Pull arm64 updates from Will Deacon:
"There's good stuff across the board, including some nice mm
improvements for CPUs with the 'noabort' BBML2 feature and a clever
patch to allow ptdump to play nicely with block mappings in the
vmalloc area.
Confidential computing:
- Add support for accepting secrets from firmware (e.g. ACPI CCEL)
and mapping them with appropriate attributes.
CPU features:
- Advertise atomic floating-point instructions to userspace
- Extend Spectre workarounds to cover additional Arm CPU variants
- Extend list of CPUs that support break-before-make level 2 and
guarantee not to generate TLB conflict aborts for changes of
mapping granularity (BBML2_NOABORT)
- Add GCS support to our uprobes implementation.
Documentation:
- Remove bogus SME documentation concerning register state when
entering/exiting streaming mode.
Entry code:
- Switch over to the generic IRQ entry code (GENERIC_IRQ_ENTRY)
- Micro-optimise syscall entry path with a compiler branch hint.
Memory management:
- Enable huge mappings in vmalloc space even when kernel page-table
dumping is enabled
- Tidy up the types used in our early MMU setup code
- Rework rodata= for closer parity with the behaviour on x86
- For CPUs implementing BBML2_NOABORT, utilise block mappings in the
linear map even when rodata= applies to virtual aliases
- Don't re-allocate the virtual region between '_text' and '_stext',
as doing so confused tools parsing /proc/vmcore.
Miscellaneous:
- Clean-up Kconfig menuconfig text for architecture features
- Avoid redundant bitmap_empty() during determination of supported
SME vector lengths
- Re-enable warnings when building the 32-bit vDSO object
- Avoid breaking our eggs at the wrong end.
Perf and PMUs:
- Support for v3 of the Hisilicon L3C PMU
- Support for Hisilicon's MN and NoC PMUs
- Support for Fujitsu's Uncore PMU
- Support for SPE's extended event filtering feature
- Preparatory work to enable data source filtering in SPE
- Support for multiple lanes in the DWC PCIe PMU
- Support for i.MX94 in the IMX DDR PMU driver
- MAINTAINERS update (Thank you, Yicong)
- Minor driver fixes (PERF_IDX2OFF() overflow, CMN register offsets).
Selftests:
- Add basic LSFE check to the existing hwcaps test
- Support nolibc in GCS tests
- Extend SVE ptrace test to pass unsupported regsets and invalid
vector lengths
- Minor cleanups (typos, cosmetic changes).
System registers:
- Fix ID_PFR1_EL1 definition
- Fix incorrect signedness of some fields in ID_AA64MMFR4_EL1
- Sync TCR_EL1 definition with the latest Arm ARM (L.b)
- Be stricter about the input fed into our AWK sysreg generator
script
- Typo fixes and removal of redundant definitions.
ACPI, EFI and PSCI:
- Decouple Arm's "Software Delegated Exception Interface" (SDEI)
support from the ACPI GHES code so that it can be used by platforms
booted with device-tree
- Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
runtime calls
- Fix a node refcount imbalance in the PSCI device-tree code.
CPU Features:
- Ensure register sanitisation is applied to fields in ID_AA64MMFR4
- Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM
guests can reliably query the underlying CPU types from the VMM
- Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
to our context-switching, signal handling and ptrace code"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
arm64: cpufeature: Remove duplicate asm/mmu.h header
arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
perf/dwc_pcie: Fix use of uninitialized variable
arm/syscalls: mark syscall invocation as likely in invoke_syscall
Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU
Documentation: hisi-pmu: Fix of minor format error
drivers/perf: hisi: Add support for L3C PMU v3
drivers/perf: hisi: Refactor the event configuration of L3C PMU
drivers/perf: hisi: Extend the field of tt_core
drivers/perf: hisi: Extract the event filter check of L3C PMU
drivers/perf: hisi: Simplify the probe process of each L3C PMU version
drivers/perf: hisi: Export hisi_uncore_pmu_isr()
drivers/perf: hisi: Relax the event ID check in the framework
perf: Fujitsu: Add the Uncore PMU driver
arm64: map [_text, _stext) virtual address range non-executable+read-only
arm64/sysreg: Update TCR_EL1 register
arm64: Enable vmalloc-huge with ptdump
arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
arm64: errata: Apply workarounds for Neoverse-V3AE
arm64: cputype: Add Neoverse-V3AE definitions
...
The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).
Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
The generic entry code expects architecture code to provide
regs_irqs_disabled(regs) function, but arm64 does not have this and
provides interrupts_enabled(regs), which has the opposite polarity.
In preparation for moving arm64 over to the generic entry code,
relace arm64's interrupts_enabled() with regs_irqs_disabled() and
update its callers under arch/arm64.
For the moment, a definition of interrupts_enabled() is provided for
the GICv3 driver. Once arch/arm implement regs_irqs_disabled(), this
can be removed.
Delete the fast_interrupts_enabled() macro as it is unused and we
don't want any new users to show up.
No functional changes.
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
* arm64/for-next/perf: (23 commits)
drivers/perf: hisi: Support PMUs with no interrupt
drivers/perf: hisi: Relax the event number check of v2 PMUs
drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
drivers/perf: hisi: Simplify the probe process for each DDRC version
perf/arm-ni: Support sharing IRQs within an NI instance
perf/arm-ni: Consolidate CPU affinity handling
perf/cxlpmu: Fix typos in cxl_pmu.c comments and documentation
perf/cxlpmu: Remove unintended newline from IRQ name format string
perf/cxlpmu: Fix devm_kcalloc() argument order in cxl_pmu_probe()
perf: arm_spe: Relax period restriction
perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)
KVM: arm64: nvhe: Disable branch generation in nVHE guests
arm64: Handle BRBE booting requirements
arm64/sysreg: Add BRBE registers and fields
perf/arm: Add missing .suppress_bind_attrs
perf/arm-cmn: Reduce stack usage during discovery
perf: imx9_perf: make the read-only array mask static const
perf/arm-cmn: Broaden module description for wider interconnect support
...
* for-next/livepatch:
: Support for HAVE_LIVEPATCH on arm64
arm64: Kconfig: Keep selects somewhat alphabetically ordered
arm64: Implement HAVE_LIVEPATCH
arm64: stacktrace: Implement arch_stack_walk_reliable()
arm64: stacktrace: Check kretprobe_find_ret_addr() return value
arm64/module: Use text-poke API for late relocations.
* for-next/user-contig-bbml2:
: Optimise the TLBI when folding/unfolding contigous PTEs on hardware with BBML2 and no TLB conflict aborts
arm64/mm: Elide tlbi in contpte_convert() under BBML2
iommu/arm: Add BBM Level 2 smmu feature
arm64: Add BBM Level 2 cpu feature
arm64: cpufeature: Introduce MATCH_ALL_EARLY_CPUS capability type
* for-next/misc:
: Miscellaneous arm64 patches
arm64/gcs: task_gcs_el0_enable() should use passed task
arm64: signal: Remove ISB when resetting POR_EL0
arm64/mm: Drop redundant addr increment in set_huge_pte_at()
arm64: Mark kernel as tainted on SAE and SError panic
arm64/gcs: Don't call gcs_free() when releasing task_struct
arm64: fix unnecessary rebuilding when CONFIG_DEBUG_EFI=y
arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get
arm64: pi: use 'targets' instead of extra-y in Makefile
* for-next/acpi:
: Various ACPI arm64 changes
ACPI: Suppress misleading SPCR console message when SPCR table is absent
ACPI: Return -ENODEV from acpi_parse_spcr() when SPCR support is disabled
* for-next/debug-entry:
: Simplify the debug exception entry path
arm64: debug: remove debug exception registration infrastructure
arm64: debug: split bkpt32 exception entry
arm64: debug: split brk64 exception entry
arm64: debug: split hardware watchpoint exception entry
arm64: debug: split single stepping exception entry
arm64: debug: refactor reinstall_suspended_bps()
arm64: debug: split hardware breakpoint exception entry
arm64: entry: Add entry and exit functions for debug exceptions
arm64: debug: remove break/step handler registration infrastructure
arm64: debug: call step handlers statically
arm64: debug: call software breakpoint handlers statically
arm64: refactor aarch32_break_handler()
arm64: debug: clean up single_step_handler logic
* for-next/feat_mte_tagged_far:
: Support for reporting the non-address bits during a synchronous MTE tag check fault
kselftest/arm64/mte: Add mtefar tests on check_mmap_options
kselftest/arm64/mte: Refactor check_mmap_option test
kselftest/arm64/mte: Add verification for address tag in signal handler
kselftest/arm64/mte: Add address tag related macro and function
kselftest/arm64/mte: Check MTE_FAR feature is supported
kselftest/arm64/mte: Register mte signal handler with SA_EXPOSE_TAGBITS
kselftest/arm64: Add MTE_FAR hwcap test
KVM: arm64: Expose FEAT_MTE_TAGGED_FAR feature to guest
arm64: Report address tag when FEAT_MTE_TAGGED_FAR is supported
arm64/cpufeature: Add FEAT_MTE_TAGGED_FAR feature
* for-next/kselftest:
: Kselftest updates for arm64
kselftest/arm64: Handle attempts to disable SM on SME only systems
kselftest/arm64: Fix SVE write data generation for SME only systems
kselftest/arm64: Test SME on SME only systems in fp-ptrace
kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
kselftest/arm64: Allow sve-ptrace to run on SME only systems
kselftest/arm4: Provide local defines for AT_HWCAP3
kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace
kselftest/arm64: Fix test for streaming FPSIMD write in sve-ptrace
kselftest/arm64: Fix check for setting new VLs in sve-ptrace
kselftest/arm64: Convert tpidr2 test to use kselftest.h
* for-next/mdscr-cleanup:
: Drop redundant DBG_MDSCR_* macros
KVM: selftests: Change MDSCR_EL1 register holding variables as uint64_t
arm64/debug: Drop redundant DBG_MDSCR_* macros
* for-next/vmap-stack:
: Force VMAP_STACK on arm64
arm64: remove CONFIG_VMAP_STACK checks from entry code
arm64: remove CONFIG_VMAP_STACK checks from SDEI stack handling
arm64: remove CONFIG_VMAP_STACK checks from stacktrace overflow logic
arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stack
arm64: remove CONFIG_VMAP_STACK conditionals from irq stack setup
arm64: Remove CONFIG_VMAP_STACK conditionals from THREAD_SHIFT and THREAD_ALIGN
arm64: efi: Remove CONFIG_VMAP_STACK check
arm64: Mandate VMAP_STACK
arm64: efi: Fix KASAN false positive for EFI runtime stack
arm64/ptrace: Fix stack-out-of-bounds read in regs_get_kernel_stack_nth()
arm64/gcs: Don't call gcs_free() during flush_gcs()
arm64: Restrict pagetable teardown to avoid false warning
docs: arm64: Fix ICC_SRE_EL2 register typo in booting.rst
Now that debug exceptions are handled individually and without the need
for dynamic registration, remove the unused registration infrastructure.
This removes the external caller for `debug_exception_enter()` and
`debug_exception_exit()`.
Make them static again and remove them from the header.
Remove `early_brk64()` as it has been made redundant by
(arm64: debug: split brk64 exception entry) and is not used anymore.
Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally
as a fall-through, but now `call_break_hook()` only calls it if the
immediate matches.
This does not change the behaviour in early boot, as if
`bug_brk_handler()` was called on a non-BUG immediate it would return
DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate
matches.
Remove `trap_init()`, as it would be empty and a weak definition already
exists in `init/main.c`.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.
The BKPT32 exception can only be triggered by a BKPT instruction. Thus,
we know that the PC is a legitimate address and isn't being used to train
a branch predictor with a bogus address : we don't need to call
`arm64_apply_bp_hardening()`.
The handler for this exception only pends a signal and doesn't depend
on any per-CPU state : we don't need to inhibit preemption, nor do we
need to keep the DAIF exceptions masked, so we can unmask them earlier.
Split the BKPT32 exception entry and adjust function signatures and its
behaviour to match its relaxed constraints compared to other
debug exceptions.
We can also remove `NOKRPOBE_SYMBOL`, as this cannot lead to a kprobe
recursion.
This replaces the last usage of `el0_dbg()`, so remove it.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-13-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.
The BRK64 instruction can only be triggered by a BRK instruction. Thus,
we know that the PC is a legitimate address and isn't being used to train
a branch predictor with a bogus address : we don't need to call
`arm64_apply_bp_hardening()`.
We do not need to handle the Cortex-A76 erratum #1463225 either, as it
only relevant for single stepping at EL1.
BRK64 does not write FAR_EL1 either, as only hardware watchpoints do so.
Split the BRK64 exception entry, adjust the function signature, and its
behaviour to match the lack of needed mitigations.
Further, as the EL0 and EL1 code paths are cleanly separated, we can split
`do_brk64()` into `do_el0_brk64()` and `do_el1_brk64()`, and call them
directly from the relevant entry paths.
Use `die()` directly for the EL1 error path, as in `do_el1_bti()` and
`do_el1_undef()`.
We can also remove `NOKRPOBE_SYMBOL` for the EL0 path, as it cannot
lead to a kprobe recursion.
When taking a BRK64 exception from EL0, the exception handling is safely
preemptible : the only possible handler is `uprobe_brk_handler()`.
It only operates on task-local data and properly checks its validity,
then raises a Thread Information Flag, processed before returning
to userspace in `do_notify_resume()`, which is already preemptible.
Thus we can safely unmask interrupts and enable preemption before
handling the break itself, fixing a PREEMPT_RT issue where the handler
could call a sleeping function with preemption disabled.
Given that the break hook registration is handled statically in
`call_break_hook` since
(arm64: debug: call software break handlers statically)
and that we now bypass the exception handler registration, this change
renders `early_brk64` redundant : its functionality is now handled through
the post-init path.
This also removes the last usage of `el1_dbg()`.
This also removes the last usage of `el0_dbg()` without `CONFIG_COMPAT`.
Mark it `__maybe_unused`, to prevent a warning when building this patch
without `CONFIG_COMPAT`, as the following patch removes `el0_dbg()`.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-12-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.
The single stepping exception has the most constraints : it can be
exploited to train branch predictors and it needs special handling at EL1
for the Cortex-A76 erratum #1463225. We need to conserve all those
mitigations.
However, it does not write an address at FAR_EL1, as only hardware
watchpoints do so.
The single-step handler does its own signaling if it needs to and only
returns 0, so we can call it directly from `entry-common.c`.
Split the single stepping exception entry, adjust the function signature,
keep the security mitigation and erratum handling.
Further, as the EL0 and EL1 code paths are cleanly separated, we can split
`do_softstep()` into `do_el0_softstep()` and `do_el1_softstep()` and
call them directly from the relevant entry paths.
We can also remove `NOKPROBE_SYMBOL` for the EL0 path, as it cannot
lead to a kprobe recursion.
Move the call to `arm64_apply_bp_hardening()` to `entry-common.c` so that
we can do it as early as possible, and only for the exceptions coming
from EL0, where it is needed.
This is safe to do as it is `noinstr`, as are all the functions it
may call. `el0_ia()` and `el0_pc()` already call it this way.
When taking a soft-step exception from EL0, most of the single stepping
handling is safely preemptible : the only possible handler is
`uprobe_single_step_handler()`. It only operates on task-local data and
properly checks its validity, then raises a Thread Information Flag,
processed before returning to userspace in `do_notify_resume()`, which
is already preemptible.
However, the soft-step handler first calls `reinstall_suspended_bps()`
to check if there is any hardware breakpoint or watchpoint pending
or already stepped through.
This cannot be preempted as it manipulates the hardware breakpoint and
watchpoint registers.
Move the call to `try_step_suspended_breakpoints()` to `entry-common.c`
and adjust the relevant comments.
We can now safely unmask interrupts before handling the step itself,
fixing a PREEMPT_RT issue where the handler could call a sleeping function
with preemption disabled.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Closes: https://lore.kernel.org/linux-arm-kernel/Z6YW_Kx4S2tmj2BP@uudg.org/
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-10-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
`reinstall_suspended_bps()` plays a key part in the stepping process
when we have hardware breakpoints and watchpoints enabled.
It checks if we need to step one, will re-enable it if it has
been handled and will return whether or not we need to proceed with
a single-step.
However, the current naming and return values make it harder to understand
the logic and goal of the function.
Rename it `try_step_suspended_breakpoints()` and change the return value
to a boolean, aligning it with similar functions used in
`do_el0_undef()` like `try_emulate_mrs()`, and making its behaviour
more obvious.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-9-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Software stepping checks for the correct handler by iterating over a list
of dynamically registered handlers and calling all of them until one
handles the exception.
This is the only generic way to handle software stepping handlers in arm64
as the exception does not provide an immediate that could be checked,
contrary to software breakpoints.
However, the registration mechanism is not exported and has only
two current users : the KGDB stepping handler, and the uprobe single step
handler.
Given that one comes from user mode and the other from kernel mode, call
the appropriate one by checking the source EL of the exception.
Add a stand-in that returns DBG_HOOK_ERROR when the configuration
options are not enabled.
Remove `arch_init_uprobes()` as it is not useful anymore and is
specific to arm64.
Unify the naming of the handler to XXX_single_step_handler(), making it
clear they are related.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-5-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Software breakpoints pass an immediate value in ESR ("comment") that can
be used to call a specialized handler (KGDB, KASAN...).
We do so in two different ways :
- During early boot, `early_brk64` statically checks against known
immediates and calls the corresponding handler,
- During init, handlers are dynamically registered into a list. When
called, the generic software breakpoint handler will iterate over
the list to find the appropriate handler.
The dynamic registration does not provide any benefit here as it is not
exported and all its uses are within the arm64 tree. It also depends on an
RCU list, whose safe access currently relies on the non-preemptible state
of `do_debug_exception`.
Replace the list iteration logic in `call_break_hooks` to call
the breakpoint handlers statically if they are enabled, like in
`early_brk64`.
Expose the handlers in their respective headers to be reachable from
`arch/arm64/kernel/debug-monitors.c` at link time.
Unify the naming of the software breakpoint handlers to XXX_brk_handler(),
making it clear they are related and to differentiate from the
hardware breakpoints.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-4-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
`aarch32_break_handler()` is called in `do_el0_undef()` when we
are trying to handle an exception whose Exception Syndrome is unknown.
It checks if the instruction hit might be a 32-bit arm break (be it
A32 or T2), and sends a SIGTRAP to userspace if it is so that it can
be handled.
However, this is badly represented in the naming of the function, and
is not consistent with the other functions called with the same logic
in `do_el0_undef()`.
Rename it `try_handle_aarch32_break()` and change the return value to
a boolean to align with the logic of the other tentative handlers in
`do_el0_undef()`, the previous error code being ignored anyway.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250707114109.35672-3-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
MDSCR_EL1 has already been defined in tools sysreg format and hence can be
used in all debug monitor related call paths. But using generated sysreg
definitions causes build warnings because there is a mismatch between mdscr
variable (u32) and GENMASK() based masks (long unsigned int). Convert all
variables handling MDSCR_EL1 register as u64 which also reflects its true
width as well.
--------------------------------------------------------------------------
arch/arm64/kernel/debug-monitors.c: In function ‘disable_debug_monitors’:
arch/arm64/kernel/debug-monitors.c:108:13: warning: conversion from ‘long
unsigned int’ to ‘u32’ {aka ‘unsigned int’} changes value from
‘18446744073709518847’ to ‘4294934527’ [-Woverflow]
108 | disable = ~MDSCR_EL1_MDE;
| ^
--------------------------------------------------------------------------
While here, replace an open encoding with MDSCR_EL1_TDCC in __cpu_setup().
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250613023646.1215700-2-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We will soon be using MOPS instructions in the kernel, so wire up the
exception handler to handle exceptions from EL1 caused by the copy/set
operation being stopped and resumed on a different type of CPU.
Add a helper for advancing the single step state machine, similarly to
what the EL0 exception handler does.
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20240930161051.3777828-3-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently only the first attempt to single-step has any effect. After
that all further stepping remains "stuck" at the same program counter
value.
Refer to the ARM Architecture Reference Manual (ARM DDI 0487E.a) D2.12,
PSTATE.SS=1 should be set at each step before transferring the PE to the
'Active-not-pending' state. The problem here is PSTATE.SS=1 is not set
since the second single-step.
After the first single-step, the PE transferes to the 'Inactive' state,
with PSTATE.SS=0 and MDSCR.SS=1, thus PSTATE.SS won't be set to 1 due to
kernel_active_single_step()=true. Then the PE transferes to the
'Active-pending' state when ERET and returns to the debugger by step
exception.
Before this patch:
==================
Entering kdb (current=0xffff3376039f0000, pid 1) on processor 0 due to Keyboard Entry
[0]kdb>
[0]kdb>
[0]kdb> bp write_sysrq_trigger
Instruction(i) BP #0 at 0xffffa45c13d09290 (write_sysrq_trigger)
is enabled addr at ffffa45c13d09290, hardtype=0 installed=0
[0]kdb> go
$ echo h > /proc/sysrq-trigger
Entering kdb (current=0xffff4f7e453f8000, pid 175) on processor 1 due to Breakpoint @ 0xffffad651a309290
[1]kdb> ss
Entering kdb (current=0xffff4f7e453f8000, pid 175) on processor 1 due to SS trap @ 0xffffad651a309294
[1]kdb> ss
Entering kdb (current=0xffff4f7e453f8000, pid 175) on processor 1 due to SS trap @ 0xffffad651a309294
[1]kdb>
After this patch:
=================
Entering kdb (current=0xffff6851c39f0000, pid 1) on processor 0 due to Keyboard Entry
[0]kdb> bp write_sysrq_trigger
Instruction(i) BP #0 at 0xffffc02d2dd09290 (write_sysrq_trigger)
is enabled addr at ffffc02d2dd09290, hardtype=0 installed=0
[0]kdb> go
$ echo h > /proc/sysrq-trigger
Entering kdb (current=0xffff6851c53c1840, pid 174) on processor 1 due to Breakpoint @ 0xffffc02d2dd09290
[1]kdb> ss
Entering kdb (current=0xffff6851c53c1840, pid 174) on processor 1 due to SS trap @ 0xffffc02d2dd09294
[1]kdb> ss
Entering kdb (current=0xffff6851c53c1840, pid 174) on processor 1 due to SS trap @ 0xffffc02d2dd09298
[1]kdb> ss
Entering kdb (current=0xffff6851c53c1840, pid 174) on processor 1 due to SS trap @ 0xffffc02d2dd0929c
[1]kdb>
Fixes: 44679a4f14 ("arm64: KGDB: Add step debugging support")
Co-developed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20230202073148.657746-3-sumit.garg@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64DFR0_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The naming scheme the architecture uses for the fields in ID_AA64DFR0_EL1
does not align well with kernel conventions, using as it does a lot of
MixedCase in various arrangements. In preparation for automatically
generating the defines for this register rename the defines used to match
what is in the architecture.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In the initial release of the ARM Architecture Reference Manual for
ARMv8-A, the ESR_ELx registers were defined as 32-bit registers. This
changed in 2018 with version D.a (ARM DDI 0487D.a) of the architecture,
when they became 64-bit registers, with bits [63:32] defined as RES0. In
version G.a, a new field was added to ESR_ELx, ISS2, which covers bits
[36:32]. This field is used when the Armv8.7 extension FEAT_LS64 is
implemented.
As a result of the evolution of the register width, Linux stores it as
both a 64-bit value and a 32-bit value, which hasn't affected correctness
so far as Linux only uses the lower 32 bits of the register.
Make the register type consistent and always treat it as 64-bit wide. The
register is redefined as an "unsigned long", which is an unsigned
double-word (64-bit quantity) for the LP64 machine (aapcs64 [1], Table 1,
page 14). The type was chosen because "unsigned int" is the most frequent
type for ESR_ELx and because FAR_ELx, which is used together with ESR_ELx
in exception handling, is also declared as "unsigned long". The 64-bit type
also makes adding support for architectural features that use fields above
bit 31 easier in the future.
The KVM hypervisor will receive a similar update in a subsequent patch.
[1] https://github.com/ARM-software/abi-aa/releases/download/2021Q3/aapcs64.pdf
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-4-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When generating instructions at runtime, for example due to kernel text
patching or the BPF JIT, we can emit a trapping BRK instruction if we
are asked to encode an invalid instruction such as an out-of-range]
branch. This is indicative of a bug in the caller, and will result in a
crash on executing the generated code. Unfortunately, the message from
the crash is really unhelpful, and mumbles something about ptrace:
| Unexpected kernel BRK exception at EL1
| Internal error: ptrace BRK handler: f2000100 [#1] SMP
We can do better than this. Install a break handler for FAULT_BRK_IMM,
which is the immediate used to encode the "I've been asked to generate
an invalid instruction" error, and triage the faulting PC to determine
whether or not the failure occurred in the BPF JIT.
Link: https://lore.kernel.org/r/20200915141707.GB26439@willie-the-truck
Reported-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
