Commit Graph

3108 Commits

Author SHA1 Message Date
Daniel Borkmann
75a1a607bb uaccess: Add strict non-pagefault kernel-space read function
Add two new probe_kernel_read_strict() and strncpy_from_unsafe_strict()
helpers which by default alias to the __probe_kernel_read() and the
__strncpy_from_unsafe(), respectively, but can be overridden by archs
which have non-overlapping address ranges for kernel space and user
space in order to bail out with -EFAULT when attempting to probe user
memory including non-canonical user access addresses [0]:

  4-level page tables:
    user-space mem: 0x0000000000000000 - 0x00007fffffffffff
    non-canonical:  0x0000800000000000 - 0xffff7fffffffffff

  5-level page tables:
    user-space mem: 0x0000000000000000 - 0x00ffffffffffffff
    non-canonical:  0x0100000000000000 - 0xfeffffffffffffff

The idea is that these helpers are complementary to the probe_user_read()
and strncpy_from_unsafe_user() which probe user-only memory. Both added
helpers here do the same, but for kernel-only addresses.

Both set of helpers are going to be used for BPF tracing. They also
explicitly avoid throwing the splat for non-canonical user addresses from
00c42373d3 ("x86-64: add warning for non-canonical user access address
dereferences").

For compat, the current probe_kernel_read() and strncpy_from_unsafe() are
left as-is.

  [0] Documentation/x86/x86_64/mm.txt

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: x86@kernel.org
Link: https://lore.kernel.org/bpf/eefeefd769aa5a013531f491a71f0936779e916b.1572649915.git.daniel@iogearbox.net
2019-11-02 12:39:12 -07:00
Linus Torvalds
aefcf2f4b5 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
2019-09-28 08:14:15 -07:00
Mark Rutland
b4ed71f557 mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-26 10:10:44 -07:00
Michel Lespinasse
315cc066b8 augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks
for the case where the augmented value is a scalar whose definition
follows a max(f(node)) pattern.  This actually covers all present uses of
RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the
various RBCOMPUTE function definitions.

[walken@google.com: fix mm/vmalloc.c]
  Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com
[walken@google.com: re-add check to check_augmented()]
  Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com
Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Mike Rapoport
782de70c42 mm: consolidate pgtable_cache_init() and pgd_cache_init()
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>		[arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>	[x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:09 -07:00
Linus Torvalds
45824fc0da powerpc updates for 5.4
- Initial support for running on a system with an Ultravisor, which is software
    that runs below the hypervisor and protects guests against some attacks by
    the hypervisor.
 
  - Support for building the kernel to run as a "Secure Virtual Machine", ie. as
    a guest capable of running on a system with an Ultravisor.
 
  - Some changes to our DMA code on bare metal, to allow devices with medium
    sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space.
 
  - Support for firmware assisted crash dumps on bare metal (powernv).
 
  - Two series fixing bugs in and refactoring our PCI EEH code.
 
  - A large series refactoring our exception entry code to use gas macros, both
    to make it more readable and also enable some future optimisations.
 
 As well as many cleanups and other minor features & fixups.
 
 Thanks to:
   Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh
   Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin
   Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy,
   Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens,
   David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar,
   Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari
   Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras,
   Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
   Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor,
   Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram
   Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj,
   Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung
   Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde.
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Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "This is a bit late, partly due to me travelling, and partly due to a
  power outage knocking out some of my test systems *while* I was
  travelling.

   - Initial support for running on a system with an Ultravisor, which
     is software that runs below the hypervisor and protects guests
     against some attacks by the hypervisor.

   - Support for building the kernel to run as a "Secure Virtual
     Machine", ie. as a guest capable of running on a system with an
     Ultravisor.

   - Some changes to our DMA code on bare metal, to allow devices with
     medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
     DMA space.

   - Support for firmware assisted crash dumps on bare metal (powernv).

   - Two series fixing bugs in and refactoring our PCI EEH code.

   - A large series refactoring our exception entry code to use gas
     macros, both to make it more readable and also enable some future
     optimisations.

  As well as many cleanups and other minor features & fixups.

  Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
  Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
  JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
  Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
  Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
  Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
  Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
  Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
  Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
  Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
  Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
  Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
  Lendacky, Vasant Hegde"

* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
  powerpc/mm/mce: Keep irqs disabled during lockless page table walk
  powerpc: Use ftrace_graph_ret_addr() when unwinding
  powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  ftrace: Look up the address of return_to_handler() using helpers
  powerpc: dump kernel log before carrying out fadump or kdump
  docs: powerpc: Add missing documentation reference
  powerpc/xmon: Fix output of XIVE IPI
  powerpc/xmon: Improve output of XIVE interrupts
  powerpc/mm/radix: remove useless kernel messages
  powerpc/fadump: support holes in kernel boot memory area
  powerpc/fadump: remove RMA_START and RMA_END macros
  powerpc/fadump: update documentation about option to release opalcore
  powerpc/fadump: consider f/w load area
  powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
  powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
  powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
  powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
  powerpc/fadump: improve how crashed kernel's memory is reserved
  powerpc/fadump: consider reserved ranges while releasing memory
  powerpc/fadump: make crash memory ranges array allocation generic
  ...
2019-09-20 11:48:06 -07:00
Linus Torvalds
3fb7f3a6ed Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner:
 "Two small PTI updates:

   - Handle unaligned addresses gracefully in pti_clone_pagetable(). Not
     an issue with current callers, but a correctness problem. Adds a
     warning so any caller which hands in an unaligned address gets
     pointed out clearly.

   - Prevent PTI functions from being invoked when PTI is disabled at
     boottime. While this does not cause any harm today, it's pointless
     code executed and prone to cause subtle issues if the PTI
     implementation changes internally over time"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/pti: Do not invoke PTI functions when PTI is disabled
  x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable()
2019-09-17 11:02:21 -07:00
Linus Torvalds
ac51667b5b Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:

 - Make cpumask_of_node() more robust against invalid node IDs

 - Simplify and speed up load_mm_cr4()

 - Unexport and remove various unused set_memory_*() APIs

 - Misc cleanups

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix cpumask_of_node() error condition
  x86/mm: Remove the unused set_memory_wt() function
  x86/mm: Remove set_pages_x() and set_pages_nx()
  x86/mm: Remove the unused set_memory_array_*() functions
  x86/mm: Unexport set_memory_x() and set_memory_nx()
  x86/fixmap: Cleanup outdated comments
  x86/kconfig: Remove X86_DIRECT_GBPAGES dependency on !DEBUG_PAGEALLOC
  x86/mm: Avoid redundant interrupt disable in load_mm_cr4()
2019-09-16 19:21:34 -07:00
Linus Torvalds
cc9b499a1f Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:

 - refactor the EFI config table handling across architectures

 - add support for the Dell EMC OEM config table

 - include AER diagnostic output to CPER handling of fatal PCIe errors

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: cper: print AER info of PCIe fatal error
  efi: Export Runtime Configuration Interface table to sysfs
  efi: ia64: move SAL systab handling out of generic EFI code
  efi/x86: move UV_SYSTAB handling into arch/x86
  efi: x86: move efi_is_table_address() into arch/x86
2019-09-16 16:47:38 -07:00
Peter Zijlstra
bc04a049f0 x86/mm: Fix cpumask_of_node() error condition
When CONFIG_DEBUG_PER_CPU_MAPS=y we validate that the @node argument of
cpumask_of_node() is a valid node_id. It however forgets to check for
negative numbers. Fix this by explicitly casting to unsigned int.

  (unsigned)node >= nr_node_ids

verifies: 0 <= node < nr_node_ids

Also ammend the error message to match the condition.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Link: https://lkml.kernel.org/r/20190903075352.GY2369@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-05 13:03:04 +02:00
Christoph Hellwig
aeb415fbe9 x86/mm: Remove the unused set_memory_wt() function
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190826075558.8125-5-hch@lst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03 09:26:37 +02:00
Christoph Hellwig
185be15143 x86/mm: Remove set_pages_x() and set_pages_nx()
These wrappers don't provide a real benefit over just using
set_memory_x() and set_memory_nx().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190826075558.8125-4-hch@lst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03 09:26:37 +02:00
Christoph Hellwig
a919198b97 x86/mm: Remove the unused set_memory_array_*() functions
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190826075558.8125-3-hch@lst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03 09:26:37 +02:00
Christoph Hellwig
ec46133d3b x86/mm: Unexport set_memory_x() and set_memory_nx()
No module currently messed with clearing or setting the execute
permission of kernel memory, and none really should.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190826075558.8125-2-hch@lst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03 09:26:37 +02:00
Ingo Molnar
ae1ad26388 Linux 5.3-rc7
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Merge tag 'v5.3-rc7' into x86/mm, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03 09:23:41 +02:00
Thomas Gleixner
990784b577 x86/mm/pti: Do not invoke PTI functions when PTI is disabled
When PTI is disabled at boot time either because the CPU is not affected or
PTI has been disabled on the command line, the boot code still calls into
pti_finalize() which then unconditionally invokes:

     pti_clone_entry_text()
     pti_clone_kernel_text()

pti_clone_kernel_text() was called unconditionally before the 32bit support
was added and 32bit added the call to pti_clone_entry_text().

The call has no side effects as cloning the page tables into the available
second one, which was allocated for PTI does not create damage. But it does
not make sense either and in case that this functionality would be extended
later this might actually lead to hard to diagnose issues.

Neither function should be called when PTI is runtime disabled. Make the
invocation conditional.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190828143124.063353972@linutronix.de
2019-08-29 20:52:53 +02:00
Song Liu
825d0b73cd x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable()
pti_clone_pmds() assumes that the supplied address is either:

 - properly PUD/PMD aligned
or
 - the address is actually mapped which means that independently
   of the mapping level (PUD/PMD/PTE) the next higher mapping
   exists.

If that's not the case the unaligned address can be incremented by PUD or
PMD size incorrectly. All callers supply mapped and/or aligned addresses,
but for the sake of robustness it's better to handle that case properly and
to emit a warning.

[ tglx: Rewrote changelog and added WARN_ON_ONCE() ]

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282352470.1938@nanos.tec.linutronix.de
2019-08-29 20:52:52 +02:00
Thomas Gleixner
7af0145067 x86/mm/cpa: Prevent large page split when ftrace flips RW on kernel text
ftrace does not use text_poke() for enabling trace functionality. It uses
its own mechanism and flips the whole kernel text to RW and back to RO.

The CPA rework removed a loop based check of 4k pages which tried to
preserve a large page by checking each 4k page whether the change would
actually cover all pages in the large page.

This resulted in endless loops for nothing as in testing it turned out that
it actually never preserved anything. Of course testing missed to include
ftrace, which is the one and only case which benefitted from the 4k loop.

As a consequence enabling function tracing or ftrace based kprobes results
in a full 4k split of the kernel text, which affects iTLB performance.

The kernel RO protection is the only valid case where this can actually
preserve large pages.

All other static protections (RO data, data NX, PCI, BIOS) are truly
static.  So a conflict with those protections which results in a split
should only ever happen when a change of memory next to a protected region
is attempted. But these conflicts are rightfully splitting the large page
to preserve the protected regions. In fact a change to the protected
regions itself is a bug and is warned about.

Add an exception for the static protection check for kernel text RO when
the to be changed region spawns a full large page which allows to preserve
the large mappings. This also prevents the syslog to be spammed about CPA
violations when ftrace is used.

The exception needs to be removed once ftrace switched over to text_poke()
which avoids the whole issue.

Fixes: 585948f4f6 ("x86/mm/cpa: Avoid the 4k pages check completely")
Reported-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282355340.1938@nanos.tec.linutronix.de
2019-08-29 20:48:44 +02:00
David Howells
906357f77a x86/mmiotrace: Lock down the testmmiotrace module
The testmmiotrace module shouldn't be permitted when the kernel is locked
down as it can be used to arbitrarily read and write MMIO space. This is
a runtime check rather than buildtime in order to allow configurations
where the same kernel may be run in both locked down or permissive modes
depending on local policy.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Howells <dhowells@redhat.com
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: Thomas Gleixner <tglx@linutronix.de>
cc: Steven Rostedt <rostedt@goodmis.org>
cc: Ingo Molnar <mingo@kernel.org>
cc: "H. Peter Anvin" <hpa@zytor.com>
cc: x86@kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
2019-08-19 21:54:16 -07:00
Thiago Jung Bauermann
ae7eb82a92 fs/core/vmcore: Move sev_active() reference to x86 arch code
Secure Encrypted Virtualization is an x86-specific feature, so it shouldn't
appear in generic kernel code because it forces non-x86 architectures to
define the sev_active() function, which doesn't make a lot of sense.

To solve this problem, add an x86 elfcorehdr_read() function to override
the generic weak implementation. To do that, it's necessary to make
read_from_oldmem() public so that it can be used outside of vmcore.c.

Also, remove the export for sev_active() since it's only used in files that
won't be built as modules.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806044919.10622-6-bauerman@linux.ibm.com
2019-08-09 22:52:10 +10:00
Thiago Jung Bauermann
284e21fab2 x86, s390/mm: Move sme_active() and sme_me_mask to x86-specific header
Now that generic code doesn't reference them, move sme_active() and
sme_me_mask to x86's <asm/mem_encrypt.h>.

Also remove the export for sme_active() since it's only used in files that
won't be built as modules. sme_me_mask on the other hand is used in
arch/x86/kvm/svm.c (via __sme_set() and __psp_pa()) which can be built as a
module so its export needs to stay.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806044919.10622-5-bauerman@linux.ibm.com
2019-08-09 22:52:08 +10:00
Ard Biesheuvel
e55f31a599 efi: x86: move efi_is_table_address() into arch/x86
The function efi_is_table_address() and the associated array of table
pointers is specific to x86. Since we will be adding some more x86
specific tables, let's move this code out of the generic code first.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2019-08-08 11:01:48 +03:00
Jan Kiszka
21e450d21c x86/mm: Avoid redundant interrupt disable in load_mm_cr4()
load_mm_cr4() is always called with interrupts disabled from:

 - switch_mm_irqs_off()
 - refresh_pce(), which is a on_each_cpu() callback

Thus, disabling interrupts in cr4_set/clear_bits() is redundant.

Implement cr4_set/clear_bits_irqsoff() helpers, rename load_mm_cr4() to
load_mm_cr4_irqsoff() and use the new helpers. The new helpers do not need
a lockdep assert as __cr4_set() has one already.

The renaming in combination with the checks in __cr4_set() ensure that any
changes in the boundary conditions at the call sites will be detected.

[ tglx: Massaged change log ]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/0fbbcb64-5f26-4ffb-1bb9-4f5f48426893@siemens.com
2019-07-24 14:43:37 +02:00
Joerg Roedel
8e998fc24d x86/mm: Sync also unmappings in vmalloc_sync_all()
With huge-page ioremap areas the unmappings also need to be synced between
all page-tables. Otherwise it can cause data corruption when a region is
unmapped and later re-used.

Make the vmalloc_sync_one() function ready to sync unmappings and make sure
vmalloc_sync_all() iterates over all page-tables even when an unmapped PMD
is found.

Fixes: 5d72b4fba4 ('x86, mm: support huge I/O mapping capability I/F')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20190719184652.11391-3-joro@8bytes.org
2019-07-22 10:18:30 +02:00
Joerg Roedel
51b75b5b56 x86/mm: Check for pfn instead of page in vmalloc_sync_one()
Do not require a struct page for the mapped memory location because it
might not exist. This can happen when an ioremapped region is mapped with
2MB pages.

Fixes: 5d72b4fba4 ('x86, mm: support huge I/O mapping capability I/F')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20190719184652.11391-2-joro@8bytes.org
2019-07-22 10:18:30 +02:00
Linus Torvalds
ac60602a6d dma-mapping fixes for 5.3-rc1
Fix various regressions:
 
  - force unencrypted dma-coherent buffers if encryption bit can't fit
    into the dma coherent mask (Tom Lendacky)
  - avoid limiting request size if swiotlb is not used (me)
  - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device
    (Fugang Duan)
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Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions:

   - force unencrypted dma-coherent buffers if encryption bit can't fit
     into the dma coherent mask (Tom Lendacky)

   - avoid limiting request size if swiotlb is not used (me)

   - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang
     Duan)"

* tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device
  dma-direct: only limit the mapping size if swiotlb could be used
  dma-mapping: add a dma_addressing_limited helper
  dma-direct: Force unencrypted DMA under SME for certain DMA masks
2019-07-20 12:09:52 -07:00
Linus Torvalds
c6dd78fcb8 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A set of x86 specific fixes and updates:

   - The CR2 corruption fixes which store CR2 early in the entry code
     and hand the stored address to the fault handlers.

   - Revert a forgotten leftover of the dropped FSGSBASE series.

   - Plug a memory leak in the boot code.

   - Make the Hyper-V assist functionality robust by zeroing the shadow
     page.

   - Remove a useless check for dead processes with LDT

   - Update paravirt and VMware maintainers entries.

   - A few cleanup patches addressing various compiler warnings"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Prevent clobbering of saved CR2 value
  x86/hyper-v: Zero out the VP ASSIST PAGE on allocation
  x86, boot: Remove multiple copy of static function sanitize_boot_params()
  x86/boot/compressed/64: Remove unused variable
  x86/boot/efi: Remove unused variables
  x86/mm, tracing: Fix CR2 corruption
  x86/entry/64: Update comments and sanity tests for create_gap
  x86/entry/64: Simplify idtentry a little
  x86/entry/32: Simplify common_exception
  x86/paravirt: Make read_cr2() CALLEE_SAVE
  MAINTAINERS: Update PARAVIRT_OPS_INTERFACE and VMWARE_HYPERVISOR_INTERFACE
  x86/process: Delete useless check for dead process with LDT
  x86: math-emu: Hide clang warnings for 16-bit overflow
  x86/e820: Use proper booleans instead of 0/1
  x86/apic: Silence -Wtype-limits compiler warnings
  x86/mm: Free sme_early_buffer after init
  x86/boot: Fix memory leak in default_get_smp_config()
  Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test
2019-07-20 11:24:49 -07:00
Dan Williams
e9c0a3f054 mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()
Allow sub-section sized ranges to be added to the memmap.

populate_section_memmap() takes an explict pfn range rather than
assuming a full section, and those parameters are plumbed all the way
through to vmmemap_populate().  There should be no sub-section usage in
current deployments.  New warnings are added to clarify which memmap
allocation paths are sub-section capable.

Link: http://lkml.kernel.org/r/156092352058.979959.6551283472062305149.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
David Hildenbrand
80ec922dbd mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE
We want to improve error handling while adding memory by allowing to use
arch_remove_memory() and __remove_pages() even if
CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:

	arch_add_memory()
	rc = do_something();
	if (rc) {
		arch_remove_memory();
	}

We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
quite some dependencies for memory offlining.

Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:06 -07:00
Peter Zijlstra
a0d14b8909 x86/mm, tracing: Fix CR2 corruption
Despite the current efforts to read CR2 before tracing happens there still
exist a number of possible holes:

  idtentry page_fault             do_page_fault           has_error_code=1
    call error_entry
      TRACE_IRQS_OFF
        call trace_hardirqs_off*
          #PF // modifies CR2

      CALL_enter_from_user_mode
        __context_tracking_exit()
          trace_user_exit(0)
            #PF // modifies CR2

    call do_page_fault
      address = read_cr2(); /* whoopsie */

And similar for i386.

Fix it by pulling the CR2 read into the entry code, before any of that
stuff gets a chance to run and ruin things.

Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: jgross@suse.com
Cc: joel@joelfernandes.org
Link: https://lkml.kernel.org/r/20190711114336.116812491@infradead.org

Debugged-by: Steven Rostedt <rostedt@goodmis.org>
2019-07-17 23:17:38 +02:00
Anshuman Khandual
b98cca444d mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault()
Architectures which support kprobes have very similar boilerplate around
calling kprobe_fault_handler().  Use a helper function in kprobes.h to
unify them, based on the x86 code.

This changes the behaviour for other architectures when preemption is
enabled.  Previously, they would have disabled preemption while calling
the kprobe handler.  However, preemption would be disabled if this fault
was due to a kprobe, so we know the fault was not due to a kprobe
handler and can simply return failure.

This behaviour was introduced in commit a980c0ef9f ("x86/kprobes:
Refactor kprobes_fault() like kprobe_exceptions_notify()")

[anshuman.khandual@arm.com: export kprobe_fault_handler()]
  Link: http://lkml.kernel.org/r/1561133358-8876-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1560420444-25737-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:22 -07:00
Anshuman Khandual
0f472d04f5 mm/ioremap: probe platform for p4d huge map support
Finish up what commit c2febafc67 ("mm: convert generic code to 5-level
paging") started while levelling up P4D huge mapping support at par with
PUD and PMD.  A new arch call back arch_ioremap_p4d_supported() is added
which just maintains status quo (P4D huge map not supported) on x86,
arm64 and powerpc.

When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the
arch about the support, hence runtime effects are minimal.

Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:22 -07:00
David Rientjes
ffdb07f312 x86/mm: Free sme_early_buffer after init
The contents of sme_early_buffer should be cleared after
__sme_early_enc_dec() because it is used to move encrypted and decrypted
data, but since __sme_early_enc_dec() is __init this buffer simply can be
freed after init.

This saves a page that is otherwise unreferenced after init.

Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907101318170.197432@chino.kir.corp.google.com
2019-07-16 23:13:48 +02:00
Tom Lendacky
9087c37584 dma-direct: Force unencrypted DMA under SME for certain DMA masks
If a device doesn't support DMA to a physical address that includes the
encryption bit (currently bit 47, so 48-bit DMA), then the DMA must
occur to unencrypted memory. SWIOTLB is used to satisfy that requirement
if an IOMMU is not active (enabled or configured in passthrough mode).

However, commit fafadcd165 ("swiotlb: don't dip into swiotlb pool for
coherent allocations") modified the coherent allocation support in
SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU
is not active, this resulted in dma_alloc_coherent() failing for devices
that didn't support DMA addresses that included the encryption bit.

Addressing this requires changes to the force_dma_unencrypted() function
in kernel/dma/direct.c. Since the function is now non-trivial and
SME/SEV specific, update the DMA direct support to add an arch override
for the force_dma_unencrypted() function. The arch override is selected
when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in
the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either
SEV is active or SME is active and the device does not support DMA to
physical addresses that include the encryption bit.

Fixes: fafadcd165 ("swiotlb: don't dip into swiotlb pool for coherent allocations")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
[hch: moved the force_dma_unencrypted declaration to dma-mapping.h,
      fold the s390 fix from Halil Pasic]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-07-16 22:15:46 +02:00
Linus Torvalds
fec88ab0af HMM patches for 5.3
Improvements and bug fixes for the hmm interface in the kernel:
 
 - Improve clarity, locking and APIs related to the 'hmm mirror' feature
   merged last cycle. In linux-next we now see AMDGPU and nouveau to be
   using this API.
 
 - Remove old or transitional hmm APIs. These are hold overs from the past
   with no users, or APIs that existed only to manage cross tree conflicts.
   There are still a few more of these cleanups that didn't make the merge
   window cut off.
 
 - Improve some core mm APIs:
   * export alloc_pages_vma() for driver use
   * refactor into devm_request_free_mem_region() to manage
     DEVICE_PRIVATE resource reservations
   * refactor duplicative driver code into the core dev_pagemap
     struct
 
 - Remove hmm wrappers of improved core mm APIs, instead have drivers use
   the simplified API directly
 
 - Remove DEVICE_PUBLIC
 
 - Simplify the kconfig flow for the hmm users and core code
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull HMM updates from Jason Gunthorpe:
 "Improvements and bug fixes for the hmm interface in the kernel:

   - Improve clarity, locking and APIs related to the 'hmm mirror'
     feature merged last cycle. In linux-next we now see AMDGPU and
     nouveau to be using this API.

   - Remove old or transitional hmm APIs. These are hold overs from the
     past with no users, or APIs that existed only to manage cross tree
     conflicts. There are still a few more of these cleanups that didn't
     make the merge window cut off.

   - Improve some core mm APIs:
       - export alloc_pages_vma() for driver use
       - refactor into devm_request_free_mem_region() to manage
         DEVICE_PRIVATE resource reservations
       - refactor duplicative driver code into the core dev_pagemap
         struct

   - Remove hmm wrappers of improved core mm APIs, instead have drivers
     use the simplified API directly

   - Remove DEVICE_PUBLIC

   - Simplify the kconfig flow for the hmm users and core code"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
  mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
  mm: remove the HMM config option
  mm: sort out the DEVICE_PRIVATE Kconfig mess
  mm: simplify ZONE_DEVICE page private data
  mm: remove hmm_devmem_add
  mm: remove hmm_vma_alloc_locked_page
  nouveau: use devm_memremap_pages directly
  nouveau: use alloc_page_vma directly
  PCI/P2PDMA: use the dev_pagemap internal refcount
  device-dax: use the dev_pagemap internal refcount
  memremap: provide an optional internal refcount in struct dev_pagemap
  memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
  memremap: remove the data field in struct dev_pagemap
  memremap: add a migrate_to_ram method to struct dev_pagemap_ops
  memremap: lift the devmap_enable manipulation into devm_memremap_pages
  memremap: pass a struct dev_pagemap to ->kill and ->cleanup
  memremap: move dev_pagemap callbacks into a separate structure
  memremap: validate the pagemap type passed to devm_memremap_pages
  mm: factor out a devm_request_free_mem_region helper
  mm: export alloc_pages_vma
  ...
2019-07-14 19:42:11 -07:00
Linus Torvalds
f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00
Mike Rapoport
5fba4af445 asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
Most architectures have identical or very similar implementation of
pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and
pte_free().

Add a generic implementation that can be reused across architectures and
enable its use on x86.

The generic implementation uses

	GFP_KERNEL | __GFP_ZERO

for the kernel page tables and

	GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT

for the user page tables.

The "base" functions for PTE allocation, namely __pte_alloc_one_kernel()
and __pte_alloc_one() are intended for the architectures that require
additional actions after actual memory allocation or must use non-default
GFP flags.

x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and
pte_free().

x86 still implements pte_alloc_one() to allow run-time control of GFP
flags required for "userpte" command line option.

Link: http://lkml.kernel.org/r/1557296232-15361-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:45 -07:00
Linus Torvalds
e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Linus Torvalds
565eb5f8c5 Merge branch 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x865 kdump updates from Thomas Gleixner:
 "Yet more kexec/kdump updates:

   - Properly support kexec when AMD's memory encryption (SME) is
     enabled

   - Pass reserved e820 ranges to the kexec kernel so both PCI and SME
     can work"

* 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  fs/proc/vmcore: Enable dumping of encrypted memory when SEV was active
  x86/kexec: Set the C-bit in the identity map page table when SEV is active
  x86/kexec: Do not map kexec area as decrypted when SEV is active
  x86/crash: Add e820 reserved ranges to kdump kernel's e820 table
  x86/mm: Rework ioremap resource mapping determination
  x86/e820, ioport: Add a new I/O resource descriptor IORES_DESC_RESERVED
  x86/mm: Create a workarea in the kernel for SME early encryption
  x86/mm: Identify the end of the kernel area to be reserved
2019-07-09 11:52:34 -07:00
Linus Torvalds
5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...
2019-07-08 21:48:15 -07:00
Linus Torvalds
0d37dde706 Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 vsyscall updates from Thomas Gleixner:
 "Further hardening of the legacy vsyscall by providing support for
  execute only mode and switching the default to it.

  This prevents a certain class of attacks which rely on the vsyscall
  page being accessible at a fixed address in the canonical kernel
  address space"

* 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/x86: Add a test for process_vm_readv() on the vsyscall page
  x86/vsyscall: Add __ro_after_init to global variables
  x86/vsyscall: Change the default vsyscall mode to xonly
  selftests/x86/vsyscall: Verify that vsyscall=none blocks execution
  x86/vsyscall: Document odd SIGSEGV error code for vsyscalls
  x86/vsyscall: Show something useful on a read fault
  x86/vsyscall: Add a new vsyscall=xonly mode
  Documentation/admin: Remove the vsyscall=native documentation
2019-07-08 11:42:09 -07:00
Christoph Hellwig
514caf23a7 memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
Add a flags field to struct dev_pagemap to replace the altmap_valid
boolean to be a little more extensible.  Also add a pgmap_altmap() helper
to find the optional altmap and clean up the code using the altmap using
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-02 14:32:44 -03:00
Linus Torvalds
728254541e Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes all over the place:

   - might_sleep() atomicity fix in the microcode loader

   - resctrl boundary condition fix

   - APIC arithmethics bug fix for frequencies >= 4.2 GHz

   - three 5-level paging crash fixes

   - two speculation fixes

   - a perf/stacktrace fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/unwind/orc: Fall back to using frame pointers for generated code
  perf/x86: Always store regs->ip in perf_callchain_kernel()
  x86/speculation: Allow guests to use SSBD even if host does not
  x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init()
  x86/boot/64: Add missing fixup_pointer() for next_early_pgt access
  x86/boot/64: Fix crash if kernel image crosses page table boundary
  x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz
  x86/resctrl: Prevent possible overrun during bitmap operations
  x86/microcode: Fix the microcode load on CPU hotplug for real
2019-06-29 19:42:30 +08:00
Andy Lutomirski
e0a446ce39 x86/vsyscall: Document odd SIGSEGV error code for vsyscalls
Even if vsyscall=none, user page faults on the vsyscall page are reported
as though the PROT bit in the error code was set.  Add a comment explaining
why this is probably okay and display the value in the test case.

While at it, explain why the behavior is correct with respect to PKRU.

Modify also the selftest to print the odd error code so that there is a
way to demonstrate the odd behaviour.

If anyone really cares about more accurate emulation, the behaviour could
be changed. But that needs a real good justification.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/75c91855fd850649ace162eec5495a1354221aaa.1561610354.git.luto@kernel.org
2019-06-28 00:04:39 +02:00
Andy Lutomirski
918ce32509 x86/vsyscall: Show something useful on a read fault
Just segfaulting the application when it tries to read the vsyscall page in
xonly mode is not helpful for those who need to debug it.

Emit a hint.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Link: https://lkml.kernel.org/r/8016afffe0eab497be32017ad7f6f7030dc3ba66.1561610354.git.luto@kernel.org
2019-06-28 00:04:39 +02:00
Kirill A. Shutemov
432c833218 x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init()
Kyle has reported occasional crashes when booting a kernel in 5-level
paging mode with KASLR enabled:

  WARNING: CPU: 0 PID: 0 at arch/x86/mm/init_64.c:87 phys_p4d_init+0x1d4/0x1ea
  RIP: 0010:phys_p4d_init+0x1d4/0x1ea
  Call Trace:
   __kernel_physical_mapping_init+0x10a/0x35c
   kernel_physical_mapping_init+0xe/0x10
   init_memory_mapping+0x1aa/0x3b0
   init_range_memory_mapping+0xc8/0x116
   init_mem_mapping+0x225/0x2eb
   setup_arch+0x6ff/0xcf5
   start_kernel+0x64/0x53b
   ? copy_bootdata+0x1f/0xce
   x86_64_start_reservations+0x24/0x26
   x86_64_start_kernel+0x8a/0x8d
   secondary_startup_64+0xb6/0xc0

which causes later:

  BUG: unable to handle page fault for address: ff484d019580eff8
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  BAD
  Oops: 0000 [#1] SMP NOPTI
  RIP: 0010:fill_pud+0x13/0x130
  Call Trace:
   set_pte_vaddr_p4d+0x2e/0x50
   set_pte_vaddr+0x6f/0xb0
   __native_set_fixmap+0x28/0x40
   native_set_fixmap+0x39/0x70
   register_lapic_address+0x49/0xb6
   early_acpi_boot_init+0xa5/0xde
   setup_arch+0x944/0xcf5
   start_kernel+0x64/0x53b

Kyle bisected the issue to commit b569c18434 ("x86/mm/KASLR: Reduce
randomization granularity for 5-level paging to 1GB")

Before this commit PAGE_OFFSET was always aligned to P4D_SIZE when booting
5-level paging mode. But now only PUD_SIZE alignment is guaranteed.

In the case I was able to reproduce the following vaddr/paddr values were
observed in phys_p4d_init():

Iteration     vaddr			paddr
   1 	      0xff4228027fe00000 	0x033fe00000
   2	      0xff42287f40000000	0x8000000000

'vaddr' in both cases belongs to the same p4d entry.

But due to the original assumption that PAGE_OFFSET is aligned to P4D_SIZE
this overlap cannot be handled correctly. The code assumes strictly aligned
entries and unconditionally increments the index into the P4D table, which
creates false duplicate entries. Once the index reaches the end, the last
entry in the page table is missing.

Aside of that the 'paddr >= paddr_end' condition can evaluate wrong which
causes an P4D entry to be cleared incorrectly.

Change the loop in phys_p4d_init() to walk purely based on virtual
addresses like __kernel_physical_mapping_init() does. This makes it work
correctly with unaligned virtual addresses.

Fixes: b569c18434 ("x86/mm/KASLR: Reduce randomization granularity for 5-level paging to 1GB")
Reported-by: Kyle Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kyle Pelton <kyle.d.pelton@intel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190624123150.920-1-kirill.shutemov@linux.intel.com
2019-06-26 07:25:09 +02:00
Lianbo Jiang
5da04cc86d x86/mm: Rework ioremap resource mapping determination
On ioremap(), __ioremap_check_mem() does a couple of checks on the
supplied memory range to determine how the range should be mapped and in
particular what protection flags should be used.

Generalize the procedure by introducing IORES_MAP_* flags which control
different aspects of the ioremapping and use them in the respective
helpers which determine which descriptor flags should be set per range.

 [ bp:
   - Rewrite commit message.
   - Add/improve comments.
   - Reflow __ioremap_caller()'s args.
   - s/__ioremap_check_desc/__ioremap_check_encrypted/g;
   - s/__ioremap_res_check/__ioremap_collect_map_flags/g;
   - clarify __ioremap_check_ram()'s purpose. ]

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Co-developed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: bhe@redhat.com
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: dyoung@redhat.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kexec@lists.infradead.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190423013007.17838-3-lijiang@redhat.com
2019-06-20 09:58:07 +02:00
Thomas Lendacky
e1bfa87399 x86/mm: Create a workarea in the kernel for SME early encryption
In order for the kernel to be encrypted "in place" during boot, a workarea
outside of the kernel must be used. This SME workarea used during early
encryption of the kernel is situated on a 2MB boundary after the end of
the kernel text, data, etc. sections (_end).

This works well during initial boot of a compressed kernel because of
the relocation used for decompression of the kernel. But when performing
a kexec boot, there's a chance that the SME workarea may not be mapped
by the kexec pagetables or that some of the other data used by kexec
could exist in this range.

Create a section for SME in vmlinux.lds.S. Position it after "_end", which
is after "__end_of_kernel_reserve", so that the memory will be reclaimed
during boot and since this area is all zeroes, it compresses well. This
new section will be part of the kernel image, so kexec will account for it
in pagetable mappings and placement of data after the kernel.

Here's an example of a kernel size without and with the SME section:

	without:
		vmlinux:	36,501,616
		bzImage:	 6,497,344

		100000000-47f37ffff : System RAM
		  1e4000000-1e47677d4 : Kernel code	(0x7677d4)
		  1e47677d5-1e4e2e0bf : Kernel data	(0x6c68ea)
		  1e5074000-1e5372fff : Kernel bss	(0x2fefff)

	with:
		vmlinux:	44,419,408
		bzImage:	 6,503,136

		880000000-c7ff7ffff : System RAM
		  8cf000000-8cf7677d4 : Kernel code	(0x7677d4)
		  8cf7677d5-8cfe2e0bf : Kernel data	(0x6c68ea)
		  8d0074000-8d0372fff : Kernel bss	(0x2fefff)

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Tested-by: Lianbo Jiang <lijiang@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael Ávila de Espíndola" <rafael@espindo.la>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/3c483262eb4077b1654b2052bd14a8d011bffde3.1560969363.git.thomas.lendacky@amd.com
2019-06-20 09:44:26 +02:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Linus Torvalds
963172d9c7 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "The accumulated fixes from this and last week:

   - Fix vmalloc TLB flush and map range calculations which lead to
     stale TLBs, spurious faults and other hard to diagnose issues.

   - Use fault_in_pages_writable() for prefaulting the user stack in the
     FPU code as it's less fragile than the current solution

   - Use the PF_KTHREAD flag when checking for a kernel thread instead
     of current->mm as the latter can give the wrong answer due to
     use_mm()

   - Compute the vmemmap size correctly for KASLR and 5-Level paging.
     Otherwise this can end up with a way too small vmemmap area.

   - Make KASAN and 5-level paging work again by making sure that all
     invalid bits are masked out when computing the P4D offset. This
     worked before but got broken recently when the LDT remap area was
     moved.

   - Prevent a NULL pointer dereference in the resource control code
     which can be triggered with certain mount options when the
     requested resource is not available.

   - Enforce ordering of microcode loading vs. perf initialization on
     secondary CPUs. Otherwise perf tries to access a non-existing MSR
     as the boot CPU marked it as available.

   - Don't stop the resource control group walk early otherwise the
     control bitmaps are not updated correctly and become inconsistent.

   - Unbreak kgdb by returning 0 on success from
     kgdb_arch_set_breakpoint() instead of an error code.

   - Add more Icelake CPU model defines so depending changes can be
     queued in other trees"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
  x86/kasan: Fix boot with 5-level paging and KASAN
  x86/fpu: Don't use current->mm to check for a kthread
  x86/kgdb: Return 0 from kgdb_arch_set_breakpoint()
  x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
  x86/resctrl: Don't stop walking closids when a locksetup group is found
  x86/fpu: Update kernel's FPU state before using for the fsave header
  x86/mm/KASLR: Compute the size of the vmemmap section properly
  x86/fpu: Use fault_in_pages_writeable() for pre-faulting
  x86/CPU: Add more Icelake model numbers
  mm/vmalloc: Avoid rare case of flushing TLB with weird arguments
  mm/vmalloc: Fix calculation of direct map addr range
2019-06-16 07:28:14 -10:00