linux-stable.git/arch/x86/kernel/setup.c, branch linux-4.8.y

x86/smpboot: Init apic mapping before usage

2016-11-10T15:38:50+00:00

commit 1e90a13d0c3dc94512af1ccb2b6563e8297838fa upstream.

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 
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610282114380.5053@nanos
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/boot: Fix another __read_cr4() case on 486

2016-09-30T10:37:40+00:00

The condition for reading CR4 was wrong: there are some CPUs with
CPUID but not CR4.  Rather than trying to make the condition exact,
use __read_cr4_safe().

Fixes: 18bc7bd523e0 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Brian Gerst 
Link: http://lkml.kernel.org/r/8c453a61c4f44ab6ff43c29780ba04835234d2e5.1475178369.git.luto@kernel.org
Signed-off-by: Thomas Gleixner

x86/boot: Defer setup_real_mode() to early_initcall time

2016-08-11T09:15:00+00:00

There's no need to run setup_real_mode() as early as we run it.
Defer it to the same early_initcall that sets up the page
permissions for the real mode code.

This should be a code size reduction.  More importantly, it give us
a longer window in which we can allocate the real mode trampoline.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Mario Limonciello 
Cc: Matt Fleming 
Cc: Matthew Garrett 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/fd62f0da4f79357695e9bf3e365623736b05f119.1470821230.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly

2016-08-11T09:15:00+00:00

The initialization process for trampoline_cr4_features and
mmu_cr4_features was confusing.  The intent is for mmu_cr4_features
and *trampoline_cr4_features to stay in sync, but
trampoline_cr4_features is NULL until setup_real_mode() runs.  The
old code synchronized *trampoline_cr4_features *twice*, once in
setup_real_mode() and once in setup_arch().  It also initialized
mmu_cr4_features in setup_real_mode(), which causes the actual value
of mmu_cr4_features to potentially depend on when setup_real_mode()
is called.

With this patch, mmu_cr4_features is initialized directly in
setup_arch(), and *trampoline_cr4_features is synchronized to
mmu_cr4_features when the trampoline is set up.

After this patch, it should be safe to defer setup_real_mode().

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Mario Limonciello 
Cc: Matt Fleming 
Cc: Matthew Garrett 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/d48a263f9912389b957dd495a7127b009259ffe0.1470821230.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/boot: Run reserve_bios_regions() after we initialize the memory map

2016-08-11T09:14:59+00:00

reserve_bios_regions() is a quirk that reserves memory that we might
otherwise think is available.  There's no need to run it so early,
and running it before we have the memory map initialized with its
non-quirky inputs makes it hard to make reserve_bios_regions() more
intelligent.

Move it right after we populate the memblock state.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Mario Limonciello 
Cc: Matt Fleming 
Cc: Matthew Garrett 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/59f58618911005c799c6c9979ce6ae4881d907c2.1470821230.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization

2016-08-10T12:45:19+00:00

Initialize KASLR memory randomization after max_pfn is initialized. Also
ensure the size is rounded up. It could create problems on machines
with more than 1Tb of memory on certain random addresses.

Signed-off-by: Thomas Garnier 
Cc: Aleksey Makarov 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Baoquan He 
Cc: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: Denys Vlasenko 
Cc: Fabian Frederick 
Cc: H. Peter Anvin 
Cc: Joerg Roedel 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Lv Zheng 
Cc: Mark Salter 
Cc: Peter Zijlstra 
Cc: Rafael J . Wysocki 
Cc: Thomas Gleixner 
Cc: Toshi Kani 
Cc: kernel-hardening@lists.openwall.com
Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions")
Link: http://lkml.kernel.org/r/1470762665-88032-1-git-send-email-thgarnie@google.com
Signed-off-by: Ingo Molnar

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

2016-08-01T18:23:42+00:00

Pull x86 header cleanups from Ingo Molnar:
 "This tree is a cleanup of the x86 tree reducing spurious uses of
  module.h - which should improve build performance a bit"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
  x86/apic: Remove duplicated include from probe_64.c
  x86/ce4100: Remove duplicated include from ce4100.c
  x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
  x86/platform: Delete extraneous MODULE_* tags fromm ts5500
  x86: Audit and remove any remaining unnecessary uses of module.h
  x86/kvm: Audit and remove any unnecessary uses of module.h
  x86/xen: Audit and remove any unnecessary uses of module.h
  x86/platform: Audit and remove any unnecessary uses of module.h
  x86/lib: Audit and remove any unnecessary uses of module.h
  x86/kernel: Audit and remove any unnecessary uses of module.h
  x86/mm: Audit and remove any unnecessary uses of module.h
  x86: Don't use module.h just for AUTHOR / LICENSE tags

Merge tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2016-07-27T00:56:45+00:00

Pull ACPI updates from Rafael Wysocki:
 "The new feaures here are the support for ACPI overlays (allowing ACPI
  tables to be loaded at any time from EFI variables or via configfs)
  and the LPI (Low-Power Idle) support.  Also notable is the ACPI-based
  NUMA support for ARM64.

  Apart from that we have two new drivers, for the DPTF (Dynamic Power
  and Thermal Framework) power participant device and for the Intel
  Broxton WhiskeyCove PMIC, some more PMIC-related changes, support for
  the Boot Error Record Table (BERT) in APEI and support for
  platform-initiated graceful shutdown.

  Plus two new pieces of documentation and usual assorted fixes and
  cleanups in quite a few places.

  Specifics:

   - Support for ACPI SSDT overlays allowing Secondary System
     Description Tables (SSDTs) to be loaded at any time from EFI
     variables or via configfs (Octavian Purdila, Mika Westerberg).

   - Support for the ACPI LPI (Low-Power Idle) feature introduced in
     ACPI 6.0 and allowing processor idle states to be represented in
     ACPI tables in a hierarchical way (with the help of Processor
     Container objects) and support for ACPI idle states management on
     ARM64, based on LPI (Sudeep Holla).

   - General improvements of ACPI support for NUMA and ARM64 support for
     ACPI-based NUMA (Hanjun Guo, David Daney, Robert Richter).

   - General improvements of the ACPI table upgrade mechanism and ARM64
     support for that feature (Aleksey Makarov, Jon Masters).

   - Support for the Boot Error Record Table (BERT) in APEI and
     improvements of kernel messages printed by the error injection code
     (Huang Ying, Borislav Petkov).

   - New driver for the Intel Broxton WhiskeyCove PMIC operation region
     and support for the REGS operation region on Broxton, PMIC code
     cleanups (Bin Gao, Felipe Balbi, Paul Gortmaker).

   - New driver for the power participant device which is part of the
     Dynamic Power and Thermal Framework (DPTF) and DPTF-related code
     reorganization (Srinivas Pandruvada).

   - Support for the platform-initiated graceful shutdown feature
     introduced in ACPI 6.1 (Prashanth Prakash).

   - ACPI button driver update related to lid input events generated
     automatically on initialization and system resume that have been
     problematic for some time (Lv Zheng).

   - ACPI EC driver cleanups (Lv Zheng).

   - Documentation of the ACPICA release automation process and the
     in-kernel ACPI AML debugger (Lv Zheng).

   - New blacklist entry and two fixes for the ACPI backlight driver
     (Alex Hung, Arvind Yadav, Ralf Gerbig).

   - Cleanups of the ACPI pci_slot driver (Joe Perches, Paul Gortmaker).

   - ACPI CPPC code changes to make it more robust against possible
     defects in ACPI tables and new symbol definitions for PCC (Hoan
     Tran).

   - System reboot code modification to execute the ACPI _PTS (Prepare
     To Sleep) method in addition to _TTS (Ocean He).

   - ACPICA-related change to carry out lock ordering checks in ACPICA
     if ACPICA debug is enabled in the kernel (Lv Zheng).

   - Assorted minor fixes and cleanups (Andy Shevchenko, Baoquan He,
     Bhaktipriya Shridhar, Paul Gortmaker, Rafael Wysocki)"

* tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (71 commits)
  ACPI: enable ACPI_PROCESSOR_IDLE on ARM64
  arm64: add support for ACPI Low Power Idle(LPI)
  drivers: firmware: psci: initialise idle states using ACPI LPI
  cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}
  arm64: cpuidle: drop __init section marker to arm_cpuidle_init
  ACPI / processor_idle: Add support for Low Power Idle(LPI) states
  ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE
  ACPI / DPTF: move int340x_thermal.c to the DPTF folder
  ACPI / DPTF: Add DPTF power participant driver
  ACPI / lpat: make it explicitly non-modular
  ACPI / dock: make dock explicitly non-modular
  ACPI / PCI: make pci_slot explicitly non-modular
  ACPI / PMIC: remove modular references from non-modular code
  ACPICA: Linux: Enable ACPI_MUTEX_DEBUG for Linux kernel
  ACPI: Rename configfs.c to acpi_configfs.c to prevent link error
  ACPI / debugger: Add AML debugger documentation
  ACPI: Add documentation describing ACPICA release automation
  ACPI: add support for loading SSDTs via configfs
  ACPI: add support for configfs
  efi / ACPI: load SSTDs from EFI variables
  ...

x86/kernel: Audit and remove any unnecessary uses of module.h

2016-07-14T13:06:41+00:00

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).

Signed-off-by: Paul Gortmaker 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar

x86/mm: Implement ASLR for kernel memory regions

2016-07-08T15:33:46+00:00

Randomizes the virtual address space of kernel memory regions for
x86_64. This first patch adds the infrastructure and does not randomize
any region. The following patches will randomize the physical memory
mapping, vmalloc and vmemmap regions.

This security feature mitigates exploits relying on predictable kernel
addresses. These addresses can be used to disclose the kernel modules
base addresses or corrupt specific structures to elevate privileges
bypassing the current implementation of KASLR. This feature can be
enabled with the CONFIG_RANDOMIZE_MEMORY option.

The order of each memory region is not changed. The feature looks at the
available space for the regions based on different configuration options
and randomizes the base and space between each. The size of the physical
memory mapping is the available physical memory. No performance impact
was detected while testing the feature.

Entropy is generated using the KASLR early boot functions now shared in
the lib directory (originally written by Kees Cook). Randomization is
done on PGD & PUD page table levels to increase possible addresses. The
physical memory mapping code was adapted to support PUD level virtual
addresses. This implementation on the best configuration provides 30,000
possible virtual addresses in average for each memory region.  An
additional low memory page is used to ensure each CPU can start with a
PGD aligned virtual address (for realmode).

x86/dump_pagetable was updated to correctly display each region.

Updated documentation on x86_64 memory layout accordingly.

Performance data, after all patches in the series:

Kernbench shows almost no difference (-+ less than 1%):

Before:

Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.63 (1.2695)
User Time 1034.89 (1.18115) System Time 87.056 (0.456416) Percent CPU 1092.9
(13.892) Context Switches 199805 (3455.33) Sleeps 97907.8 (900.636)

After:

Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.489 (1.10636)
User Time 1034.86 (1.36053) System Time 87.764 (0.49345) Percent CPU 1095
(12.7715) Context Switches 199036 (4298.1) Sleeps 97681.6 (1031.11)

Hackbench shows 0% difference on average (hackbench 90 repeated 10 times):

attemp,before,after 1,0.076,0.069 2,0.072,0.069 3,0.066,0.066 4,0.066,0.068
5,0.066,0.067 6,0.066,0.069 7,0.067,0.066 8,0.063,0.067 9,0.067,0.065
10,0.068,0.071 average,0.0677,0.0677

Signed-off-by: Thomas Garnier 
Signed-off-by: Kees Cook 
Cc: Alexander Kuleshov 
Cc: Alexander Popov 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Aneesh Kumar K.V 
Cc: Baoquan He 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: Denys Vlasenko 
Cc: Dmitry Vyukov 
Cc: H. Peter Anvin 
Cc: Jan Beulich 
Cc: Joerg Roedel 
Cc: Jonathan Corbet 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kirill A. Shutemov 
Cc: Linus Torvalds 
Cc: Lv Zheng 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Fleming 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Cc: Thomas Gleixner 
Cc: Toshi Kani 
Cc: Xiao Guangrong 
Cc: Yinghai Lu 
Cc: kernel-hardening@lists.openwall.com
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1466556426-32664-6-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar