- 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).
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Merge tag 'acpi-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
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
...
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 <thgarnie@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
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 <mingo@kernel.org>
Refer initrd_start, initrd_end directly from drivers/acpi/tables.c.
This allows to use the table upgrade feature in architectures
other than x86. Also this simplifies header files.
The patch renames acpi_table_initrd_init() to acpi_table_upgrade()
(what reflects the purpose of the function) and removes the unneeded
wraps early_acpi_table_init() and early_initrd_acpi_init().
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In arch/x86/kernel/setup.c, the #ifdef kept for CONFIG_ACPI actually is
related to the accessibility of initrd_start/initrd_end, so the stub should
be provided from this source file and should only be dependent on
CONFIG_BLK_DEV_INITRD.
Note that when ACPI=n and BLK_DEV_INITRD=y, early_initrd_acpi_init() is
still a stub because of the stub prepared for early_acpi_table_init().
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch moves acpi_os_table_override() and
acpi_os_physical_table_override() to tables.c.
Along with the mechanisms, acpi_initrd_initialize_tables() is also moved to
tables.c to form a static function. The following functions are renamed
according to this change:
1. acpi_initrd_override() -> renamed to early_acpi_table_init(), which
invokes acpi_table_initrd_init()
2. acpi_os_physical_table_override() -> which invokes
acpi_table_initrd_override()
3. acpi_initialize_initrd_tables() -> renamed to acpi_table_initrd_scan()
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This reverts commit c4004b02f8.
Sadly, my hope that nobody would actually use the special kernel entries
in /proc/iomem were dashed by kexec. Which reads /proc/iomem explicitly
to find the kernel base address. Nasty.
Anyway, that means we can't do the sane and simple thing and just remove
the entries, and we'll instead have to mask them out based on permissions.
Reported-by: Zhengyu Zhang <zhezhang@redhat.com>
Reported-by: Dave Young <dyoung@redhat.com>
Reported-by: Freeman Zhang <freeman.zhang1992@gmail.com>
Reported-by: Emrah Demir <ed@abdsec.com>
Reported-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's see if anybody even notices. I doubt anybody uses this, and it
does expose addresses that should be randomized, so let's just remove
the code. It's old and traditional, and it used to be cute, but we
should have removed this long ago.
If it turns out anybody notices and this breaks something, we'll have to
revert this, and maybe we'll end up using other approaches instead
(using %pK or similar). But removing unnecessary code is always the
preferred option.
Noted-by: Emrah Demir <ed@abdsec.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 protection key support from Ingo Molnar:
"This tree adds support for a new memory protection hardware feature
that is available in upcoming Intel CPUs: 'protection keys' (pkeys).
There's a background article at LWN.net:
https://lwn.net/Articles/643797/
The gist is that protection keys allow the encoding of
user-controllable permission masks in the pte. So instead of having a
fixed protection mask in the pte (which needs a system call to change
and works on a per page basis), the user can map a (handful of)
protection mask variants and can change the masks runtime relatively
cheaply, without having to change every single page in the affected
virtual memory range.
This allows the dynamic switching of the protection bits of large
amounts of virtual memory, via user-space instructions. It also
allows more precise control of MMU permission bits: for example the
executable bit is separate from the read bit (see more about that
below).
This tree adds the MM infrastructure and low level x86 glue needed for
that, plus it adds a high level API to make use of protection keys -
if a user-space application calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice
this special case, and will set a special protection key on this
memory range. It also sets the appropriate bits in the Protection
Keys User Rights (PKRU) register so that the memory becomes unreadable
and unwritable.
So using protection keys the kernel is able to implement 'true'
PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies
PROT_READ as well. Unreadable executable mappings have security
advantages: they cannot be read via information leaks to figure out
ASLR details, nor can they be scanned for ROP gadgets - and they
cannot be used by exploits for data purposes either.
We know about no user-space code that relies on pure PROT_EXEC
mappings today, but binary loaders could start making use of this new
feature to map binaries and libraries in a more secure fashion.
There is other pending pkeys work that offers more high level system
call APIs to manage protection keys - but those are not part of this
pull request.
Right now there's a Kconfig that controls this feature
(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled
(like most x86 CPU feature enablement code that has no runtime
overhead), but it's not user-configurable at the moment. If there's
any serious problem with this then we can make it configurable and/or
flip the default"
* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
x86/mm/pkeys: Fix mismerge of protection keys CPUID bits
mm/pkeys: Fix siginfo ABI breakage caused by new u64 field
x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA
mm/core, x86/mm/pkeys: Add execute-only protection keys support
x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags
x86/mm/pkeys: Allow kernel to modify user pkey rights register
x86/fpu: Allow setting of XSAVE state
x86/mm: Factor out LDT init from context init
mm/core, x86/mm/pkeys: Add arch_validate_pkey()
mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits()
x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
x86/mm/pkeys: Add Kconfig prompt to existing config option
x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps
x86/mm/pkeys: Dump PKRU with other kernel registers
mm/core, x86/mm/pkeys: Differentiate instruction fetches
x86/mm/pkeys: Optimize fault handling in access_error()
mm/core: Do not enforce PKEY permissions on remote mm access
um, pkeys: Add UML arch_*_access_permitted() methods
mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys
x86/mm/gup: Simplify get_user_pages() PTE bit handling
...
The protection key can now be just as important as read/write
permissions on a VMA. We need some debug mechanism to help
figure out if it is in play. smaps seems like a logical
place to expose it.
arch/x86/kernel/setup.c is a bit of a weirdo place to put
this code, but it already had seq_file.h and there was not
a much better existing place to put it.
We also use no #ifdef. If protection keys is .config'd out we
will effectively get the same function as if we used the weak
generic function.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mark Williamson <mwilliamson@undo-software.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210227.4F8EB3F8@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change e820_reserve_resources() to set 'flags' and 'desc' from
e820 types.
Set E820_RESERVED_KERN and E820_RAM's (System RAM) io resource
type to IORESOURCE_SYSTEM_RAM.
Do the same for "Kernel data", "Kernel code", and "Kernel bss",
which are child nodes of System RAM.
I/O resource descriptor is set to 'desc' for entries that are
(and will be) target ranges of walk_iomem_res() and
region_intersects().
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 mm updates from Ingo Molnar:
"The main changes in this cycle were:
- make the debugfs 'kernel_page_tables' file read-only, as it only
has read ops. (Borislav Petkov)
- micro-optimize clflush_cache_range() (Chris Wilson)
- swiotlb enhancements, which fixes certain KVM emulated devices
(Igor Mammedov)
- fix an LDT related debug message (Jan Beulich)
- modularize CONFIG_X86_PTDUMP (Kees Cook)
- tone down an overly alarming warning (Laura Abbott)
- Mark variable __initdata (Rasmus Villemoes)
- PAT additions (Toshi Kani)"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Micro-optimise clflush_cache_range()
x86/mm/pat: Change free_memtype() to support shrinking case
x86/mm/pat: Add untrack_pfn_moved for mremap
x86/mm: Drop WARN from multi-BAR check
x86/LDT: Print the real LDT base address
x86/mm/64: Enable SWIOTLB if system has SRAT memory regions above MAX_DMA32_PFN
x86/mm: Introduce max_possible_pfn
x86/mm/ptdump: Make (debugfs)/kernel_page_tables read-only
x86/mm/mtrr: Mark the 'range_new' static variable in mtrr_calc_range_state() as __initdata
x86/mm: Turn CONFIG_X86_PTDUMP into a module
max_possible_pfn will be used for tracking max possible
PFN for memory that isn't present in E820 table and
could be hotplugged later.
By default max_possible_pfn is initialized with max_pfn,
but later it could be updated with highest PFN of
hotpluggable memory ranges declared in ACPI SRAT table
if any present.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: konrad.wilk@oracle.com
Cc: pbonzini@redhat.com
Cc: revers@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1449234426-273049-2-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Running microcode_init() from setup_arch() is a bad idea because
not even kmalloc() is ready at that point and the loader does
all kinds of allocations and init/registration with various
subsystems.
Make it a late initcall when required facilities are initialized
so that the microcode driver initialization can succeed too.
Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20151120112400.GC4028@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The commit f5f3497cad extended the low identity mapping. However, if
the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory
split), the normal memory mapping is overwritten by the low identity
mapping causing a crash. To avoid overwritting, limit the low identity
map to cover only memory before kernel range (PAGE_OFFSET).
Fixes: f5f3497cad "x86/setup: Extend low identity map to cover whole kernel range
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull RAS changes from Ingo Molnar:
"The main system reliability related changes were from x86, but also
some generic RAS changes:
- AMD MCE error injection subsystem enhancements. (Aravind
Gopalakrishnan)
- Fix MCE and CPU hotplug interaction bug. (Ashok Raj)
- kcrash bootup robustness fix. (Baoquan He)
- kcrash cleanups. (Borislav Petkov)
- x86 microcode driver rework: simplify it by unmodularizing it and
other cleanups. (Borislav Petkov)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/mce: Add a default case to the switch in __mcheck_cpu_ancient_init()
x86/mce: Add a Scalable MCA vendor flags bit
MAINTAINERS: Unify the microcode driver section
x86/microcode/intel: Move #ifdef DEBUG inside the function
x86/microcode/amd: Remove maintainers from comments
x86/microcode: Remove modularization leftovers
x86/microcode: Merge the early microcode loader
x86/microcode: Unmodularize the microcode driver
x86/mce: Fix thermal throttling reporting after kexec
kexec/crash: Say which char is the unrecognized
x86/setup/crash: Check memblock_reserve() retval
x86/setup/crash: Cleanup some more
x86/setup/crash: Remove alignment variable
x86/setup: Cleanup crashkernel reservation functions
x86/amd_nb, EDAC: Rename amd_get_node_id()
x86/setup: Do not reserve crashkernel high memory if low reservation failed
x86/microcode/amd: Do not overwrite final patch levels
x86/microcode/amd: Extract current patch level read to a function
x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC
x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts
...
Pull EFI changes from Ingo Molnar:
"The main changes in this cycle were:
- further EFI code generalization to make it more workable for ARM64
- various extensions, such as 64-bit framebuffer address support,
UEFI v2.5 EFI_PROPERTIES_TABLE support
- code modularization simplifications and cleanups
- new debugging parameters
- various fixes and smaller additions"
* 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
efi: Fix warning of int-to-pointer-cast on x86 32-bit builds
efi: Use correct type for struct efi_memory_map::phys_map
x86/efi: Fix kernel panic when CONFIG_DEBUG_VIRTUAL is enabled
efi: Add "efi_fake_mem" boot option
x86/efi: Rename print_efi_memmap() to efi_print_memmap()
efi: Auto-load the efi-pstore module
efi: Introduce EFI_NX_PE_DATA bit and set it from properties table
efi: Add support for UEFIv2.5 Properties table
efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()
efifb: Add support for 64-bit frame buffer addresses
efi/arm64: Clean up efi_get_fdt_params() interface
arm64: Use core efi=debug instead of uefi_debug command line parameter
efi/x86: Move efi=debug option parsing to core
drivers/firmware: Make efi/esrt.c driver explicitly non-modular
efi: Use the generic efi.memmap instead of 'memmap'
acpi/apei: Use appropriate pgprot_t to map GHES memory
arm64, acpi/apei: Implement arch_apei_get_mem_attributes()
arm64/mm: Add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT
acpi, x86: Implement arch_apei_get_mem_attributes()
efi, x86: Rearrange efi_mem_attributes()
...
Make CONFIG_MICROCODE a bool. It was practically a bool already anyway,
since early loader was forcing it to =y.
Regardless, there's no real reason to have something be a module which
gets built-in on the majority of installations out there. And its not
like there's noticeable change in functionality - we still can load late
microcode - just the module glue disappears.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1445334889-300-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
memblock_reserve() can fail but the crashkernel reservation code
doesn't check that and this can lead the user into believing
that the crashkernel region was actually reserved. Make sure we
check that return value and we exit early with a failure message
in the error case.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: WANG Chao <chaowang@redhat.com>
Cc: jerry_hoemann@hp.com
Link: http://lkml.kernel.org/r/1445246268-26285-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
People reported that when allocating crashkernel memory using
the ",high" and ",low" syntax, there were cases where the
reservation of the high portion succeeds but the reservation of
the low portion fails.
Then kexec can load the kdump kernel successfully, but booting
the kdump kernel fails as there's no low memory.
The low memory allocation for the kdump kernel can fail on large
systems for a couple of reasons. For example, the manually
specified crashkernel low memory can be too large and thus no
adequate memblock region would be found.
Therefore, we try to reserve low memory for the crash kernel
*after* the high memory portion has been allocated. If that
fails, we free crashkernel high memory too and return. The user
can then take measures accordingly.
Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Baoquan He <bhe@redhat.com>
[ Massage text. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: WANG Chao <chaowang@redhat.com>
Cc: jerry_hoemann@hp.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/1445246268-26285-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On 32-bit systems, the initial_page_table is reused by
efi_call_phys_prolog as an identity map to call
SetVirtualAddressMap. efi_call_phys_prolog takes care of
converting the current CPU's GDT to a physical address too.
For PAE kernels the identity mapping is achieved by aliasing the
first PDPE for the kernel memory mapping into the first PDPE
of initial_page_table. This makes the EFI stub's trick "just work".
However, for non-PAE kernels there is no guarantee that the identity
mapping in the initial_page_table extends as far as the GDT; in this
case, accesses to the GDT will cause a page fault (which quickly becomes
a triple fault). Fix this by copying the kernel mappings from
swapper_pg_dir to initial_page_table twice, both at PAGE_OFFSET and at
identity mapping.
For some reason, this is only reproducible with QEMU's dynamic translation
mode, and not for example with KVM. However, even under KVM one can clearly
see that the page table is bogus:
$ qemu-system-i386 -pflash OVMF.fd -M q35 vmlinuz0 -s -S -daemonize
$ gdb
(gdb) target remote localhost:1234
(gdb) hb *0x02858f6f
Hardware assisted breakpoint 1 at 0x2858f6f
(gdb) c
Continuing.
Breakpoint 1, 0x02858f6f in ?? ()
(gdb) monitor info registers
...
GDT= 0724e000 000000ff
IDT= fffbb000 000007ff
CR0=0005003b CR2=ff896000 CR3=032b7000 CR4=00000690
...
The page directory is sane:
(gdb) x/4wx 0x32b7000
0x32b7000: 0x03398063 0x03399063 0x0339a063 0x0339b063
(gdb) x/4wx 0x3398000
0x3398000: 0x00000163 0x00001163 0x00002163 0x00003163
(gdb) x/4wx 0x3399000
0x3399000: 0x00400003 0x00401003 0x00402003 0x00403003
but our particular page directory entry is empty:
(gdb) x/1wx 0x32b7000 + (0x724e000 >> 22) * 4
0x32b7070: 0x00000000
[ It appears that you can skate past this issue if you don't receive
any interrupts while the bogus GDT pointer is loaded, or if you avoid
reloading the segment registers in general.
Andy Lutomirski provides some additional insight:
"AFAICT it's entirely permissible for the GDTR and/or LDT
descriptor to point to unmapped memory. Any attempt to use them
(segment loads, interrupts, IRET, etc) will try to access that memory
as if the access came from CPL 0 and, if the access fails, will
generate a valid page fault with CR2 pointing into the GDT or
LDT."
Up until commit 23a0d4e8fa ("efi: Disable interrupts around EFI
calls, not in the epilog/prolog calls") interrupts were disabled
around the prolog and epilog calls, and the functional GDT was
re-installed before interrupts were re-enabled.
Which explains why no one has hit this issue until now. ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Laszlo Ersek <lersek@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
[ Updated changelog. ]
non-modular by ripping out the module_* code since Kconfig doesn't
allow it to be built as a module anyway - Paul Gortmaker
* Make the x86 efi=debug kernel parameter, which enables EFI debug
code and output, generic and usable by arm64 - Leif Lindholm
* Add support to the x86 EFI boot stub for 64-bit Graphics Output
Protocol frame buffer addresses - Matt Fleming
* Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled
in the firmware and set an efi.flags bit so the kernel knows when
it can apply more strict runtime mapping attributes - Ard Biesheuvel
* Auto-load the efi-pstore module on EFI systems, just like we
currently do for the efivars module - Ben Hutchings
* Add "efi_fake_mem" kernel parameter which allows the system's EFI
memory map to be updated with additional attributes for specific
memory ranges. This is useful for testing the kernel code that handles
the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware
doesn't include support - Taku Izumi
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi
Pull v4.4 EFI updates from Matt Fleming:
- Make the EFI System Resource Table (ESRT) driver explicitly
non-modular by ripping out the module_* code since Kconfig doesn't
allow it to be built as a module anyway. (Paul Gortmaker)
- Make the x86 efi=debug kernel parameter, which enables EFI debug
code and output, generic and usable by arm64. (Leif Lindholm)
- Add support to the x86 EFI boot stub for 64-bit Graphics Output
Protocol frame buffer addresses. (Matt Fleming)
- Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled
in the firmware and set an efi.flags bit so the kernel knows when
it can apply more strict runtime mapping attributes - Ard Biesheuvel
- Auto-load the efi-pstore module on EFI systems, just like we
currently do for the efivars module. (Ben Hutchings)
- Add "efi_fake_mem" kernel parameter which allows the system's EFI
memory map to be updated with additional attributes for specific
memory ranges. This is useful for testing the kernel code that handles
the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware
doesn't include support. (Taku Izumi)
Note: there is a semantic conflict between the following two commits:
8a53554e12 ("x86/efi: Fix multiple GOP device support")
ae2ee627dc ("efifb: Add support for 64-bit frame buffer addresses")
I fixed up the interaction in the merge commit, changing the type of
current_fb_base from u32 to u64.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch introduces new boot option named "efi_fake_mem".
By specifying this parameter, you can add arbitrary attribute
to specific memory range.
This is useful for debugging of Address Range Mirroring feature.
For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000"
is specified, the original (firmware provided) EFI memmap will be
updated so that the specified memory regions have
EFI_MEMORY_MORE_RELIABLE attribute (0x10000):
<original>
efi: mem36: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)
<updated>
efi: mem36: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
efi: mem37: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
efi: mem38: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
efi: mem39: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)
And you will find that the following message is output:
efi: Memory: 4096M/131455M mirrored memory
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.
And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.
The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.
Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.
Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The early_ioremap library now has a generic copy_from_early_mem()
function. Use the generic copy function for x86 relocate_initrd().
[akpm@linux-foundation.org: remove MAX_MAP_CHUNK define, per Yinghai Lu]
Signed-off-by: Mark Salter <msalter@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel does not support the MCA bus anymroe, so mark sys_desc_table
as obsolete: remove any reference from the code together with the remaining
of MCA logic.
bloat-o-meter output:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-55 (-55)
function old new delta
i386_start_kernel 128 119 -9
setup_arch 1421 1375 -46
Signed-off-by: Paolo Pisati <p.pisati@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437409430-8491-1-git-send-email-p.pisati@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Two FPU rewrite related fixes. This addresses all known x86
regressions at this stage. Also some other misc fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Fix boot crash in the early FPU code
x86/asm/entry/64: Update path names
x86/fpu: Fix FPU related boot regression when CPUID masking BIOS feature is enabled
x86/boot/setup: Clean up the e820_reserve_setup_data() code
x86/kaslr: Fix typo in the KASLR_FLAG documentation
UEFI GetMemoryMap() uses a new attribute bit to mark mirrored memory
address ranges. See UEFI 2.5 spec pages 157-158:
http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf
On EFI enabled systems scan the memory map and tell memblock about any
mirrored ranges.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Xiexiuqi <xiexiuqi@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull livepatching fixes from Jiri Kosina:
- symbol lookup locking fix, from Miroslav Benes
- error handling improvements in case of failure of the module coming
notifier, from Minfei Huang
- we were too pessimistic when kASLR has been enabled on x86 and were
dropping address hints on the floor unnecessarily in such case. Fix
from Jiri Kosina
- a few other small fixes and cleanups
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: add module locking around kallsyms calls
livepatch: annotate klp_init() with __init
livepatch: introduce patch/func-walking helpers
livepatch: make kobject in klp_object statically allocated
livepatch: Prevent patch inconsistencies if the coming module notifier fails
livepatch: match return value to function signature
x86: kaslr: fix build due to missing ALIGN definition
livepatch: x86: make kASLR logic more accurate
x86: introduce kaslr_offset()
Pull x86 core updates from Ingo Molnar:
"There were so many changes in the x86/asm, x86/apic and x86/mm topics
in this cycle that the topical separation of -tip broke down somewhat -
so the result is a more traditional architecture pull request,
collected into the 'x86/core' topic.
The topics were still maintained separately as far as possible, so
bisectability and conceptual separation should still be pretty good -
but there were a handful of merge points to avoid excessive
dependencies (and conflicts) that would have been poorly tested in the
end.
The next cycle will hopefully be much more quiet (or at least will
have fewer dependencies).
The main changes in this cycle were:
* x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
Gleixner)
- This is the second and most intrusive part of changes to the x86
interrupt handling - full conversion to hierarchical interrupt
domains:
[IOAPIC domain] -----
|
[MSI domain] --------[Remapping domain] ----- [ Vector domain ]
| (optional) |
[HPET MSI domain] ----- |
|
[DMAR domain] -----------------------------
|
[Legacy domain] -----------------------------
This now reflects the actual hardware and allowed us to distangle
the domain specific code from the underlying parent domain, which
can be optional in the case of interrupt remapping. It's a clear
separation of functionality and removes quite some duct tape
constructs which plugged the remap code between ioapic/msi/hpet
and the vector management.
- Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
injection into guests (Feng Wu)
* x86/asm changes:
- Tons of cleanups and small speedups, micro-optimizations. This
is in preparation to move a good chunk of the low level entry
code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
Brian Gerst)
- Moved all system entry related code to a new home under
arch/x86/entry/ (Ingo Molnar)
- Removal of the fragile and ugly CFI dwarf debuginfo annotations.
Conversion to C will reintroduce many of them - but meanwhile
they are only getting in the way, and the upstream kernel does
not rely on them (Ingo Molnar)
- NOP handling refinements. (Borislav Petkov)
* x86/mm changes:
- Big PAT and MTRR rework: making the code more robust and
preparing to phase out exposing direct MTRR interfaces to drivers -
in favor of using PAT driven interfaces (Toshi Kani, Luis R
Rodriguez, Borislav Petkov)
- New ioremap_wt()/set_memory_wt() interfaces to support
Write-Through cached memory mappings. This is especially
important for good performance on NVDIMM hardware (Toshi Kani)
* x86/ras changes:
- Add support for deferred errors on AMD (Aravind Gopalakrishnan)
This is an important RAS feature which adds hardware support for
poisoned data. That means roughly that the hardware marks data
which it has detected as corrupted but wasn't able to correct, as
poisoned data and raises an APIC interrupt to signal that in the
form of a deferred error. It is the OS's responsibility then to
take proper recovery action and thus prolonge system lifetime as
far as possible.
- Add support for Intel "Local MCE"s: upcoming CPUs will support
CPU-local MCE interrupts, as opposed to the traditional system-
wide broadcasted MCE interrupts (Ashok Raj)
- Misc cleanups (Borislav Petkov)
* x86/platform changes:
- Intel Atom SoC updates
... and lots of other cleanups, fixlets and other changes - see the
shortlog and the Git log for details"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
x86/hpet: Use proper hpet device number for MSI allocation
x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
genirq: Prevent crash in irq_move_irq()
genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
iommu, x86: Properly handle posted interrupts for IOMMU hotplug
iommu, x86: Provide irq_remapping_cap() interface
iommu, x86: Setup Posted-Interrupts capability for Intel iommu
iommu, x86: Add cap_pi_support() to detect VT-d PI capability
iommu, x86: Avoid migrating VT-d posted interrupts
iommu, x86: Save the mode (posted or remapped) of an IRTE
iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
iommu: dmar: Provide helper to copy shared irte fields
iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
iommu: Add new member capability to struct irq_remap_ops
x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
...
When the crash kernel is loaded above 4GiB in memory, the
first kernel allocates only 72MiB of low-memory for the DMA
requirements of the second kernel. On systems with many
devices this is not enough and causes device driver
initialization errors and failed crash dumps. Testing by
SUSE and Redhat has shown that 256MiB is a good default
value for now and the discussion has lead to this value as
well. So set this default value to 256MiB to make sure there
is enough memory available for DMA.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
[ Reflow comment. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jörg Rödel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Link: http://lkml.kernel.org/r/1433500202-25531-4-git-send-email-joro@8bytes.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Deobfuscate the 'found' logic, it can be replaced with a simple:
if (!pa_data)
return;
and 'found' can be eliminated.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1433398729-8314-1-git-send-email-weiyang@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Offset that has been chosen for kaslr during kernel decompression can be
easily computed as a difference between _text and __START_KERNEL. We are
already making use of this in dump_kernel_offset() notifier and in
arch_crash_save_vmcoreinfo().
Introduce kaslr_offset() that makes this computation instead of hard-coding
it, so that other kernel code (such as live patching) can make use of it.
Also convert existing users to make use of it.
This patch is equivalent transofrmation without any effects on the resulting
code:
$ diff -u vmlinux.old.asm vmlinux.new.asm
--- vmlinux.old.asm 2015-04-28 17:55:19.520983368 +0200
+++ vmlinux.new.asm 2015-04-28 17:55:24.141206072 +0200
@@ -1,5 +1,5 @@
-vmlinux.old: file format elf64-x86-64
+vmlinux.new: file format elf64-x86-64
Disassembly of section .text:
$
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
io_apic_ops.init() is either NULL, if IO-APIC support is disabled at
compile time or native_io_apic_init_mappings(). No point to have that
as we can achieve the same thing with an empty inline.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 mm changes from Ingo Molnar:
"The main changes in this cycle were:
- reduce the x86/32 PAE per task PGD allocation overhead from 4K to
0.032k (Fenghua Yu)
- early_ioremap/memunmap() usage cleanups (Juergen Gross)
- gbpages support cleanups (Luis R Rodriguez)
- improve AMD Bulldozer (family 0x15) ASLR I$ aliasing workaround to
increase randomization by 3 bits (per bootup) (Hector
Marco-Gisbert)
- misc fixlets"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Improve AMD Bulldozer ASLR workaround
x86/mm/pat: Initialize __cachemode2pte_tbl[] and __pte2cachemode_tbl[] in a bit more readable fashion
init.h: Clean up the __setup()/early_param() macros
x86/mm: Simplify probe_page_size_mask()
x86/mm: Further simplify 1 GB kernel linear mappings handling
x86/mm: Use early_param_on_off() for direct_gbpages
init.h: Add early_param_on_off()
x86/mm: Simplify enabling direct_gbpages
x86/mm: Use IS_ENABLED() for direct_gbpages
x86/mm: Unexport set_memory_ro() and set_memory_rw()
x86/mm, efi: Use early_ioremap() in arch/x86/platform/efi/efi-bgrt.c
x86/mm: Use early_memunmap() instead of early_iounmap()
x86/mm/pat: Ensure different messages in STRICT_DEVMEM and PAT cases
x86/mm: Reduce PAE-mode per task pgd allocation overhead from 4K to 32 bytes
Commit:
e2b32e6785 ("x86, kaslr: randomize module base load address")
made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:
f47233c2d3 ("x86/mm/ASLR: Propagate base load address calculation")
In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.
Originally-From: Jiri Kosina <jkosina@suse.cz>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit:
f47233c2d3 ("x86/mm/ASLR: Propagate base load address calculation")
The main reason for the revert is that the new boot flag does not work
at all currently, and in order to make this work, we need non-trivial
changes to the x86 boot code which we didn't manage to get done in
time for merging.
And even if we did, they would've been too risky so instead of
rushing things and break booting 4.1 on boxes left and right, we
will be very strict and conservative and will take our time with
this to fix and test it properly.
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150316100628.GD22995@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull misc x86 fixes from Ingo Molnar:
"This contains:
- EFI fixes
- a boot printout fix
- ASLR/kASLR fixes
- intel microcode driver fixes
- other misc fixes
Most of the linecount comes from an EFI revert"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch
x86/microcode/intel: Handle truncated microcode images more robustly
x86/microcode/intel: Guard against stack overflow in the loader
x86, mm/ASLR: Fix stack randomization on 64-bit systems
x86/mm/init: Fix incorrect page size in init_memory_mapping() printks
x86/mm/ASLR: Propagate base load address calculation
Documentation/x86: Fix path in zero-page.txt
x86/apic: Fix the devicetree build in certain configs
Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes"
x86/efi: Avoid triple faults during EFI mixed mode calls
Pull ASLR and kASLR fixes from Borislav Petkov:
- Add a global flag announcing KASLR state so that relevant code can do
informed decisions based on its setting. (Jiri Kosina)
- Fix a stack randomization entropy decrease bug. (Hector Marco-Gisbert)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
e2b32e6785 ("x86, kaslr: randomize module base load address")
makes the base address for module to be unconditionally randomized in
case when CONFIG_RANDOMIZE_BASE is defined and "nokaslr" option isn't
present on the commandline.
This is not consistent with how choose_kernel_location() decides whether
it will randomize kernel load base.
Namely, CONFIG_HIBERNATION disables kASLR (unless "kaslr" option is
explicitly specified on kernel commandline), which makes the state space
larger than what module loader is looking at. IOW CONFIG_HIBERNATION &&
CONFIG_RANDOMIZE_BASE is a valid config option, kASLR wouldn't be applied
by default in that case, but module loader is not aware of that.
Instead of fixing the logic in module.c, this patch takes more generic
aproach. It introduces a new bootparam setup data_type SETUP_KASLR and
uses that to pass the information whether kaslr has been applied during
kernel decompression, and sets a global 'kaslr_enabled' variable
accordingly, so that any kernel code (module loading, livepatching, ...)
can make decisions based on its value.
x86 module loader is converted to make use of this flag.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Link: https://lkml.kernel.org/r/alpine.LNX.2.00.1502101411280.10719@pobox.suse.cz
[ Always dump correct kaslr status when panicking ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Pull x86 perf updates from Ingo Molnar:
"This series tightens up RDPMC permissions: currently even highly
sandboxed x86 execution environments (such as seccomp) have permission
to execute RDPMC, which may leak various perf events / PMU state such
as timing information and other CPU execution details.
This 'all is allowed' RDPMC mode is still preserved as the
(non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is
that RDPMC access is only allowed if a perf event is mmap-ed (which is
needed to correctly interpret RDPMC counter values in any case).
As a side effect of these changes CR4 handling is cleaned up in the
x86 code and a shadow copy of the CR4 value is added.
The extra CR4 manipulation adds ~ <50ns to the context switch cost
between rdpmc-capable and rdpmc-non-capable mms"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
perf/x86: Only allow rdpmc if a perf_event is mapped
perf: Pass the event to arch_perf_update_userpage()
perf: Add pmu callbacks to track event mapping and unmapping
x86: Add a comment clarifying LDT context switching
x86: Store a per-cpu shadow copy of CR4
x86: Clean up cr4 manipulation
This patch adds arch specific code for kernel address sanitizer.
16TB of virtual addressed used for shadow memory. It's located in range
[ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup
stacks.
At early stage we map whole shadow region with zero page. Latter, after
pages mapped to direct mapping address range we unmap zero pages from
corresponding shadow (see kasan_map_shadow()) and allocate and map a real
shadow memory reusing vmemmap_populate() function.
Also replace __pa with __pa_nodebug before shadow initialized. __pa with
CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr)
__phys_addr is instrumented, so __asan_load could be called before shadow
area initialized.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Context switches and TLB flushes can change individual bits of CR4.
CR4 reads take several cycles, so store a shadow copy of CR4 in a
per-cpu variable.
To avoid wasting a cache line, I added the CR4 shadow to
cpu_tlbstate, which is already touched in switch_mm. The heaviest
users of the cr4 shadow will be switch_mm and __switch_to_xtra, and
__switch_to_xtra is called shortly after switch_mm during context
switch, so the cacheline is likely to be hot.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
early_memremap() takes care of page alignment and map size, so we can
just remap the required data size and get rid of the adjustments in
the setup code.
[tglx: Massaged changelog ]
Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Link: http://lkml.kernel.org/r/1420628150-16872-1-git-send-email-chaowang@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull x86 vdso updates from Ingo Molnar:
"Various vDSO updates from Andy Lutomirski, mostly cleanups and
reorganization to improve maintainability, but also some
micro-optimizations and robustization changes"
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86_64/vsyscall: Restore orig_ax after vsyscall seccomp
x86_64: Add a comment explaining the TASK_SIZE_MAX guard page
x86_64,vsyscall: Make vsyscall emulation configurable
x86_64, vsyscall: Rewrite comment and clean up headers in vsyscall code
x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none
x86,vdso: Use LSL unconditionally for vgetcpu
x86: vdso: Fix build with older gcc
x86_64/vdso: Clean up vgetcpu init and merge the vdso initcalls
x86_64/vdso: Remove jiffies from the vvar page
x86/vdso: Make the PER_CPU segment 32 bits
x86/vdso: Make the PER_CPU segment start out accessed
x86/vdso: Change the PER_CPU segment to use struct desc_struct
x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c
x86_64/vsyscall: Move all of the gate_area code to vsyscall_64.c
This is really the meat of the MPX patch set. If there is one patch to
review in the entire series, this is the one. There is a new ABI here
and this kernel code also interacts with userspace memory in a
relatively unusual manner. (small FAQ below).
Long Description:
This patch adds two prctl() commands to provide enable or disable the
management of bounds tables in kernel, including on-demand kernel
allocation (See the patch "on-demand kernel allocation of bounds tables")
and cleanup (See the patch "cleanup unused bound tables"). Applications
do not strictly need the kernel to manage bounds tables and we expect
some applications to use MPX without taking advantage of this kernel
support. This means the kernel can not simply infer whether an application
needs bounds table management from the MPX registers. The prctl() is an
explicit signal from userspace.
PR_MPX_ENABLE_MANAGEMENT is meant to be a signal from userspace to
require kernel's help in managing bounds tables.
PR_MPX_DISABLE_MANAGEMENT is the opposite, meaning that userspace don't
want kernel's help any more. With PR_MPX_DISABLE_MANAGEMENT, the kernel
won't allocate and free bounds tables even if the CPU supports MPX.
PR_MPX_ENABLE_MANAGEMENT will fetch the base address of the bounds
directory out of a userspace register (bndcfgu) and then cache it into
a new field (->bd_addr) in the 'mm_struct'. PR_MPX_DISABLE_MANAGEMENT
will set "bd_addr" to an invalid address. Using this scheme, we can
use "bd_addr" to determine whether the management of bounds tables in
kernel is enabled.
Also, the only way to access that bndcfgu register is via an xsaves,
which can be expensive. Caching "bd_addr" like this also helps reduce
the cost of those xsaves when doing table cleanup at munmap() time.
Unfortunately, we can not apply this optimization to #BR fault time
because we need an xsave to get the value of BNDSTATUS.
==== Why does the hardware even have these Bounds Tables? ====
MPX only has 4 hardware registers for storing bounds information.
If MPX-enabled code needs more than these 4 registers, it needs to
spill them somewhere. It has two special instructions for this
which allow the bounds to be moved between the bounds registers
and some new "bounds tables".
They are similar conceptually to a page fault and will be raised by
the MPX hardware during both bounds violations or when the tables
are not present. This patch handles those #BR exceptions for
not-present tables by carving the space out of the normal processes
address space (essentially calling the new mmap() interface indroduced
earlier in this patch set.) and then pointing the bounds-directory
over to it.
The tables *need* to be accessed and controlled by userspace because
the instructions for moving bounds in and out of them are extremely
frequent. They potentially happen every time a register pointing to
memory is dereferenced. Any direct kernel involvement (like a syscall)
to access the tables would obviously destroy performance.
==== Why not do this in userspace? ====
This patch is obviously doing this allocation in the kernel.
However, MPX does not strictly *require* anything in the kernel.
It can theoretically be done completely from userspace. Here are
a few ways this *could* be done. I don't think any of them are
practical in the real-world, but here they are.
Q: Can virtual space simply be reserved for the bounds tables so
that we never have to allocate them?
A: As noted earlier, these tables are *HUGE*. An X-GB virtual
area needs 4*X GB of virtual space, plus 2GB for the bounds
directory. If we were to preallocate them for the 128TB of
user virtual address space, we would need to reserve 512TB+2GB,
which is larger than the entire virtual address space today.
This means they can not be reserved ahead of time. Also, a
single process's pre-popualated bounds directory consumes 2GB
of virtual *AND* physical memory. IOW, it's completely
infeasible to prepopulate bounds directories.
Q: Can we preallocate bounds table space at the same time memory
is allocated which might contain pointers that might eventually
need bounds tables?
A: This would work if we could hook the site of each and every
memory allocation syscall. This can be done for small,
constrained applications. But, it isn't practical at a larger
scale since a given app has no way of controlling how all the
parts of the app might allocate memory (think libraries). The
kernel is really the only place to intercept these calls.
Q: Could a bounds fault be handed to userspace and the tables
allocated there in a signal handler instead of in the kernel?
A: (thanks to tglx) mmap() is not on the list of safe async
handler functions and even if mmap() would work it still
requires locking or nasty tricks to keep track of the
allocation state there.
Having ruled out all of the userspace-only approaches for managing
bounds tables that we could think of, we create them on demand in
the kernel.
Based-on-patch-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151829.AD4310DE@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
