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2021-01-05x86/mm: Fix leak of pmd ptlockDan Williams1-0/+2
Commit 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") introduced a new location where a pmd was released, but neglected to run the pmd page destructor. In fact, this happened previously for a different pmd release path and was fixed by commit: c283610e44ec ("x86, mm: do not leak page->ptl for pmd page tables"). This issue was hidden until recently because the failure mode is silent, but commit: b2b29d6d0119 ("mm: account PMD tables like PTE tables") turns the failure mode into this signature: BUG: Bad page state in process lt-pmem-ns pfn:15943d page:000000007262ed7b refcount:0 mapcount:-1024 mapping:0000000000000000 index:0x0 pfn:0x15943d flags: 0xaffff800000000() raw: 00affff800000000 dead000000000100 0000000000000000 0000000000000000 raw: 0000000000000000 ffff913a029bcc08 00000000fffffbff 0000000000000000 page dumped because: nonzero mapcount [..] dump_stack+0x8b/0xb0 bad_page.cold+0x63/0x94 free_pcp_prepare+0x224/0x270 free_unref_page+0x18/0xd0 pud_free_pmd_page+0x146/0x160 ioremap_pud_range+0xe3/0x350 ioremap_page_range+0x108/0x160 __ioremap_caller.constprop.0+0x174/0x2b0 ? memremap+0x7a/0x110 memremap+0x7a/0x110 devm_memremap+0x53/0xa0 pmem_attach_disk+0x4ed/0x530 [nd_pmem] ? __devm_release_region+0x52/0x80 nvdimm_bus_probe+0x85/0x210 [libnvdimm] Given this is a repeat occurrence it seemed prudent to look for other places where this destructor might be missing and whether a better helper is needed. try_to_free_pmd_page() looks like a candidate, but testing with setting up and tearing down pmd mappings via the dax unit tests is thus far not triggering the failure. As for a better helper pmd_free() is close, but it is a messy fit due to requiring an @mm arg. Also, ___pmd_free_tlb() wants to call paravirt_tlb_remove_table() instead of free_page(), so open-coded pgtable_pmd_page_dtor() seems the best way forward for now. Debugged together with Matthew Wilcox <willy@infradead.org>. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Yi Zhang <yi.zhang@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/160697689204.605323.17629854984697045602.stgit@dwillia2-desk3.amr.corp.intel.com
2020-12-16Merge branch 'stable/for-linus-5.11' of ↵Linus Torvalds1-0/+31
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb update from Konrad Rzeszutek Wilk: "A generic (but for right now engaged only with AMD SEV) mechanism to adjust a larger size SWIOTLB based on the total memory of the SEV guests which right now require the bounce buffer for interacting with the outside world. Normal knobs (swiotlb=XYZ) still work" * 'stable/for-linus-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests
2020-12-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+2
Merge misc updates from Andrew Morton: - a few random little subsystems - almost all of the MM patches which are staged ahead of linux-next material. I'll trickle to post-linux-next work in as the dependents get merged up. Subsystems affected by this patch series: kthread, kbuild, ide, ntfs, ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation, kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction, oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc, uaccess, zram, and cleanups). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits) mm: cleanup kstrto*() usage mm: fix fall-through warnings for Clang mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at mm: shmem: convert shmem_enabled_show to use sysfs_emit_at mm:backing-dev: use sysfs_emit in macro defining functions mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening mm: use sysfs_emit for struct kobject * uses mm: fix kernel-doc markups zram: break the strict dependency from lzo zram: add stat to gather incompressible pages since zram set up zram: support page writeback mm/process_vm_access: remove redundant initialization of iov_r mm/zsmalloc.c: rework the list_add code in insert_zspage() mm/zswap: move to use crypto_acomp API for hardware acceleration mm/zswap: fix passing zero to 'PTR_ERR' warning mm/zswap: make struct kernel_param_ops definitions const userfaultfd/selftests: hint the test runner on required privilege userfaultfd/selftests: fix retval check for userfaultfd_open() userfaultfd/selftests: always dump something in modes userfaultfd: selftests: make __{s,u}64 format specifiers portable ...
2020-12-15arch, mm: make kernel_page_present() always availableMike Rapoport1-3/+1
For architectures that enable ARCH_HAS_SET_MEMORY having the ability to verify that a page is mapped in the kernel direct map can be useful regardless of hibernation. Add RISC-V implementation of kernel_page_present(), update its forward declarations and stubs to be a part of set_memory API and remove ugly ifdefery in inlcude/linux/mm.h around current declarations of kernel_page_present(). Link: https://lkml.kernel.org/r/20201109192128.960-5-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Len Brown <len.brown@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOCMike Rapoport1-0/+2
The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must never fail. With this assumption is wouldn't be safe to allow general usage of this function. Moreover, some architectures that implement __kernel_map_pages() have this function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap pages when page allocation debugging is disabled at runtime. As all the users of __kernel_map_pages() were converted to use debug_pagealloc_map_pages() it is safe to make it available only when DEBUG_PAGEALLOC is set. Link: https://lkml.kernel.org/r/20201109192128.960-4-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Len Brown <len.brown@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-14Merge tag 'core-mm-2020-12-14' of ↵Linus Torvalds3-128/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull kmap updates from Thomas Gleixner: "The new preemtible kmap_local() implementation: - Consolidate all kmap_atomic() internals into a generic implementation which builds the base for the kmap_local() API and make the kmap_atomic() interface wrappers which handle the disabling/enabling of preemption and pagefaults. - Switch the storage from per-CPU to per task and provide scheduler support for clearing mapping when scheduling out and restoring them when scheduling back in. - Merge the migrate_disable/enable() code, which is also part of the scheduler pull request. This was required to make the kmap_local() interface available which does not disable preemption when a mapping is established. It has to disable migration instead to guarantee that the virtual address of the mapped slot is the same across preemption. - Provide better debug facilities: guard pages and enforced utilization of the mapping mechanics on 64bit systems when the architecture allows it. - Provide the new kmap_local() API which can now be used to cleanup the kmap_atomic() usage sites all over the place. Most of the usage sites do not require the implicit disabling of preemption and pagefaults so the penalty on 64bit and 32bit non-highmem systems is removed and quite some of the code can be simplified. A wholesale conversion is not possible because some usage depends on the implicit side effects and some need to be cleaned up because they work around these side effects. The migrate disable side effect is only effective on highmem systems and when enforced debugging is enabled. On 64bit and 32bit non-highmem systems the overhead is completely avoided" * tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) ARM: highmem: Fix cache_is_vivt() reference x86/crashdump/32: Simplify copy_oldmem_page() io-mapping: Provide iomap_local variant mm/highmem: Provide kmap_local* sched: highmem: Store local kmaps in task struct x86: Support kmap_local() forced debugging mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL microblaze/mm/highmem: Add dropped #ifdef back xtensa/mm/highmem: Make generic kmap_atomic() work correctly mm/highmem: Take kmap_high_get() properly into account highmem: High implementation details and document API Documentation/io-mapping: Remove outdated blurb io-mapping: Cleanup atomic iomap mm/highmem: Remove the old kmap_atomic cruft highmem: Get rid of kmap_types.h xtensa/mm/highmem: Switch to generic kmap atomic sparc/mm/highmem: Switch to generic kmap atomic powerpc/mm/highmem: Switch to generic kmap atomic nds32/mm/highmem: Switch to generic kmap atomic ...
2020-12-14Merge tag 'x86_cleanups_for_v5.11' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "Another branch with a nicely negative diffstat, just the way I like 'em: - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end (Gabriel Krisman Bertazi) - All kinds of minor cleanups all over the tree" * tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/ia32_signal: Propagate __user annotation properly x86/alternative: Update text_poke_bp() kernel-doc comment x86/PCI: Make a kernel-doc comment a normal one x86/asm: Drop unused RDPID macro x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg x86/head64: Remove duplicate include x86/mm: Declare 'start' variable where it is used x86/head/64: Remove unused GET_CR2_INTO() macro x86/boot: Remove unused finalize_identity_maps() x86/uaccess: Document copy_from_user_nmi() x86/dumpstack: Make show_trace_log_lvl() static x86/mtrr: Fix a kernel-doc markup x86/setup: Remove unused MCA variables x86, libnvdimm/test: Remove COPY_MC_TEST x86: Reclaim TIF_IA32 and TIF_X32 x86/mm: Convert mmu context ia32_compat into a proper flags field x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() elf: Expose ELF header on arch_setup_additional_pages() x86/elf: Use e_machine to select start_thread for x32 elf: Expose ELF header in compat_start_thread() ...
2020-12-14Merge tag 'x86_mm_for_v5.11' of ↵Linus Torvalds1-2/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm update from Borislav Petkov: "A single improvement to check ident_pud_init()'s return value (Arvind Sankar)" * tag 'x86_mm_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ident_map: Check for errors from ident_pud_init()
2020-12-14Merge tag 'x86_sgx_for_v5.11' of ↵Linus Torvalds1-12/+33
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SGC support from Borislav Petkov: "Intel Software Guard eXtensions enablement. This has been long in the making, we were one revision number short of 42. :) Intel SGX is new hardware functionality that can be used by applications to populate protected regions of user code and data called enclaves. Once activated, the new hardware protects enclave code and data from outside access and modification. Enclaves provide a place to store secrets and process data with those secrets. SGX has been used, for example, to decrypt video without exposing the decryption keys to nosy debuggers that might be used to subvert DRM. Software has generally been rewritten specifically to run in enclaves, but there are also projects that try to run limited unmodified software in enclaves. Most of the functionality is concentrated into arch/x86/kernel/cpu/sgx/ except the addition of a new mprotect() hook to control enclave page permissions and support for vDSO exceptions fixup which will is used by SGX enclaves. All this work by Sean Christopherson, Jarkko Sakkinen and many others" * tag 'x86_sgx_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits) x86/sgx: Return -EINVAL on a zero length buffer in sgx_ioc_enclave_add_pages() x86/sgx: Fix a typo in kernel-doc markup x86/sgx: Fix sgx_ioc_enclave_provision() kernel-doc comment x86/sgx: Return -ERESTARTSYS in sgx_ioc_enclave_add_pages() selftests/sgx: Use a statically generated 3072-bit RSA key x86/sgx: Clarify 'laundry_list' locking x86/sgx: Update MAINTAINERS Documentation/x86: Document SGX kernel architecture x86/sgx: Add ptrace() support for the SGX driver x86/sgx: Add a page reclaimer selftests/x86: Add a selftest for SGX x86/vdso: Implement a vDSO for Intel SGX enclave call x86/traps: Attempt to fixup exceptions in vDSO before signaling x86/fault: Add a helper function to sanitize error code x86/vdso: Add support for exception fixup in vDSO functions x86/sgx: Add SGX_IOC_ENCLAVE_PROVISION x86/sgx: Add SGX_IOC_ENCLAVE_INIT x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES x86/sgx: Add SGX_IOC_ENCLAVE_CREATE x86/sgx: Add an SGX misc driver interface ...
2020-12-11x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guestsAshish Kalra1-0/+31
For SEV, all DMA to and from guest has to use shared (un-encrypted) pages. SEV uses SWIOTLB to make this happen without requiring changes to device drivers. However, depending on the workload being run, the default 64MB of it might not be enough and it may run out of buffers to use for DMA, resulting in I/O errors and/or performance degradation for high I/O workloads. Adjust the default size of SWIOTLB for SEV guests using a percentage of the total memory available to guest for the SWIOTLB buffers. Adds a new sev_setup_arch() function which is invoked from setup_arch() and it calls into a new swiotlb generic code function swiotlb_adjust_size() to do the SWIOTLB buffer adjustment. v5 fixed build errors and warnings as Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Co-developed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-12-10x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WPArvind Sankar1-2/+2
The PAT bit is in different locations for 4k and 2M/1G page table entries. Add a definition for _PAGE_LARGE_CACHE_MASK to represent the three caching bits (PWT, PCD, PAT), similar to _PAGE_CACHE_MASK for 4k pages, and use it in the definition of PMD_FLAGS_DEC_WP to get the correct PAT index for write-protected pages. Fixes: 6ebcb060713f ("x86/mm: Add support to encrypt the kernel in-place") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20201111160946.147341-1-nivedita@alum.mit.edu
2020-12-09x86/membarrier: Get rid of a dubious optimizationAndy Lutomirski1-2/+8
sync_core_before_usermode() had an incorrect optimization. If the kernel returns from an interrupt, it can get to usermode without IRET. It just has to schedule to a different task in the same mm and do SYSRET. Fortunately, there were no callers of sync_core_before_usermode() that could have had in_irq() or in_nmi() equal to true, because it's only ever called from the scheduler. While at it, clarify a related comment. Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/5afc7632be1422f91eaf7611aaaa1b5b8580a086.1607058304.git.luto@kernel.org
2020-11-22mm: fix phys_to_target_node() and memory_add_physaddr_to_nid() exportsDan Williams1-0/+2
The core-mm has a default __weak implementation of phys_to_target_node() to mirror the weak definition of memory_add_physaddr_to_nid(). That symbol is exported for modules. However, while the export in mm/memory_hotplug.c exported the symbol in the configuration cases of: CONFIG_NUMA_KEEP_MEMINFO=y CONFIG_MEMORY_HOTPLUG=y ...and: CONFIG_NUMA_KEEP_MEMINFO=n CONFIG_MEMORY_HOTPLUG=y ...it failed to export the symbol in the case of: CONFIG_NUMA_KEEP_MEMINFO=y CONFIG_MEMORY_HOTPLUG=n Not only is that broken, but Christoph points out that the kernel should not be exporting any __weak symbol, which means that memory_add_physaddr_to_nid() example that phys_to_target_node() copied is broken too. Rework the definition of phys_to_target_node() and memory_add_physaddr_to_nid() to not require weak symbols. Move to the common arch override design-pattern of an asm header defining a symbol to replace the default implementation. The only common header that all memory_add_physaddr_to_nid() producing architectures implement is asm/sparsemem.h. In fact, powerpc already defines its memory_add_physaddr_to_nid() helper in sparsemem.h. Double-down on that observation and define phys_to_target_node() where necessary in asm/sparsemem.h. An alternate consideration that was discarded was to put this override in asm/numa.h, but that entangles with the definition of MAX_NUMNODES relative to the inclusion of linux/nodemask.h, and requires powerpc to grow a new header. The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid now that the symbol is properly exported / stubbed in all combinations of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG. [dan.j.williams@intel.com: v4] Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com [dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning] Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: a035b6bf863e ("mm/memory_hotplug: introduce default phys_to_target_node() implementation") Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-20x86/mm: Declare 'start' variable where it is usedLukas Bulwahn1-2/+4
It is not required to initialize the local variable start in memory_map_top_down(), as the variable will be initialized in any path before it is used. make clang-analyzer on x86_64 tinyconfig reports: arch/x86/mm/init.c:612:15: warning: Although the value stored to 'start' \ is used in the enclosing expression, the value is never actually read \ from 'start' [clang-analyzer-deadcode.DeadStores] Move the variable declaration into the loop, where it is used. No code changed: # arch/x86/mm/init.o: text data bss dec hex filename 7105 1424 26768 35297 89e1 init.o.before 7105 1424 26768 35297 89e1 init.o.after md5: a8d76c1bb5fce9cae251780a7ee7730f init.o.before.asm a8d76c1bb5fce9cae251780a7ee7730f init.o.after.asm [ bp: Massage. ] Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20200928100004.25674-1-lukas.bulwahn@gmail.com
2020-11-18x86/traps: Attempt to fixup exceptions in vDSO before signalingSean Christopherson1-0/+7
vDSO functions can now leverage an exception fixup mechanism similar to kernel exception fixup. For vDSO exception fixup, the initial user is Intel's Software Guard Extensions (SGX), which will wrap the low-level transitions to/from the enclave, i.e. EENTER and ERESUME instructions, in a vDSO function and leverage fixup to intercept exceptions that would otherwise generate a signal. This allows the vDSO wrapper to return the fault information directly to its caller, obviating the need for SGX applications and libraries to juggle signal handlers. Attempt to fixup vDSO exceptions immediately prior to populating and sending signal information. Except for the delivery mechanism, an exception in a vDSO function should be treated like any other exception in userspace, e.g. any fault that is successfully handled by the kernel should not be directly visible to userspace. Although it's debatable whether or not all exceptions are of interest to enclaves, defer to the vDSO fixup to decide whether to do fixup or generate a signal. Future users of vDSO fixup, if there ever are any, will undoubtedly have different requirements than SGX enclaves, e.g. the fixup vs. signal logic can be made function specific if/when necessary. Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-19-jarkko@kernel.org
2020-11-18x86/fault: Add a helper function to sanitize error codeSean Christopherson1-12/+14
vDSO exception fixup is a replacement for signals in limited situations. Signals and vDSO exception fixup need to provide similar information to userspace, including the hardware error code. That hardware error code needs to be sanitized. For instance, if userspace accesses a kernel address, the error code could indicate to userspace whether the address had a Present=1 PTE. That can leak information about the kernel layout to userspace, which is bad. The existing signal code does this sanitization, but fairly late in the signal process. The vDSO exception code runs before the sanitization happens. Move error code sanitization out of the signal code and into a helper. Call the helper in the signal code. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-18-jarkko@kernel.org
2020-11-17x86/mm: Signal SIGSEGV with PF_SGXSean Christopherson1-0/+12
The x86 architecture has a set of page fault error codes. These indicate things like whether the fault occurred from a write, or whether it originated in userspace. The SGX hardware architecture has its own per-page memory management metadata (EPCM) [*] and hardware which is separate from the normal x86 MMU. The architecture has a new page fault error code: PF_SGX. This new error code bit is set whenever a page fault occurs as the result of the SGX MMU. These faults occur for a variety of reasons. For instance, an access attempt to enclave memory from outside the enclave causes a PF_SGX fault. PF_SGX would also be set for permission conflicts, such as if a write to an enclave page occurs and the page is marked read-write in the x86 page tables but is read-only in the EPCM. These faults do not always indicate errors, though. SGX pages are encrypted with a key that is destroyed at hardware reset, including suspend. Throwing a SIGSEGV allows user space software to react and recover when these events occur. Include PF_SGX in the PF error codes list and throw SIGSEGV when it is encountered. [*] Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM) [ bp: Add bit 15 to the comment above enum x86_pf_error_code too. ] Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-7-jarkko@kernel.org
2020-11-06io-mapping: Cleanup atomic iomapThomas Gleixner1-4/+2
Switch the atomic iomap implementation over to kmap_local and stick the preempt/pagefault mechanics into the generic code similar to the kmap_atomic variants. Rename the x86 map function in preparation for a non-atomic variant. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201103095858.625310005@linutronix.de
2020-11-06x86/mm/highmem: Use generic kmap atomic implementationThomas Gleixner3-128/+5
Convert X86 to the generic kmap atomic implementation and make the iomap_atomic() naming convention consistent while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201103095857.375127260@linutronix.de
2020-10-29x86/head/64: Check SEV encryption before switching to kernel page-tableJoerg Roedel1-0/+1
When SEV is enabled, the kernel requests the C-bit position again from the hypervisor to build its own page-table. Since the hypervisor is an untrusted source, the C-bit position needs to be verified before the kernel page-table is used. Call sev_verify_cbit() before writing the CR3. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-5-joro@8bytes.org
2020-10-28x86/mm/ident_map: Check for errors from ident_pud_init()Arvind Sankar1-2/+10
Commit ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support") added ident_p4d_init() to support 5-level paging, but this function doesn't check and return errors from ident_pud_init(). For example, the decompressor stub uses this code to create an identity mapping. If it runs out of pages while trying to allocate a PMD pagetable, the error will be currently ignored. Fix this to propagate errors. [ bp: Space out statements for better readability. ] Fixes: ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Joerg Roedel <jroedel@suse.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20201027230648.1885111-1-nivedita@alum.mit.edu
2020-10-25treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches2-4/+4
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-5/+8
Pull KVM updates from Paolo Bonzini: "For x86, there is a new alternative and (in the future) more scalable implementation of extended page tables that does not need a reverse map from guest physical addresses to host physical addresses. For now it is disabled by default because it is still lacking a few of the existing MMU's bells and whistles. However it is a very solid piece of work and it is already available for people to hammer on it. Other updates: ARM: - New page table code for both hypervisor and guest stage-2 - Introduction of a new EL2-private host context - Allow EL2 to have its own private per-CPU variables - Support of PMU event filtering - Complete rework of the Spectre mitigation PPC: - Fix for running nested guests with in-kernel IRQ chip - Fix race condition causing occasional host hard lockup - Minor cleanups and bugfixes x86: - allow trapping unknown MSRs to userspace - allow userspace to force #GP on specific MSRs - INVPCID support on AMD - nested AMD cleanup, on demand allocation of nested SVM state - hide PV MSRs and hypercalls for features not enabled in CPUID - new test for MSR_IA32_TSC writes from host and guest - cleanups: MMU, CPUID, shared MSRs - LAPIC latency optimizations ad bugfixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits) kvm: x86/mmu: NX largepage recovery for TDP MMU kvm: x86/mmu: Don't clear write flooding count for direct roots kvm: x86/mmu: Support MMIO in the TDP MMU kvm: x86/mmu: Support write protection for nesting in tdp MMU kvm: x86/mmu: Support disabling dirty logging for the tdp MMU kvm: x86/mmu: Support dirty logging for the TDP MMU kvm: x86/mmu: Support changed pte notifier in tdp MMU kvm: x86/mmu: Add access tracking for tdp_mmu kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU kvm: x86/mmu: Add TDP MMU PF handler kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg kvm: x86/mmu: Support zapping SPTEs in the TDP MMU KVM: Cache as_id in kvm_memory_slot kvm: x86/mmu: Add functions to handle changed TDP SPTEs kvm: x86/mmu: Allocate and free TDP MMU roots kvm: x86/mmu: Init / Uninit the TDP MMU kvm: x86/mmu: Introduce tdp_iter KVM: mmu: extract spte.h and spte.c KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp ...
2020-10-21x86/kvm: Update the comment about asynchronous page fault in exc_page_fault()Vitaly Kuznetsov1-5/+8
KVM was switched to interrupt-based mechanism for 'page ready' event delivery in Linux-5.8 (see commit 2635b5c4a0e4 ("KVM: x86: interrupt based APF 'page ready' event delivery")) and #PF (ab)use for 'page ready' event delivery was removed. Linux guest switched to this new mechanism exclusively in 5.9 (see commit b1d405751cd5 ("KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery")) so it is not possible to get #PF for a 'page ready' event even when the guest is running on top of an older KVM (APF mechanism won't be enabled). Update the comment in exc_page_fault() to reflect the new reality. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20201002154313.1505327-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-14Merge tag 'acpi-5.10-rc1' of ↵Linus Torvalds1-0/+21
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI updates from Rafael Wysocki: "These add support for generic initiator-only proximity domains to the ACPI NUMA code and the architectures using it, clean up some non-ACPICA code referring to debug facilities from ACPICA, reduce the overhead related to accessing GPE registers, add a new DPTF (Dynamic Power and Thermal Framework) participant driver, update the ACPICA code in the kernel to upstream revision 20200925, add a new ACPI backlight whitelist entry, fix a few assorted issues and clean up some code. Specifics: - Add support for generic initiator-only proximity domains to the ACPI NUMA code and the architectures using it (Jonathan Cameron) - Clean up some non-ACPICA code referring to debug facilities from ACPICA that are not actually used in there (Hanjun Guo) - Add new DPTF driver for the PCH FIVR participant (Srinivas Pandruvada) - Reduce overhead related to accessing GPE registers in ACPICA and the OS interface layer and make it possible to access GPE registers using logical addresses if they are memory-mapped (Rafael Wysocki) - Update the ACPICA code in the kernel to upstream revision 20200925 including changes as follows: + Add predefined names from the SMBus sepcification (Bob Moore) + Update acpi_help UUID list (Bob Moore) + Return exceptions for string-to-integer conversions in iASL (Bob Moore) + Add a new "ALL <NameSeg>" debugger command (Bob Moore) + Add support for 64 bit risc-v compilation (Colin Ian King) + Do assorted cleanups (Bob Moore, Colin Ian King, Randy Dunlap) - Add new ACPI backlight whitelist entry for HP 635 Notebook (Alex Hung) - Move TPS68470 OpRegion driver to drivers/acpi/pmic/ and split out Kconfig and Makefile specific for ACPI PMIC (Andy Shevchenko) - Clean up the ACPI SoC driver for AMD SoCs (Hanjun Guo) - Add missing config_item_put() to fix refcount leak (Hanjun Guo) - Drop lefrover field from struct acpi_memory_device (Hanjun Guo) - Make the ACPI extlog driver check for RDMSR failures (Ben Hutchings) - Fix handling of lid state changes in the ACPI button driver when input device is closed (Dmitry Torokhov) - Fix several assorted build issues (Barnabás Pőcze, John Garry, Nathan Chancellor, Tian Tao) - Drop unused inline functions and reduce code duplication by using kobj_to_dev() in the NFIT parsing code (YueHaibing, Wang Qing) - Serialize tools/power/acpi Makefile (Thomas Renninger)" * tag 'acpi-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits) ACPICA: Update version to 20200925 Version 20200925 ACPICA: Remove unnecessary semicolon ACPICA: Debugger: Add a new command: "ALL <NameSeg>" ACPICA: iASL: Return exceptions for string-to-integer conversions ACPICA: acpi_help: Update UUID list ACPICA: Add predefined names found in the SMBus sepcification ACPICA: Tree-wide: fix various typos and spelling mistakes ACPICA: Drop the repeated word "an" in a comment ACPICA: Add support for 64 bit risc-v compilation ACPI: button: fix handling lid state changes when input device closed tools/power/acpi: Serialize Makefile ACPI: scan: Replace ACPI_DEBUG_PRINT() with pr_debug() ACPI: memhotplug: Remove 'state' from struct acpi_memory_device ACPI / extlog: Check for RDMSR failure ACPI: Make acpi_evaluate_dsm() prototype consistent docs: mm: numaperf.rst Add brief description for access class 1. node: Add access1 class to represent CPU to memory characteristics ACPI: HMAT: Fix handling of changes from ACPI 6.2 to ACPI 6.3 ACPI: Let ACPI know we support Generic Initiator Affinity Structures x86: Support Generic Initiator only proximity domains ...
2020-10-14Merge tag 'x86_seves_for_v5.10' of ↵Linus Torvalds4-5/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV-ES support from Borislav Petkov: "SEV-ES enhances the current guest memory encryption support called SEV by also encrypting the guest register state, making the registers inaccessible to the hypervisor by en-/decrypting them on world switches. Thus, it adds additional protection to Linux guests against exfiltration, control flow and rollback attacks. With SEV-ES, the guest is in full control of what registers the hypervisor can access. This is provided by a guest-host exchange mechanism based on a new exception vector called VMM Communication Exception (#VC), a new instruction called VMGEXIT and a shared Guest-Host Communication Block which is a decrypted page shared between the guest and the hypervisor. Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest so in order for that exception mechanism to work, the early x86 init code needed to be made able to handle exceptions, which, in itself, brings a bunch of very nice cleanups and improvements to the early boot code like an early page fault handler, allowing for on-demand building of the identity mapping. With that, !KASLR configurations do not use the EFI page table anymore but switch to a kernel-controlled one. The main part of this series adds the support for that new exchange mechanism. The goal has been to keep this as much as possibly separate from the core x86 code by concentrating the machinery in two SEV-ES-specific files: arch/x86/kernel/sev-es-shared.c arch/x86/kernel/sev-es.c Other interaction with core x86 code has been kept at minimum and behind static keys to minimize the performance impact on !SEV-ES setups. Work by Joerg Roedel and Thomas Lendacky and others" * tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits) x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer x86/sev-es: Check required CPU features for SEV-ES x86/efi: Add GHCB mappings when SEV-ES is active x86/sev-es: Handle NMI State x86/sev-es: Support CPU offline/online x86/head/64: Don't call verify_cpu() on starting APs x86/smpboot: Load TSS and getcpu GDT entry before loading IDT x86/realmode: Setup AP jump table x86/realmode: Add SEV-ES specific trampoline entry point x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES x86/sev-es: Handle #DB Events x86/sev-es: Handle #AC Events x86/sev-es: Handle VMMCALL Events x86/sev-es: Handle MWAIT/MWAITX Events x86/sev-es: Handle MONITOR/MONITORX Events x86/sev-es: Handle INVD Events x86/sev-es: Handle RDPMC Events x86/sev-es: Handle RDTSC(P) Events ...
2020-10-13memblock: use separate iterators for memory and reserved regionsMike Rapoport1-1/+1
for_each_memblock() is used to iterate over memblock.memory in a few places that use data from memblock_region rather than the memory ranges. Introduce separate for_each_mem_region() and for_each_reserved_mem_region() to improve encapsulation of memblock internals from its users. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> [x86] Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> [MIPS] Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> [.clang-format] Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-18-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/memory_hotplug: introduce default phys_to_target_node() implementationDan Williams1-1/+0
In preparation to set a fallback value for dev_dax->target_node, introduce generic fallback helpers for phys_to_target_node() A generic implementation based on node-data or memblock was proposed, but as noted by Mike: "Here again, I would prefer to add a weak default for phys_to_target_node() because the "generic" implementation is not really generic. The fallback to reserved ranges is x86 specfic because on x86 most of the reserved areas is not in memblock.memory. AFAIK, no other architecture does this." The info message in the generic memory_add_physaddr_to_nid() implementation is fixed up to properly reflect that memory_add_physaddr_to_nid() communicates "online" node info and phys_to_target_node() indicates "target / to-be-onlined" node info. [akpm@linux-foundation.org: fix CONFIG_MEMORY_HOTPLUG=n build] Link: https://lkml.kernel.org/r/202008252130.7YrHIyMI%25lkp@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jia He <justin.he@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Link: https://lkml.kernel.org/r/159643097768.4062302.3135192588966888630.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13x86/numa: add 'nohmat' optionDan Williams1-0/+2
Disable parsing of the HMAT for debug, to workaround broken platform instances, or cases where it is otherwise not wanted. [rdunlap@infradead.org: fix build when CONFIG_ACPI is not set] Link: https://lkml.kernel.org/r/70e5ee34-9809-a997-7b49-499e4be61307@infradead.org Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.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: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Link: https://lkml.kernel.org/r/159643095540.4062302.732962081968036212.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13x86/numa: cleanup configuration dependent command-line optionsDan Williams2-7/+4
Patch series "device-dax: Support sub-dividing soft-reserved ranges", v5. The device-dax facility allows an address range to be directly mapped through a chardev, or optionally hotplugged to the core kernel page allocator as System-RAM. It is the mechanism for converting persistent memory (pmem) to be used as another volatile memory pool i.e. the current Memory Tiering hot topic on linux-mm. In the case of pmem the nvdimm-namespace-label mechanism can sub-divide it, but that labeling mechanism is not available / applicable to soft-reserved ("EFI specific purpose") memory [3]. This series provides a sysfs-mechanism for the daxctl utility to enable provisioning of volatile-soft-reserved memory ranges. The motivations for this facility are: 1/ Allow performance differentiated memory ranges to be split between kernel-managed and directly-accessed use cases. 2/ Allow physical memory to be provisioned along performance relevant address boundaries. For example, divide a memory-side cache [4] along cache-color boundaries. 3/ Parcel out soft-reserved memory to VMs using device-dax as a security / permissions boundary [5]. Specifically I have seen people (ab)using memmap=nn!ss (mark System-RAM as Persistent Memory) just to get the device-dax interface on custom address ranges. A follow-on for the VM use case is to teach device-dax to dynamically allocate 'struct page' at runtime to reduce the duplication of 'struct page' space in both the guest and the host kernel for the same physical pages. [2]: http://lore.kernel.org/r/20200713160837.13774-11-joao.m.martins@oracle.com [3]: http://lore.kernel.org/r/157309097008.1579826.12818463304589384434.stgit@dwillia2-desk3.amr.corp.intel.com [4]: http://lore.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com [5]: http://lore.kernel.org/r/20200110190313.17144-1-joao.m.martins@oracle.com This patch (of 23): In preparation for adding a new numa= option clean up the existing ones to avoid ifdefs in numa_setup(), and provide feedback when the option is numa=fake= option is invalid due to kernel config. The same does not need to be done for numa=noacpi, since the capability is already hard disabled at compile-time. Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Link: https://lkml.kernel.org/r/160106109960.30709.7379926726669669398.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lkml.kernel.org/r/159643094279.4062302.17779410714418721328.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lkml.kernel.org/r/159643094925.4062302.14979872973043772305.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-12Merge tag 'x86-mm-2020-10-12' of ↵Linus Torvalds1-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "Do not sync vmalloc/ioremap mappings on x86-64 kernels. Hopefully now without the bugs!" * tag 'x86-mm-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/64: Update comment in preallocate_vmalloc_pages() x86/mm/64: Do not sync vmalloc/ioremap mappings
2020-10-12Merge tag 'x86_platform_for_v5.10' of ↵Linus Torvalds1-24/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Borislav Petkov: - Cleanup different aspects of the UV code and start adding support for the new UV5 class of systems (Mike Travis) - Use a flexible array for a dynamically sized struct uv_rtc_timer_head (Gustavo A. R. Silva) * tag 'x86_platform_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Update Copyrights to conform to HPE standards x86/platform/uv: Update for UV5 NMI MMR changes x86/platform/uv: Update UV5 TSC checking x86/platform/uv: Update node present counting x86/platform/uv: Update UV5 MMR references in UV GRU x86/platform/uv: Adjust GAM MMR references affected by UV5 updates x86/platform/uv: Update MMIOH references based on new UV5 MMRs x86/platform/uv: Add and decode Arch Type in UVsystab x86/platform/uv: Add UV5 direct references x86/platform/uv: Update UV MMRs for UV5 drivers/misc/sgi-xp: Adjust references in UV kernel modules x86/platform/uv: Remove SCIR MMR references for UV systems x86/platform/uv: Remove UV BAU TLB Shootdown Handler x86/uv/time: Use a flexible array in struct uv_rtc_timer_head
2020-10-12Merge tag 'x86_cpu_for_v5.10' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Borislav Petkov: - Add support for hardware-enforced cache coherency on AMD which obviates the need to flush cachelines before changing the PTE encryption bit (Krish Sadhukhan) - Add Centaur initialization support for families >= 7 (Tony W Wang-oc) - Add a feature flag for, and expose TSX suspend load tracking feature to KVM (Cathy Zhang) - Emulate SLDT and STR so that windows programs don't crash on UMIP machines (Brendan Shanks and Ricardo Neri) - Use the new SERIALIZE insn on Intel hardware which supports it (Ricardo Neri) - Misc cleanups and fixes * tag 'x86_cpu_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM: SVM: Don't flush cache if hardware enforces cache coherency across encryption domains x86/mm/pat: Don't flush cache if hardware enforces cache coherency across encryption domnains x86/cpu: Add hardware-enforced cache coherency as a CPUID feature x86/cpu/centaur: Add Centaur family >=7 CPUs initialization support x86/cpu/centaur: Replace two-condition switch-case with an if statement x86/kvm: Expose TSX Suspend Load Tracking feature x86/cpufeatures: Enumerate TSX suspend load address tracking instructions x86/umip: Add emulation/spoofing for SLDT and STR instructions x86/cpu: Fix typos and improve the comments in sync_core() x86/cpu: Use XGETBV and XSETBV mnemonics in fpu/internal.h x86/cpu: Use SERIALIZE in sync_core() when available
2020-10-12Merge tag 'ras_updates_for_v5.10' of ↵Linus Torvalds2-5/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS updates from Borislav Petkov: - Extend the recovery from MCE in kernel space also to processes which encounter an MCE in kernel space but while copying from user memory by sending them a SIGBUS on return to user space and umapping the faulty memory, by Tony Luck and Youquan Song. - memcpy_mcsafe() rework by splitting the functionality into copy_mc_to_user() and copy_mc_to_kernel(). This, as a result, enables support for new hardware which can recover from a machine check encountered during a fast string copy and makes that the default and lets the older hardware which does not support that advance recovery, opt in to use the old, fragile, slow variant, by Dan Williams. - New AMD hw enablement, by Yazen Ghannam and Akshay Gupta. - Do not use MSR-tracing accessors in #MC context and flag any fault while accessing MCA architectural MSRs as an architectural violation with the hope that such hw/fw misdesigns are caught early during the hw eval phase and they don't make it into production. - Misc fixes, improvements and cleanups, as always. * tag 'ras_updates_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Allow for copy_mc_fragile symbol checksum to be generated x86/mce: Decode a kernel instruction to determine if it is copying from user x86/mce: Recover from poison found while copying from user space x86/mce: Avoid tail copy when machine check terminated a copy from user x86/mce: Add _ASM_EXTABLE_CPY for copy user access x86/mce: Provide method to find out the type of an exception handler x86/mce: Pass pointer to saved pt_regs to severity calculation routines x86/copy_mc: Introduce copy_mc_enhanced_fast_string() x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list x86/mce: Add Skylake quirk for patrol scrub reported errors RAS/CEC: Convert to DEFINE_SHOW_ATTRIBUTE() x86/mce: Annotate mce_rd/wrmsrl() with noinstr x86/mce/dev-mcelog: Do not update kflags on AMD systems x86/mce: Stop mce_reign() from re-computing severity for every CPU x86/mce: Make mce_rdmsrl() panic on an inaccessible MSR x86/mce: Increase maximum number of banks to 64 x86/mce: Delay clearing IA32_MCG_STATUS to the end of do_machine_check() x86/MCE/AMD, EDAC/mce_amd: Remove struct smca_hwid.xec_bitmap RAS/CEC: Fix cec_init() prototype
2020-10-07x86/mce: Decode a kernel instruction to determine if it is copying from userTony Luck1-1/+1
All instructions copying data between kernel and user memory are tagged with either _ASM_EXTABLE_UA or _ASM_EXTABLE_CPY entries in the exception table. ex_fault_handler_type() returns EX_HANDLER_UACCESS for both of these. Recovery is only possible when the machine check was triggered on a read from user memory. In this case the same strategy for recovery applies as if the user had made the access in ring3. If the fault was in kernel memory while copying to user there is no current recovery plan. For MOV and MOVZ instructions a full decode of the instruction is done to find the source address. For MOVS instructions the source address is in the %rsi register. The function fault_in_kernel_space() determines whether the source address is kernel or user, upgrade it from "static" so it can be used here. Co-developed-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201006210910.21062-7-tony.luck@intel.com
2020-10-07x86/mce: Add _ASM_EXTABLE_CPY for copy user accessYouquan Song1-1/+13
_ASM_EXTABLE_UA is a general exception entry to record the exception fixup for all exception spots between kernel and user space access. To enable recovery from machine checks while coping data from user addresses it is necessary to be able to distinguish the places that are looping copying data from those that copy a single byte/word/etc. Add a new macro _ASM_EXTABLE_CPY and use it in place of _ASM_EXTABLE_UA in the copy functions. Record the exception reason number to regs->ax at ex_handler_uaccess which is used to check MCE triggered. The new fixup routine ex_handler_copy() is almost an exact copy of ex_handler_uaccess() The difference is that it sets regs->ax to the trap number. Following patches use this to avoid trying to copy remaining bytes from the tail of the copy and possibly hitting the poison again. New mce.kflags bit MCE_IN_KERNEL_COPYIN will be used by mce_severity() calculation to indicate that a machine check is recoverable because the kernel was copying from user space. Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201006210910.21062-4-tony.luck@intel.com
2020-10-07x86/mce: Provide method to find out the type of an exception handlerTony Luck1-4/+8
Avoid a proliferation of ex_has_*_handler() functions by having just one function that returns the type of the handler (if any). Drop the __visible attribute for this function. It is not called from assembler so the attribute is not necessary. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201006210910.21062-3-tony.luck@intel.com
2020-10-07x86/platform/uv: Remove UV BAU TLB Shootdown HandlerMike Travis1-24/+0
The Broadcast Assist Unit (BAU) TLB shootdown handler is being rewritten to become the UV BAU APIC driver. It is designed to speed up sending IPIs to selective CPUs within the system. Remove the current TLB shutdown handler (tlb_uv.c) file and a couple of kernel hooks in the interim. Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com> Link: https://lkml.kernel.org/r/20201005203929.148656-2-mike.travis@hpe.com
2020-10-02x86: Support Generic Initiator only proximity domainsJonathan Cameron1-0/+21
In common with memoryless domains only register GI domains if the proximity node is not online. If a domain is already a memory containing domain, or a memoryless domain there is nothing to do just because it also contains a Generic Initiator. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-18x86/mm/pat: Don't flush cache if hardware enforces cache coherency across ↵Krish Sadhukhan1-1/+1
encryption domnains In some hardware implementations, coherency between the encrypted and unencrypted mappings of the same physical page is enforced. In such a system, it is not required for software to flush the page from all CPU caches in the system prior to changing the value of the C-bit for the page. So check that bit before flushing the cache. [ bp: Massage commit message. ] Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200917212038.5090-3-krish.sadhukhan@oracle.com
2020-09-09x86/dumpstack/64: Add noinstr version of get_stack_info()Joerg Roedel1-1/+2
The get_stack_info() functionality is needed in the entry code for the #VC exception handler. Provide a version of it in the .text.noinstr section which can be called safely from there. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-45-joro@8bytes.org
2020-09-09x86/sev-es: Setup GHCB-based boot #VC handlerJoerg Roedel1-0/+1
Add the infrastructure to handle #VC exceptions when the kernel runs on virtual addresses and has mapped a GHCB. This handler will be used until the runtime #VC handler takes over. Since the handler runs very early, disable instrumentation for sev-es.c. [ bp: Make vc_ghcb_invalidate() __always_inline so that it can be inlined in noinstr functions like __sev_es_nmi_complete(). ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200908123816.GB3764@8bytes.org
2020-09-08x86/sev-es: Print SEV-ES info into the kernel logJoerg Roedel1-3/+26
Refactor the message printed to the kernel log which indicates whether SEV or SME, etc is active. This will scale better in the future when more memory encryption features might be added. Also add SEV-ES to the list of features. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200907131613.12703-38-joro@8bytes.org
2020-09-07x86/sev-es: Add SEV-ES Feature DetectionJoerg Roedel2-1/+11
Add a sev_es_active() function for checking whether SEV-ES is enabled. Also cache the value of MSR_AMD64_SEV at boot to speed up the feature checking in the running code. [ bp: Remove "!!" in sev_active() too. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200907131613.12703-37-joro@8bytes.org
2020-09-04x86, fakenuma: Fix invalid starting node IDHuang Ying1-1/+1
Commit: cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability") uses "-1" as the starting node ID, which causes the strange kernel log as follows, when "numa=fake=32G" is added to the kernel command line: Faking node -1 at [mem 0x0000000000000000-0x0000000893ffffff] (35136MB) Faking node 0 at [mem 0x0000001840000000-0x000000203fffffff] (32768MB) Faking node 1 at [mem 0x0000000894000000-0x000000183fffffff] (64192MB) Faking node 2 at [mem 0x0000002040000000-0x000000283fffffff] (32768MB) Faking node 3 at [mem 0x0000002840000000-0x000000303fffffff] (32768MB) And finally the kernel crashes: BUG: Bad page state in process swapper pfn:00011 page:(____ptrval____) refcount:0 mapcount:1 mapping:(____ptrval____) index:0x55cd7e44b270 pfn:0x11 failed to read mapping contents, not a valid kernel address? flags: 0x5(locked|uptodate) raw: 0000000000000005 000055cd7e44af30 000055cd7e44af50 0000000100000006 raw: 000055cd7e44b270 000055cd7e44b290 0000000000000000 000055cd7e44b510 page dumped because: page still charged to cgroup page->mem_cgroup:000055cd7e44b510 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.9.0-rc2 #1 Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 Call Trace: dump_stack+0x57/0x80 bad_page.cold+0x63/0x94 __free_pages_ok+0x33f/0x360 memblock_free_all+0x127/0x195 mem_init+0x23/0x1f5 start_kernel+0x219/0x4f5 secondary_startup_64+0xb6/0xc0 Fix this bug via using 0 as the starting node ID. This restores the original behavior before cc9aec03e58f. [ mingo: Massaged the changelog. ] Fixes: cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200904061047.612950-1-ying.huang@intel.com
2020-09-03x86/mm/32: Bring back vmalloc faulting on x86_32Joerg Roedel1-0/+78
One can not simply remove vmalloc faulting on x86-32. Upstream commit: 7f0a002b5a21 ("x86/mm: remove vmalloc faulting") removed it on x86 alltogether because previously the arch_sync_kernel_mappings() interface was introduced. This interface added synchronization of vmalloc/ioremap page-table updates to all page-tables in the system at creation time and was thought to make vmalloc faulting obsolete. But that assumption was incredibly naive. It turned out that there is a race window between the time the vmalloc or ioremap code establishes a mapping and the time it synchronizes this change to other page-tables in the system. During this race window another CPU or thread can establish a vmalloc mapping which uses the same intermediate page-table entries (e.g. PMD or PUD) and does no synchronization in the end, because it found all necessary mappings already present in the kernel reference page-table. But when these intermediate page-table entries are not yet synchronized, the other CPU or thread will continue with a vmalloc address that is not yet mapped in the page-table it currently uses, causing an unhandled page fault and oops like below: BUG: unable to handle page fault for address: fe80c000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page *pde = 33183067 *pte = a8648163 Oops: 0002 [#1] SMP CPU: 1 PID: 13514 Comm: cve-2017-17053 Tainted: G ... Call Trace: ldt_dup_context+0x66/0x80 dup_mm+0x2b3/0x480 copy_process+0x133b/0x15c0 _do_fork+0x94/0x3e0 __ia32_sys_clone+0x67/0x80 __do_fast_syscall_32+0x3f/0x70 do_fast_syscall_32+0x29/0x60 do_SYSENTER_32+0x15/0x20 entry_SYSENTER_32+0x9f/0xf2 EIP: 0xb7eef549 So the arch_sync_kernel_mappings() interface is racy, but removing it would mean to re-introduce the vmalloc_sync_all() interface, which is even more awful. Keep arch_sync_kernel_mappings() in place and catch the race condition in the page-fault handler instead. Do a partial revert of above commit to get vmalloc faulting on x86-32 back in place. Fixes: 7f0a002b5a21 ("x86/mm: remove vmalloc faulting") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200902155904.17544-1-joro@8bytes.org
2020-08-30Merge tag 'locking-urgent-2020-08-30' of ↵Linus Torvalds1-11/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A set of fixes for lockdep, tracing and RCU: - Prevent recursion by using raw_cpu_* operations - Fixup the interrupt state in the cpu idle code to be consistent - Push rcu_idle_enter/exit() invocations deeper into the idle path so that the lock operations are inside the RCU watching sections - Move trace_cpu_idle() into generic code so it's called before RCU goes idle. - Handle raw_local_irq* vs. local_irq* operations correctly - Move the tracepoints out from under the lockdep recursion handling which turned out to be fragile and inconsistent" * tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep,trace: Expose tracepoints lockdep: Only trace IRQ edges mips: Implement arch_irqs_disabled() arm64: Implement arch_irqs_disabled() nds32: Implement arch_irqs_disabled() locking/lockdep: Cleanup x86/entry: Remove unused THUNKs cpuidle: Move trace_cpu_idle() into generic code cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic sched,idle,rcu: Push rcu_idle deeper into the idle path cpuidle: Fixup IRQ state lockdep: Use raw_cpu_*() for per-cpu variables
2020-08-26cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED genericPeter Zijlstra1-11/+2
This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-15x86/mm/64: Update comment in preallocate_vmalloc_pages()Joerg Roedel1-5/+10
The comment explaining why 4-level systems only need to allocate on the P4D level caused some confustion. Update it to better explain why on 4-level systems the allocation on PUD level is necessary. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200814151947.26229-3-joro@8bytes.org
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