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126 commits

Author SHA1 Message Date
Linus Torvalds
6112bd00e8 powerpc updates for 5.19
- Convert to the generic mmap support (ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT).
 
  - Add support for outline-only KASAN with 64-bit Radix MMU (P9 or later).
 
  - Increase SIGSTKSZ and MINSIGSTKSZ and add support for AT_MINSIGSTKSZ.
 
  - Enable the DAWR (Data Address Watchpoint) on POWER9 DD2.3 or later.
 
  - Drop support for system call instruction emulation.
 
  - Many other small features and fixes.
 
 Thanks to: Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Bagas Sanjaya, Bjorn
 Helgaas, Bo Liu, Chen Huang, Christophe Leroy, Colin Ian King, Daniel Axtens, Dwaipayan
 Ray, Fabiano Rosas, Finn Thain, Frank Rowand, Fuqian Huang, Guilherme G. Piccoli, Hangyu
 Hua, Haowen Bai, Haren Myneni, Hari Bathini, He Ying, Jason Wang, Jiapeng Chong, Jing
 Yangyang, Joel Stanley, Julia Lawall, Kajol Jain, Kevin Hao, Krzysztof Kozlowski, Laurent
 Dufour, Lv Ruyi, Madhavan Srinivasan, Magali Lemes, Miaoqian Lin, Minghao Chi, Nathan
 Chancellor, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Oscar Salvador, Pali Rohár,
 Paul Mackerras, Peng Wu, Qing Wang, Randy Dunlap, Reza Arbab, Russell Currey, Sohaib
 Mohamed, Vaibhav Jain, Vasant Hegde, Wang Qing, Wang Wensheng, Xiang wangx, Xiaomeng Tong,
 Xu Wang, Yang Guang, Yang Li, Ye Bin, YueHaibing, Yu Kuai, Zheng Bin, Zou Wei, Zucheng
 Zheng.
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Merge tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Convert to the generic mmap support (ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)

 - Add support for outline-only KASAN with 64-bit Radix MMU (P9 or later)

 - Increase SIGSTKSZ and MINSIGSTKSZ and add support for AT_MINSIGSTKSZ

 - Enable the DAWR (Data Address Watchpoint) on POWER9 DD2.3 or later

 - Drop support for system call instruction emulation

 - Many other small features and fixes

Thanks to Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Bagas
Sanjaya, Bjorn Helgaas, Bo Liu, Chen Huang, Christophe Leroy, Colin Ian
King, Daniel Axtens, Dwaipayan Ray, Fabiano Rosas, Finn Thain, Frank
Rowand, Fuqian Huang, Guilherme G. Piccoli, Hangyu Hua, Haowen Bai,
Haren Myneni, Hari Bathini, He Ying, Jason Wang, Jiapeng Chong, Jing
Yangyang, Joel Stanley, Julia Lawall, Kajol Jain, Kevin Hao, Krzysztof
Kozlowski, Laurent Dufour, Lv Ruyi, Madhavan Srinivasan, Magali Lemes,
Miaoqian Lin, Minghao Chi, Nathan Chancellor, Naveen N. Rao, Nicholas
Piggin, Oliver O'Halloran, Oscar Salvador, Pali Rohár, Paul Mackerras,
Peng Wu, Qing Wang, Randy Dunlap, Reza Arbab, Russell Currey, Sohaib
Mohamed, Vaibhav Jain, Vasant Hegde, Wang Qing, Wang Wensheng, Xiang
wangx, Xiaomeng Tong, Xu Wang, Yang Guang, Yang Li, Ye Bin, YueHaibing,
Yu Kuai, Zheng Bin, Zou Wei, and Zucheng Zheng.

* tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits)
  powerpc/64: Include cache.h directly in paca.h
  powerpc/64s: Only set HAVE_ARCH_UNMAPPED_AREA when CONFIG_PPC_64S_HASH_MMU is set
  powerpc/xics: Include missing header
  powerpc/powernv/pci: Drop VF MPS fixup
  powerpc/fsl_book3e: Don't set rodata RO too early
  powerpc/microwatt: Add mmu bits to device tree
  powerpc/powernv/flash: Check OPAL flash calls exist before using
  powerpc/powermac: constify device_node in of_irq_parse_oldworld()
  powerpc/powermac: add missing g5_phy_disable_cpu1() declaration
  selftests/powerpc/pmu: fix spelling mistake "mis-match" -> "mismatch"
  powerpc: Enable the DAWR on POWER9 DD2.3 and above
  powerpc/64s: Add CPU_FTRS_POWER10 to ALWAYS mask
  powerpc/64s: Add CPU_FTRS_POWER9_DD2_2 to CPU_FTRS_ALWAYS mask
  powerpc: Fix all occurences of "the the"
  selftests/powerpc/pmu/ebb: remove fixed_instruction.S
  powerpc/platforms/83xx: Use of_device_get_match_data()
  powerpc/eeh: Drop redundant spinlock initialization
  powerpc/iommu: Add missing of_node_put in iommu_init_early_dart
  powerpc/pseries/vas: Call misc_deregister if sysfs init fails
  powerpc/papr_scm: Fix leaking nvdimm_events_map elements
  ...
2022-05-28 11:27:17 -07:00
Linus Torvalds
0bf13a8436 kernel-hardening updates for v5.19-rc1
- usercopy hardening expanded to check other allocation types
   (Matthew Wilcox, Yuanzheng Song)
 
 - arm64 stackleak behavioral improvements (Mark Rutland)
 
 - arm64 CFI code gen improvement (Sami Tolvanen)
 
 - LoadPin LSM block dev API adjustment (Christoph Hellwig)
 
 - Clang randstruct support (Bill Wendling, Kees Cook)
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Merge tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:

 - usercopy hardening expanded to check other allocation types (Matthew
   Wilcox, Yuanzheng Song)

 - arm64 stackleak behavioral improvements (Mark Rutland)

 - arm64 CFI code gen improvement (Sami Tolvanen)

 - LoadPin LSM block dev API adjustment (Christoph Hellwig)

 - Clang randstruct support (Bill Wendling, Kees Cook)

* tag 'kernel-hardening-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (34 commits)
  loadpin: stop using bdevname
  mm: usercopy: move the virt_addr_valid() below the is_vmalloc_addr()
  gcc-plugins: randstruct: Remove cast exception handling
  af_unix: Silence randstruct GCC plugin warning
  niu: Silence randstruct warnings
  big_keys: Use struct for internal payload
  gcc-plugins: Change all version strings match kernel
  randomize_kstack: Improve docs on requirements/rationale
  lkdtm/stackleak: fix CONFIG_GCC_PLUGIN_STACKLEAK=n
  arm64: entry: use stackleak_erase_on_task_stack()
  stackleak: add on/off stack variants
  lkdtm/stackleak: check stack boundaries
  lkdtm/stackleak: prevent unexpected stack usage
  lkdtm/stackleak: rework boundary management
  lkdtm/stackleak: avoid spurious failure
  stackleak: rework poison scanning
  stackleak: rework stack high bound handling
  stackleak: clarify variable names
  stackleak: rework stack low bound handling
  stackleak: remove redundant check
  ...
2022-05-24 12:27:09 -07:00
Mark Brown
ec0067a63e arm64/sme: Remove _EL0 from name of SVCR - FIXME sysreg.h
The defines for SVCR call it SVCR_EL0 however the architecture calls the
register SVCR with no _EL0 suffix. In preparation for generating the sysreg
definitions rename to match the architecture, no functional change.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-16 19:50:20 +01:00
Mark Brown
e65fc01bf2 arm64/sme: Standardise bitfield names for SVCR
The bitfield definitions for SVCR have a SYS_ added to the names of the
constant which will be a problem for automatic generation. Remove the
prefixes, no functional change.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-5-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-16 19:50:20 +01:00
Mark Rutland
e85094c31d arm64: stackleak: fix current_top_of_stack()
Due to some historical confusion, arm64's current_top_of_stack() isn't
what the stackleak code expects. This could in theory result in a number
of problems, and practically results in an unnecessary performance hit.
We can avoid this by aligning the arm64 implementation with the x86
implementation.

The arm64 implementation of current_top_of_stack() was added
specifically for stackleak in commit:

  0b3e336601 ("arm64: Add support for STACKLEAK gcc plugin")

This was intended to be equivalent to the x86 implementation, but the
implementation, semantics, and performance characteristics differ
wildly:

* On x86, current_top_of_stack() returns the top of the current task's
  task stack, regardless of which stack is in active use.

  The implementation accesses a percpu variable which the x86 entry code
  maintains, and returns the location immediately above the pt_regs on
  the task stack (above which x86 has some padding).

* On arm64 current_top_of_stack() returns the top of the stack in active
  use (i.e. the one which is currently being used).

  The implementation checks the SP against a number of
  potentially-accessible stacks, and will BUG() if no stack is found.

The core stackleak_erase() code determines the upper bound of stack to
erase with:

| if (on_thread_stack())
|         boundary = current_stack_pointer;
| else
|         boundary = current_top_of_stack();

On arm64 stackleak_erase() is always called on a task stack, and
on_thread_stack() should always be true. On x86, stackleak_erase() is
mostly called on a trampoline stack, and is sometimes called on a task
stack.

Currently, this results in a lot of unnecessary code being generated for
arm64 for the impossible !on_thread_stack() case. Some of this is
inlined, bloating stackleak_erase(), while portions of this are left
out-of-line and permitted to be instrumented (which would be a
functional problem if that code were reachable).

As a first step towards improving this, this patch aligns arm64's
implementation of current_top_of_stack() with x86's, always returning
the top of the current task's stack. With GCC 11.1.0 this results in the
bulk of the unnecessary code being removed, including all of the
out-of-line instrumentable code.

While I don't believe there's a functional problem in practice I've
marked this as a fix since the semantic was clearly wrong, the fix
itself is simple, and other code might rely upon this in future.

Fixes: 0b3e336601 ("arm64: Add support for STACKLEAK gcc plugin")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-2-mark.rutland@arm.com
2022-05-08 01:33:07 -07:00
Christophe Leroy
2cb4de085f mm: Add len and flags parameters to arch_get_mmap_end()
Powerpc needs flags and len to make decision on arch_get_mmap_end().

So add them as parameters to arch_get_mmap_end().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b556daabe7d2bdb2361c4d6130280da7c1ba2c14.1649523076.git.christophe.leroy@csgroup.eu
2022-05-05 22:11:57 +10:00
Mark Brown
85ed24dad2 arm64/sme: Implement streaming SVE signal handling
When in streaming mode we have the same set of SVE registers as we do in
regular SVE mode with the exception of FFR and the use of the SME vector
length. Provide signal handling for these registers by taking one of the
reserved words in the SVE signal context as a flags field and defining a
flag which is set for streaming mode. When the flag is set the vector
length is set to the streaming mode vector length and we save and
restore streaming mode data. We support entering or leaving streaming
mode based on the value of the flag but do not support changing the
vector length, this is not currently supported SVE signal handling.

We could instead allocate a separate record in the signal frame for the
streaming mode SVE context but this inflates the size of the maximal signal
frame required and adds complication when validating signal frames from
userspace, especially given the current structure of the code.

Any implementation of support for streaming mode vectors in signals will
have some potential for causing issues for applications that attempt to
handle SVE vectors in signals, use streaming mode but do not understand
streaming mode in their signal handling code, it is hard to identify a
case that is clearly better than any other - they all have cases where
they could cause unexpected register corruption or faults.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-19-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:51:10 +01:00
Mark Brown
0033cd9339 arm64/sme: Implement ZA context switching
Allocate space for storing ZA on first access to SME and use that to save
and restore ZA state when context switching. We do this by using the vector
form of the LDR and STR ZA instructions, these do not require streaming
mode and have implementation recommendations that they avoid contention
issues in shared SMCU implementations.

Since ZA is architecturally guaranteed to be zeroed when enabled we do not
need to explicitly zero ZA, either we will be restoring from a saved copy
or trapping on first use of SME so we know that ZA must be disabled.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-16-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:51:02 +01:00
Mark Brown
af7167d6d2 arm64/sme: Implement streaming SVE context switching
When in streaming mode we need to save and restore the streaming mode
SVE register state rather than the regular SVE register state. This uses
the streaming mode vector length and omits FFR but is otherwise identical,
if TIF_SVE is enabled when we are in streaming mode then streaming mode
takes precedence.

This does not handle use of streaming SVE state with KVM, ptrace or
signals. This will be updated in further patches.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-15-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:51:00 +01:00
Mark Brown
b40c559b45 arm64/sme: Implement SVCR context switching
In SME the use of both streaming SVE mode and ZA are tracked through
PSTATE.SM and PSTATE.ZA, visible through the system register SVCR.  In
order to context switch the floating point state for SME we need to
context switch the contents of this register as part of context
switching the floating point state.

Since changing the vector length exits streaming SVE mode and disables
ZA we also make sure we update SVCR appropriately when setting vector
length, and similarly ensure that new threads have streaming SVE mode
and ZA disabled.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-14-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:50:58 +01:00
Mark Brown
a9d6915859 arm64/sme: Implement support for TPIDR2
The Scalable Matrix Extension introduces support for a new thread specific
data register TPIDR2 intended for use by libc. The kernel must save the
value of TPIDR2 on context switch and should ensure that all new threads
start off with a default value of 0. Add a field to the thread_struct to
store TPIDR2 and context switch it with the other thread specific data.

In case there are future extensions which also use TPIDR2 we introduce
system_supports_tpidr2() and use that rather than system_supports_sme()
for TPIDR2 handling.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-13-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:50:56 +01:00
Mark Brown
9e4ab6c891 arm64/sme: Implement vector length configuration prctl()s
As for SVE provide a prctl() interface which allows processes to
configure their SME vector length.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-12-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:50:54 +01:00
Mark Brown
b42990d3bf arm64/sme: Identify supported SME vector lengths at boot
The vector lengths used for SME are controlled through a similar set of
registers to those for SVE and enumerated using a similar algorithm with
some slight differences due to the fact that unlike SVE there are no
restrictions on which combinations of vector lengths can be supported
nor any mandatory vector lengths which must be implemented.  Add a new
vector type and implement support for enumerating it.

One slightly awkward feature is that we need to read the current vector
length using a different instruction (or enter streaming mode which
would have the same issue and be higher cost).  Rather than add an ops
structure we add special cases directly in the otherwise generic
vec_probe_vqs() function, this is a bit inelegant but it's the only
place where this is an issue.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-10-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:50:51 +01:00
Mark Brown
766121ba5d arm64/mte: Add userspace interface for enabling asymmetric mode
The architecture provides an asymmetric mode for MTE where tag mismatches
are checked asynchronously for stores but synchronously for loads. Allow
userspace processes to select this and make it available as a default mode
via the existing per-CPU sysfs interface.

Since there PR_MTE_TCF_ values are a bitmask (allowing the kernel to choose
between the multiple modes) and there are no free bits adjacent to the
existing PR_MTE_TCF_ bits the set of bits used to specify the mode becomes
disjoint. Programs using the new interface should be aware of this and
programs that do not use it will not see any change in behaviour.

When userspace requests two possible modes but the system default for the
CPU is the third mode (eg, default is synchronous but userspace requests
either asynchronous or asymmetric) the preference order is:

   ASYMM > ASYNC > SYNC

This situation is not currently possible since there are only two modes and
it is mandatory to have a system default so there could be no ambiguity and
there is no ABI change. The chosen order is basically arbitrary as we do not
have a clear metric for what is better here.

If userspace requests specifically asymmetric mode via the prctl() and the
system does not support it then we will return an error, this mirrors
how we handle the case where userspace enables MTE on a system that does
not support MTE at all and the behaviour that will be seen if running on
an older kernel that does not support userspace use of asymmetric mode.

Attempts to set asymmetric mode as the default mode will result in an error
if the system does not support it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Tested-by: Branislav Rankov <branislav.rankov@arm.com>
Link: https://lore.kernel.org/r/20220216173224.2342152-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-02-25 14:41:05 +00:00
Linus Torvalds
46f8763228 arm64 updates for 5.16
- Support for the Arm8.6 timer extensions, including a self-synchronising
   view of the system registers to elide some expensive ISB instructions.
 
 - Exception table cleanup and rework so that the fixup handlers appear
   correctly in backtraces.
 
 - A handful of miscellaneous changes, the main one being selection of
   CONFIG_HAVE_POSIX_CPU_TIMERS_TASK_WORK.
 
 - More mm and pgtable cleanups.
 
 - KASAN support for "asymmetric" MTE, where tag faults are reported
   synchronously for loads (via an exception) and asynchronously for
   stores (via a register).
 
 - Support for leaving the MMU enabled during kexec relocation, which
   significantly speeds up the operation.
 
 - Minor improvements to our perf PMU drivers.
 
 - Improvements to the compat vDSO build system, particularly when
   building with LLVM=1.
 
 - Preparatory work for handling some Coresight TRBE tracing errata.
 
 - Cleanup and refactoring of the SVE code to pave the way for SME
   support in future.
 
 - Ensure SCS pages are unpoisoned immediately prior to freeing them
   when KASAN is enabled for the vmalloc area.
 
 - Try moving to the generic pfn_valid() implementation again now that
   the DMA mapping issue from last time has been resolved.
 
 - Numerous improvements and additions to our FPSIMD and SVE selftests.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "There's the usual summary below, but the highlights are support for
  the Armv8.6 timer extensions, KASAN support for asymmetric MTE, the
  ability to kexec() with the MMU enabled and a second attempt at
  switching to the generic pfn_valid() implementation.

  Summary:

   - Support for the Arm8.6 timer extensions, including a
     self-synchronising view of the system registers to elide some
     expensive ISB instructions.

   - Exception table cleanup and rework so that the fixup handlers
     appear correctly in backtraces.

   - A handful of miscellaneous changes, the main one being selection of
     CONFIG_HAVE_POSIX_CPU_TIMERS_TASK_WORK.

   - More mm and pgtable cleanups.

   - KASAN support for "asymmetric" MTE, where tag faults are reported
     synchronously for loads (via an exception) and asynchronously for
     stores (via a register).

   - Support for leaving the MMU enabled during kexec relocation, which
     significantly speeds up the operation.

   - Minor improvements to our perf PMU drivers.

   - Improvements to the compat vDSO build system, particularly when
     building with LLVM=1.

   - Preparatory work for handling some Coresight TRBE tracing errata.

   - Cleanup and refactoring of the SVE code to pave the way for SME
     support in future.

   - Ensure SCS pages are unpoisoned immediately prior to freeing them
     when KASAN is enabled for the vmalloc area.

   - Try moving to the generic pfn_valid() implementation again now that
     the DMA mapping issue from last time has been resolved.

   - Numerous improvements and additions to our FPSIMD and SVE
     selftests"

[ armv8.6 timer updates were in a shared branch and already came in
  through -tip in the timer pull  - Linus ]

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits)
  arm64: Select POSIX_CPU_TIMERS_TASK_WORK
  arm64: Document boot requirements for FEAT_SME_FA64
  arm64/sve: Fix warnings when SVE is disabled
  arm64/sve: Add stub for sve_max_virtualisable_vl()
  arm64: errata: Add detection for TRBE write to out-of-range
  arm64: errata: Add workaround for TSB flush failures
  arm64: errata: Add detection for TRBE overwrite in FILL mode
  arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
  selftests: arm64: Factor out utility functions for assembly FP tests
  arm64: vmlinux.lds.S: remove `.fixup` section
  arm64: extable: add load_unaligned_zeropad() handler
  arm64: extable: add a dedicated uaccess handler
  arm64: extable: add `type` and `data` fields
  arm64: extable: use `ex` for `exception_table_entry`
  arm64: extable: make fixup_exception() return bool
  arm64: extable: consolidate definitions
  arm64: gpr-num: support W registers
  arm64: factor out GPR numbering helpers
  arm64: kvm: use kvm_exception_table_entry
  arm64: lib: __arch_copy_to_user(): fold fixups into body
  ...
2021-11-01 16:33:53 -07:00
Mark Brown
5838a15579 arm64/sve: Track vector lengths for tasks in an array
As for SVE we will track a per task SME vector length for tasks. Convert
the existing storage for the vector length into an array and update
fpsimd_flush_task() to initialise this in a function.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21 10:18:17 +01:00
Mark Brown
b5bc00ffdd arm64/sve: Put system wide vector length information into structs
With the introduction of SME we will have a second vector length in the
system, enumerated and configured in a very similar fashion to the
existing SVE vector length.  While there are a few differences in how
things are handled this is a relatively small portion of the overall
code so in order to avoid code duplication we factor out

We create two structs, one vl_info for the static hardware properties
and one vl_config for the runtime configuration, with an array
instantiated for each and update all the users to reference these. Some
accessor functions are provided where helpful for readability, and the
write to set the vector length is put into a function since the system
register being updated needs to be chosen at compile time.

This is a mostly mechanical replacement, further work will be required
to actually make things generic, ensuring that we handle those places
where there are differences properly.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-8-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21 10:18:17 +01:00
Mark Brown
0423eedcf4 arm64/sve: Use accessor functions for vector lengths in thread_struct
In a system with SME there are parallel vector length controls for SVE and
SME vectors which function in much the same way so it is desirable to
share the code for handling them as much as possible. In order to prepare
for doing this add a layer of accessor functions for the various VL related
operations on tasks.

Since almost all current interactions are actually via task->thread rather
than directly with the thread_info the accessors use that. Accessors are
provided for both generic and SVE specific usage, the generic accessors
should be used for cases where register state is being manipulated since
the registers are shared between streaming and regular SVE so we know that
when SME support is implemented we will always have to be in the appropriate
mode already and hence can generalise now.

Since we are using task_struct and we don't want to cause widespread
inclusion of sched.h the acessors are all out of line, it is hoped that
none of the uses are in a sufficiently critical path for this to be an
issue. Those that are most likely to present an issue are in the same
translation unit so hopefully the compiler may be able to inline anyway.

This is purely adding the layer of abstraction, additional work will be
needed to support tasks using SME.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21 10:18:17 +01:00
Kees Cook
42a20f86dc sched: Add wrapper for get_wchan() to keep task blocked
Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
2021-10-15 11:25:14 +02:00
Peter Collingbourne
d2e0d8f974 arm64: move preemption disablement to prctl handlers
In the next patch, we will start reading sctlr_user from
mte_update_sctlr_user and subsequently writing a new value based on the
task's TCF setting and potentially the per-CPU TCF preference. This
means that we need to be careful to disable preemption around any
code sequences that read from sctlr_user and subsequently write to
sctlr_user and/or SCTLR_EL1, so that we don't end up writing a stale
value (based on the previous CPU's TCF preference) to either of them.

We currently have four such sequences, in the prctl handlers for
PR_SET_TAGGED_ADDR_CTRL and PR_PAC_SET_ENABLED_KEYS, as well as in
the task initialization code that resets the prctl settings. Change
the prctl handlers to disable preemption in the handlers themselves
rather than the functions that they call, and change the task
initialization code to call the respective prctl handlers instead of
setting sctlr_user directly.

As a result of this change, we no longer need the helper function
set_task_sctlr_el1, nor does its behavior make sense any more, so
remove it.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Ic0e8a0c00bb47d786c1e8011df0b7fe99bee4bb5
Link: https://lore.kernel.org/r/20210727205300.2554659-4-pcc@google.com
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:33:49 +01:00
Peter Collingbourne
433c38f40f arm64: mte: change ASYNC and SYNC TCF settings into bitfields
Allow the user program to specify both ASYNC and SYNC TCF modes by
repurposing the existing constants as bitfields. This will allow the
kernel to select one of the modes on behalf of the user program. With
this patch the kernel will always select async mode, but a subsequent
patch will make this configurable.

Link: https://linux-review.googlesource.com/id/Icc5923c85a8ea284588cc399ae74fd19ec291230
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210727205300.2554659-3-pcc@google.com
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:33:43 +01:00
Peter Collingbourne
638982a03f arm64: mte: rename gcr_user_excl to mte_ctrl
We are going to use this field to store more data. To prepare for
that, rename it and change the users to rely on the bit position of
gcr_user_excl in mte_ctrl.

Link: https://linux-review.googlesource.com/id/Ie1fd18e480100655f5d22137f5b22f4f3a9f9e2e
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210727205300.2554659-2-pcc@google.com
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:33:19 +01:00
Will Deacon
bd23fdba41 Merge branch 'for-next/ptrauth' into for-next/core
Allow Pointer Authentication to be configured independently for kernel
and userspace.

* for-next/ptrauth:
  arm64: Conditionally configure PTR_AUTH key of the kernel.
  arm64: Add ARM64_PTR_AUTH_KERNEL config option
2021-06-24 14:06:23 +01:00
Will Deacon
6cf61e061e Merge branch 'for-next/entry' into for-next/core
The never-ending entry.S refactoring continues, putting us in a much
better place wrt compiler instrumentation whilst moving more of the code
into C.

* for-next/entry:
  arm64: idle: don't instrument idle code with KCOV
  arm64: entry: don't instrument entry code with KCOV
  arm64: entry: make NMI entry/exit functions static
  arm64: entry: split SDEI entry
  arm64: entry: split bad stack entry
  arm64: entry: fold el1_inv() into el1h_64_sync_handler()
  arm64: entry: handle all vectors with C
  arm64: entry: template the entry asm functions
  arm64: entry: improve bad_mode()
  arm64: entry: move bad_mode() to entry-common.c
  arm64: entry: consolidate EL1 exception returns
  arm64: entry: organise entry vectors consistently
  arm64: entry: organise entry handlers consistently
  arm64: entry: convert IRQ+FIQ handlers to C
  arm64: entry: add a call_on_irq_stack helper
  arm64: entry: move NMI preempt logic to C
  arm64: entry: move arm64_preempt_schedule_irq to entry-common.c
  arm64: entry: convert SError handlers to C
  arm64: entry: unmask IRQ+FIQ after EL0 handling
  arm64: remove redundant local_daif_mask() in bad_mode()
2021-06-24 14:01:55 +01:00
Daniel Kiss
d053e71ac8 arm64: Conditionally configure PTR_AUTH key of the kernel.
If the kernel is not compiled with CONFIG_ARM64_PTR_AUTH_KERNEL=y,
then no PACI/AUTI instructions are expected while the kernel is running
so the kernel's key will not be used. Write of a system registers
is expensive therefore avoid if not required.

Signed-off-by: Daniel Kiss <daniel.kiss@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210613092632.93591-3-daniel.kiss@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-15 11:32:31 +01:00
Mark Rutland
064dbfb416 arm64: entry: convert IRQ+FIQ handlers to C
For various reasons we'd like to convert the bulk of arm64's exception
triage logic to C. As a step towards that, this patch converts the EL1
and EL0 IRQ+FIQ triage logic to C.

Separate C functions are added for the native and compat cases so that
in subsequent patches we can handle native/compat differences in C.

Since the triage functions can now call arm64_apply_bp_hardening()
directly, the do_el0_irq_bp_hardening() wrapper function is removed.

Since the user_exit_irqoff macro is now unused, it is removed. The
user_enter_irqoff macro is still used by the ret_to_user code, and
cannot be removed at this time.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-8-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07 11:35:55 +01:00
Peter Collingbourne
76734d26b5 arm64: Change the on_*stack functions to take a size argument
unwind_frame() was previously implicitly checking that the frame
record is in bounds of the stack by enforcing that FP is both aligned
to 16 and in bounds of the stack. Once the FP alignment requirement
is relaxed to 8 this will not be sufficient because it does not
account for the case where FP points to 8 bytes before the end of the
stack.

Make the check explicit by changing the on_*stack functions to take a
size argument and adjusting the callers to pass the appropriate sizes.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Ib7a3eb3eea41b0687ffaba045ceb2012d077d8b4
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210526174927.2477847-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26 20:01:17 +01:00
Linus Torvalds
31a24ae89c arm64 updates for 5.13:
- MTE asynchronous support for KASan. Previously only synchronous
   (slower) mode was supported. Asynchronous is faster but does not allow
   precise identification of the illegal access.
 
 - Run kernel mode SIMD with softirqs disabled. This allows using NEON in
   softirq context for crypto performance improvements. The conditional
   yield support is modified to take softirqs into account and reduce the
   latency.
 
 - Preparatory patches for Apple M1: handle CPUs that only have the VHE
   mode available (host kernel running at EL2), add FIQ support.
 
 - arm64 perf updates: support for HiSilicon PA and SLLC PMU drivers, new
   functions for the HiSilicon HHA and L3C PMU, cleanups.
 
 - Re-introduce support for execute-only user permissions but only when
   the EPAN (Enhanced Privileged Access Never) architecture feature is
   available.
 
 - Disable fine-grained traps at boot and improve the documented boot
   requirements.
 
 - Support CONFIG_KASAN_VMALLOC on arm64 (only with KASAN_GENERIC).
 
 - Add hierarchical eXecute Never permissions for all page tables.
 
 - Add arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) allowing user programs
   to control which PAC keys are enabled in a particular task.
 
 - arm64 kselftests for BTI and some improvements to the MTE tests.
 
 - Minor improvements to the compat vdso and sigpage.
 
 - Miscellaneous cleanups.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - MTE asynchronous support for KASan. Previously only synchronous
   (slower) mode was supported. Asynchronous is faster but does not
   allow precise identification of the illegal access.

 - Run kernel mode SIMD with softirqs disabled. This allows using NEON
   in softirq context for crypto performance improvements. The
   conditional yield support is modified to take softirqs into account
   and reduce the latency.

 - Preparatory patches for Apple M1: handle CPUs that only have the VHE
   mode available (host kernel running at EL2), add FIQ support.

 - arm64 perf updates: support for HiSilicon PA and SLLC PMU drivers,
   new functions for the HiSilicon HHA and L3C PMU, cleanups.

 - Re-introduce support for execute-only user permissions but only when
   the EPAN (Enhanced Privileged Access Never) architecture feature is
   available.

 - Disable fine-grained traps at boot and improve the documented boot
   requirements.

 - Support CONFIG_KASAN_VMALLOC on arm64 (only with KASAN_GENERIC).

 - Add hierarchical eXecute Never permissions for all page tables.

 - Add arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) allowing user programs
   to control which PAC keys are enabled in a particular task.

 - arm64 kselftests for BTI and some improvements to the MTE tests.

 - Minor improvements to the compat vdso and sigpage.

 - Miscellaneous cleanups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (86 commits)
  arm64/sve: Add compile time checks for SVE hooks in generic functions
  arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG.
  arm64: pac: Optimize kernel entry/exit key installation code paths
  arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS)
  arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere
  arm64/sve: Remove redundant system_supports_sve() tests
  arm64: fpsimd: run kernel mode NEON with softirqs disabled
  arm64: assembler: introduce wxN aliases for wN registers
  arm64: assembler: remove conditional NEON yield macros
  kasan, arm64: tests supports for HW_TAGS async mode
  arm64: mte: Report async tag faults before suspend
  arm64: mte: Enable async tag check fault
  arm64: mte: Conditionally compile mte_enable_kernel_*()
  arm64: mte: Enable TCO in functions that can read beyond buffer limits
  kasan: Add report for async mode
  arm64: mte: Drop arch_enable_tagging()
  kasan: Add KASAN mode kernel parameter
  arm64: mte: Add asynchronous mode support
  arm64: Get rid of CONFIG_ARM64_VHE
  arm64: Cope with CPUs stuck in VHE mode
  ...
2021-04-26 10:25:03 -07:00
Peter Collingbourne
201698626f arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS)
This change introduces a prctl that allows the user program to control
which PAC keys are enabled in a particular task. The main reason
why this is useful is to enable a userspace ABI that uses PAC to
sign and authenticate function pointers and other pointers exposed
outside of the function, while still allowing binaries conforming
to the ABI to interoperate with legacy binaries that do not sign or
authenticate pointers.

The idea is that a dynamic loader or early startup code would issue
this prctl very early after establishing that a process may load legacy
binaries, but before executing any PAC instructions.

This change adds a small amount of overhead to kernel entry and exit
due to additional required instruction sequences.

On a DragonBoard 845c (Cortex-A75) with the powersave governor, the
overhead of similar instruction sequences was measured as 4.9ns when
simulating the common case where IA is left enabled, or 43.7ns when
simulating the uncommon case where IA is disabled. These numbers can
be seen as the worst case scenario, since in more realistic scenarios
a better performing governor would be used and a newer chip would be
used that would support PAC unlike Cortex-A75 and would be expected
to be faster than Cortex-A75.

On an Apple M1 under a hypervisor, the overhead of the entry/exit
instruction sequences introduced by this patch was measured as 0.3ns
in the case where IA is left enabled, and 33.0ns in the case where
IA is disabled.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ibc41a5e6a76b275efbaa126b31119dc197b927a5
Link: https://lore.kernel.org/r/d6609065f8f40397a4124654eb68c9f490b4d477.1616123271.git.pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-13 17:31:44 +01:00
Peter Collingbourne
2f79d2fc39 arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere
In an upcoming change we are going to introduce per-task SCTLR_EL1
bits for PAC. Move the existing per-task SCTLR_EL1 field out of the
MTE-specific code so that we will be able to use it from both the
PAC and MTE code paths and make the task switching code more efficient.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Ic65fac78a7926168fa68f9e8da591c9e04ff7278
Link: https://lore.kernel.org/r/13d725cb8e741950fb9d6e64b2cd9bd54ff7c3f9.1616123271.git.pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-13 17:31:44 +01:00
Maninder Singh
baa96377bc arm64/process.c: fix Wmissing-prototypes build warnings
Fix GCC warnings reported when building with "-Wmissing-prototypes":

  arch/arm64/kernel/process.c:261:6: warning: no previous prototype for '__show_regs' [-Wmissing-prototypes]
      261 | void __show_regs(struct pt_regs *regs)
          |      ^~~~~~~~~~~
  arch/arm64/kernel/process.c:307:6: warning: no previous prototype for '__show_regs_alloc_free' [-Wmissing-prototypes]
      307 | void __show_regs_alloc_free(struct pt_regs *regs)
          |      ^~~~~~~~~~~~~~~~~~~~~~
  arch/arm64/kernel/process.c:365:5: warning: no previous prototype for 'arch_dup_task_struct' [-Wmissing-prototypes]
      365 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
          |     ^~~~~~~~~~~~~~~~~~~~
  arch/arm64/kernel/process.c:546:41: warning: no previous prototype for '__switch_to' [-Wmissing-prototypes]
      546 | __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev,
          |                                         ^~~~~~~~~~~
  arch/arm64/kernel/process.c:710:25: warning: no previous prototype for 'arm64_preempt_schedule_irq' [-Wmissing-prototypes]
      710 | asmlinkage void __sched arm64_preempt_schedule_irq(void)
          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~

Link: https://lore.kernel.org/lkml/202103192250.AennsfXM-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Link: https://lore.kernel.org/r/1616568899-986-1-git-send-email-maninder1.s@samsung.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-03-25 09:50:16 +00:00
Catalin Marinas
d78050ee35 arm64: Remove arm64_dma32_phys_limit and its uses
With the introduction of a dynamic ZONE_DMA range based on DT or IORT
information, there's no need for CMA allocations from the wider
ZONE_DMA32 since on most platforms ZONE_DMA will cover the 32-bit
addressable range. Remove the arm64_dma32_phys_limit and set
arm64_dma_phys_limit to cover the smallest DMA range required on the
platform. CMA allocation and crashkernel reservation now go in the
dynamically sized ZONE_DMA, allowing correct functionality on RPi4.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> # On RPi4B
2021-01-12 17:49:25 +00:00
Nicolas Saenz Julienne
095507dc13 arm64: mm: Fix ARCH_LOW_ADDRESS_LIMIT when !CONFIG_ZONE_DMA
Systems configured with CONFIG_ZONE_DMA32, CONFIG_ZONE_NORMAL and
!CONFIG_ZONE_DMA will fail to properly setup ARCH_LOW_ADDRESS_LIMIT. The
limit will default to ~0ULL, effectively spanning the whole memory,
which is too high for a configuration that expects low memory to be
capped at 4GB.

Fix ARCH_LOW_ADDRESS_LIMIT by falling back to arm64_dma32_phys_limit
when arm64_dma_phys_limit isn't set. arm64_dma32_phys_limit will honour
CONFIG_ZONE_DMA32, or span the entire memory when not enabled.

Fixes: 1a8e1cef76 ("arm64: use both ZONE_DMA and ZONE_DMA32")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20201218163307.10150-1-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-01-04 11:06:13 +00:00
Vincenzo Frascino
620954a67b arm64: mte: convert gcr_user into an exclude mask
The gcr_user mask is a per thread mask that represents the tags that are
excluded from random generation when the Memory Tagging Extension is
present and an 'irg' instruction is invoked.

gcr_user affects the behavior on EL0 only.

Currently that mask is an include mask and it is controlled by the user
via prctl() while GCR_EL1 accepts an exclude mask.

Convert the include mask into an exclude one to make it easier the
register setting.

Note: This change will affect gcr_kernel (for EL1) introduced with a
future patch.

Link: https://lkml.kernel.org/r/946dd31be833b660334c4f93410acf6d6c4cf3c4.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-22 12:55:07 -08:00
Mark Rutland
3d2403fd10 arm64: uaccess: remove set_fs()
Now that the uaccess primitives dont take addr_limit into account, we
have no need to manipulate this via set_fs() and get_fs(). Remove
support for these, along with some infrastructure this renders
redundant.

We no longer need to flip UAO to access kernel memory under KERNEL_DS,
and head.S unconditionally clears UAO for all kernel configurations via
an ERET in init_kernel_el. Thus, we don't need to dynamically flip UAO,
nor do we need to context-switch it. However, we still need to adjust
PAN during SDEI entry.

Masking of __user pointers no longer needs to use the dynamic value of
addr_limit, and can use a constant derived from the maximum possible
userspace task size. A new TASK_SIZE_MAX constant is introduced for
this, which is also used by core code. In configurations supporting
52-bit VAs, this may include a region of unusable VA space above a
48-bit TTBR0 limit, but never includes any portion of TTBR1.

Note that TASK_SIZE_MAX is an exclusive limit, while USER_DS and
KERNEL_DS were inclusive limits, and is converted to a mask by
subtracting one.

As the SDEI entry code repurposes the otherwise unnecessary
pt_regs::orig_addr_limit field to store the TTBR1 of the interrupted
context, for now we rename that to pt_regs::sdei_ttbr1. In future we can
consider factoring that out.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201202131558.39270-10-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02 19:49:11 +00:00
Will Deacon
baab853229 Merge branch 'for-next/mte' into for-next/core
Add userspace support for the Memory Tagging Extension introduced by
Armv8.5.

(Catalin Marinas and others)
* for-next/mte: (30 commits)
  arm64: mte: Fix typo in memory tagging ABI documentation
  arm64: mte: Add Memory Tagging Extension documentation
  arm64: mte: Kconfig entry
  arm64: mte: Save tags when hibernating
  arm64: mte: Enable swap of tagged pages
  mm: Add arch hooks for saving/restoring tags
  fs: Handle intra-page faults in copy_mount_options()
  arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset
  arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support
  arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks
  arm64: mte: Restore the GCR_EL1 register after a suspend
  arm64: mte: Allow user control of the generated random tags via prctl()
  arm64: mte: Allow user control of the tag check mode via prctl()
  mm: Allow arm64 mmap(PROT_MTE) on RAM-based files
  arm64: mte: Validate the PROT_MTE request via arch_validate_flags()
  mm: Introduce arch_validate_flags()
  arm64: mte: Add PROT_MTE support to mmap() and mprotect()
  mm: Introduce arch_calc_vm_flag_bits()
  arm64: mte: Tags-aware aware memcmp_pages() implementation
  arm64: Avoid unnecessary clear_user_page() indirection
  ...
2020-10-02 12:16:11 +01:00
Will Deacon
c28762070c arm64: Rewrite Spectre-v4 mitigation code
Rewrite the Spectre-v4 mitigation handling code to follow the same
approach as that taken by Spectre-v2.

For now, report to KVM that the system is vulnerable (by forcing
'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in
subsequent steps.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:16 +01:00
Will Deacon
a8de949893 arm64: Group start_thread() functions together
The is_ttbrX_addr() functions have somehow ended up in the middle of
the start_thread() functions, so move them out of the way to keep the
code readable.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:16 +01:00
Will Deacon
d4647f0a2a arm64: Rewrite Spectre-v2 mitigation code
The Spectre-v2 mitigation code is pretty unwieldy and hard to maintain.
This is largely due to it being written hastily, without much clue as to
how things would pan out, and also because it ends up mixing policy and
state in such a way that it is very difficult to figure out what's going
on.

Rewrite the Spectre-v2 mitigation so that it clearly separates state from
policy and follows a more structured approach to handling the mitigation.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:15 +01:00
Catalin Marinas
93f067f6ca arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks
In preparation for ptrace() access to the prctl() value, allow calling
these functions on non-current tasks.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:07 +01:00
Catalin Marinas
af5ce95282 arm64: mte: Allow user control of the generated random tags via prctl()
The IRG, ADDG and SUBG instructions insert a random tag in the resulting
address. Certain tags can be excluded via the GCR_EL1.Exclude bitmap
when, for example, the user wants a certain colour for freed buffers.
Since the GCR_EL1 register is not accessible at EL0, extend the
prctl(PR_SET_TAGGED_ADDR_CTRL) interface to include a 16-bit field in
the first argument for controlling which tags can be generated by the
above instruction (an include rather than exclude mask). Note that by
default all non-zero tags are excluded. This setting is per-thread.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:07 +01:00
Catalin Marinas
1c101da8b9 arm64: mte: Allow user control of the tag check mode via prctl()
By default, even if PROT_MTE is set on a memory range, there is no tag
check fault reporting (SIGSEGV). Introduce a set of option to the
exiting prctl(PR_SET_TAGGED_ADDR_CTRL) to allow user control of the tag
check fault mode:

  PR_MTE_TCF_NONE  - no reporting (default)
  PR_MTE_TCF_SYNC  - synchronous tag check fault reporting
  PR_MTE_TCF_ASYNC - asynchronous tag check fault reporting

These options translate into the corresponding SCTLR_EL1.TCF0 bitfield,
context-switched by the kernel. Note that the kernel accesses to the
user address space (e.g. read() system call) are not checked if the user
thread tag checking mode is PR_MTE_TCF_NONE or PR_MTE_TCF_ASYNC. If the
tag checking mode is PR_MTE_TCF_SYNC, the kernel makes a best effort to
check its user address accesses, however it cannot always guarantee it.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:07 +01:00
Linus Torvalds
3cd86a58f7 arm64 updates for 5.7:
- In-kernel Pointer Authentication support (previously only offered to
   user space).
 
 - ARM Activity Monitors (AMU) extension support allowing better CPU
   utilisation numbers for the scheduler (frequency invariance).
 
 - Memory hot-remove support for arm64.
 
 - Lots of asm annotations (SYM_*) in preparation for the in-kernel
   Branch Target Identification (BTI) support.
 
 - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the PMU
   init callbacks, support for new DT compatibles.
 
 - IPv6 header checksum optimisation.
 
 - Fixes: SDEI (software delegated exception interface) double-lock on
   hibernate with shared events.
 
 - Minor clean-ups and refactoring: cpu_ops accessor, cpu_do_switch_mm()
   converted to C, cpufeature finalisation helper.
 
 - sys_mremap() comment explaining the asymmetric address untagging
   behaviour.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The bulk is in-kernel pointer authentication, activity monitors and
  lots of asm symbol annotations. I also queued the sys_mremap() patch
  commenting the asymmetry in the address untagging.

  Summary:

   - In-kernel Pointer Authentication support (previously only offered
     to user space).

   - ARM Activity Monitors (AMU) extension support allowing better CPU
     utilisation numbers for the scheduler (frequency invariance).

   - Memory hot-remove support for arm64.

   - Lots of asm annotations (SYM_*) in preparation for the in-kernel
     Branch Target Identification (BTI) support.

   - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the
     PMU init callbacks, support for new DT compatibles.

   - IPv6 header checksum optimisation.

   - Fixes: SDEI (software delegated exception interface) double-lock on
     hibernate with shared events.

   - Minor clean-ups and refactoring: cpu_ops accessor,
     cpu_do_switch_mm() converted to C, cpufeature finalisation helper.

   - sys_mremap() comment explaining the asymmetric address untagging
     behaviour"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  mm/mremap: Add comment explaining the untagging behaviour of mremap()
  arm64: head: Convert install_el2_stub to SYM_INNER_LABEL
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  ...
2020-03-31 10:05:01 -07:00
Vincenzo Frascino
f511e07917 arm64: Introduce asm/vdso/processor.h
The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.

Introduce asm/vdso/processor.h to contain all the arm64 specific
functions that are suitable for vDSO inclusion.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200320145351.32292-20-vincenzo.frascino@arm.com
2020-03-21 15:24:01 +01:00
Kristina Martsenko
33e4523498 arm64: initialize and switch ptrauth kernel keys
Set up keys to use pointer authentication within the kernel. The kernel
will be compiled with APIAKey instructions, the other keys are currently
unused. Each task is given its own APIAKey, which is initialized during
fork. The key is changed during context switch and on kernel entry from
EL0.

The keys for idle threads need to be set before calling any C functions,
because it is not possible to enter and exit a function with different
keys.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Modified secondary cores key structure, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:20 +00:00
Kristina Martsenko
91a1b6ccff arm64: rename ptrauth key structures to be user-specific
We currently enable ptrauth for userspace, but do not use it within the
kernel. We're going to enable it for the kernel, and will need to manage
a separate set of ptrauth keys for the kernel.

We currently keep all 5 keys in struct ptrauth_keys. However, as the
kernel will only need to use 1 key, it is a bit wasteful to allocate a
whole ptrauth_keys struct for every thread.

Therefore, a subsequent patch will define a separate struct, with only 1
key, for the kernel. In preparation for that, rename the existing struct
(and associated macros and functions) to reflect that they are specific
to userspace.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Re-positioned the patch to reduce the diff]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:18 +00:00
Catalin Marinas
6be22809e5 Merge branches 'for-next/elf-hwcap-docs', 'for-next/smccc-conduit-cleanup', 'for-next/zone-dma', 'for-next/relax-icc_pmr_el1-sync', 'for-next/double-page-fault', 'for-next/misc', 'for-next/kselftest-arm64-signal' and 'for-next/kaslr-diagnostics' into for-next/core
* for-next/elf-hwcap-docs:
  : Update the arm64 ELF HWCAP documentation
  docs/arm64: cpu-feature-registers: Rewrite bitfields that don't follow [e, s]
  docs/arm64: cpu-feature-registers: Documents missing visible fields
  docs/arm64: elf_hwcaps: Document HWCAP_SB
  docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value

* for-next/smccc-conduit-cleanup:
  : SMC calling convention conduit clean-up
  firmware: arm_sdei: use common SMCCC_CONDUIT_*
  firmware/psci: use common SMCCC_CONDUIT_*
  arm: spectre-v2: use arm_smccc_1_1_get_conduit()
  arm64: errata: use arm_smccc_1_1_get_conduit()
  arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

* for-next/zone-dma:
  : Reintroduction of ZONE_DMA for Raspberry Pi 4 support
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
  dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
  arm64: Make arm64_dma32_phys_limit static
  arm64: mm: Fix unused variable warning in zone_sizes_init
  mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type'
  arm64: use both ZONE_DMA and ZONE_DMA32
  arm64: rename variables used to calculate ZONE_DMA32's size
  arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys()

* for-next/relax-icc_pmr_el1-sync:
  : Relax ICC_PMR_EL1 (GICv3) accesses when ICC_CTLR_EL1.PMHE is clear
  arm64: Document ICC_CTLR_EL3.PMHE setting requirements
  arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear

* for-next/double-page-fault:
  : Avoid a double page fault in __copy_from_user_inatomic() if hw does not support auto Access Flag
  mm: fix double page fault on arm64 if PTE_AF is cleared
  x86/mm: implement arch_faults_on_old_pte() stub on x86
  arm64: mm: implement arch_faults_on_old_pte() on arm64
  arm64: cpufeature: introduce helper cpu_has_hw_af()

* for-next/misc:
  : Various fixes and clean-ups
  arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
  arm64: mm: Remove MAX_USER_VA_BITS definition
  arm64: mm: simplify the page end calculation in __create_pgd_mapping()
  arm64: print additional fault message when executing non-exec memory
  arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
  arm64: pgtable: Correct typo in comment
  arm64: docs: cpu-feature-registers: Document ID_AA64PFR1_EL1
  arm64: cpufeature: Fix typos in comment
  arm64/mm: Poison initmem while freeing with free_reserved_area()
  arm64: use generic free_initrd_mem()
  arm64: simplify syscall wrapper ifdeffery

* for-next/kselftest-arm64-signal:
  : arm64-specific kselftest support with signal-related test-cases
  kselftest: arm64: fake_sigreturn_misaligned_sp
  kselftest: arm64: fake_sigreturn_bad_size
  kselftest: arm64: fake_sigreturn_duplicated_fpsimd
  kselftest: arm64: fake_sigreturn_missing_fpsimd
  kselftest: arm64: fake_sigreturn_bad_size_for_magic0
  kselftest: arm64: fake_sigreturn_bad_magic
  kselftest: arm64: add helper get_current_context
  kselftest: arm64: extend test_init functionalities
  kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht]
  kselftest: arm64: mangle_pstate_invalid_daif_bits
  kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils
  kselftest: arm64: extend toplevel skeleton Makefile

* for-next/kaslr-diagnostics:
  : Provide diagnostics on boot for KASLR
  arm64: kaslr: Check command line before looking for a seed
  arm64: kaslr: Announce KASLR status on boot
2019-11-08 17:46:11 +00:00
Bhupesh Sharma
218564b164 arm64: mm: Remove MAX_USER_VA_BITS definition
commit 9b31cf493f ("arm64: mm: Introduce MAX_USER_VA_BITS definition")
introduced the MAX_USER_VA_BITS definition, which was used to support
the arm64 mm use-cases where the user-space could use 52-bit virtual
addresses whereas the kernel-space would still could a maximum of 48-bit
virtual addressing.

But, now with commit b6d00d47e8 ("arm64: mm: Introduce 52-bit Kernel
VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence
there is no longer any scenario where user VA != kernel VA size
(even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true).

Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to
VA_BITS (maximum VA space size) in all possible use-cases. Note that
even though the 'vabits_actual' value would be 48 for arm64 hardware
which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52
is enabled), VA_BITS would still be set to a value 52. Hence this change
would be safe in all possible VA address space combinations.

Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-kernel@vger.kernel.org
Cc: kexec@lists.infradead.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06 11:19:25 +00:00
James Morse
bfe298745a arm64: entry-common: don't touch daif before bp-hardening
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:54 +00:00
Alexandre Ghiti
67f3977f80 arm64, mm: move generic mmap layout functions to mm
arm64 handles top-down mmap layout in a way that can be easily reused by
other architectures, so make it available in mm.  It then introduces a new
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other
architectures to benefit from those functions.  Note that this new config
depends on MMU being enabled, if selected without MMU support, a warning
will be thrown.

Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:11 -07:00