance regressions. This is not enforced as the compiler is free to place these variables, so these entry relevant variables should move into a data structure to make this enforceable. The seccomp_benchmark doesn't show any performance loss in the "getpid native" test result. Actually, the result changes from 93ns before to 92ns with this change when KPTI is disabled. The test is very stable and although the test doesn't show a higher degree of precision it gives enough confidence that moving cpu_current_top_of_stack does not cause a regression. [ tglx: Removed unneeded export. Massaged changelog ] Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210125173444.22696-2-jiangshanlai@gmail.com
2021-03-23x86/mem_encrypt: Correct physical address calculation in __set_clr_pte_enc()Isaku Yamahata
The pfn variable contains the page frame number as returned by the pXX_pfn() functions, shifted to the right by PAGE_SHIFT to remove the page bits. After page protection computations are done to it, it gets shifted back to the physical address using page_level_shift(). That is wrong, of course, because that function determines the shift length based on the level of the page in the page table but in all the cases, it was shifted by PAGE_SHIFT before. Therefore, shift it back using PAGE_SHIFT to get the correct physical address. [ bp: Rewrite commit message. ] Fixes: dfaaec9033b8 ("x86: Add support for changing memory encryption attribute in early boot") Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/81abbae1657053eccc535c16151f63cd049dcb97.1616098294.git.isaku.yamahata@intel.com
2021-03-21x86: Fix various typos in comments, take #2Ingo Molnar
Fix another ~42 single-word typos in arch/x86/ code comments, missed a few in the first pass, in particular in .S files. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
2021-03-18x86/sev: Do not require Hypervisor CPUID bit for SEV guestsJoerg Roedel
A malicious hypervisor could disable the CPUID intercept for an SEV or SEV-ES guest and trick it into the no-SEV boot path, where it could potentially reveal secrets. This is not an issue for SEV-SNP guests, as the CPUID intercept can't be disabled for those. Remove the Hypervisor CPUID bit check from the SEV detection code to protect against this kind of attack and add a Hypervisor bit equals zero check to the SME detection path to prevent non-encrypted guests from trying to enable SME. This handles the following cases: 1) SEV(-ES) guest where CPUID intercept is disabled. The guest will still see leaf 0x8000001f and the SEV bit. It can retrieve the C-bit and boot normally. 2) Non-encrypted guests with intercepted CPUID will check the SEV_STATUS MSR and find it 0 and will try to enable SME. This will fail when the guest finds MSR_K8_SYSCFG to be zero, as it is emulated by KVM. But we can't rely on that, as there might be other hypervisors which return this MSR with bit 23 set. The Hypervisor bit check will prevent that the guest tries to enable SME in this case. 3) Non-encrypted guests on SEV capable hosts with CPUID intercept disabled (by a malicious hypervisor) will try to boot into the SME path. This will fail, but it is also not considered a problem because non-encrypted guests have no protection against the hypervisor anyway. [ bp: s/non-SEV/non-encrypted/g ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20210312123824.306-3-joro@8bytes.org
2021-03-18x86: Fix various typos in commentsIngo Molnar
Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
2021-03-08x86/virtio: Have SEV guests enforce restricted virtio memory accessTom Lendacky
An SEV guest requires that virtio devices use the DMA API to allow the hypervisor to successfully access guest memory as needed. The VIRTIO_F_VERSION_1 and VIRTIO_F_ACCESS_PLATFORM features tell virtio to use the DMA API. Add arch_has_restricted_virtio_memory_access() for x86, to fail the device probe if these features have not been set for the device when running as an SEV guest. [ bp: Fix -Wmissing-prototypes warning Reported-by: kernel test robot <lkp@intel.com> ] Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/b46e0211f77ca1831f11132f969d470a6ffc9267.1614897610.git.thomas.lendacky@amd.com
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