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2020-10-07x86/platform/uv: Remove UV BAU TLB Shootdown HandlerMike Travis
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 Cameron
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 Sadhukhan
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 Roedel
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 Roedel
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 Roedel
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 Roedel
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 Ying
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 Roedel
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 Torvalds
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 Zijlstra
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. Silva
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 Roedel
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
2020-08-15x86/mm/64: Do not sync vmalloc/ioremap mappingsJoerg Roedel
Remove the code to sync the vmalloc and ioremap ranges for x86-64. The page-table pages are all pre-allocated so that synchronization is no longer necessary. This is a patch that already went into the kernel as: commit 8bb9bf242d1f ("x86/mm/64: Do not sync vmalloc/ioremap mappings") But it had to be reverted later because it unveiled a bug from: commit 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area") The bug in that commit causes the P4D/PUD pages not to be correctly allocated, making the synchronization still necessary. That issue got fixed meanwhile upstream: commit 995909a4e22b ("x86/mm/64: Do not dereference non-present PGD entries") With that fix it is safe again to remove the page-table synchronization for vmalloc/ioremap ranges on x86-64. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200814151947.26229-2-joro@8bytes.org
2020-08-12mm/x86: use general page fault accountingPeter Xu
Use the general page fault accounting by passing regs into handle_mm_fault(). Signed-off-by: Peter Xu <peterx@redhat.com> 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> Link: http://lkml.kernel.org/r/20200707225021.200906-23-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12mm: do page fault accounting in handle_mm_faultPeter Xu
Patch series "mm: Page fault accounting cleanups", v5. This is v5 of the pf accounting cleanup series. It originates from Gerald Schaefer's report on an issue a week ago regarding to incorrect page fault accountings for retried page fault after commit 4064b9827063 ("mm: allow VM_FAULT_RETRY for multiple times"): https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/ What this series did: - Correct page fault accounting: we do accounting for a page fault (no matter whether it's from #PF handling, or gup, or anything else) only with the one that completed the fault. For example, page fault retries should not be counted in page fault counters. Same to the perf events. - Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf event is used in an adhoc way across different archs. Case (1): for many archs it's done at the entry of a page fault handler, so that it will also cover e.g. errornous faults. Case (2): for some other archs, it is only accounted when the page fault is resolved successfully. Case (3): there're still quite some archs that have not enabled this perf event. Since this series will touch merely all the archs, we unify this perf event to always follow case (1), which is the one that makes most sense. And since we moved the accounting into handle_mm_fault, the other two MAJ/MIN perf events are well taken care of naturally. - Unify definition of "major faults": the definition of "major fault" is slightly changed when used in accounting (not VM_FAULT_MAJOR). More information in patch 1. - Always account the page fault onto the one that triggered the page fault. This does not matter much for #PF handlings, but mostly for gup. More information on this in patch 25. Patchset layout: Patch 1: Introduced the accounting in handle_mm_fault(), not enabled. Patch 2-23: Enable the new accounting for arch #PF handlers one by one. Patch 24: Enable the new accounting for the rest outliers (gup, iommu, etc.) Patch 25: Cleanup GUP task_struct pointer since it's not needed any more This patch (of 25): This is a preparation patch to move page fault accountings into the general code in handle_mm_fault(). This includes both the per task flt_maj/flt_min counters, and the major/minor page fault perf events. To do this, the pt_regs pointer is passed into handle_mm_fault(). PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault handlers. So far, all the pt_regs pointer that passed into handle_mm_fault() is NULL, which means this patch should have no intented functional change. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12mm/memory_hotplug: introduce default dummy memory_add_physaddr_to_nid()Jia He
This is to introduce a general dummy helper. memory_add_physaddr_to_nid() is a fallback option to get the nid in case NUMA_NO_NID is detected. After this patch, arm64/sh/s390 can simply use the general dummy version. PowerPC/x86/ia64 will still use their specific version. This is the preparation to set a fallback value for dev_dax->target_node. Signed-off-by: Jia He <justin.he@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chuhong Yuan <hslester96@gmail.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Cc: Kaly Xin <Kaly.Xin@arm.com> Link: http://lkml.kernel.org/r/20200710031619.18762-2-justin.he@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12x86/mm: use max memory block size on bare metalDaniel Jordan
Some of our servers spend significant time at kernel boot initializing memory block sysfs directories and then creating symlinks between them and the corresponding nodes. The slowness happens because the machines get stuck with the smallest supported memory block size on x86 (128M), which results in 16,288 directories to cover the 2T of installed RAM. The search for each memory block is noticeable even with commit 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup"). Commit 078eb6aa50dc ("x86/mm/memory_hotplug: determine block size based on the end of boot memory") chooses the block size based on alignment with memory end. That addresses hotplug failures in qemu guests, but for bare metal systems whose memory end isn't aligned to even the smallest size, it leaves them at 128M. Make kernels that aren't running on a hypervisor use the largest supported size (2G) to minimize overhead on big machines. Kernel boot goes 7% faster on the aforementioned servers, shaving off half a second. [daniel.m.jordan@oracle.com: v3] Link: http://lkml.kernel.org/r/20200714205450.945834-1-daniel.m.jordan@oracle.com Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200609225451.3542648-1-daniel.m.jordan@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-10Merge tag 'locking-urgent-2020-08-10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Thomas Gleixner: "A set of locking fixes and updates: - Untangle the header spaghetti which causes build failures in various situations caused by the lockdep additions to seqcount to validate that the write side critical sections are non-preemptible. - The seqcount associated lock debug addons which were blocked by the above fallout. seqcount writers contrary to seqlock writers must be externally serialized, which usually happens via locking - except for strict per CPU seqcounts. As the lock is not part of the seqcount, lockdep cannot validate that the lock is held. This new debug mechanism adds the concept of associated locks. sequence count has now lock type variants and corresponding initializers which take a pointer to the associated lock used for writer serialization. If lockdep is enabled the pointer is stored and write_seqcount_begin() has a lockdep assertion to validate that the lock is held. Aside of the type and the initializer no other code changes are required at the seqcount usage sites. The rest of the seqcount API is unchanged and determines the type at compile time with the help of _Generic which is possible now that the minimal GCC version has been moved up. Adding this lockdep coverage unearthed a handful of seqcount bugs which have been addressed already independent of this. While generally useful this comes with a Trojan Horse twist: On RT kernels the write side critical section can become preemtible if the writers are serialized by an associated lock, which leads to the well known reader preempts writer livelock. RT prevents this by storing the associated lock pointer independent of lockdep in the seqcount and changing the reader side to block on the lock when a reader detects that a writer is in the write side critical section. - Conversion of seqcount usage sites to associated types and initializers" * tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) locking/seqlock, headers: Untangle the spaghetti monster locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header x86/headers: Remove APIC headers from <asm/smp.h> seqcount: More consistent seqprop names seqcount: Compress SEQCNT_LOCKNAME_ZERO() seqlock: Fold seqcount_LOCKNAME_init() definition seqlock: Fold seqcount_LOCKNAME_t definition seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g hrtimer: Use sequence counter with associated raw spinlock kvm/eventfd: Use sequence counter with associated spinlock userfaultfd: Use sequence counter with associated spinlock NFSv4: Use sequence counter with associated spinlock iocost: Use sequence counter with associated spinlock raid5: Use sequence counter with associated spinlock vfs: Use sequence counter with associated spinlock timekeeping: Use sequence counter with associated raw spinlock xfrm: policy: Use sequence counters with associated lock netfilter: nft_set_rbtree: Use sequence counter with associated rwlock netfilter: conntrack: Use sequence counter with associated spinlock sched: tasks: Use sequence counter with associated spinlock ...
2020-08-09Merge tag 'kbuild-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
2020-08-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: - a few MM hotfixes - kthread, tools, scripts, ntfs and ocfs2 - some of MM Subsystems affected by this patch series: kthread, tools, scripts, ntfs, ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore, sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits) mm: vmscan: consistent update to pgrefill mm/vmscan.c: fix typo khugepaged: khugepaged_test_exit() check mmget_still_valid() khugepaged: retract_page_tables() remember to test exit khugepaged: collapse_pte_mapped_thp() protect the pmd lock khugepaged: collapse_pte_mapped_thp() flush the right range mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible mm: thp: replace HTTP links with HTTPS ones mm/page_alloc: fix memalloc_nocma_{save/restore} APIs mm/page_alloc.c: skip setting nodemask when we are in interrupt mm/page_alloc: fallbacks at most has 3 elements mm/page_alloc: silence a KASAN false positive mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask() mm/page_alloc.c: simplify pageblock bitmap access mm/page_alloc.c: extract the common part in pfn_to_bitidx() mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits mm/shuffle: remove dynamic reconfiguration mm/memory_hotplug: document why shuffle_zone() is relevant mm/page_alloc: remove nr_free_pagecache_pages() mm: remove vm_total_pages ...
2020-08-07mm/sparse: cleanup the code surrounding memory_present()Mike Rapoport
After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent functions that call memory_present() for each region in memblock.memory: sparse_memory_present_with_active_regions() and membocks_present(). Moreover, all architectures have a call to either of these functions preceding the call to sparse_init() and in the most cases they are called one after the other. Mark the regions from memblock.memory as present during sparce_init() by making sparse_init() call memblocks_present(), make memblocks_present() and memory_present() functions static and remove redundant sparse_memory_present_with_active_regions() function. Also remove no longer required HAVE_MEMORY_PRESENT configuration option. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200712083130.22919-1-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/sparsemem: enable vmem_altmap support in vmemmap_alloc_block_buf()Anshuman Khandual
There are many instances where vmemap allocation is often switched between regular memory and device memory just based on whether altmap is available or not. vmemmap_alloc_block_buf() is used in various platforms to allocate vmemmap mappings. Lets also enable it to handle altmap based device memory allocation along with existing regular memory allocations. This will help in avoiding the altmap based allocation switch in many places. To summarize there are two different methods to call vmemmap_alloc_block_buf(). vmemmap_alloc_block_buf(size, node, NULL) /* Allocate from system RAM */ vmemmap_alloc_block_buf(size, node, altmap) /* Allocate from altmap */ This converts altmap_alloc_block_buf() into a static function, drops it's entry from the header and updates Documentation/vm/memory-model.rst. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jia He <justin.he@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Will Deacon <will@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> 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: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yu Zhao <yuzhao@google.com> Link: http://lkml.kernel.org/r/1594004178-8861-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/sparsemem: enable vmem_altmap support in vmemmap_populate_basepages()Anshuman Khandual
Patch series "arm64: Enable vmemmap mapping from device memory", v4. This series enables vmemmap backing memory allocation from device memory ranges on arm64. But before that, it enables vmemmap_populate_basepages() and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based alocation requests. This patch (of 3): vmemmap_populate_basepages() is used across platforms to allocate backing memory for vmemmap mapping. This is used as a standard default choice or as a fallback when intended huge pages allocation fails. This just creates entire vmemmap mapping with base pages (PAGE_SIZE). On arm64 platforms, vmemmap_populate_basepages() is called instead of the platform specific vmemmap_populate() when ARM64_SWAPPER_USES_SECTION_MAPS is not enabled as in case for ARM64_16K_PAGES and ARM64_64K_PAGES configs. At present vmemmap_populate_basepages() does not support allocating from driver defined struct vmem_altmap while trying to create vmemmap mapping for a device memory range. It prevents ARM64_16K_PAGES and ARM64_64K_PAGES configs on arm64 from supporting device memory with vmemap_altmap request. This enables vmem_altmap support in vmemmap_populate_basepages() unlocking device memory allocation for vmemap mapping on arm64 platforms with 16K or 64K base page configs. Each architecture should evaluate and decide on subscribing device memory based base page allocation through vmemmap_populate_basepages(). Hence lets keep it disabled on all archs in order to preserve the existing semantics. A subsequent patch enables it on arm64. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jia He <justin.he@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> 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: Mike Rapoport <rppt@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Yu Zhao <yuzhao@google.com> Link: http://lkml.kernel.org/r/1594004178-8861-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r/1594004178-8861-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: remove unneeded includes of <asm/pgalloc.h>Mike Rapoport
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07x86/mm/64: Do not dereference non-present PGD entriesJoerg Roedel
The code for preallocate_vmalloc_pages() was written under the assumption that the p4d_offset() and pud_offset() functions will perform present checks before dereferencing the parent entries. This assumption is wrong an leads to a bug in the code which causes the physical address found in the PGD be used as a page-table page, even if the PGD is not present. So the code flow currently is: pgd = pgd_offset_k(addr); p4d = p4d_offset(pgd, addr); if (p4d_none(*p4d)) p4d = p4d_alloc(&init_mm, pgd, addr); This lacks a check for pgd_none() at least, the correct flow would be: pgd = pgd_offset_k(addr); if (pgd_none(*pgd)) p4d = p4d_alloc(&init_mm, pgd, addr); else p4d = p4d_offset(pgd, addr); But this is the same flow that the p4d_alloc() and the pud_alloc() functions use internally, so there is no need to duplicate them. Remove the p?d_none() checks from the function and just call into p4d_alloc() and pud_alloc() to correctly pre-allocate the PGD entries. Reported-and-tested-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Fixes: 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area") Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06Revert "x86/mm/64: Do not sync vmalloc/ioremap mappings"Linus Torvalds
This reverts commit 8bb9bf242d1fee925636353807c511d54fde8986. It seems the vmalloc page tables aren't always preallocated in all situations, because Jason Donenfeld reports an oops with this commit: BUG: unable to handle page fault for address: ffffe8ffffd00608 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 2 PID: 22 Comm: kworker/2:0 Not tainted 5.8.0+ #154 RIP: process_one_work+0x2c/0x2d0 Code: 41 56 41 55 41 54 55 48 89 f5 53 48 89 fb 48 83 ec 08 48 8b 06 4c 8b 67 40 49 89 c6 45 30 f6 a8 04 b8 00 00 00 00 4c 0f 44 f0 <49> 8b 46 08 44 8b a8 00 01 05 Call Trace: worker_thread+0x4b/0x3b0 ? rescuer_thread+0x360/0x360 kthread+0x116/0x140 ? __kthread_create_worker+0x110/0x110 ret_from_fork+0x1f/0x30 CR2: ffffe8ffffd00608 and that page fault address is right in that vmalloc space, and we clearly don't have a PGD/P4D entry for it. Looking at the "Code:" line, the actual fault seems to come from the 'pwq->wq' dereference at the top of the process_one_work() function: struct pool_workqueue *pwq = get_work_pwq(work); struct worker_pool *pool = worker->pool; bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE; so 'struct pool_workqueue *pwq' is the allocation that hasn't been synchronized across CPUs. Just revert for now, while Joerg figures out the cause. Reported-and-bisected-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06locking/seqlock, headers: Untangle the spaghetti monsterPeter Zijlstra
By using lockdep_assert_*() from seqlock.h, the spaghetti monster attacked. Attack back by reducing seqlock.h dependencies from two key high level headers: - <linux/seqlock.h>: -Remove <linux/ww_mutex.h> - <linux/time.h>: -Remove <linux/seqlock.h> - <linux/sched.h>: +Add <linux/seqlock.h> The price was to add it to sched.h ... Core header fallout, we add direct header dependencies instead of gaining them parasitically from higher level headers: - <linux/dynamic_queue_limits.h>: +Add <asm/bug.h> - <linux/hrtimer.h>: +Add <linux/seqlock.h> - <linux/ktime.h>: +Add <asm/bug.h> - <linux/lockdep.h>: +Add <linux/smp.h> - <linux/sched.h>: +Add <linux/seqlock.h> - <linux/videodev2.h>: +Add <linux/kernel.h> Arch headers fallout: - PARISC: <asm/timex.h>: +Add <asm/special_insns.h> - SH: <asm/io.h>: +Add <asm/page.h> - SPARC: <asm/timer_64.h>: +Add <uapi/asm/asi.h> - SPARC: <asm/vvar.h>: +Add <asm/processor.h>, <asm/barrier.h> -Remove <linux/seqlock.h> - X86: <asm/fixmap.h>: +Add <asm/pgtable_types.h> -Remove <asm/acpi.h> There's also a bunch of parasitic header dependency fallout in .c files, not listed separately. [ mingo: Extended the changelog, split up & fixed the original patch. ] Co-developed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200804133438.GK2674@hirez.programming.kicks-ass.net
2020-08-04Merge tag 'x86-entry-2020-08-04' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 conversion to generic entry code from Thomas Gleixner: "The conversion of X86 syscall, interrupt and exception entry/exit handling to the generic code. Pretty much a straight-forward 1:1 conversion plus the consolidation of the KVM handling of pending work before entering guest mode" * tag 'x86-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kvm: Use __xfer_to_guest_mode_work_pending() in kvm_run_vcpu() x86/kvm: Use generic xfer to guest work function x86/entry: Cleanup idtentry_enter/exit x86/entry: Use generic interrupt entry/exit code x86/entry: Cleanup idtentry_entry/exit_user x86/entry: Use generic syscall exit functionality x86/entry: Use generic syscall entry function x86/ptrace: Provide pt_regs helper for entry/exit x86/entry: Move user return notifier out of loop x86/entry: Consolidate 32/64 bit syscall entry x86/entry: Consolidate check_user_regs() x86: Correct noinstr qualifiers x86/idtentry: Remove stale comment
2020-08-04Merge tag 'uninit-macro-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var()
2020-08-03Merge tag 'x86-mm-2020-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mmm update from Ingo Molnar: "The biggest change is to not sync the vmalloc and ioremap ranges for x86-64 anymore" * tag 'x86-mm-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/64: Make sync_global_pgds() static x86/mm/64: Do not sync vmalloc/ioremap mappings x86/mm: Pre-allocate P4D/PUD pages for vmalloc area
2020-08-03Merge tag 'x86-cleanups-2020-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups all around the place" * tag 'x86-cleanups-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ioperm: Initialize pointer bitmap with NULL rather than 0 x86: uv: uv_hub.h: Delete duplicated word x86: cmpxchg_32.h: Delete duplicated word x86: bootparam.h: Delete duplicated word x86/mm: Remove the unused mk_kernel_pgd() #define x86/tsc: Remove unused "US_SCALE" and "NS_SCALE" leftover macros x86/ioapic: Remove unused "IOAPIC_AUTO" define x86/mm: Drop unused MAX_PHYSADDR_BITS x86/msr: Move the F15h MSRs where they belong x86/idt: Make idt_descr static initrd: Remove erroneous comment x86/mm/32: Fix -Wmissing prototypes warnings for init.c cpu/speculation: Add prototype for cpu_show_srbds() x86/mm: Fix -Wmissing-prototypes warnings for arch/x86/mm/init.c x86/asm: Unify __ASSEMBLY__ blocks x86/cpufeatures: Mark two free bits in word 3 x86/msr: Lift AMD family 0x15 power-specific MSRs
2020-08-01Merge branch 'kcsan' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/core Pull v5.9 KCSAN bits from Paul E. McKenney. Perhaps the most important change is that GCC 11 now has all fixes in place to support KCSAN, so GCC support can be enabled again. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-27x86/mm/64: Make sync_global_pgds() staticJoerg Roedel
The function is only called from within init_64.c and can be static. Also remove it from pgtable_64.h. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20200721095953.6218-4-joro@8bytes.org
2020-07-27x86/mm/64: Do not sync vmalloc/ioremap mappingsJoerg Roedel
Remove the code to sync the vmalloc and ioremap ranges for x86-64. The page-table pages are all pre-allocated now so that synchronization is no longer necessary. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20200721095953.6218-3-joro@8bytes.org
2020-07-27x86/mm: Pre-allocate P4D/PUD pages for vmalloc areaJoerg Roedel
Pre-allocate the page-table pages for the vmalloc area at the level which needs synchronization on x86-64, which is P4D for 5-level and PUD for 4-level paging. Doing this at boot makes sure no synchronization of that area is necessary at runtime. The synchronization takes the pgd_lock and iterates over all page-tables in the system, so it can take quite long and is better avoided. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20200721095953.6218-2-joro@8bytes.org
2020-07-26Merge branch 'x86/urgent' into x86/cleanupsIngo Molnar
Refresh the branch for a dependent commit. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-24x86/entry: Cleanup idtentry_enter/exitThomas Gleixner
Remove the temporary defines and fixup all references. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200722220520.855839271@linutronix.de
2020-07-16x86/mm/numa: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. As a precursor to removing[2] this[3] macro[4], refactor code to avoid its need. The original reason for its use here was to work around the #ifdef being the only place the variable was used. This is better expressed using IS_ENABLED() and a new code block where the variable can be used unconditionally. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Fixes: 1e01979c8f50 ("x86, numa: Implement pfn -> nid mapping granularity check") Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-07-06x86/entry: Rename idtentry_enter/exit_cond_rcu() to idtentry_enter/exit()Andy Lutomirski
They were originally called _cond_rcu because they were special versions with conditional RCU handling. Now they're the standard entry and exit path, so the _cond_rcu part is just confusing. Drop it. Also change the signature to make them more extensible and more foolproof. No functional change -- it's pure refactoring. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/247fc67685263e0b673e1d7f808182d28ff80359.1593795633.git.luto@kernel.org
2020-06-29x86/mm/pat: Mark an intentional data raceQian Cai
cpa_4k_install could be accessed concurrently as noticed by KCSAN, read to 0xffffffffaa59a000 of 8 bytes by interrupt on cpu 7: cpa_inc_4k_install arch/x86/mm/pat/set_memory.c:131 [inline] __change_page_attr+0x10cf/0x1840 arch/x86/mm/pat/set_memory.c:1514 __change_page_attr_set_clr+0xce/0x490 arch/x86/mm/pat/set_memory.c:1636 __set_pages_np+0xc4/0xf0 arch/x86/mm/pat/set_memory.c:2148 __kernel_map_pages+0xb0/0xc8 arch/x86/mm/pat/set_memory.c:2178 kernel_map_pages include/linux/mm.h:2719 [inline] <snip> write to 0xffffffffaa59a000 of 8 bytes by task 1 on cpu 6: cpa_inc_4k_install arch/x86/mm/pat/set_memory.c:131 [inline] __change_page_attr+0x10ea/0x1840 arch/x86/mm/pat/set_memory.c:1514 __change_page_attr_set_clr+0xce/0x490 arch/x86/mm/pat/set_memory.c:1636 __set_pages_p+0xc4/0xf0 arch/x86/mm/pat/set_memory.c:2129 __kernel_map_pages+0x2e/0xc8 arch/x86/mm/pat/set_memory.c:2176 kernel_map_pages include/linux/mm.h:2719 [inline] <snip> Both accesses are due to the same "cpa_4k_install++" in cpa_inc_4k_install. A data race here could be potentially undesirable: depending on compiler optimizations or how x86 executes a non-LOCK'd increment, it may lose increments, corrupt the counter, etc. Since this counter only seems to be used for printing some stats, this data race itself is unlikely to cause harm to the system though. Thus, mark this intentional data race using the data_race() marco. Suggested-by: Macro Elver <elver@google.com> Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-18maccess: rename probe_kernel_address to get_kernel_nofaultChristoph Hellwig
Better describe what this helper does, and match the naming of copy_from_kernel_nofault. Also switch the argument order around, so that it acts and looks like get_user(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17x86/mm: Fix -Wmissing-prototypes warnings for arch/x86/mm/init.cBenjamin Thiel
Fix -Wmissing-prototypes warnings: arch/x86/mm/init.c:81:6: warning: no previous prototype for ‘x86_has_pat_wp’ [-Wmissing-prototypes] bool x86_has_pat_wp(void) arch/x86/mm/init.c:86:22: warning: no previous prototype for ‘pgprot2cachemode’ [-Wmissing-prototypes] enum page_cache_mode pgprot2cachemode(pgprot_t pgprot) by including the respective header containing prototypes. Also fix: arch/x86/mm/init.c:893:13: warning: no previous prototype for ‘mem_encrypt_free_decrypted_mem’ [-Wmissing-prototypes] void __weak mem_encrypt_free_decrypted_mem(void) { } by making it static inline for the !CONFIG_AMD_MEM_ENCRYPT case. This warning happens when CONFIG_AMD_MEM_ENCRYPT is not enabled (defconfig for example): ./arch/x86/include/asm/mem_encrypt.h:80:27: warning: inline function ‘mem_encrypt_free_decrypted_mem’ declared weak [-Wattributes] static inline void __weak mem_encrypt_free_decrypted_mem(void) { } ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ It's ok to convert to static inline because the function is used only in x86. Is not shared with other architectures so drop the __weak too. [ bp: Massage and adjust __weak comments while at it. ] Signed-off-by: Benjamin Thiel <b.thiel@posteo.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200606122629.2720-1-b.thiel@posteo.de
2020-06-13Merge tag 'x86-entry-2020-06-12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 entry updates from Thomas Gleixner: "The x86 entry, exception and interrupt code rework This all started about 6 month ago with the attempt to move the Posix CPU timer heavy lifting out of the timer interrupt code and just have lockless quick checks in that code path. Trivial 5 patches. This unearthed an inconsistency in the KVM handling of task work and the review requested to move all of this into generic code so other architectures can share. Valid request and solved with another 25 patches but those unearthed inconsistencies vs. RCU and instrumentation. Digging into this made it obvious that there are quite some inconsistencies vs. instrumentation in general. The int3 text poke handling in particular was completely unprotected and with the batched update of trace events even more likely to expose to endless int3 recursion. In parallel the RCU implications of instrumenting fragile entry code came up in several discussions. The conclusion of the x86 maintainer team was to go all the way and make the protection against any form of instrumentation of fragile and dangerous code pathes enforcable and verifiable by tooling. A first batch of preparatory work hit mainline with commit d5f744f9a2ac ("Pull x86 entry code updates from Thomas Gleixner") That (almost) full solution introduced a new code section '.noinstr.text' into which all code which needs to be protected from instrumentation of all sorts goes into. Any call into instrumentable code out of this section has to be annotated. objtool has support to validate this. Kprobes now excludes this section fully which also prevents BPF from fiddling with it and all 'noinstr' annotated functions also keep ftrace off. The section, kprobes and objtool changes are already merged. The major changes coming with this are: - Preparatory cleanups - Annotating of relevant functions to move them into the noinstr.text section or enforcing inlining by marking them __always_inline so the compiler cannot misplace or instrument them. - Splitting and simplifying the idtentry macro maze so that it is now clearly separated into simple exception entries and the more interesting ones which use interrupt stacks and have the paranoid handling vs. CR3 and GS. - Move quite some of the low level ASM functionality into C code: - enter_from and exit to user space handling. The ASM code now calls into C after doing the really necessary ASM handling and the return path goes back out without bells and whistels in ASM. - exception entry/exit got the equivivalent treatment - move all IRQ tracepoints from ASM to C so they can be placed as appropriate which is especially important for the int3 recursion issue. - Consolidate the declaration and definition of entry points between 32 and 64 bit. They share a common header and macros now. - Remove the extra device interrupt entry maze and just use the regular exception entry code. - All ASM entry points except NMI are now generated from the shared header file and the corresponding macros in the 32 and 64 bit entry ASM. - The C code entry points are consolidated as well with the help of DEFINE_IDTENTRY*() macros. This allows to ensure at one central point that all corresponding entry points share the same semantics. The actual function body for most entry points is in an instrumentable and sane state. There are special macros for the more sensitive entry points, e.g. INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF. They allow to put the whole entry instrumentation and RCU handling into safe places instead of the previous pray that it is correct approach. - The INT3 text poke handling is now completely isolated and the recursion issue banned. Aside of the entry rework this required other isolation work, e.g. the ability to force inline bsearch. - Prevent #DB on fragile entry code, entry relevant memory and disable it on NMI, #MC entry, which allowed to get rid of the nested #DB IST stack shifting hackery. - A few other cleanups and enhancements which have been made possible through this and already merged changes, e.g. consolidating and further restricting the IDT code so the IDT table becomes RO after init which removes yet another popular attack vector - About 680 lines of ASM maze are gone. There are a few open issues: - An escape out of the noinstr section in the MCE handler which needs some more thought but under the aspect that MCE is a complete trainwreck by design and the propability to survive it is low, this was not high on the priority list. - Paravirtualization When PV is enabled then objtool complains about a bunch of indirect calls out of the noinstr section. There are a few straight forward ways to fix this, but the other issues vs. general correctness were more pressing than parawitz. - KVM KVM is inconsistent as well. Patches have been posted, but they have not yet been commented on or picked up by the KVM folks. - IDLE Pretty much the same problems can be found in the low level idle code especially the parts where RCU stopped watching. This was beyond the scope of the more obvious and exposable problems and is on the todo list. The lesson learned from this brain melting exercise to morph the evolved code base into something which can be validated and understood is that once again the violation of the most important engineering principle "correctness first" has caused quite a few people to spend valuable time on problems which could have been avoided in the first place. The "features first" tinkering mindset really has to stop. With that I want to say thanks to everyone involved in contributing to this effort. Special thanks go to the following people (alphabetical order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra, Vitaly Kuznetsov, and Will Deacon" * tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits) x86/entry: Force rcu_irq_enter() when in idle task x86/entry: Make NMI use IDTENTRY_RAW x86/entry: Treat BUG/WARN as NMI-like entries x86/entry: Unbreak __irqentry_text_start/end magic x86/entry: __always_inline CR2 for noinstr lockdep: __always_inline more for noinstr x86/entry: Re-order #DB handler to avoid *SAN instrumentation x86/entry: __always_inline arch_atomic_* for noinstr x86/entry: __always_inline irqflags for noinstr x86/entry: __always_inline debugreg for noinstr x86/idt: Consolidate idt functionality x86/idt: Cleanup trap_init() x86/idt: Use proper constants for table size x86/idt: Add comments about early #PF handling x86/idt: Mark init only functions __init x86/entry: Rename trace_hardirqs_off_prepare() x86/entry: Clarify irq_{enter,exit}_rcu() x86/entry: Remove DBn stacks x86/entry: Remove debug IDT frobbing x86/entry: Optimize local_db_save() for virt ...
2020-06-12x86/entry: Treat BUG/WARN as NMI-like entriesAndy Lutomirski
BUG/WARN are cleverly optimized using UD2 to handle the BUG/WARN out of line in an exception fixup. But if BUG or WARN is issued in a funny RCU context, then the idtentry_enter...() path might helpfully WARN that the RCU context is invalid, which results in infinite recursion. Split the BUG/WARN handling into an nmi_enter()/nmi_exit() path in exc_invalid_op() to increase the chance to survive the experience. [ tglx: Make the declaration match the implementation ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/f8fe40e0088749734b4435b554f73eee53dcf7a8.1591932307.git.luto@kernel.org
2020-06-11Rebase locking/kcsan to locking/urgentThomas Gleixner
Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11x86/entry: Unbreak __irqentry_text_start/end magicThomas Gleixner
The entry rework moved interrupt entry code from the irqentry to the noinstr section which made the irqentry section empty. This breaks boundary checks which rely on the __irqentry_text_start/end markers to find out whether a function in a stack trace is interrupt/exception entry code. This affects the function graph tracer and filter_irq_stacks(). As the IDT entry points are all sequentialy emitted this is rather simple to unbreak by injecting __irqentry_text_start/end as global labels. To make this work correctly: - Remove the IRQENTRY_TEXT section from the x86 linker script - Define __irqentry so it breaks the build if it's used - Adjust the entry mirroring in PTI - Remove the redundant kprobes and unwinder bound checks Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11x86/idt: Consolidate idt functionalityThomas Gleixner
- Move load_current_idt() out of line and replace the hideous comment with a lockdep assert. This allows to make idt_table and idt_descr static. - Mark idt_table read only after the IDT initialization is complete. - Shuffle code around to consolidate the #ifdef sections into one. - Adapt the F00F bug code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145523.084915381@linutronix.de