1030210 Commits

Author SHA1 Message Date
Catalin Marinas
1a7f67e618 Merge branch 'for-next/entry' into for-next/core
* for-next/entry:
  : More entry.S clean-ups and conversion to C.
  arm64: entry: call exit_to_user_mode() from C
  arm64: entry: move bulk of ret_to_user to C
  arm64: entry: clarify entry/exit helpers
  arm64: entry: consolidate entry/exit helpers
2021-08-26 11:49:33 +01:00
Catalin Marinas
622909e51a Merge branches 'for-next/mte', 'for-next/misc' and 'for-next/kselftest', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf:
  arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF

* for-next/mte:
  : Miscellaneous MTE improvements.
  arm64/cpufeature: Optionally disable MTE via command-line
  arm64: kasan: mte: remove redundant mte_report_once logic
  arm64: kasan: mte: use a constant kernel GCR_EL1 value
  arm64: avoid double ISB on kernel entry
  arm64: mte: optimize GCR_EL1 modification on kernel entry/exit
  Documentation: document the preferred tag checking mode feature
  arm64: mte: introduce a per-CPU tag checking mode preference
  arm64: move preemption disablement to prctl handlers
  arm64: mte: change ASYNC and SYNC TCF settings into bitfields
  arm64: mte: rename gcr_user_excl to mte_ctrl
  arm64: mte: avoid TFSRE0_EL1 related operations unless in async mode

* for-next/misc:
  : Miscellaneous updates.
  arm64: Do not trap PMSNEVFR_EL1
  arm64: mm: fix comment typo of pud_offset_phys()
  arm64: signal32: Drop pointless call to sigdelsetmask()
  arm64/sve: Better handle failure to allocate SVE register storage
  arm64: Document the requirement for SCR_EL3.HCE
  arm64: head: avoid over-mapping in map_memory
  arm64/sve: Add a comment documenting the binutils needed for SVE asm
  arm64/sve: Add some comments for sve_save/load_state()
  arm64: replace in_irq() with in_hardirq()
  arm64: mm: Fix TLBI vs ASID rollover
  arm64: entry: Add SYM_CODE annotation for __bad_stack
  arm64: fix typo in a comment
  arm64: move the (z)install rules to arch/arm64/Makefile
  arm64/sve: Make fpsimd_bind_task_to_cpu() static
  arm64: unnecessary end 'return;' in void functions
  arm64/sme: Document boot requirements for SME
  arm64: use __func__ to get function name in pr_err
  arm64: SSBS/DIT: print SSBS and DIT bit when printing PSTATE
  arm64: cpufeature: Use defined macro instead of magic numbers
  arm64/kexec: Test page size support with new TGRAN range values

* for-next/kselftest:
  : Kselftest additions for arm64.
  kselftest/arm64: signal: Add a TODO list for signal handling tests
  kselftest/arm64: signal: Add test case for SVE register state in signals
  kselftest/arm64: signal: Verify that signals can't change the SVE vector length
  kselftest/arm64: signal: Check SVE signal frame shows expected vector length
  kselftest/arm64: signal: Support signal frames with SVE register data
  kselftest/arm64: signal: Add SVE to the set of features we can check for
  kselftest/arm64: pac: Fix skipping of tests on systems without PAC
  kselftest/arm64: mte: Fix misleading output when skipping tests
  kselftest/arm64: Add a TODO list for floating point tests
  kselftest/arm64: Add tests for SVE vector configuration
  kselftest/arm64: Validate vector lengths are set in sve-probe-vls
  kselftest/arm64: Provide a helper binary and "library" for SVE RDVL
  kselftest/arm64: Ignore check_gcr_el1_cswitch binary
2021-08-26 11:49:27 +01:00
Alexandru Elisei
50cb99fa89 arm64: Do not trap PMSNEVFR_EL1
Commit 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot") zeroed
the fine grained trap registers to prevent unwanted register traps from
occuring. However, for the PMSNEVFR_EL1 register, the corresponding
HDFG{R,W}TR_EL2.nPMSNEVFR_EL1 fields must be 1 to disable trapping. Set
both fields to 1 if FEAT_SPEv1p2 is detected to disable read and write
traps.

Fixes: 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot")
Cc: <stable@vger.kernel.org> # 5.13.x
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210824154523.906270-1-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-26 11:35:09 +01:00
Xujun Leng
5845e703f9 arm64: mm: fix comment typo of pud_offset_phys()
Fix a typo in the comment of macro pud_offset_phys().

Signed-off-by: Xujun Leng <lengxujun2007@126.com>
Link: https://lore.kernel.org/r/20210825150526.12582-1-lengxujun2007@126.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-25 18:21:58 +01:00
Will Deacon
24de5838db arm64: signal32: Drop pointless call to sigdelsetmask()
Commit 77097ae503b1 ("most of set_current_blocked() callers want
SIGKILL/SIGSTOP removed from set") extended set_current_blocked() to
remove SIGKILL and SIGSTOP from the new signal set and updated all
callers accordingly.

Unfortunately, this collided with the merge of the arm64 architecture,
which duly removes these signals when restoring the compat sigframe, as
this was what was previously done by arch/arm/.

Remove the redundant call to sigdelsetmask() from
compat_restore_sigframe().

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210825093911.24493-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-25 17:44:04 +01:00
Mark Brown
7559b7d7d6 arm64/sve: Better handle failure to allocate SVE register storage
Currently we "handle" failure to allocate the SVE register storage by
doing a BUG_ON() and hoping for the best. This is obviously not great and
the memory allocation failure will already be loud enough without the
BUG_ON(). As the comment says it is a corner case but let's try to do a bit
better, remove the BUG_ON() and add code to handle the failure in the
callers.

For the ptrace and signal code we can return -ENOMEM gracefully however
we have no real error reporting path available to us for the SVE access
trap so instead generate a SIGKILL if the allocation fails there. This
at least means that we won't try to soldier on and end up trying to
access the nonexistant state and while it's obviously not ideal for
userspace SIGKILL doesn't allow any handling so minimises the ABI
impact, making it easier to improve the interface later if we come up
with a better idea.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210824153417.18371-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24 16:44:30 +01:00
Marc Zyngier
e384976503 arm64: Document the requirement for SCR_EL3.HCE
It is amazing that we never documented this absolutely basic
requirement: if you boot the kernel at EL2, you'd better
enable the HVC instruction from EL3.

Really, just do it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210812190213.2601506-6-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24 16:44:23 +01:00
Mark Rutland
90268574a3 arm64: head: avoid over-mapping in map_memory
The `compute_indices` and `populate_entries` macros operate on inclusive
bounds, and thus the `map_memory` macro which uses them also operates
on inclusive bounds.

We pass `_end` and `_idmap_text_end` to `map_memory`, but these are
exclusive bounds, and if one of these is sufficiently aligned (as a
result of kernel configuration, physical placement, and KASLR), then:

* In `compute_indices`, the computed `iend` will be in the page/block *after*
  the final byte of the intended mapping.

* In `populate_entries`, an unnecessary entry will be created at the end
  of each level of table. At the leaf level, this entry will map up to
  SWAPPER_BLOCK_SIZE bytes of physical addresses that we did not intend
  to map.

As we may map up to SWAPPER_BLOCK_SIZE bytes more than intended, we may
violate the boot protocol and map physical address past the 2MiB-aligned
end address we are permitted to map. As we map these with Normal memory
attributes, this may result in further problems depending on what these
physical addresses correspond to.

The final entry at each level may require an additional table at that
level. As EARLY_ENTRIES() calculates an inclusive bound, we allocate
enough memory for this.

Avoid the extraneous mapping by having map_memory convert the exclusive
end address to an inclusive end address by subtracting one, and do
likewise in EARLY_ENTRIES() when calculating the number of required
tables. For clarity, comments are updated to more clearly document which
boundaries the macros operate on.  For consistency with the other
macros, the comments in map_memory are also updated to describe `vstart`
and `vend` as virtual addresses.

Fixes: 0370b31e4845 ("arm64: Extend early page table code to allow for larger kernels")
Cc: <stable@vger.kernel.org> # 4.16.x
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210823101253.55567-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24 16:44:23 +01:00
Mark Brown
04fa17d136 arm64/sve: Add a comment documenting the binutils needed for SVE asm
At some point it would be nice to avoid the need to manually encode SVE
instructions, add a note of the binutils version required to save looking
it up.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210816125024.8112-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24 16:44:23 +01:00
Mark Brown
38ee3c5e36 arm64/sve: Add some comments for sve_save/load_state()
The use of macros for the actual function bodies means legibility is always
going to be a bit of a challenge, especially while we can't rely on SVE
support in the toolchain, but this helps a little.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210812201143.35578-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24 16:44:23 +01:00
Mark Brown
fa5ca80db8 kselftest/arm64: signal: Add a TODO list for signal handling tests
Note down a few gaps in our coverage.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-7-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:05 +01:00
Mark Brown
5262b216f4 kselftest/arm64: signal: Add test case for SVE register state in signals
Currently this doesn't actually verify that the register contents do the
right thing, it just verifes that a SVE context with appropriate size
appears.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:05 +01:00
Mark Brown
d25ac50ce8 kselftest/arm64: signal: Verify that signals can't change the SVE vector length
We do not support changing the SVE vector length as part of signal return,
verify that this is the case if the system supports multiple vector lengths.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-5-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:05 +01:00
Mark Brown
c1f67a19c1 kselftest/arm64: signal: Check SVE signal frame shows expected vector length
As a basic check that the SVE signal frame is being set up correctly
verify that the vector length in the signal frame is the vector length
that the process has.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:05 +01:00
Mark Brown
ace19b1845 kselftest/arm64: signal: Support signal frames with SVE register data
A signal frame with SVE may validly either be a bare struct sve_context or
a struct sve_context followed by vector length dependent register data.
Support either in the generic helpers for the signal tests, and while we're
at it validate the SVE vector length reported.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:04 +01:00
Mark Brown
d4e4dc4fab kselftest/arm64: signal: Add SVE to the set of features we can check for
Allow testcases for SVE signal handling to flag the dependency and be
skipped on systems without SVE support.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 11:11:04 +01:00
Changbin Du
090bf6f84b arm64: replace in_irq() with in_hardirq()
Replace the obsolete and ambiguos macro in_irq() with new
macro in_hardirq().

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Link: https://lore.kernel.org/r/20210814005405.2658-1-changbin.du@gmail.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-20 19:49:38 +01:00
Mark Brown
0c69bd2ca6 kselftest/arm64: pac: Fix skipping of tests on systems without PAC
The PAC tests check to see if the system supports the relevant PAC features
but instead of skipping the tests if they can't be executed they fail the
tests which makes things look like they're not working when they are.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819165723.43903-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-20 12:06:59 +01:00
Mark Brown
83e5dcbece kselftest/arm64: mte: Fix misleading output when skipping tests
When skipping the tests due to a lack of system support for MTE we
currently print a message saying FAIL which makes it look like the test
failed even though the test did actually report KSFT_SKIP, creating some
confusion. Change the error message to say SKIP instead so things are
clearer.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819172902.56211-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-20 11:11:05 +01:00
Anshuman Khandual
fd264b3105 arm64/perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF
ID_AA64DFR0_PMUVER_IMP_DEF, indicating an "implementation defined" PMU,
never actually gets used although there are '0xf' instances scattered
all around. Use the symbolic name instead of the raw hex constant.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/1628652427-24695-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-11 11:02:12 +01:00
Will Deacon
5e10f9887e arm64: mm: Fix TLBI vs ASID rollover
When switching to an 'mm_struct' for the first time following an ASID
rollover, a new ASID may be allocated and assigned to 'mm->context.id'.
This reassignment can happen concurrently with other operations on the
mm, such as unmapping pages and subsequently issuing TLB invalidation.

Consequently, we need to ensure that (a) accesses to 'mm->context.id'
are atomic and (b) all page-table updates made prior to a TLBI using the
old ASID are guaranteed to be visible to CPUs running with the new ASID.

This was found by inspection after reviewing the VMID changes from
Shameer but it looks like a real (yet hard to hit) bug.

Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210806113109.2475-2-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-06 13:52:03 +01:00
Mark Brown
ede3241a5f arm64: entry: Add SYM_CODE annotation for __bad_stack
When converting arm64 to modern assembler annotations __bad_stack was left
as a raw local label without annotations. While this will have little if
any practical impact at present it may cause issues in the future if we
start using the annotations for things like reliable stack trace. Add
SYM_CODE annotations to fix this.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210804181710.19059-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-06 11:12:45 +01:00
Mark Rutland
e130338eed arm64: entry: call exit_to_user_mode() from C
When handling an exception from EL0, we perform the entry work in that
exception's C handler, and once the C handler has finished, we return
back to the entry assembly. Subsequently in the common `ret_to_user`
assembly we perform the exit work that balances with the entry work.
This can be somewhat difficult to follow, and makes it hard to rework
the return paths (e.g. to pass additional context to the exit code, or
to have exception return logic for specific exceptions).

This patch reworks the entry code such that each EL0 C exception handler
is responsible for both the entry and exit work. This clearly balances
the two (and will permit additional variation in future), and avoids an
unnecessary bounce between assembly and C in the common case, leaving
`ret_from_fork` as the only place assembly has to call the exit code.
This means that the exit work is now inlined into the C handler, which
is already the case for the entry work, and allows the compiler to
generate better code (e.g. by immediately returning when there is no
exit work to perform).

To align with other exception entry/exit helpers, enter_from_user_mode()
is updated to take the EL0 pt_regs as a parameter, though this is
currently unused.

There should be no functional change as a result of this patch. However,
this should lead to slightly better backtraces when an error is
encountered within do_notify_resume(), as the C handler should appear in
the backtrace, indicating the specific exception that the kernel was
entered with.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20210802140733.52716-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-05 14:10:32 +01:00
Mark Rutland
4d1c2ee270 arm64: entry: move bulk of ret_to_user to C
In `ret_to_user` we perform some conditional work depending on the
thread flags, then perform some IRQ/context tracking which is intended
to balance with the IRQ/context tracking performed in the entry C code.

For simplicity and consistency, it would be preferable to move this all
to C. As a step towards that, this patch moves the conditional work and
IRQ/context tracking into a C helper function. To aid bisectability,
this is called from the `ret_to_user` assembly, and a subsequent patch
will move the call to C code.

As local_daif_mask() handles all necessary tracing and PMR manipulation,
we no longer need to handle this explicitly. As we call
exit_to_user_mode() directly, the `user_enter_irqoff` macro is no longer
used, and can be removed. As enter_from_user_mode() and
exit_to_user_mode() are no longer called from assembly, these can be
made static, and as these are typically very small, they are marked
__always_inline to avoid the overhead of a function call.

For now, enablement of single-step is left in entry.S, and for this we
still need to read the flags in ret_to_user(). It is safe to read this
separately as TIF_SINGLESTEP is not part of _TIF_WORK_MASK.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20210802140733.52716-4-mark.rutland@arm.com
[catalin.marinas@arm.com: removed unused gic_prio_kentry_setup macro]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-05 14:09:49 +01:00
Mark Rutland
bc29b71f53 arm64: entry: clarify entry/exit helpers
When entering an exception, we must perform irq/context state management
before we can use instrumentable C code. Similarly, when exiting an
exception we cannot use instrumentable C code after we perform
irq/context state management.

Originally, we'd intended that the enter_from_*() and exit_to_*()
helpers would enforce this by virtue of being the first and last
functions called, respectively, in an exception handler. However, as
they now call instrumentable code themselves, this is not as clearly
true.

To make this more robust, this patch splits the irq/context state
management into separate helpers, with all the helpers commented to make
their intended purpose more obvious.

In exit_to_kernel_mode() we'll now check TFSR_EL1 before we assert that
IRQs are disabled, but this ordering is not important, and other than
this there should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20210802140733.52716-3-mark.rutland@arm.com
[catalin.marinas@arm.com: comment typos fix-up]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-05 14:06:55 +01:00
Mark Rutland
46a2b02d23 arm64: entry: consolidate entry/exit helpers
To make the various entry/exit helpers easier to understand and easier
to compare, this patch moves all the entry/exit helpers to be adjacent
at the top of entry-common.c, rather than being spread out throughout
the file.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20210802140733.52716-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-05 14:04:19 +01:00
Mark Brown
e96595c55d kselftest/arm64: Add a TODO list for floating point tests
Write down some ideas for additional coverage for floating point in case
someone feels inspired to look into them.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20210803140450.46624-5-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:20:05 +01:00
Mark Brown
95cf3f2387 kselftest/arm64: Add tests for SVE vector configuration
We provide interfaces for configuring the SVE vector length seen by
processes using prctl and also via /proc for configuring the default
values. Provide tests that exercise all these interfaces and verify that
they take effect as expected, though at present no test fully enumerates
all the possible vector lengths.

A subset of this is already tested via sve-probe-vls but the /proc
interfaces are not currently covered at all.

In preparation for the forthcoming support for SME, the Scalable Matrix
Extension, which has separately but similarly configured vector lengths
which we expect to offer similar userspace interfaces for, all the actual
files and prctls used are parameterised and we don't validate that the
architectural minimum vector length is the minimum we see.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20210803140450.46624-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:20:05 +01:00
Mark Brown
b43ab36a6d kselftest/arm64: Validate vector lengths are set in sve-probe-vls
Currently sve-probe-vls does not verify that the vector lengths reported
by the prctl() interface are actually what is reported by the architecture,
use the rdvl_sve() helper to validate this.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20210803140450.46624-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:20:05 +01:00
Mark Brown
7710861017 kselftest/arm64: Provide a helper binary and "library" for SVE RDVL
SVE provides an instruction RDVL which reports the currently configured
vector length. In order to validate that our vector length configuration
interfaces are working correctly without having to build the C code for
our test programs with SVE enabled provide a trivial assembly library
with a C callable function that executes RDVL. Since these interfaces
also control behaviour on exec*() provide a trivial wrapper program which
reports the currently configured vector length on stdout, tests can use
this to verify that behaviour on exec*() is as expected.

In preparation for providing similar helper functionality for SME, the
Scalable Matrix Extension, which allows separately configured vector
lengths to be read back both the assembler function and wrapper binary
have SVE included in their name.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20210803140450.46624-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:20:05 +01:00
Jason Wang
312b7104f3 arm64: fix typo in a comment
The double 'the' after 'If' in this comment "If the the TLB range ops
are supported..." is repeated. Consequently, one 'the' should be
removed from the comment.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Link: https://lore.kernel.org/r/20210803142020.124230-1-wangborong@cdjrlc.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:19:33 +01:00
Masahiro Yamada
70a4039bd4 arm64: move the (z)install rules to arch/arm64/Makefile
Currently, the (z)install targets in arch/arm64/Makefile descend into
arch/arm64/boot/Makefile to invoke the shell script, but there is no
good reason to do so.

arch/arm64/Makefile can run the shell script directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210729140527.443116-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 16:19:03 +01:00
Yee Lee
7a062ce318 arm64/cpufeature: Optionally disable MTE via command-line
MTE support needs to be optionally disabled in runtime
for HW issue workaround, FW development and some
evaluation works on system resource and performance.

This patch makes two changes:
(1) moves init of tag-allocation bits(ATA/ATA0) to
cpu_enable_mte() as not cached in TLB.

(2) allows ID_AA64PFR1_EL1.MTE to be overridden on
its shadow value by giving "arm64.nomte" on cmdline.

When the feature value is off, ATA and TCF will not set
and the related functionalities are accordingly suppressed.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Marc Zyngier <maz@kernel.org>
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Link: https://lore.kernel.org/r/20210803070824.7586-2-yee.lee@mediatek.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-03 15:48:01 +01:00
Mark Rutland
7672150301 arm64: kasan: mte: remove redundant mte_report_once logic
We have special logic to suppress MTE tag check fault reporting, based
on a global `mte_report_once` and `reported` variables. These can be
used to suppress calling kasan_report() when taking a tag check fault,
but do not prevent taking the fault in the first place, nor does they
affect the way we disable tag checks upon taking a fault.

The core KASAN code already defaults to reporting a single fault, and
has a `multi_shot` control to permit reporting multiple faults. The only
place we transiently alter `mte_report_once` is in lib/test_kasan.c,
where we also the `multi_shot` state as the same time. Thus
`mte_report_once` and `reported` are redundant, and can be removed.

When a tag check fault is taken, tag checking will be disabled by
`do_tag_recovery` and must be explicitly re-enabled if desired. The test
code does this by calling kasan_enable_tagging_sync().

This patch removes the redundant mte_report_once() logic and associated
variables.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210714143843.56537-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 18:15:28 +01:00
Mark Rutland
8286824789 arm64: kasan: mte: use a constant kernel GCR_EL1 value
When KASAN_HW_TAGS is selected, KASAN is enabled at boot time, and the
hardware supports MTE, we'll initialize `kernel_gcr_excl` with a value
dependent on KASAN_TAG_MAX. While the resulting value is a constant
which depends on KASAN_TAG_MAX, we have to perform some runtime work to
generate the value, and have to read the value from memory during the
exception entry path. It would be better if we could generate this as a
constant at compile-time, and use it as such directly.

Early in boot within __cpu_setup(), we initialize GCR_EL1 to a safe
value, and later override this with the value required by KASAN. If
CONFIG_KASAN_HW_TAGS is not selected, or if KASAN is disabeld at boot
time, the kernel will not use IRG instructions, and so the initial value
of GCR_EL1 is does not matter to the kernel. Thus, we can instead have
__cpu_setup() initialize GCR_EL1 to a value consistent with
KASAN_TAG_MAX, and avoid the need to re-initialize it during hotplug and
resume form suspend.

This patch makes arem64 use a compile-time constant KERNEL_GCR_EL1
value, which is compatible with KASAN_HW_TAGS when this is selected.
This removes the need to re-initialize GCR_EL1 dynamically, and acts as
an optimization to the entry assembly, which no longer needs to load
this value from memory. The redundant initialization hooks are removed.

In order to do this, KASAN_TAG_MAX needs to be visible outside of the
core KASAN code. To do this, I've moved the KASAN_TAG_* values into
<linux/kasan-tags.h>.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210714143843.56537-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 18:14:21 +01:00
Mark Brown
b24b520509 arm64/sve: Make fpsimd_bind_task_to_cpu() static
This function is not referenced outside fpsimd.c so can be static, making
it that little bit easier to follow what is called from where.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210730165846.18558-1-broonie@kernel.org
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 17:48:16 +01:00
Mark Brown
dac3ce63bf kselftest/arm64: Ignore check_gcr_el1_cswitch binary
We added check_gcr_el1_cswitch but did not ignore the generated binary,
add it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210728173539.6231-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 13:21:30 +01:00
Jason Wang
8f1fbc975b arm64: unnecessary end 'return;' in void functions
The end 'return;' in a void function is useless and verbose. It can
be removed safely.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Link: https://lore.kernel.org/r/20210726123940.63232-1-wangborong@cdjrlc.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 11:51:01 +01:00
Mark Brown
a8caaa239c arm64/sme: Document boot requirements for SME
Document our requirements for initialisation of the Scalable Matrix
Extension (SME) at kernel start. While we do have the ability to handle
mismatched vector lengths we will reject any late CPUs that can't support
the minimum set we determine at boot so for clarity we document a
requirement that all CPUs make the same vector length available.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210720204220.22951-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 11:05:24 +01:00
Jason Wang
2806556c5e arm64: use __func__ to get function name in pr_err
Prefer using '"%s...", __func__' to get current function's name in
a debug message.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210726122907.51529-1-wangborong@cdjrlc.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-30 16:26:16 +01:00
Lingyan Huang
ec63e300fa arm64: SSBS/DIT: print SSBS and DIT bit when printing PSTATE
The current code to print PSTATE when generating backtraces does not
include SSBS bit and DIT bit, so add this information.

Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Lingyan Huang <huanglingyan2@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/1626920436-54816-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-30 16:26:07 +01:00
Shaokun Zhang
ff85f10ba8 arm64: cpufeature: Use defined macro instead of magic numbers
Use defined macro to simplify the code and make it more readable.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1626415089-57584-1-git-send-email-zhangshaokun@hisilicon.com
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-30 16:21:47 +01:00
Anshuman Khandual
79d82cbcbb arm64/kexec: Test page size support with new TGRAN range values
The commit 26f55386f964 ("arm64/mm: Fix __enable_mmu() for new TGRAN range
values") had already switched into testing ID_AA64MMFR0_TGRAN range values.
This just changes system_supports_[4|16|64]kb_granule() helpers to perform
similar range tests as well. While here, it standardizes page size specific
supported min and max TGRAN values.

Cc: Will Deacon <will@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/1626237975-1909-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-30 11:48:02 +01:00
Peter Collingbourne
d914b80a8f arm64: avoid double ISB on kernel entry
Although an ISB is required in order to make the MTE-related system
register update to GCR_EL1 effective, and the same is true for
PAC-related updates to SCTLR_EL1 or APIAKey{Hi,Lo}_EL1, we issue two
ISBs on machines that support both features while we only need to
issue one. To avoid the unnecessary additional ISB, remove the ISBs
from the PAC and MTE-specific alternative blocks and add a couple
of additional blocks that cause us to only execute one ISB if both
features are supported.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Idee7e8114d5ae5a0b171d06220a0eb4bb015a51c
Link: https://lore.kernel.org/r/20210727205439.2557419-1-pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:40:12 +01:00
Peter Collingbourne
afdfd93a53 arm64: mte: optimize GCR_EL1 modification on kernel entry/exit
Accessing GCR_EL1 and issuing an ISB can be expensive on some
microarchitectures. Although we must write to GCR_EL1, we can
restructure the code to avoid reading from it because the new value
can be derived entirely from the exclusion mask, which is already in
a GPR. Do so.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/I560a190a74176ca4cc5191dad08f77f6b1577c75
Link: https://lore.kernel.org/r/20210714013638.3995315-1-pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:40:12 +01:00
Peter Collingbourne
80c7c36fb3 Documentation: document the preferred tag checking mode feature
Document the functionality added in the previous patches.

Link: https://linux-review.googlesource.com/id/I48217cc3e8b8da33abc08cbaddc11cf4360a1b86
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210727205300.2554659-6-pcc@google.com
Acked-by: Will Deacon <will@kernel.org>
[catalin.marinas@arm.com: clarify that the change happens on task scheduling]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:39:26 +01:00
Peter Collingbourne
dd061616ed arm64: mte: introduce a per-CPU tag checking mode preference
Add a per-CPU sysfs node, mte_tcf_preferred, that allows the preferred
tag checking mode to be configured. The current possible values are
async and sync.

Link: https://linux-review.googlesource.com/id/I7493dcd533a2785a1437b16c3f6b50919f840854
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210727205300.2554659-5-pcc@google.com
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-28 18:33:55 +01:00
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