Commit Graph

10640 Commits

Author SHA1 Message Date
Nicholas Piggin
6f680e70b6 mm/vmalloc: provide fallback arch huge vmap support functions
If an architecture doesn't support a particular page table level as a huge
vmap page size then allow it to skip defining the support query function.

Link: https://lkml.kernel.org/r/20210317062402.533919-11-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:40 -07:00
Nicholas Piggin
97dc2a1548 x86: inline huge vmap supported functions
This allows unsupported levels to be constant folded away, and so
p4d_free_pud_page can be removed because it's no longer linked to.

Link: https://lkml.kernel.org/r/20210317062402.533919-10-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:40 -07:00
Nicholas Piggin
bbc180a5ad mm: HUGE_VMAP arch support cleanup
This changes the awkward approach where architectures provide init
functions to determine which levels they can provide large mappings for,
to one where the arch is queried for each call.

This removes code and indirection, and allows constant-folding of dead
code for unsupported levels.

This also adds a prot argument to the arch query.  This is unused
currently but could help with some architectures (e.g., some powerpc
processors can't map uncacheable memory with large pages).

Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:40 -07:00
Linus Torvalds
635de956a7 Merge tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 tlb updates from Ingo Molnar:
 "The x86 MM changes in this cycle were:

   - Implement concurrent TLB flushes, which overlaps the local TLB
     flush with the remote TLB flush.

     In testing this improved sysbench performance measurably by a
     couple of percentage points, especially if TLB-heavy security
     mitigations are active.

   - Further micro-optimizations to improve the performance of TLB
     flushes"

* tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Micro-optimize smp_call_function_many_cond()
  smp: Inline on_each_cpu_cond() and on_each_cpu()
  x86/mm/tlb: Remove unnecessary uses of the inline keyword
  cpumask: Mark functions as pure
  x86/mm/tlb: Do not make is_lazy dirty for no reason
  x86/mm/tlb: Privatize cpu_tlbstate
  x86/mm/tlb: Flush remote and local TLBs concurrently
  x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()
  x86/mm/tlb: Unify flush_tlb_func_local() and flush_tlb_func_remote()
  smp: Run functions concurrently in smp_call_function_many_cond()
2021-04-29 11:41:43 -07:00
Linus Torvalds
0080665fbd Merge tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:

 - Refactor powerpc and arm64 kexec DT handling to common code. This
   enables IMA on arm64.

 - Add kbuild support for applying DT overlays at build time. The first
   user are the DT unittests.

 - Fix kerneldoc formatting and W=1 warnings in drivers/of/

 - Fix handling 64-bit flag on PCI resources

 - Bump dtschema version required to v2021.2.1

 - Enable undocumented compatible checks for dtbs_check. This allows
   tracking of missing binding schemas.

 - DT docs improvements. Regroup the DT docs and add the example schema
   and DT kernel ABI docs to the doc build.

 - Convert Broadcom Bluetooth and video-mux bindings to schema

 - Add QCom sm8250 Venus video codec binding schema

 - Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
   Technologies Inc.

 - Cleanup of DT schema type references on common properties and
   standard unit properties

* tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits)
  powerpc: If kexec_build_elf_info() fails return immediately from elf64_load()
  powerpc: Free fdt on error in elf64_load()
  of: overlay: Fix kerneldoc warning in of_overlay_remove()
  of: linux/of.h: fix kernel-doc warnings
  of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses
  dt-bindings: bcm4329-fmac: add optional brcm,ccode-map
  docs: dt: update writing-schema.rst references
  dt-bindings: media: venus: Add sm8250 dt schema
  of: base: Fix spelling issue with function param 'prop'
  docs: dt: Add DT API documentation
  of: Add missing 'Return' section in kerneldoc comments
  of: Fix kerneldoc output formatting
  docs: dt: Group DT docs into relevant sub-sections
  docs: dt: Make 'Devicetree' wording more consistent
  docs: dt: writing-schema: Include the example schema in the doc build
  docs: dt: writing-schema: Remove spurious indentation
  dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc
  dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3
  dt-bindings: media: video-interfaces: Drop the example
  devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt
  ...
2021-04-28 15:50:24 -07:00
Linus Torvalds
fc05860628 Merge tag 'for-5.13/drivers-2021-04-27' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:

 - MD changes via Song:
        - raid5 POWER fix
        - raid1 failure fix
        - UAF fix for md cluster
        - mddev_find_or_alloc() clean up
        - Fix NULL pointer deref with external bitmap
        - Performance improvement for raid10 discard requests
        - Fix missing information of /proc/mdstat

 - rsxx const qualifier removal (Arnd)

 - Expose allocated brd pages (Calvin)

 - rnbd via Gioh Kim:
        - Change maintainer
        - Change domain address of maintainers' email
        - Add polling IO mode and document update
        - Fix memory leak and some bug detected by static code analysis
          tools
        - Code refactoring

 - Series of floppy cleanups/fixes (Denis)

 - s390 dasd fixes (Julian)

 - kerneldoc fixes (Lee)

 - null_blk double free (Lv)

 - null_blk virtual boundary addition (Max)

 - Remove xsysace driver (Michal)

 - umem driver removal (Davidlohr)

 - ataflop fixes (Dan)

 - Revalidate disk removal (Christoph)

 - Bounce buffer cleanups (Christoph)

 - Mark lightnvm as deprecated (Christoph)

 - mtip32xx init cleanups (Shixin)

 - Various fixes (Tian, Gustavo, Coly, Yang, Zhang, Zhiqiang)

* tag 'for-5.13/drivers-2021-04-27' of git://git.kernel.dk/linux-block: (143 commits)
  async_xor: increase src_offs when dropping destination page
  drivers/block/null_blk/main: Fix a double free in null_init.
  md/raid1: properly indicate failure when ending a failed write request
  md-cluster: fix use-after-free issue when removing rdev
  nvme: introduce generic per-namespace chardev
  nvme: cleanup nvme_configure_apst
  nvme: do not try to reconfigure APST when the controller is not live
  nvme: add 'kato' sysfs attribute
  nvme: sanitize KATO setting
  nvmet: avoid queuing keep-alive timer if it is disabled
  brd: expose number of allocated pages in debugfs
  ataflop: fix off by one in ataflop_probe()
  ataflop: potential out of bounds in do_format()
  drbd: Fix fall-through warnings for Clang
  block/rnbd: Use strscpy instead of strlcpy
  block/rnbd-clt-sysfs: Remove copy buffer overlap in rnbd_clt_get_path_name
  block/rnbd-clt: Remove max_segment_size
  block/rnbd-clt: Generate kobject_uevent when the rnbd device state changes
  block/rnbd-srv: Remove unused arguments of rnbd_srv_rdma_ev
  Documentation/ABI/rnbd-clt: Add description for nr_poll_queues
  ...
2021-04-28 14:39:37 -07:00
Linus Torvalds
42dec9a936 Merge tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event updates from Ingo Molnar:

 - Improve Intel uncore PMU support:

     - Parse uncore 'discovery tables' - a new hardware capability
       enumeration method introduced on the latest Intel platforms. This
       table is in a well-defined PCI namespace location and is read via
       MMIO. It is organized in an rbtree.

       These uncore tables will allow the discovery of standard counter
       blocks, but fancier counters still need to be enumerated
       explicitly.

     - Add Alder Lake support

     - Improve IIO stacks to PMON mapping support on Skylake servers

 - Add Intel Alder Lake PMU support - which requires the introduction of
   'hybrid' CPUs and PMUs. Alder Lake is a mix of Golden Cove ('big')
   and Gracemont ('small' - Atom derived) cores.

   The CPU-side feature set is entirely symmetrical - but on the PMU
   side there's core type dependent PMU functionality.

 - Reduce data loss with CPU level hardware tracing on Intel PT / AUX
   profiling, by fixing the AUX allocation watermark logic.

 - Improve ring buffer allocation on NUMA systems

 - Put 'struct perf_event' into their separate kmem_cache pool

 - Add support for synchronous signals for select perf events. The
   immediate motivation is to support low-overhead sampling-based race
   detection for user-space code. The feature consists of the following
   main changes:

     - Add thread-only event inheritance via
       perf_event_attr::inherit_thread, which limits inheritance of
       events to CLONE_THREAD.

     - Add the ability for events to not leak through exec(), via
       perf_event_attr::remove_on_exec.

     - Allow the generation of SIGTRAP via perf_event_attr::sigtrap,
       extend siginfo with an u64 ::si_perf, and add the breakpoint
       information to ::si_addr and ::si_perf if the event is
       PERF_TYPE_BREAKPOINT.

   The siginfo support is adequate for breakpoints right now - but the
   new field can be used to introduce support for other types of
   metadata passed over siginfo as well.

 - Misc fixes, cleanups and smaller updates.

* tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  signal, perf: Add missing TRAP_PERF case in siginfo_layout()
  signal, perf: Fix siginfo_t by avoiding u64 on 32-bit architectures
  perf/x86: Allow for 8<num_fixed_counters<16
  perf/x86/rapl: Add support for Intel Alder Lake
  perf/x86/cstate: Add Alder Lake CPU support
  perf/x86/msr: Add Alder Lake CPU support
  perf/x86/intel/uncore: Add Alder Lake support
  perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
  perf/x86/intel: Add Alder Lake Hybrid support
  perf/x86: Support filter_match callback
  perf/x86/intel: Add attr_update for Hybrid PMUs
  perf/x86: Add structures for the attributes of Hybrid PMUs
  perf/x86: Register hybrid PMUs
  perf/x86: Factor out x86_pmu_show_pmu_cap
  perf/x86: Remove temporary pmu assignment in event_init
  perf/x86/intel: Factor out intel_pmu_check_extra_regs
  perf/x86/intel: Factor out intel_pmu_check_event_constraints
  perf/x86/intel: Factor out intel_pmu_check_num_counters
  perf/x86: Hybrid PMU support for extra_regs
  perf/x86: Hybrid PMU support for event constraints
  ...
2021-04-28 13:03:44 -07:00
Linus Torvalds
0ff0edb550 Merge tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:

 - rtmutex cleanup & spring cleaning pass that removes ~400 lines of
   code

 - Futex simplifications & cleanups

 - Add debugging to the CSD code, to help track down a tenacious race
   (or hw problem)

 - Add lockdep_assert_not_held(), to allow code to require a lock to not
   be held, and propagate this into the ath10k driver

 - Misc LKMM documentation updates

 - Misc KCSAN updates: cleanups & documentation updates

 - Misc fixes and cleanups

 - Fix locktorture bugs with ww_mutexes

* tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  kcsan: Fix printk format string
  static_call: Relax static_call_update() function argument type
  static_call: Fix unused variable warn w/o MODULE
  locking/rtmutex: Clean up signal handling in __rt_mutex_slowlock()
  locking/rtmutex: Restrict the trylock WARN_ON() to debug
  locking/rtmutex: Fix misleading comment in rt_mutex_postunlock()
  locking/rtmutex: Consolidate the fast/slowpath invocation
  locking/rtmutex: Make text section and inlining consistent
  locking/rtmutex: Move debug functions as inlines into common header
  locking/rtmutex: Decrapify __rt_mutex_init()
  locking/rtmutex: Remove pointless CONFIG_RT_MUTEXES=n stubs
  locking/rtmutex: Inline chainwalk depth check
  locking/rtmutex: Move rt_mutex_debug_task_free() to rtmutex.c
  locking/rtmutex: Remove empty and unused debug stubs
  locking/rtmutex: Consolidate rt_mutex_init()
  locking/rtmutex: Remove output from deadlock detector
  locking/rtmutex: Remove rtmutex deadlock tester leftovers
  locking/rtmutex: Remove rt_mutex_timed_lock()
  MAINTAINERS: Add myself as futex reviewer
  locking/mutex: Remove repeated declaration
  ...
2021-04-28 12:37:53 -07:00
Linus Torvalds
c6536676c7 Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 updates from Borislav Petkov:

 - Turn the stack canary into a normal __percpu variable on 32-bit which
   gets rid of the LAZY_GS stuff and a lot of code.

 - Add an insn_decode() API which all users of the instruction decoder
   should preferrably use. Its goal is to keep the details of the
   instruction decoder away from its users and simplify and streamline
   how one decodes insns in the kernel. Convert its users to it.

 - kprobes improvements and fixes

 - Set the maximum DIE per package variable on Hygon

 - Rip out the dynamic NOP selection and simplify all the machinery
   around selecting NOPs. Use the simplified NOPs in objtool now too.

 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN

 - Simplify the retpolines by folding the entire thing into an
   alternative now that objtool can handle alternatives with stack ops.
   Then, have objtool rewrite the call to the retpoline with the
   alternative which then will get patched at boot time.

 - Document Intel uarch per models in intel-family.h

 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
   exception on Intel.

* tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  x86, sched: Treat Intel SNC topology as default, COD as exception
  x86/cpu: Comment Skylake server stepping too
  x86/cpu: Resort and comment Intel models
  objtool/x86: Rewrite retpoline thunk calls
  objtool: Skip magical retpoline .altinstr_replacement
  objtool: Cache instruction relocs
  objtool: Keep track of retpoline call sites
  objtool: Add elf_create_undef_symbol()
  objtool: Extract elf_symbol_add()
  objtool: Extract elf_strtab_concat()
  objtool: Create reloc sections implicitly
  objtool: Add elf_create_reloc() helper
  objtool: Rework the elf_rebuild_reloc_section() logic
  objtool: Fix static_call list generation
  objtool: Handle per arch retpoline naming
  objtool: Correctly handle retpoline thunk calls
  x86/retpoline: Simplify retpolines
  x86/alternatives: Optimize optimize_nops()
  x86: Add insn_decode_kernel()
  x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration
  ...
2021-04-27 17:45:09 -07:00
Linus Torvalds
4d480dbf21 Merge tag 'hyperv-next-signed-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull Hyper-V updates from Wei Liu:

 - VMBus enhancement

 - Free page reporting support for Hyper-V balloon driver

 - Some patches for running Linux as Arm64 Hyper-V guest

 - A few misc clean-up patches

* tag 'hyperv-next-signed-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (30 commits)
  drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
  x86/hyperv: Move hv_do_rep_hypercall to asm-generic
  video: hyperv_fb: Add ratelimit on error message
  Drivers: hv: vmbus: Increase wait time for VMbus unload
  Drivers: hv: vmbus: Initialize unload_event statically
  Drivers: hv: vmbus: Check for pending channel interrupts before taking a CPU offline
  Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce CHANNELMSG_MODIFYCHANNEL_RESPONSE
  Drivers: hv: vmbus: Introduce and negotiate VMBus protocol version 5.3
  Drivers: hv: vmbus: Use after free in __vmbus_open()
  Drivers: hv: vmbus: remove unused function
  Drivers: hv: vmbus: Remove unused linux/version.h header
  x86/hyperv: remove unused linux/version.h header
  x86/Hyper-V: Support for free page reporting
  x86/hyperv: Fix unused variable 'hi' warning in hv_apic_read
  x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait
  hv: hyperv.h: a few mundane typo fixes
  drivers: hv: Fix EXPORT_SYMBOL and tab spaces issue
  Drivers: hv: vmbus: Drop error message when 'No request id available'
  asm-generic/hyperv: Add missing function prototypes per -W1 warnings
  clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts
  ...
2021-04-26 10:44:16 -07:00
Linus Torvalds
64f8e73de0 Merge tag 'x86-splitlock-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 bus lock detection updates from Thomas Gleixner:
 "Support for enhanced split lock detection:

  Newer CPUs provide a second mechanism to detect operations with lock
  prefix which go accross a cache line boundary. Such operations have to
  take bus lock which causes a system wide performance degradation when
  these operations happen frequently.

  The new mechanism is not using the #AC exception. It triggers #DB and
  is restricted to operations in user space. Kernel side split lock
  access can only be detected by the #AC based variant.

  Contrary to the #AC based mechanism the #DB based variant triggers
  _after_ the instruction was executed. The mechanism is CPUID
  enumerated and contrary to the #AC version which is based on the magic
  TEST_CTRL_MSR and model/family based enumeration on the way to become
  architectural"

* tag 'x86-splitlock-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/admin-guide: Change doc for split_lock_detect parameter
  x86/traps: Handle #DB for bus lock
  x86/cpufeatures: Enumerate #DB for bus lock detection
2021-04-26 10:09:38 -07:00
Linus Torvalds
eea2647e74 Merge tag 'x86-entry-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull entry code update from Thomas Gleixner:
 "Provide support for randomized stack offsets per syscall to make
  stack-based attacks harder which rely on the deterministic stack
  layout.

  The feature is based on the original idea of PaX's RANDSTACK feature,
  but uses a significantly different implementation.

  The offset does not affect the pt_regs location on the task stack as
  this was agreed on to be of dubious value. The offset is applied
  before the actual syscall is invoked.

  The offset is stored per cpu and the randomization happens at the end
  of the syscall which is less predictable than on syscall entry.

  The mechanism to apply the offset is via alloca(), i.e. abusing the
  dispised VLAs. This comes with the drawback that
  stack-clash-protection has to be disabled for the affected compilation
  units and there is also a negative interaction with stack-protector.

  Those downsides are traded with the advantage that this approach does
  not require any intrusive changes to the low level assembly entry
  code, does not affect the unwinder and the correct stack alignment is
  handled automatically by the compiler.

  The feature is guarded with a static branch which avoids the overhead
  when disabled.

  Currently this is supported for X86 and ARM64"

* tag 'x86-entry-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64: entry: Enable random_kstack_offset support
  lkdtm: Add REPORT_STACK for checking stack offsets
  x86/entry: Enable random_kstack_offset support
  stack: Optionally randomize kernel stack offset each syscall
  init_on_alloc: Optimize static branches
  jump_label: Provide CONFIG-driven build state defaults
2021-04-26 10:02:09 -07:00
Linus Torvalds
ea5bc7b977 Merge tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 cleanups from Borislav Petkov:
 "Trivial cleanups and fixes all over the place"

* tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove me from IDE/ATAPI section
  x86/pat: Do not compile stubbed functions when X86_PAT is off
  x86/asm: Ensure asm/proto.h can be included stand-alone
  x86/platform/intel/quark: Fix incorrect kernel-doc comment syntax in files
  x86/msr: Make locally used functions static
  x86/cacheinfo: Remove unneeded dead-store initialization
  x86/process/64: Move cpu_current_top_of_stack out of TSS
  tools/turbostat: Unmark non-kernel-doc comment
  x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()
  x86/fpu/math-emu: Fix function cast warning
  x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes
  x86: Fix various typos in comments, take #2
  x86: Remove unusual Unicode characters from comments
  x86/kaslr: Return boolean values from a function returning bool
  x86: Fix various typos in comments
  x86/setup: Remove unused RESERVE_BRK_ARRAY()
  stacktrace: Move documentation for arch_stack_walk_reliable() to header
  x86: Remove duplicate TSC DEADLINE MSR definitions
2021-04-26 09:25:47 -07:00
Linus Torvalds
81a489790a Merge tag 'x86_sgx_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Borislav Petkov:
 "Add the guest side of SGX support in KVM guests. Work by Sean
  Christopherson, Kai Huang and Jarkko Sakkinen.

  Along with the usual fixes, cleanups and improvements"

* tag 'x86_sgx_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/sgx: Mark sgx_vepc_vm_ops static
  x86/sgx: Do not update sgx_nr_free_pages in sgx_setup_epc_section()
  x86/sgx: Move provisioning device creation out of SGX driver
  x86/sgx: Add helpers to expose ECREATE and EINIT to KVM
  x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs
  x86/sgx: Add encls_faulted() helper
  x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT)
  x86/sgx: Move ENCLS leaf definitions to sgx.h
  x86/sgx: Expose SGX architectural definitions to the kernel
  x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled
  x86/cpu/intel: Allow SGX virtualization without Launch Control support
  x86/sgx: Introduce virtual EPC for use by KVM guests
  x86/sgx: Add SGX_CHILD_PRESENT hardware error code
  x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
  x86/cpufeatures: Add SGX1 and SGX2 sub-features
  x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit
  x86/sgx: Remove unnecessary kmap() from sgx_ioc_enclave_init()
  selftests/sgx: Use getauxval() to simplify test code
  selftests/sgx: Improve error detection and messages
  x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()
  ...
2021-04-26 09:15:56 -07:00
Linus Torvalds
2c5ce2dba2 Merge tag 'x86_alternatives_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 alternatives/paravirt updates from Borislav Petkov:
 "First big cleanup to the paravirt infra to use alternatives and thus
  eliminate custom code patching.

  For that, the alternatives infrastructure is extended to accomodate
  paravirt's needs and, as a result, a lot of paravirt patching code
  goes away, leading to a sizeable cleanup and simplification.

  Work by Juergen Gross"

* tag 'x86_alternatives_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/paravirt: Have only one paravirt patch function
  x86/paravirt: Switch functions with custom code to ALTERNATIVE
  x86/paravirt: Add new PVOP_ALT* macros to support pvops in ALTERNATIVEs
  x86/paravirt: Switch iret pvops to ALTERNATIVE
  x86/paravirt: Simplify paravirt macros
  x86/paravirt: Remove no longer needed 32-bit pvops cruft
  x86/paravirt: Add new features for paravirt patching
  x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has()
  x86/alternative: Support ALTERNATIVE_TERNARY
  x86/alternative: Support not-feature
  x86/paravirt: Switch time pvops functions to use static_call()
  static_call: Add function to query current function
  static_call: Move struct static_call_key definition to static_call_types.h
  x86/alternative: Merge include files
  x86/alternative: Drop unused feature parameter from ALTINSTR_REPLACEMENT()
2021-04-26 09:01:29 -07:00
Joseph Salisbury
753ed9c95c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Joseph Salisbury
6523592cee x86/hyperv: Move hv_do_rep_hypercall to asm-generic
This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h

hv_do_rep_hypercall() is architecture independent, so it makes sense that it
should be in the architecture independent mshyperv.h, not in the x86-specific
mshyperv.h.

This is done in preperation for a follow up patch which creates a consistent
pattern for checking Hyper-V hypercall status.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-1-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Colin Ian King
b53002e035 floppy: remove redundant assignment to variable st
The variable st is being assigned a value that is never read and
it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Denis Efremov <efremov@linux.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20210415130020.1959951-1-colin.king@canonical.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-20 08:59:03 -06:00
Kan Liang
d0946a882e perf/x86/intel: Hybrid PMU support for perf capabilities
Some platforms, e.g. Alder Lake, have hybrid architecture. Although most
PMU capabilities are the same, there are still some unique PMU
capabilities for different hybrid PMUs. Perf should register a dedicated
pmu for each hybrid PMU.

Add a new struct x86_hybrid_pmu, which saves the dedicated pmu and
capabilities for each hybrid PMU.

The architecture MSR, MSR_IA32_PERF_CAPABILITIES, only indicates the
architecture features which are available on all hybrid PMUs. The
architecture features are stored in the global x86_pmu.intel_cap.

For Alder Lake, the model-specific features are perf metrics and
PEBS-via-PT. The corresponding bits of the global x86_pmu.intel_cap
should be 0 for these two features. Perf should not use the global
intel_cap to check the features on a hybrid system.
Add a dedicated intel_cap in the x86_hybrid_pmu to store the
model-specific capabilities. Use the dedicated intel_cap to replace
the global intel_cap for thse two features. The dedicated intel_cap
will be set in the following "Add Alder Lake Hybrid support" patch.

Add is_hybrid() to distinguish a hybrid system. ADL may have an
alternative configuration. With that configuration, the
X86_FEATURE_HYBRID_CPU is not set. Perf cannot rely on the feature bit.
Add a new static_key_false, perf_is_hybrid, to indicate a hybrid system.
It will be assigned in the following "Add Alder Lake Hybrid support"
patch as well.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1618237865-33448-5-git-send-email-kan.liang@linux.intel.com
2021-04-19 20:03:24 +02:00
Ricardo Neri
250b3c0d79 x86/cpu: Add helper function to get the type of the current hybrid CPU
On processors with Intel Hybrid Technology (i.e., one having more than
one type of CPU in the same package), all CPUs support the same
instruction set and enumerate the same features on CPUID. Thus, all
software can run on any CPU without restrictions. However, there may be
model-specific differences among types of CPUs. For instance, each type
of CPU may support a different number of performance counters. Also,
machine check error banks may be wired differently. Even though most
software will not care about these differences, kernel subsystems
dealing with these differences must know.

Add and expose a new helper function get_this_hybrid_cpu_type() to query
the type of the current hybrid CPU. The function will be used later in
the perf subsystem.

The Intel Software Developer's Manual defines the CPU type as 8-bit
identifier.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1618237865-33448-3-git-send-email-kan.liang@linux.intel.com
2021-04-19 20:03:23 +02:00
Ricardo Neri
a161545ab5 x86/cpufeatures: Enumerate Intel Hybrid Technology feature bit
Add feature enumeration to identify a processor with Intel Hybrid
Technology: one in which CPUs of more than one type are the same package.
On a hybrid processor, all CPUs support the same homogeneous (i.e.,
symmetric) instruction set. All CPUs enumerate the same features in CPUID.
Thus, software (user space and kernel) can run and migrate to any CPU in
the system as well as utilize any of the enumerated features without any
change or special provisions. The main difference among CPUs in a hybrid
processor are power and performance properties.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1618237865-33448-2-git-send-email-kan.liang@linux.intel.com
2021-04-19 20:03:23 +02:00
Jan Kiszka
f7b21a0e41 x86/asm: Ensure asm/proto.h can be included stand-alone
Fix:

  ../arch/x86/include/asm/proto.h:14:30: warning: ‘struct task_struct’ declared \
    inside parameter list will not be visible outside of this definition or declaration
  long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2);
                               ^~~~~~~~~~~

  .../arch/x86/include/asm/proto.h:40:34: warning: ‘struct task_struct’ declared \
    inside parameter list will not be visible outside of this definition or declaration
   long do_arch_prctl_common(struct task_struct *task, int option,
                                    ^~~~~~~~~~~

if linux/sched.h hasn't be included previously. This fixes a build error
when this header is used outside of the kernel tree.

 [ bp: Massage commit message. ]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/b76b4be3-cf66-f6b2-9a6c-3e7ef54f9845@web.de
2021-04-12 13:12:46 +02:00
Andrew Cooper
99cb64de36 x86/cpu: Comment Skylake server stepping too
Further to

  53375a5a21 ("x86/cpu: Resort and comment Intel models"),

CascadeLake and CooperLake are steppings of Skylake, and make up the 1st
to 3rd generation "Xeon Scalable Processor" line.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210409121027.16437-1-andrew.cooper3@citrix.com
2021-04-10 11:14:33 +02:00
Linus Torvalds
adb2c4174f Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (kasan, gup, pagecache,
  and kfence), MAINTAINERS, mailmap, nds32, gcov, ocfs2, ia64, and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS
  kfence, x86: fix preemptible warning on KPTI-enabled systems
  lib/test_kasan_module.c: suppress unused var warning
  kasan: fix conflict with page poisoning
  fs: direct-io: fix missing sdio->boundary
  ia64: fix user_stack_pointer() for ptrace()
  ocfs2: fix deadlock between setattr and dio_end_io_write
  gcov: re-fix clang-11+ support
  nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff
  mm/gup: check page posion status for coredump.
  .mailmap: fix old email addresses
  mailmap: update email address for Jordan Crouse
  treewide: change my e-mail address, fix my name
  MAINTAINERS: update CZ.NIC's Turris information
2021-04-09 17:06:32 -07:00
Marco Elver
6a77d38efc kfence, x86: fix preemptible warning on KPTI-enabled systems
On systems with KPTI enabled, we can currently observe the following
warning:

  BUG: using smp_processor_id() in preemptible
  caller is invalidate_user_asid+0x13/0x50
  CPU: 6 PID: 1075 Comm: dmesg Not tainted 5.12.0-rc4-gda4a2b1a5479-kfence_1+ #1
  Hardware name: Hewlett-Packard HP Pro 3500 Series/2ABF, BIOS 8.11 10/24/2012
  Call Trace:
   dump_stack+0x7f/0xad
   check_preemption_disabled+0xc8/0xd0
   invalidate_user_asid+0x13/0x50
   flush_tlb_one_kernel+0x5/0x20
   kfence_protect+0x56/0x80
   ...

While it normally makes sense to require preemption to be off, so that
the expected CPU's TLB is flushed and not another, in our case it really
is best-effort (see comments in kfence_protect_page()).

Avoid the warning by disabling preemption around flush_tlb_one_kernel().

Link: https://lore.kernel.org/lkml/YGIDBAboELGgMgXy@elver.google.com/
Link: https://lkml.kernel.org/r/20210330065737.652669-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Tomi Sarvela <tomi.p.sarvela@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-09 14:54:23 -07:00
Peter Zijlstra
53375a5a21 x86/cpu: Resort and comment Intel models
The INTEL_FAM6 list has become a mess again. Try and bring some sanity
back into it.

Where previously we had one microarch per year and a number of SKUs
within that, this no longer seems to be the case. We now get different
uarch names that share a 'core' design.

Add the core name starting at skylake and reorder to keep the cores
in chronological order. Furthermore, Intel marketed the names {Amber,
Coffee, Whiskey} Lake, but those are in fact steppings of Kaby Lake, add
comments for them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/YE+HhS8i0gshHD3W@hirez.programming.kicks-ass.net
2021-04-08 14:22:10 +02:00
Kees Cook
fe950f6020 x86/entry: Enable random_kstack_offset support
Allow for a randomized stack offset on a per-syscall basis, with roughly
5-6 bits of entropy, depending on compiler and word size. Since the
method of offsetting uses macros, this cannot live in the common entry
code (the stack offset needs to be retained for the life of the syscall,
which means it needs to happen at the actual entry point).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210401232347.2791257-5-keescook@chromium.org
2021-04-08 14:05:20 +02:00
Vitaly Kuznetsov
fa26d0c778 ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m
Commit 8cdddd182b ("ACPI: processor: Fix CPU0 wakeup in
acpi_idle_play_dead()") tried to fix CPU0 hotplug breakage by copying
wakeup_cpu0() + start_cpu0() logic from hlt_play_dead()//mwait_play_dead()
into acpi_idle_play_dead(). The problem is that these functions are not
exported to modules so when CONFIG_ACPI_PROCESSOR=m build fails.

The issue could've been fixed by exporting both wakeup_cpu0()/start_cpu0()
(the later from assembly) but it seems putting the whole pattern into a
new function and exporting it instead is better.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 8cdddd182b ("CPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()")
Cc: <stable@vger.kernel.org> # 5.10+
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-04-07 19:02:43 +02:00
Sean Christopherson
b3754e5d3d x86/sgx: Move provisioning device creation out of SGX driver
And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and
export it as symbol for KVM to use.

The provisioning key is sensitive. The SGX driver only allows to create
an enclave which can access the provisioning key when the enclave
creator has permission to open /dev/sgx_provision. It should apply to
a VM as well, as the provisioning key is platform-specific, thus an
unrestricted VM can also potentially compromise the provisioning key.

Move the provisioning device creation out of sgx_drv_init() to
sgx_init() as a preparation for adding SGX virtualization support,
so that even if the SGX driver is not enabled due to flexible launch
control not being available, SGX virtualization can still be enabled,
and use it to restrict a VM's capability of being able to access the
provisioning key.

 [ bp: Massage commit message. ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/0f4d044d621561f26d5f4ef73e8dc6cd18cc7e79.1616136308.git.kai.huang@intel.com
2021-04-06 19:18:46 +02:00
Sean Christopherson
d155030b1e x86/sgx: Add helpers to expose ECREATE and EINIT to KVM
The host kernel must intercept ECREATE to impose policies on guests, and
intercept EINIT to be able to write guest's virtual SGX_LEPUBKEYHASH MSR
values to hardware before running guest's EINIT so it can run correctly
according to hardware behavior.

Provide wrappers around __ecreate() and __einit() to hide the ugliness
of overloading the ENCLS return value to encode multiple error formats
in a single int.  KVM will trap-and-execute ECREATE and EINIT as part
of SGX virtualization, and reflect ENCLS execution result to guest by
setting up guest's GPRs, or on an exception, injecting the correct fault
based on return value of __ecreate() and __einit().

Use host userspace addresses (provided by KVM based on guest physical
address of ENCLS parameters) to execute ENCLS/EINIT when possible.
Accesses to both EPC and memory originating from ENCLS are subject to
segmentation and paging mechanisms.  It's also possible to generate
kernel mappings for ENCLS parameters by resolving PFN but using
__uaccess_xx() is simpler.

 [ bp: Return early if the __user memory accesses fail, use
   cpu_feature_enabled(). ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20e09daf559aa5e9e680a0b4b5fba940f1bad86e.1616136308.git.kai.huang@intel.com
2021-04-06 19:18:27 +02:00
Sean Christopherson
32ddda8e44 x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT)
Define the ENCLS leafs that are available with SGX2, also referred to as
Enclave Dynamic Memory Management (EDMM).  The leafs will be used by KVM
to conditionally expose SGX2 capabilities to guests.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/5f0970c251ebcc6d5add132f0d750cc753b7060f.1616136308.git.kai.huang@intel.com
2021-04-06 09:43:42 +02:00
Sean Christopherson
9c55c78a73 x86/sgx: Move ENCLS leaf definitions to sgx.h
Move the ENCLS leaf definitions to sgx.h so that they can be used by
KVM.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/2e6cd7c5c1ced620cfcd292c3c6c382827fde6b2.1616136308.git.kai.huang@intel.com
2021-04-06 09:43:41 +02:00
Sean Christopherson
8ca52cc38d x86/sgx: Expose SGX architectural definitions to the kernel
Expose SGX architectural structures, as KVM will use many of the
architectural constants and structs to virtualize SGX.

Name the new header file as asm/sgx.h, rather than asm/sgx_arch.h, to
have single header to provide SGX facilities to share with other kernel
componments. Also update MAINTAINERS to include asm/sgx.h.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/6bf47acd91ab4d709e66ad1692c7803e4c9063a0.1616136308.git.kai.huang@intel.com
2021-04-06 09:43:41 +02:00
Peter Zijlstra
9bc0bb5072 objtool/x86: Rewrite retpoline thunk calls
When the compiler emits: "CALL __x86_indirect_thunk_\reg" for an
indirect call, have objtool rewrite it to:

	ALTERNATIVE "call __x86_indirect_thunk_\reg",
		    "call *%reg", ALT_NOT(X86_FEATURE_RETPOLINE)

Additionally, in order to not emit endless identical
.altinst_replacement chunks, use a global symbol for them, see
__x86_indirect_alt_*.

This also avoids objtool from having to do code generation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151300.320177914@infradead.org
2021-04-02 12:47:28 +02:00
Peter Zijlstra
119251855f x86/retpoline: Simplify retpolines
Due to:

  c9c324dc22 ("objtool: Support stack layout changes in alternatives")

it is now possible to simplify the retpolines.

Currently our retpolines consist of 2 symbols:

 - __x86_indirect_thunk_\reg: the compiler target
 - __x86_retpoline_\reg:  the actual retpoline.

Both are consecutive in code and aligned such that for any one register
they both live in the same cacheline:

  0000000000000000 <__x86_indirect_thunk_rax>:
   0:   ff e0                   jmpq   *%rax
   2:   90                      nop
   3:   90                      nop
   4:   90                      nop

  0000000000000005 <__x86_retpoline_rax>:
   5:   e8 07 00 00 00          callq  11 <__x86_retpoline_rax+0xc>
   a:   f3 90                   pause
   c:   0f ae e8                lfence
   f:   eb f9                   jmp    a <__x86_retpoline_rax+0x5>
  11:   48 89 04 24             mov    %rax,(%rsp)
  15:   c3                      retq
  16:   66 2e 0f 1f 84 00 00 00 00 00   nopw   %cs:0x0(%rax,%rax,1)

The thunk is an alternative_2, where one option is a JMP to the
retpoline. This was done so that objtool didn't need to deal with
alternatives with stack ops. But that problem has been solved, so now
it is possible to fold the entire retpoline into the alternative to
simplify and consolidate unused bytes:

  0000000000000000 <__x86_indirect_thunk_rax>:
   0:   ff e0                   jmpq   *%rax
   2:   90                      nop
   3:   90                      nop
   4:   90                      nop
   5:   90                      nop
   6:   90                      nop
   7:   90                      nop
   8:   90                      nop
   9:   90                      nop
   a:   90                      nop
   b:   90                      nop
   c:   90                      nop
   d:   90                      nop
   e:   90                      nop
   f:   90                      nop
  10:   90                      nop
  11:   66 66 2e 0f 1f 84 00 00 00 00 00        data16 nopw %cs:0x0(%rax,%rax,1)
  1c:   0f 1f 40 00             nopl   0x0(%rax)

Notice that since the longest alternative sequence is now:

   0:   e8 07 00 00 00          callq  c <.altinstr_replacement+0xc>
   5:   f3 90                   pause
   7:   0f ae e8                lfence
   a:   eb f9                   jmp    5 <.altinstr_replacement+0x5>
   c:   48 89 04 24             mov    %rax,(%rsp)
  10:   c3                      retq

17 bytes, we have 15 bytes NOP at the end of our 32 byte slot. (IOW, if
we can shrink the retpoline by 1 byte we can pack it more densely).

 [ bp: Massage commit message. ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210326151259.506071949@infradead.org
2021-04-02 12:42:04 +02:00
Peter Zijlstra
23c1ad538f x86/alternatives: Optimize optimize_nops()
Currently, optimize_nops() scans to see if the alternative starts with
NOPs. However, the emit pattern is:

  141:	\oldinstr
  142:	.skip (len-(142b-141b)), 0x90

That is, when 'oldinstr' is short, the tail is padded with NOPs. This case
never gets optimized.

Rewrite optimize_nops() to replace any trailing string of NOPs inside
the alternative to larger NOPs. Also run it irrespective of patching,
replacing NOPs in both the original and replaced code.

A direct consequence is that 'padlen' becomes superfluous, so remove it.

 [ bp:
   - Adjust commit message
   - remove a stale comment about needing to pad
   - add a comment in optimize_nops()
   - exit early if the NOP verif. loop catches a mismatch - function
     should not not add NOPs in that case
   - fix the "optimized NOPs" offsets output ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210326151259.442992235@infradead.org
2021-04-02 12:41:17 +02:00
Ingo Molnar
b1f480bc06 Merge branch 'x86/cpu' into WIP.x86/core, to merge the NOP changes & resolve a semantic conflict
Conflict-merge this main commit in essence:

  a89dfde3dc: ("x86: Remove dynamic NOP selection")

With this upstream commit:

  b908297047: ("bpf: Use NOP_ATOMIC5 instead of emit_nops(&prog, 5) for BPF_TRAMP_F_CALL_ORIG")

Semantic merge conflict:

  arch/x86/net/bpf_jit_comp.c

  - memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
  + memcpy(prog, x86_nops[5], X86_PATCH_SIZE);

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-04-02 12:36:30 +02:00
Ingo Molnar
e855e80d00 Merge tag 'v5.12-rc5' into WIP.x86/core, to pick up recent NOP related changes
In particular we want to have this upstream commit:

  b908297047: ("bpf: Use NOP_ATOMIC5 instead of emit_nops(&prog, 5) for BPF_TRAMP_F_CALL_ORIG")

... before merging in x86/cpu changes and the removal of the NOP optimizations, and
applying PeterZ's !retpoline objtool series.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-04-02 12:33:16 +02:00
Vitaly Kuznetsov
8cdddd182b ACPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()
Commit 496121c021 ("ACPI: processor: idle: Allow probing on platforms
with one ACPI C-state") broke CPU0 hotplug on certain systems, e.g.
I'm observing the following on AWS Nitro (e.g r5b.xlarge but other
instance types are affected as well):

 # echo 0 > /sys/devices/system/cpu/cpu0/online
 # echo 1 > /sys/devices/system/cpu/cpu0/online
 <10 seconds delay>
 -bash: echo: write error: Input/output error

In fact, the above mentioned commit only revealed the problem and did
not introduce it. On x86, to wakeup CPU an NMI is being used and
hlt_play_dead()/mwait_play_dead() loops are prepared to handle it:

	/*
	 * If NMI wants to wake up CPU0, start CPU0.
	 */
	if (wakeup_cpu0())
		start_cpu0();

cpuidle_play_dead() -> acpi_idle_play_dead() (which is now being called on
systems where it wasn't called before the above mentioned commit) serves
the same purpose but it doesn't have a path for CPU0. What happens now on
wakeup is:
 - NMI is sent to CPU0
 - wakeup_cpu0_nmi() works as expected
 - we get back to while (1) loop in acpi_idle_play_dead()
 - safe_halt() puts CPU0 to sleep again.

The straightforward/minimal fix is add the special handling for CPU0 on x86
and that's what the patch is doing.

Fixes: 496121c021 ("ACPI: processor: idle: Allow probing on platforms with one ACPI C-state")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-04-01 13:37:55 +02:00
Borislav Petkov
f2ac256b9a Merge 'x86/alternatives'
Pick up dependent changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
2021-03-31 18:04:19 +02:00
Peter Zijlstra
52fa82c21f x86: Add insn_decode_kernel()
Add a helper to decode kernel instructions; there's no point in
endlessly repeating those last two arguments.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210326151259.379242587@infradead.org
2021-03-31 16:20:22 +02:00
Ingo Molnar
feecb81732 Merge tag 'v5.12-rc5' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-03-29 15:56:48 +02:00
Fenghua Yu
ebb1064e7c x86/traps: Handle #DB for bus lock
Bus locks degrade performance for the whole system, not just for the CPU
that requested the bus lock. Two CPU features "#AC for split lock" and
"#DB for bus lock" provide hooks so that the operating system may choose
one of several mitigation strategies.

#AC for split lock is already implemented. Add code to use the #DB for
bus lock feature to cover additional situations with new options to
mitigate.

split_lock_detect=
		#AC for split lock		#DB for bus lock

off		Do nothing			Do nothing

warn		Kernel OOPs			Warn once per task and
		Warn once per task and		and continues to run.
		disable future checking
	 	When both features are
		supported, warn in #AC

fatal		Kernel OOPs			Send SIGBUS to user.
		Send SIGBUS to user
		When both features are
		supported, fatal in #AC

ratelimit:N	Do nothing			Limit bus lock rate to
						N per second in the
						current non-root user.

Default option is "warn".

Hardware only generates #DB for bus lock detect when CPL>0 to avoid
nested #DB from multiple bus locks while the first #DB is being handled.
So no need to handle #DB for bus lock detected in the kernel.

#DB for bus lock is enabled by bus lock detection bit 2 in DEBUGCTL MSR
while #AC for split lock is enabled by split lock detection bit 29 in
TEST_CTRL MSR.

Both breakpoint and bus lock in the same instruction can trigger one #DB.
The bus lock is handled before the breakpoint in the #DB handler.

Delivery of #DB for bus lock in userspace clears DR6[11], which is set by
the #DB handler right after reading DR6.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210322135325.682257-3-fenghua.yu@intel.com
2021-03-28 22:52:15 +02:00
Fenghua Yu
f21d4d3b97 x86/cpufeatures: Enumerate #DB for bus lock detection
A bus lock is acquired through either a split locked access to writeback
(WB) memory or any locked access to non-WB memory. This is typically >1000
cycles slower than an atomic operation within a cache line. It also
disrupts performance on other cores.

Some CPUs have the ability to notify the kernel by a #DB trap after a user
instruction acquires a bus lock and is executed. This allows the kernel to
enforce user application throttling or mitigation. Both breakpoint and bus
lock can trigger the #DB trap in the same instruction and the ordering of
handling them is the kernel #DB handler's choice.

The CPU feature flag to be shown in /proc/cpuinfo will be "bus_lock_detect".

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210322135325.682257-2-fenghua.yu@intel.com
2021-03-28 22:52:14 +02:00
Lai Jiangshan
1591584e2e x86/process/64: Move cpu_current_top_of_stack out of TSS
cpu_current_top_of_stack is currently stored in TSS.sp1. TSS is exposed
through the cpu_entry_area which is visible with user CR3 when PTI is
enabled and active.

This makes it a coveted fruit for attackers.  An attacker can fetch the
kernel stack top from it and continue next steps of actions based on the
kernel stack.

But it is actualy not necessary to be stored in the TSS.  It is only
accessed after the entry code switched to kernel CR3 and kernel GS_BASE
which means it can be in any regular percpu variable.

The reason why it is in TSS is historical (pre PTI) because TSS is also
used as scratch space in SYSCALL_64 and therefore cache hot.

A syscall also needs the per CPU variable current_task and eventually
__preempt_count, so placing cpu_current_top_of_stack next to them makes it
likely that they end up in the same cache line which should avoid
performance regressions. This is not enforced as the compiler is free to
place these variables, so these entry relevant variables should move into
a data structure to make this enforceable.

The seccomp_benchmark doesn't show any performance loss in the "getpid
native" test result.  Actually, the result changes from 93ns before to 92ns
with this change when KPTI is disabled. The test is very stable and
although the test doesn't show a higher degree of precision it gives enough
confidence that moving cpu_current_top_of_stack does not cause a
regression.

[ tglx: Removed unneeded export. Massaged changelog ]

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210125173444.22696-2-jiangshanlai@gmail.com
2021-03-28 22:40:10 +02:00
Linus Torvalds
6c20f6df61 Merge tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
 "This contains a small series with a more elegant fix of a problem
  which was originally fixed in rc2"

* tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  Revert "xen: fix p2m size in dom0 for disabled memory hotplug case"
  xen/x86: make XEN_BALLOON_MEMORY_HOTPLUG_LIMIT depend on MEMORY_HOTPLUG
2021-03-26 11:15:25 -07:00
Sean Christopherson
b8921dccf3 x86/cpufeatures: Add SGX1 and SGX2 sub-features
Add SGX1 and SGX2 feature flags, via CPUID.0x12.0x0.EAX, as scattered
features, since adding a new leaf for only two bits would be wasteful.
As part of virtualizing SGX, KVM will expose the SGX CPUID leafs to its
guest, and to do so correctly needs to query hardware and kernel support
for SGX1 and SGX2.

Suppress both SGX1 and SGX2 from /proc/cpuinfo. SGX1 basically means
SGX, and for SGX2 there is no concrete use case of using it in
/proc/cpuinfo.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/d787827dbfca6b3210ac3e432e3ac1202727e786.1616136308.git.kai.huang@intel.com
2021-03-25 17:33:11 +01:00
Masahiro Yamada
7dfe553aff x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()
Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes warnings:

  $ make W=1 kernel/sys_ni.o
    [ snip ]
    CC      kernel/sys_ni.o
     ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes]
     ...

The problem is in __COND_SYSCALL(), the __SYS_STUB0() and __SYS_STUBx() macros
defined a few lines above already have forward declarations.

Let's do likewise for __COND_SYSCALL() to fix the warnings.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210301131533.64671-2-masahiroy@kernel.org
2021-03-25 16:20:41 +01:00
Roger Pau Monne
af44a387e7 Revert "xen: fix p2m size in dom0 for disabled memory hotplug case"
This partially reverts commit 882213990d ("xen: fix p2m size in dom0
for disabled memory hotplug case")

There's no need to special case XEN_UNPOPULATED_ALLOC anymore in order
to correctly size the p2m. The generic memory hotplug option has
already been tied together with the Xen hotplug limit, so enabling
memory hotplug should already trigger a properly sized p2m on Xen PV.

Note that XEN_UNPOPULATED_ALLOC depends on ZONE_DEVICE which pulls in
MEMORY_HOTPLUG.

Leave the check added to __set_phys_to_machine and the adjusted
comment about EXTRA_MEM_RATIO.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210324122424.58685-3-roger.pau@citrix.com

[boris: fixed formatting issues]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-03-24 18:33:36 -05:00
Masami Hiramatsu
6256e668b7 x86/kprobes: Use int3 instead of debug trap for single-step
Use int3 instead of debug trap exception for single-stepping the
probed instructions. Some instructions which change the ip
registers or modify IF flags are emulated because those are not
able to be single-stepped by int3 or may allow the interrupt
while single-stepping.

This actually changes the kprobes behavior.

- kprobes can not probe following instructions; int3, iret,
  far jmp/call which get absolute address as immediate,
  indirect far jmp/call, indirect near jmp/call with addressing
  by memory (register-based indirect jmp/call are OK), and
  vmcall/vmlaunch/vmresume/vmxoff.

- If the kprobe post_handler doesn't set before registering,
  it may not be called in some case even if you set it afterwards.
  (IOW, kprobe booster is enabled at registration, user can not
   change it)

But both are rare issue, unsupported instructions will not be
used in the kernel (or rarely used), and post_handlers are
rarely used (I don't see it except for the test code).

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/161469874601.49483.11985325887166921076.stgit@devnote2
2021-03-23 16:07:56 +01:00