linux-stable.git/arch/x86/kernel/setup.c, branch linux-4.9.y

x86/speculation/l1tf: Make sure the first page is always reserved

2018-08-15T16:14:44+00:00

commit 10a70416e1f067f6c4efda6ffd8ea96002ac4223 upstream

The L1TF workaround doesn't make any attempt to mitigate speculate accesses
to the first physical page for zeroed PTEs. Normally it only contains some
data from the early real mode BIOS.

It's not entirely clear that the first page is reserved in all
configurations, so add an extra reservation call to make sure it is really
reserved. In most configurations (e.g.  with the standard reservations)
it's likely a nop.

Signed-off-by: Andi Kleen 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Josh Poimboeuf 
Acked-by: Dave Hansen 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

x86/boot/32: Fix UP boot on Quark and possibly other platforms

2018-03-22T08:17:58+00:00

commit d2b6dc61a8dd3c429609b993778cb54e75a5c5f0 upstream.

This partially reverts commit:

  23b2a4ddebdd17f ("x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up")

That commit had one definite bug and one potential bug.  The
definite bug is that setup_per_cpu_areas() uses a differnet generic
implementation on UP kernels, so initial_page_table never got
resynced.  This was fine for access to percpu data (it's in the
identity map on UP), but it breaks other users of
initial_page_table.  The potential bug is that helpers like
efi_init() would be called before the tables were synced.

Avoid both problems by just syncing the page tables in setup_arch()
*and* setup_per_cpu_areas().

Reported-by: Jan Kiszka 
Signed-off-by: Andy Lutomirski 
Cc: Andy Shevchenko 
Cc: Ard Biesheuvel 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Peter Zijlstra 
Cc: Thomas Garnier 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up

2018-03-22T08:17:41+00:00

[ Upstream commit 23b2a4ddebdd17fad265b4bb77256c2e4ec37dee ]

The x86 smpboot trampoline expects initial_page_table to have the
GDT mapped.  If the GDT ends up in a virtually mapped per-cpu page,
then it won't be in the page tables at all until perc-pu areas are
set up.  The result will be a triple fault the first time that the
CPU attempts to access the GDT after LGDT loads the perc-pu GDT.

This appears to be an old bug, but somehow the GDT fixmap rework
is triggering it.  This seems to have something to do with the
memory layout.

Signed-off-by: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Peter Zijlstra 
Cc: Thomas Garnier 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/a553264a5972c6a86f9b5caac237470a0c74a720.1490218061.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

x86/kaiser: Move feature detection up

2018-01-05T14:46:35+00:00

... before the first use of kaiser_enabled as otherwise funky
things happen:

  about to get started...
  (XEN) d0v0 Unhandled page fault fault/trap [#14, ec=0000]
  (XEN) Pagetable walk from ffff88022a449090:
  (XEN)  L4[0x110] = 0000000229e0e067 0000000000001e0e
  (XEN)  L3[0x008] = 0000000000000000 ffffffffffffffff
  (XEN) domain_crash_sync called from entry.S: fault at ffff82d08033fd08
  entry.o#create_bounce_frame+0x135/0x14d
  (XEN) Domain 0 (vcpu#0) crashed on cpu#0:
  (XEN) ----[ Xen-4.9.1_02-3.21  x86_64  debug=n   Not tainted ]----
  (XEN) CPU:    0
  (XEN) RIP:    e033:[]
  (XEN) RFLAGS: 0000000000000286   EM: 1   CONTEXT: pv guest (d0v0)

Signed-off-by: Borislav Petkov 
Signed-off-by: Greg Kroah-Hartman

x86/mm/pat: Don't report PAT on CPUs that don't support it

2017-07-15T10:16:17+00:00

commit 99c13b8c8896d7bcb92753bf0c63a8de4326e78d upstream.

The pat_enabled() logic is broken on CPUs which do not support PAT and
where the initialization code fails to call pat_init(). Due to that the
enabled flag stays true and pat_enabled() returns true wrongfully.

As a consequence the mappings, e.g. for Xorg, are set up with the wrong
caching mode and the required MTRR setups are omitted.

To cure this the following changes are required:

  1) Make pat_enabled() return true only if PAT initialization was
     invoked and successful.

  2) Invoke init_cache_modes() unconditionally in setup_arch() and
     remove the extra callsites in pat_disable() and the pat disabled
     code path in pat_init().

Also rename __pat_enabled to pat_disabled to reflect the real purpose of
this variable.

Fixes: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled")
Signed-off-by: Mikulas Patocka 
Signed-off-by: Thomas Gleixner 
Cc: Bernhard Held 
Cc: Denys Vlasenko 
Cc: Peter Zijlstra 
Cc: Brian Gerst 
Cc: "Luis R. Rodriguez" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Josh Poimboeuf 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1707041749300.3456@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Greg Kroah-Hartman

x86/smpboot: Init apic mapping before usage

2016-10-29T12:00:46+00:00

The recent changes, which forced the registration of the boot cpu on UP
systems, which do not have ACPI tables, have been fixed for systems w/o
local APIC, but left a wreckage for systems which have neither ACPI nor
mptables, but the CPU has an APIC, e.g. virtualbox.

The boot process crashes in prefill_possible_map() as it wants to register
the boot cpu, which needs to access the local apic, but the local APIC is
not yet mapped.

There is no reason why init_apic_mapping() can't be invoked before
prefill_possible_map(). So instead of playing another silly early mapping
game, as the ACPI/mptables code does, we just move init_apic_mapping()
before the call to prefill_possible_map().

In hindsight, I should have noticed that combination earlier.

Sorry for the churn (also in stable)!

Fixes: ff8560512b8d ("x86/boot/smp: Don't try to poke disabled/non-existent APIC")
Reported-and-debugged-by: Michal Necasek 
Reported-and-tested-by: Wolfgang Bauer 
Cc: prarit@redhat.com
Cc: ville.syrjala@linux.intel.com
Cc: michael.thayer@oracle.com
Cc: knut.osmundsen@oracle.com
Cc: frank.mehnert@oracle.com
Cc: Borislav Petkov 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610282114380.5053@nanos
Signed-off-by: Thomas Gleixner

Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-03T23:46:53+00:00

Pull x86 boot updates from Ingo Molnar:
 "The changes in this cycle were:

   - Save e820 table RAM footprint on larger kernel configurations.
     (Denys Vlasenko)

   - pmem related fixes (Dan Williams)

   - theoretical e820 boundary condition fix (Wei Yang)"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation
  x86/e820: Use much less memory for e820/e820_saved, save up to 120k
  x86/e820: Prepare e280 code for switch to dynamic storage
  x86/e820: Mark some static functions __init
  x86/e820: Fix very large 'size' handling boundary condition

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-03T23:13:28+00:00

Pull low-level x86 updates from Ingo Molnar:
 "In this cycle this topic tree has become one of those 'super topics'
  that accumulated a lot of changes:

   - Add CONFIG_VMAP_STACK=y support to the core kernel and enable it on
     x86 - preceded by an array of changes. v4.8 saw preparatory changes
     in this area already - this is the rest of the work. Includes the
     thread stack caching performance optimization. (Andy Lutomirski)

   - switch_to() cleanups and all around enhancements. (Brian Gerst)

   - A large number of dumpstack infrastructure enhancements and an
     unwinder abstraction. The secret long term plan is safe(r) live
     patching plus maybe another attempt at debuginfo based unwinding -
     but all these current bits are standalone enhancements in a frame
     pointer based debug environment as well. (Josh Poimboeuf)

   - More __ro_after_init and const annotations. (Kees Cook)

   - Enable KASLR for the vmemmap memory region. (Thomas Garnier)"

[ The virtually mapped stack changes are pretty fundamental, and not
  x86-specific per se, even if they are only used on x86 right now. ]

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  x86/asm: Get rid of __read_cr4_safe()
  thread_info: Use unsigned long for flags
  x86/alternatives: Add stack frame dependency to alternative_call_2()
  x86/dumpstack: Fix show_stack() task pointer regression
  x86/dumpstack: Remove dump_trace() and related callbacks
  x86/dumpstack: Convert show_trace_log_lvl() to use the new unwinder
  oprofile/x86: Convert x86_backtrace() to use the new unwinder
  x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder
  perf/x86: Convert perf_callchain_kernel() to use the new unwinder
  x86/unwind: Add new unwind interface and implementations
  x86/dumpstack: Remove NULL task pointer convention
  fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y
  sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK
  lib/syscall: Pin the task stack in collect_syscall()
  x86/process: Pin the target stack in get_wchan()
  x86/dumpstack: Pin the target stack when dumping it
  kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function
  sched/core: Add try_get_task_stack() and put_task_stack()
  x86/entry/64: Fix a minor comment rebase error
  iommu/amd: Don't put completion-wait semaphore on stack
  ...

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-03T22:36:06+00:00

Pull x86 apic updates from Ingo Molnar:
 "The main changes are:

   - Persistent CPU/node numbering across CPU hotplug/unplug events.
     This is a pretty involved series of changes that first fetches all
     the information during bootup and then uses it for the various
     hotplug/unplug methods. (Gu Zheng, Dou Liyang)

   - IO-APIC hot-add/remove fixes and enhancements. (Rui Wang)

   - ... various fixes, cleanups and enhancements"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86/apic: Fix silent & fatal merge conflict in __generic_processor_info()
  acpi: Fix broken error check in map_processor()
  acpi: Validate processor id when mapping the processor
  acpi: Provide mechanism to validate processors in the ACPI tables
  x86/acpi: Set persistent cpuid <-> nodeid mapping when booting
  x86/acpi: Enable MADT APIs to return disabled apicids
  x86/acpi: Introduce persistent storage for cpuid <-> apicid mapping
  x86/acpi: Enable acpi to register all possible cpus at boot time
  x86/numa: Online memory-less nodes at boot time
  x86/apic: Get rid of apic_version[] array
  x86/apic: Order irq_enter/exit() calls correctly vs. ack_APIC_irq()
  x86/ioapic: Ignore root bridges without a companion ACPI device
  x86/apic: Update comment about disabling processor focus
  x86/smpboot: Check APIC ID before setting up default routing
  x86/ioapic: Fix IOAPIC failing to request resource
  x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd
  x86/ioapic: Fix setup_res() failing to get resource
  x86/ioapic: Support hot-removal of IOAPICs present during boot
  x86/ioapic: Change prototype of acpi_ioapic_add()
  x86/apic, ACPI: Fix incorrect assignment when handling apic/x2apic entries
  ...

Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-10-03T18:33:18+00:00

Pull EFI updates from Ingo Molnar:
 "Main changes in this cycle were:

   - Refactor the EFI memory map code into architecture neutral files
     and allow drivers to permanently reserve EFI boot services regions
     on x86, as well as ARM/arm64. (Matt Fleming)

   - Add ARM support for the EFI ESRT driver. (Ard Biesheuvel)

   - Make the EFI runtime services and efivar API interruptible by
     swapping spinlocks for semaphores. (Sylvain Chouleur)

   - Provide the EFI identity mapping for kexec which allows kexec to
     work on SGI/UV platforms with requiring the "noefi" kernel command
     line parameter. (Alex Thorlton)

   - Add debugfs node to dump EFI page tables on arm64. (Ard Biesheuvel)

   - Merge the EFI test driver being carried out of tree until now in
     the FWTS project. (Ivan Hu)

   - Expand the list of flags for classifying EFI regions as "RAM" on
     arm64 so we align with the UEFI spec. (Ard Biesheuvel)

   - Optimise out the EFI mixed mode if it's unsupported (CONFIG_X86_32)
     or disabled (CONFIG_EFI_MIXED=n) and switch the early EFI boot
     services function table for direct calls, alleviating us from
     having to maintain the custom function table. (Lukas Wunner)

   - Miscellaneous cleanups and fixes"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE
  x86/efi: Allow invocation of arbitrary boot services
  x86/efi: Optimize away setup_gop32/64 if unused
  x86/efi: Use kmalloc_array() in efi_call_phys_prolog()
  efi/arm64: Treat regions with WT/WC set but WB cleared as memory
  efi: Add efi_test driver for exporting UEFI runtime service interfaces
  x86/efi: Defer efi_esrt_init until after memblock_x86_fill
  efi/arm64: Add debugfs node to dump UEFI runtime page tables
  x86/efi: Remove unused find_bits() function
  fs/efivarfs: Fix double kfree() in error path
  x86/efi: Map in physical addresses in efi_map_region_fixed
  lib/ucs2_string: Speed up ucs2_utf8size()
  firmware-gsmi: Delete an unnecessary check before the function call "dma_pool_destroy"
  x86/efi: Initialize status to ensure garbage is not returned on small size
  efi: Replace runtime services spinlock with semaphore
  efi: Don't use spinlocks for efi vars
  efi: Use a file local lock for efivars
  efi/arm*: esrt: Add missing call to efi_esrt_init()
  efi/esrt: Use memremap not ioremap to access ESRT table in memory
  x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data
  ...