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Linus Torvalds
48983701a1 Merge branch 'siginfo-si_trapno-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo si_trapno updates from Eric Biederman:
 "The full set of si_trapno changes was not appropriate as a fix for the
  newly added SIGTRAP TRAP_PERF, and so I postponed the rest of the
  related cleanups.

  This is the rest of the cleanups for si_trapno that reduces it from
  being a really weird arch special case that is expect to be always
  present (but isn't) on the architectures that support it to being yet
  another field in the _sigfault union of struct siginfo.

  The changes have been reviewed and marinated in linux-next. With the
  removal of this awkward special case new code (like SIGTRAP TRAP_PERF)
  that works across architectures should be easier to write and
  maintain"

* 'siginfo-si_trapno-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency
  signal: Verify the alignment and size of siginfo_t
  signal: Remove the generic __ARCH_SI_TRAPNO support
  signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
  signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP
  arm64: Add compile-time asserts for siginfo_t offsets
  arm: Add compile-time asserts for siginfo_t offsets
  sparc64: Add compile-time asserts for siginfo_t offsets
2021-09-01 14:42:36 -07:00
Thomas Gleixner
4b92d4add5 drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework
to ensure that the cache related functions are called on the upcoming CPU
because the notifier itself could run on any online CPU.

The hotplug state machine guarantees that the callbacks are invoked on the
upcoming CPU. So there is no need to have this SMP function call
obfuscation. That indirection was missed when the hotplug notifiers were
converted.

This also solves the problem of ARM64 init_cache_level() invoking ACPI
functions which take a semaphore in that context. That's invalid as SMP
function calls run with interrupts disabled. Running it just from the
callback in context of the CPU hotplug thread solves this.

Fixes: 8571890e15 ("arm64: Add support for ACPI based firmware tables")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx
2021-09-01 10:29:10 +02:00
Catalin Marinas
65266a7c6a Merge remote-tracking branch 'tip/sched/arm64' into for-next/core
* tip/sched/arm64: (785 commits)
  Documentation: arm64: describe asymmetric 32-bit support
  arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores
  arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
  arm64: Advertise CPUs capable of running 32-bit applications in sysfs
  arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system
  arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0
  arm64: Implement task_cpu_possible_mask()
  sched: Introduce dl_task_check_affinity() to check proposed affinity
  sched: Allow task CPU affinity to be restricted on asymmetric systems
  sched: Split the guts of sched_setaffinity() into a helper function
  sched: Introduce task_struct::user_cpus_ptr to track requested affinity
  sched: Reject CPU affinity changes based on task_cpu_possible_mask()
  cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq()
  cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()
  cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1
  sched: Introduce task_cpu_possible_mask() to limit fallback rq selection
  sched: Cgroup SCHED_IDLE support
  sched/topology: Skip updating masks for non-online nodes
  Linux 5.14-rc6
  lib: use PFN_PHYS() in devmem_is_allowed()
  ...
2021-08-31 09:10:00 +01:00
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
Lorenzo Pieralisi
437b38c511 ACPI: Add memory semantics to acpi_os_map_memory()
The memory attributes attached to memory regions depend on architecture
specific mappings.

For some memory regions, the attributes specified by firmware (eg
uncached) are not sufficient to determine how a memory region should be
mapped by an OS (for instance a region that is define as uncached in
firmware can be mapped as Normal or Device memory on arm64) and
therefore the OS must be given control on how to map the region to match
the expected mapping behaviour (eg if a mapping is requested with memory
semantics, it must allow unaligned accesses).

Rework acpi_os_map_memory() and acpi_os_ioremap() back-end to split
them into two separate code paths:

acpi_os_memmap() -> memory semantics
acpi_os_ioremap() -> MMIO semantics

The split allows the architectural implementation back-ends to detect
the default memory attributes required by the mapping in question
(ie the mapping API defines the semantics memory vs MMIO) and map the
memory accordingly.

Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@arm.com
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-25 19:44:57 +02:00
Will Deacon
24de5838db arm64: signal32: Drop pointless call to sigdelsetmask()
Commit 77097ae503 ("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
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: 0370b31e48 ("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
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
Boqun Feng
7d40c0f70d arm64: PCI: Support root bridge preparation for Hyper-V
Currently at root bridge preparation, the corresponding ACPI device will
be set as the companion, however for a Hyper-V virtual PCI root bridge,
there is no corresponding ACPI device, because a Hyper-V virtual PCI
root bridge is discovered via VMBus rather than ACPI table. In order to
support this, we need to make pcibios_root_bridge_prepare() work with
cfg->parent being NULL.

Use a NULL pointer as the ACPI device if there is no corresponding ACPI
device, and this is fine because: 1) ACPI_COMPANION_SET() can work with
the second parameter being NULL, 2) semantically, if a NULL pointer is
set via ACPI_COMPANION_SET(), ACPI_COMPANION() (the read API for this
field) will return NULL, and since ACPI_COMPANION() may return NULL, so
users must have handled the cases where it returns NULL, and 3) since
there is no corresponding ACPI device, it would be wrong to use any
other value here.

Link: https://lore.kernel.org/r/20210726180657.142727-5-boqun.feng@gmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 10:59:26 +01:00
Boqun Feng
b424d4d426 arm64: PCI: Restructure pcibios_root_bridge_prepare()
Restructure the pcibios_root_bridge_prepare() as the preparation for
supporting cases when no real ACPI device is related to the PCI host
bridge.

No functional change.

Link: https://lore.kernel.org/r/20210726180657.142727-4-boqun.feng@gmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-23 10:59:26 +01:00
Marc Zyngier
7c7b363d62 Merge branch kvm-arm64/pkvm-fixed-features-prologue into kvmarm-master/next
* kvm-arm64/pkvm-fixed-features-prologue:
  : Rework a bunch of common infrastructure as a prologue
  : to Fuad Tabba's protected VM fixed feature series.
  KVM: arm64: Upgrade trace_kvm_arm_set_dreg32() to 64bit
  KVM: arm64: Add config register bit definitions
  KVM: arm64: Add feature register flag definitions
  KVM: arm64: Track value of cptr_el2 in struct kvm_vcpu_arch
  KVM: arm64: Keep mdcr_el2's value as set by __init_el2_debug
  KVM: arm64: Restore mdcr_el2 from vcpu
  KVM: arm64: Refactor sys_regs.h,c for nVHE reuse
  KVM: arm64: Fix names of config register fields
  KVM: arm64: MDCR_EL2 is a 64-bit register
  KVM: arm64: Remove trailing whitespace in comment
  KVM: arm64: placeholder to check if VM is protected

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20 12:23:53 +01:00
Will Deacon
94f9c00f64 arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores
The scheduler now knows enough about these braindead systems to place
32-bit tasks accordingly, so throw out the safety checks and allow the
ret-to-user path to avoid do_notify_resume() if there is nothing to do.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-16-will@kernel.org
2021-08-20 12:33:07 +02:00
Will Deacon
ead7de462a arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
Allow systems with mismatched 32-bit support at EL0 to run 32-bit
applications based on a new kernel parameter.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-15-will@kernel.org
2021-08-20 12:33:07 +02:00
Will Deacon
7af33504d1 arm64: Advertise CPUs capable of running 32-bit applications in sysfs
Since 32-bit applications will be killed if they are caught trying to
execute on a 64-bit-only CPU in a mismatched system, advertise the set
of 32-bit capable CPUs to userspace in sysfs.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-14-will@kernel.org
2021-08-20 12:33:07 +02:00
Will Deacon
df950811f4 arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system
If we want to support 32-bit applications, then when we identify a CPU
with mismatched 32-bit EL0 support we must ensure that we will always
have an active 32-bit CPU available to us from then on. This is important
for the scheduler, because is_cpu_allowed() will be constrained to 32-bit
CPUs for compat tasks and forced migration due to a hotplug event will
hang if no 32-bit CPUs are available.

On detecting a mismatch, prevent offlining of either the mismatching CPU
if it is 32-bit capable, or find the first active 32-bit capable CPU
otherwise.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-13-will@kernel.org
2021-08-20 12:33:07 +02:00
Will Deacon
08cd8f4112 arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0
When exec'ing a 32-bit task on a system with mismatched support for
32-bit EL0, try to ensure that it starts life on a CPU that can actually
run it.

Similarly, when exec'ing a 64-bit task on such a system, try to restore
the old affinity mask if it was previously restricted.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-12-will@kernel.org
2021-08-20 12:33:06 +02:00
Fuad Tabba
95b54c3e4c KVM: arm64: Add feature register flag definitions
Add feature register flag definitions to clarify which features
might be supported.

Consolidate the various ID_AA64PFR0_ELx flags for all ELs.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210817081134.2918285-10-tabba@google.com
2021-08-20 11:12:18 +01:00
Alexey Dobriyan
39f75da7bc isystem: trim/fixup stdarg.h and other headers
Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-19 09:02:55 +09:00
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
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
Michael Kelley
9b16c2132f arm64: efi: Export screen_info
The Hyper-V frame buffer driver may be built as a module, and
it needs access to screen_info. So export screen_info.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1628092359-61351-5-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-08-04 16:54:36 +00:00
Marc Zyngier
eb48d154cd arm64: Move .hyp.rodata outside of the _sdata.._edata range
The HYP rodata section is currently lumped together with the BSS,
which isn't exactly what is expected (it gets registered with
kmemleak, for example).

Move it away so that it is actually marked RO. As an added
benefit, it isn't registered with kmemleak anymore.

Fixes: 380e18ade4 ("KVM: arm64: Introduce a BSS section for use at Hyp")
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org #5.13
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802123830.2195174-2-maz@kernel.org
2021-08-04 13:09:20 +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
0c32706dac arm64: stacktrace: avoid tracing arch_stack_walk()
When the function_graph tracer is in use, arch_stack_walk() may unwind
the stack incorrectly, erroneously reporting itself, missing the final
entry which is being traced, and reporting all traced entries between
these off-by-one from where they should be.

When ftrace hooks a function return, the original return address is
saved to the fgraph ret_stack, and the return address  in the LR (or the
function's frame record) is replaced with `return_to_handler`.

When arm64's unwinder encounter frames returning to `return_to_handler`,
it finds the associated original return address from the fgraph ret
stack, assuming the most recent `ret_to_hander` entry on the stack
corresponds to the most recent entry in the fgraph ret stack, and so on.

When arch_stack_walk() is used to dump the current task's stack, it
starts from the caller of arch_stack_walk(). However, arch_stack_walk()
can be traced, and so may push an entry on to the fgraph ret stack,
leaving the fgraph ret stack offset by one from the expected position.

This can be seen when dumping the stack via /proc/self/stack, where
enabling the graph tracer results in an unexpected
`stack_trace_save_tsk` entry at the start of the trace, and `el0_svc`
missing form the end of the trace.

This patch fixes this by marking arch_stack_walk() as notrace, as we do
for all other functions on the path to ftrace_graph_get_ret_stack().
While a few helper functions are not marked notrace, their calls/returns
are balanced, and will have no observable effect when examining the
fgraph ret stack.

It is possible for an exeption boundary to cause a similar offset if the
return address of the interrupted context was in the LR. Fixing those
cases will require some more substantial rework, and is left for
subsequent patches.

Before:

| # cat /proc/self/stack
| [<0>] proc_pid_stack+0xc4/0x140
| [<0>] proc_single_show+0x6c/0x120
| [<0>] seq_read_iter+0x240/0x4e0
| [<0>] seq_read+0xe8/0x140
| [<0>] vfs_read+0xb8/0x1e4
| [<0>] ksys_read+0x74/0x100
| [<0>] __arm64_sys_read+0x28/0x3c
| [<0>] invoke_syscall+0x50/0x120
| [<0>] el0_svc_common.constprop.0+0xc4/0xd4
| [<0>] do_el0_svc+0x30/0x9c
| [<0>] el0_svc+0x2c/0x54
| [<0>] el0t_64_sync_handler+0x1a8/0x1b0
| [<0>] el0t_64_sync+0x198/0x19c
| # echo function_graph > /sys/kernel/tracing/current_tracer
| # cat /proc/self/stack
| [<0>] stack_trace_save_tsk+0xa4/0x110
| [<0>] proc_pid_stack+0xc4/0x140
| [<0>] proc_single_show+0x6c/0x120
| [<0>] seq_read_iter+0x240/0x4e0
| [<0>] seq_read+0xe8/0x140
| [<0>] vfs_read+0xb8/0x1e4
| [<0>] ksys_read+0x74/0x100
| [<0>] __arm64_sys_read+0x28/0x3c
| [<0>] invoke_syscall+0x50/0x120
| [<0>] el0_svc_common.constprop.0+0xc4/0xd4
| [<0>] do_el0_svc+0x30/0x9c
| [<0>] el0t_64_sync_handler+0x1a8/0x1b0
| [<0>] el0t_64_sync+0x198/0x19c

After:

| # cat /proc/self/stack
| [<0>] proc_pid_stack+0xc4/0x140
| [<0>] proc_single_show+0x6c/0x120
| [<0>] seq_read_iter+0x240/0x4e0
| [<0>] seq_read+0xe8/0x140
| [<0>] vfs_read+0xb8/0x1e4
| [<0>] ksys_read+0x74/0x100
| [<0>] __arm64_sys_read+0x28/0x3c
| [<0>] invoke_syscall+0x50/0x120
| [<0>] el0_svc_common.constprop.0+0xc4/0xd4
| [<0>] do_el0_svc+0x30/0x9c
| [<0>] el0_svc+0x2c/0x54
| [<0>] el0t_64_sync_handler+0x1a8/0x1b0
| [<0>] el0t_64_sync+0x198/0x19c
| # echo function_graph > /sys/kernel/tracing/current_tracer
| # cat /proc/self/stack
| [<0>] proc_pid_stack+0xc4/0x140
| [<0>] proc_single_show+0x6c/0x120
| [<0>] seq_read_iter+0x240/0x4e0
| [<0>] seq_read+0xe8/0x140
| [<0>] vfs_read+0xb8/0x1e4
| [<0>] ksys_read+0x74/0x100
| [<0>] __arm64_sys_read+0x28/0x3c
| [<0>] invoke_syscall+0x50/0x120
| [<0>] el0_svc_common.constprop.0+0xc4/0xd4
| [<0>] do_el0_svc+0x30/0x9c
| [<0>] el0_svc+0x2c/0x54
| [<0>] el0t_64_sync_handler+0x1a8/0x1b0
| [<0>] el0t_64_sync+0x198/0x19c

Cc: <stable@vger.kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviwed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210802164845.45506-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-03 10:39:35 +01:00
Barry Song
f9c4ff2ab9 arm64: fix the doc of RANDOMIZE_MODULE_REGION_FULL
Obviously kaslr is setting the module region to 2GB rather than 4GB since
commit b2eed9b588 ("arm64/kernel: kaslr: reduce module randomization
range to 2 GB"). So fix the size of region in Kconfig.
On the other hand, even though RANDOMIZE_MODULE_REGION_FULL is not set,
module_alloc() can fall back to a 2GB window if ARM64_MODULE_PLTS is set.
In this case, veneers are still needed. !RANDOMIZE_MODULE_REGION_FULL
doesn't necessarily mean veneers are not needed.
So fix the doc to be more precise to avoid any confusion to the readers
of the code.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210730125131.13724-1-song.bao.hua@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-03 10:36:42 +01:00
Mark Rutland
e30e8d46cf arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:

* For audit and tracing, where error codes are handled as a (native)
  long, negative error codes are expected to be sign-extended to the
  native 64-bits, or they may fail to be matched correctly. Thus a
  syscall which fails with an error may erroneously be identified as
  failing.

* For ptrace, *all* compat return values should be sign-extended for
  consistency with 32-bit arm, but we currently only do this for
  negative return codes.

* As we may transiently set the upper 32 bits of some compat GPRs while
  in the kernel, these can be sampled by perf, which is somewhat
  confusing. This means that where a syscall returns a pointer above 2G,
  this will be sign-extended, but will not be mistaken for an error as
  error codes are constrained to the inclusive range [-4096, -1] where
  no user pointer can exist.

To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code.  This
patch does so, with the following changes:

* We re-organise syscall_get_return_value() to always sign-extend for
  compat tasks, and reimplement syscall_get_error() atop. We update
  syscall_trace_exit() to use syscall_get_return_value().

* We consistently use syscall_set_return_value() to set the return
  value, ensureing the upper 32 bits are never set unexpectedly.

* As the core audit code currently uses regs_return_value() rather than
  syscall_get_return_value(), we special-case this for
  compat_user_mode(regs) such that this will do the right thing. Going
  forward, we should try to move the core audit code over to
  syscall_get_return_value().

Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-03 10:35:03 +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
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
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
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
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
Peter Collingbourne
42b6b10a54 arm64: mte: avoid TFSRE0_EL1 related operations unless in async mode
There is no reason to touch TFSRE0_EL1 nor issue a DSB unless our task
is in asynchronous mode. Since these operations (especially the DSB) may
be expensive on certain microarchitectures, only perform them if
necessary.

Furthermore, stop clearing TFSRE0_EL1 on entry because it will be
cleared on exit and it is not necessary to have any particular value in
TFSRE0_EL1 between entry and exit.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Ib353a63e3d0abc2b0b008e96aa2d9692cfc1b815
Link: https://lore.kernel.org/r/20210709023532.2133673-1-pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-07-27 18:12:18 +01:00
Eric W. Biederman
50ae81305c signal: Verify the alignment and size of siginfo_t
Update the static assertions about siginfo_t to also describe
it's alignment and size.

While investigating if it was possible to add a 64bit field into
siginfo_t[1] it became apparent that the alignment of siginfo_t
is as much a part of the ABI as the size of the structure.

If the alignment changes siginfo_t when embedded in another structure
can move to a different offset.  Which is not acceptable from an ABI
structure.

So document that fact and add static assertions to notify developers
if they change change the alignment by accident.

[1] https://lkml.kernel.org/r/YJEZdhe6JGFNYlum@elver.google.com
Acked-by: Marco Elver <elver@google.com>
v1: https://lkml.kernel.org/r/20210505141101.11519-4-ebiederm@xmission.co
Link: https://lkml.kernel.org/r/875yxaxmyl.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-07-23 13:15:31 -05:00
Marco Elver
726e337b64 arm64: Add compile-time asserts for siginfo_t offsets
To help catch ABI breaks at compile-time, add compile-time assertions to
verify the siginfo_t layout.

Link: https://lkml.kernel.org/r/20210505141101.11519-3-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210429190734.624918-3-elver@google.com
Link: https://lkml.kernel.org/r/87sg0fxx92.fsf_-_@disp2133
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-07-23 11:57:45 -05:00
Jean-Philippe Brucker
a7c3acca53 arm64: smccc: Save lr before calling __arm_smccc_sve_check()
Commit cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register
saving hint") added a call to __arm_smccc_sve_check() which clobbers the
lr (register x30), causing __arm_smccc_hvc() to return to itself and
crash. Save lr on the stack before calling __arm_smccc_sve_check(). Save
the frame pointer (x29) to complete the frame record, and adjust the
offsets used to access stack parameters.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Fixes: cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210721071834.69130-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-07-21 11:23:25 +01:00
Mark Rutland
e6f85cbeb2 arm64: entry: fix KCOV suppression
We suppress KCOV for entry.o rather than entry-common.o. As entry.o is
built from entry.S, this is pointless, and permits instrumentation of
entry-common.o, which is built from entry-common.c.

Fix the Makefile to suppress KCOV for entry-common.o, as we had intended
to begin with. I've verified with objdump that this is working as
expected.

Fixes: bf6fa2c0dd ("arm64: entry: don't instrument entry code with KCOV")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210715123049.9990-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-07-15 17:37:55 +01:00
Mark Rutland
31a7f0f6c8 arm64: entry: add missing noinstr
We intend that all the early exception handling code is marked as
`noinstr`, but we forgot this for __el0_error_handler_common(), which is
called before we have completed entry from user mode. If it were
instrumented, we could run into problems with RCU, lockdep, etc.

Mark it as `noinstr` to prevent this.

The few other functions in entry-common.c which do not have `noinstr` are
called once we've completed entry, and are safe to instrument.

Fixes: bb8e93a287 ("arm64: entry: convert SError handlers to C")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: 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/20210714172801.16475-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-07-15 17:36:51 +01:00