KASAN optimisations for the hardware tagging (MTE) implementation.
* for-next/mte:
kasan: disable freed user page poisoning with HW tags
arm64: mte: handle tags zeroing at page allocation time
kasan: use separate (un)poison implementation for integrated init
mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable()
kasan: speed up mte_set_mem_tag_range
Lots of cleanup to our various page-table definitions, but also some
non-critical fixes and removal of some unnecessary memory types. The
most interesting change here is the reduction of ARCH_DMA_MINALIGN back
to 64 bytes, since we're not aware of any machines that need a higher
value with the way the code is structured (only needed for non-coherent
DMA).
* for-next/mm:
arm64: tlb: fix the TTL value of tlb_get_level
arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
arm64: head: fix code comments in set_cpu_boot_mode_flag
arm64: mm: drop unused __pa(__idmap_text_start)
arm64: mm: fix the count comments in compute_indices
arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
arm64: mm: Pass original fault address to handle_mm_fault()
arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]
arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT
arm64/mm: Drop SWAPPER_INIT_MAP_SIZE
arm64: mm: decode xFSC in mem_abort_decode()
arm64: mm: Add is_el1_data_abort() helper
arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES)
arm64: mm: Remove unused support for Normal-WT memory type
arm64: acpi: Map EFI_MEMORY_WT memory as Normal-NC
arm64: mm: Remove unused support for Device-GRE memory type
arm64: mm: Use better bitmap_zalloc()
arm64/mm: Make vmemmap_free() available only with CONFIG_MEMORY_HOTPLUG
arm64/mm: Remove [PUD|PMD]_TABLE_BIT from [pud|pmd]_bad()
arm64/mm: Validate CONFIG_PGTABLE_LEVELS
The never-ending entry.S refactoring continues, putting us in a much
better place wrt compiler instrumentation whilst moving more of the code
into C.
* for-next/entry:
arm64: idle: don't instrument idle code with KCOV
arm64: entry: don't instrument entry code with KCOV
arm64: entry: make NMI entry/exit functions static
arm64: entry: split SDEI entry
arm64: entry: split bad stack entry
arm64: entry: fold el1_inv() into el1h_64_sync_handler()
arm64: entry: handle all vectors with C
arm64: entry: template the entry asm functions
arm64: entry: improve bad_mode()
arm64: entry: move bad_mode() to entry-common.c
arm64: entry: consolidate EL1 exception returns
arm64: entry: organise entry vectors consistently
arm64: entry: organise entry handlers consistently
arm64: entry: convert IRQ+FIQ handlers to C
arm64: entry: add a call_on_irq_stack helper
arm64: entry: move NMI preempt logic to C
arm64: entry: move arm64_preempt_schedule_irq to entry-common.c
arm64: entry: convert SError handlers to C
arm64: entry: unmask IRQ+FIQ after EL0 handling
arm64: remove redundant local_daif_mask() in bad_mode()
Update booting requirements for the FEAT_HCX feature, added to v8.7 of
the architecture.
* for-next/docs:
arm64: Document requirement for access to FEAT_HCX
Fix resume from idle when pNMI is being used.
* for-next/cpuidle:
arm64: suspend: Use cpuidle context helpers in cpu_suspend()
PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter()
arm64: Convert cpu_do_idle() to using cpuidle context helpers
arm64: Add cpuidle context save/restore helpers
Additional CPU sanity checks for MTE and preparatory changes for systems
where not all of the CPUs support 32-bit EL0.
* for-next/cpufeature:
arm64: Restrict undef hook for cpufeature registers
arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs
KVM: arm64: Kill 32-bit vCPUs on systems with mismatched EL0 support
arm64: Allow mismatched 32-bit EL0 support
arm64: cpuinfo: Split AArch32 registers out into a separate struct
arm64: Check if GMID_EL1.BS is the same on all CPUs
arm64: Change the cpuinfo_arm64 member type for some sysregs to u64
Big cleanup of our cache maintenance routines, which were confusingly
named and inconsistent in their implementations.
* for-next/caches:
arm64: Rename arm64-internal cache maintenance functions
arm64: Fix cache maintenance function comments
arm64: sync_icache_aliases to take end parameter instead of size
arm64: __clean_dcache_area_pou to take end parameter instead of size
arm64: __clean_dcache_area_pop to take end parameter instead of size
arm64: __clean_dcache_area_poc to take end parameter instead of size
arm64: __flush_dcache_area to take end parameter instead of size
arm64: dcache_by_line_op to take end parameter instead of size
arm64: __inval_dcache_area to take end parameter instead of size
arm64: Fix comments to refer to correct function __flush_icache_range
arm64: Move documentation of dcache_by_line_op
arm64: assembler: remove user_alt
arm64: Downgrade flush_icache_range to invalidate
arm64: Do not enable uaccess for invalidate_icache_range
arm64: Do not enable uaccess for flush_icache_range
arm64: Apply errata to swsusp_arch_suspend_exit
arm64: assembler: add conditional cache fixups
arm64: assembler: replace `kaddr` with `addr`
Relax frame record alignment requirements to facilitate 8-byte alignment
with KASAN and Clang.
* for-next/stacktrace:
arm64: stacktrace: Relax frame record alignment requirement to 8 bytes
arm64: Change the on_*stack functions to take a size argument
arm64: Implement stack trace termination record
The TTL field indicates the level of page table walk holding the *leaf*
entry for the address being invalidated. But currently, the TTL field
may be set to an incorrent value in the following stack:
pte_free_tlb
__pte_free_tlb
tlb_remove_table
tlb_table_invalidate
tlb_flush_mmu_tlbonly
tlb_flush
In this case, we just want to flush a PTE page, but the tlb->cleared_pmds
is set and we get tlb_level = 2 in the tlb_get_level() function. This may
cause some unexpected problems.
This patch set the TTL field to 0 if tlb->freed_tables is set. The
tlb->freed_tables indicates page table pages are freed, not the leaf
entry.
Cc: <stable@vger.kernel.org> # 5.9.x
Fixes: c4ab2cbc1d ("arm64: tlb: Set the TTL field in flush_tlb_range")
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: ZhuRui <zhurui3@huawei.com>
Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
Link: https://lore.kernel.org/r/b80ead47-1f88-3a00-18e1-cacc22f54cc4@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit modifies the mask of the mrs_hook declared in
arch/arm64/kernel/cpufeatures.c which emulates only feature register
access. This is necessary because this hook's mask was too large and
thus masking any mrs instruction, even if not related to the emulated
registers which made the pmu emulation inefficient.
Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210517180256.2881891-1-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
ARM64_SWAPPER_USES_SECTION_MAPS implies that a PMD level huge page mappings
are used for swapper, idmap and vmemmap. Lets make it PMD explicit removing
any possible confusion with generic memory sections and also bit generic as
it's applicable for idmap and vmemmap mappings as well. Hence rename it as
ARM64_KERNEL_USES_PMD_MAPS instead.
Cc: Catalin Marinas <catalin.marinas@arm.com>
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
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1623991622-24294-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the
build fails due to BUILD_BUG_ON() not being defined before its uss in
<asm/insn.h>.
The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h>
includes <asm/insn.h>, creating a circular include chain:
<linux/build_bug.h>
<linux/compiler.h>
<asm/rwonce.h>
<asm/alternative-macros.h>
<asm/insn.h>
<linux/build-bug.h>
... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the
BUILD_BUG* definitions have happened yet.
To avoid this, let's move AARCH64_INSN_SIZE into a header without any
dependencies, such that it can always be safely included. At the same
time, avoid including <asm/alternative.h> in <asm/insn.h>, which should
no longer be necessary (and doesn't make sense when insn.h is consumed
by userspace).
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210621080830.GA37068@C02TD0UTHF1T.local
Fixes: 3e00e39d9d ("arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>")
Signed-off-by: Will Deacon <will@kernel.org>
Use cpuidle context helpers to switch to using DAIF.IF instead
of PMR to mask interrupts, ensuring that we suspend with
interrupts being able to reach the CPU interface.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20210615111227.2454465-5-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The PSCI CPU suspend code isn't aware of the PMR vs DAIF game,
resulting in a system that locks up if entering CPU suspend
with GICv3 pNMI enabled.
To save the day, teach the suspend code about our new cpuidle
context helpers, which will do everything that's required just
like the usual WFI cpuidle code.
This fixes my Altra system, which would otherwise lock-up at
boot time when booted with irqchip.gicv3_pseudo_nmi=1.
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20210615111227.2454465-4-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Now that we have helpers that are aware of the pseudo-NMI
feature, introduce them to cpu_do_idle(). This allows for
some nice cleanup.
No functional change intended.
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210615111227.2454465-3-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
As we need to start doing some additional work on all idle
paths, let's introduce a set of macros that will perform
the work related to the GICv3 pseudo-NMI idle entry exit.
Stubs are introduced to 32bit ARM for compatibility.
As these helpers are currently unused, there is no functional
change.
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210615111227.2454465-2-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Up to here, the CPU boot mode can either be EL1 or EL2.
Correct the code comments a bit.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210518101405.1048860-5-aisheng.dong@nxp.com
Signed-off-by: Will Deacon <will@kernel.org>
x5 is not used in the following map_memory. Instead,
__pa(__idmap_text_start) is stored in x3 which is used later.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210518101405.1048860-4-aisheng.dong@nxp.com
Signed-off-by: Will Deacon <will@kernel.org>
'count - 1' is confusing and not comply with the real code running.
'count' actually represents the extra entries required, no need minus 1.
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210518101405.1048860-3-aisheng.dong@nxp.com
Signed-off-by: Will Deacon <will@kernel.org>
When using CONFIG_ARM64_SW_TTBR0_PAN, a task's thread_info::ttbr0 must be
the TTBR0_EL1 value used to run userspace. With 52-bit PAs, the PA must be
packed into the TTBR using phys_to_ttbr(), but we forget to do this in some
of the SW PAN code. Thus, if the value is installed into TTBR0_EL1 (as may
happen in the uaccess routines), this could result in UNPREDICTABLE
behaviour.
Since hardware with 52-bit PA support almost certainly has HW PAN, which
will be used in preference, this shouldn't be a practical issue, but let's
fix this for consistency.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Fixes: 529c4b05a3 ("arm64: handle 52-bit addresses in TTBR")
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1623749578-11231-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, the lower bits of fault address is cleared before it's
passed to handle_mm_fault(). It's unnecessary since generic code
does same thing since the commit 1a29d85eb0 ("mm: use vmf->address
instead of of vmf->virtual_address").
This passes the original fault address to handle_mm_fault() in case
the generic code needs to know the exact fault address.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20210614122701.100515-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
SECTION_[SHIFT|SIZE|MASK] are essentially PMD_[SHIFT|SIZE|MASK]. But these
create confusion being similar to generic sparsemem memory sections, which
are derived from SECTION_SIZE_BITS. Section references have always implied
PMD level block mapping. Instead just use all PMD level macros which would
make it explicit and also remove confusion with sparsmem memory sections.
Cc: Catalin Marinas <catalin.marinas@arm.com>
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
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1623658706-7182-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Scheduling a 32-bit application on a 64-bit-only CPU is a bad idea.
Ensure that 32-bit applications always take the slow-path when returning
to userspace on a system with mismatched support at EL0, so that we can
avoid trying to run on a 64-bit-only CPU and force a SIGKILL instead.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210608180313.11502-5-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
If a vCPU is caught running 32-bit code on a system with mismatched
support at EL0, then we should kill it.
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210608180313.11502-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
When confronted with a mixture of CPUs, some of which support 32-bit
applications and others which don't, we quite sensibly treat the system
as 64-bit only for userspace and prevent execve() of 32-bit binaries.
Unfortunately, some crazy folks have decided to build systems like this
with the intention of running 32-bit applications, so relax our
sanitisation logic to continue to advertise 32-bit support to userspace
on these systems and track the real 32-bit capable cores in a cpumask
instead. For now, the default behaviour remains but will be tied to
a command-line option in a later patch.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210608180313.11502-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In preparation for late initialisation of the "sanitised" AArch32 register
state, move the AArch32 registers out of 'struct cpuinfo' and into their
own struct definition.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210608180313.11502-2-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
For histroical reasons, we define AARCH64_INSN_SIZE in
<asm/alternative-macros.h>, but it would make more sense to do so in
<asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary
include directives for this.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210609102301.17332-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, <asm/insn.h> includes <asm/patching.h>. We intend that
<asm/insn.h> will be usable from userspace, so it doesn't make sense to
include headers for kernel-only features such as the patching routines,
and we'd intended to restrict <asm/insn.h> to instruction encoding
details.
Let's decouple the patching code from <asm/insn.h>, and explicitly
include <asm/patching.h> where it is needed. Since <asm/patching.h>
isn't included from assembly, we can drop the __ASSEMBLY__ guards.
At the same time, sort the kprobes includes so that it's easier to see
what is and isn't incldued.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210609102301.17332-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
It would be helpful if mem_abort_decode() could decode the DFSC/IFSC, as
this can make it easier to identify common bugs (e.g. accesses which
trigger alignment faults) without having to manually decode the xFSC
value.
Decode the xFSC in mem_abort_decode().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210608123742.11921-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
GDB produces the following warning when debugging kernels built with
CONFIG_RELR:
BFD: /android0/linux-next/vmlinux: unknown type [0x13] section `.relr.dyn'
when loading a kernel built with CONFIG_RELR into GDB. It can also
prevent debugging symbols using such relocations.
Peter sugguests:
[That flag] means that lld will use dynamic tags and section type
numbers in the OS-specific range rather than the generic range. The
kernel itself doesn't care about these numbers; it determines the
location of the RELR section using symbols defined by a linker script.
Link: https://github.com/ClangBuiltLinux/linux/issues/1057
Suggested-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20210522012626.2811297-1-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
The low-level idle code in arch_cpu_idle() and its callees runs at a
time where where portions of the kernel environment aren't available.
For example, RCU may not be watching, and lockdep state may be
out-of-sync with the hardware. Due to this, it is not sound to
instrument this code.
We generally avoid instrumentation by marking the entry functions as
`noinstr`, but currently this doesn't inhibit KCOV instrumentation.
Prevent this by factoring these functions into a new idle.c so that we
can disable KCOV for the entire compilation unit, as is done for the
core idle code in kernel/sched/idle.c.
We'd like to keep instrumentation of the rest of process.c, and for the
existing code in cpuidle.c, so a new compilation unit is preferable. The
arch_cpu_idle_dead() function in process.c is a cpu hotplug function
that is safe to instrument, so it is left as-is in process.c.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-21-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
The code in entry-common.c runs at exception entry and return
boundaries, where portions of the kernel environment aren't available.
For example, RCU may not be watching, and lockdep state may be
out-of-sync with the hardware. Due to this, it is not sound to
instrument this code.
We generally avoid instrumentation by marking the entry functions as
`noinstr`, but currently this doesn't inhibit KCOV instrumentation.
Prevent this by disabling KCOV for the entire compilation unit.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-20-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Now that we only call arm64_enter_nmi() and arm64_exit_nmi() from within
entry-common.c, let's make these static to ensure this remains the case.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-19-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
We'd like to keep all the entry sequencing in entry-common.c, as this
will allow us to ensure this is consistent, and free from any unsound
instrumentation.
Currently __sdei_handler() performs the NMI entry/exit sequences in
sdei.c. Let's split the low-level entry sequence from the event
handling, moving the former to entry-common.c and keeping the latter in
sdei.c. The event handling function is renamed to do_sdei_event(),
matching the do_${FOO}() pattern used for other exception handlers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-18-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
We'd like to keep all the entry sequencing in entry-common.c, as this
will allow us to ensure this is consistent, and free from any unsound
instrumentation.
Currently handle_bad_stack() performs the NMI entry sequence in traps.c.
Let's split the low-level entry sequence from the reporting, moving the
former to entry-common.c and keeping the latter in traps.c. To make it
clear that reporting function never returns, it is renamed to
panic_bad_stack().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-17-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
An unexpected synchronous exception from EL1h could happen at any time,
and for robustness we should treat this as an NMI, making minimal
assumptions about the context the exception was taken from.
Currently el1_inv() assumes we can use enter_from_kernel_mode(), and
also assumes that we should inherit the original DAIF value. Neither of
these are desireable when we take an unexpected exception. Further,
after el1_inv() calls __panic_unhandled(), the remainder of the function
is unreachable, and therefore superfluous.
Let's address this and simplify things by having el1h_64_sync_handler()
call __panic_unhandled() directly, without any of the redundant logic.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reported-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-16-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
We have 16 architectural exception vectors, and depending on kernel
configuration we handle 8 or 12 of these with C code, with the remaining
8 or 4 of these handled as special cases in the entry assembly.
It would be nicer if the entry assembly were uniform for all exceptions,
and we deferred any specific handling of the exceptions to C code. This
way the entry assembly can be more easily templated without ifdeffery or
special cases, and it's easier to modify the handling of these cases in
future (e.g. to dump additional registers other context).
This patch reworks the entry code so that we always have a C handler for
every architectural exception vector, with the entry assembly being
completely uniform. We now have to handle exceptions from EL1t and EL1h,
and also have to handle exceptions from AArch32 even when the kernel is
built without CONFIG_COMPAT. To make this clear and to simplify
templating, we rename the top-level exception handlers with a consistent
naming scheme:
asm: <el+sp>_<regsize>_<type>
c: <el+sp>_<regsize>_<type>_handler
.. where:
<el+sp> is `el1t`, `el1h`, or `el0t`
<regsize> is `64` or `32`
<type> is `sync`, `irq`, `fiq`, or `error`
... e.g.
asm: el1h_64_sync
c: el1h_64_sync_handler
... with lower-level handlers simply using "el1" and "compat" as today.
For unexpected exceptions, this information is passed to
__panic_unhandled(), so it can report the specific vector an unexpected
exception was taken from, e.g.
| Unhandled 64-bit el1t sync exception
For vectors we never expect to enter legitimately, the C code is
generated using a macro to avoid code duplication. The exceptions are
handled via __panic_unhandled(), replacing bad_mode() (which is
removed).
The `kernel_ventry` and `entry_handler` assembly macros are updated to
handle the new naming scheme. In theory it should be possible to
generate the entry functions at the same time as the vectors using a
single table, but this will require reworking the linker script to split
the two into separate sections, so for now we have separate tables.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-15-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Now that the majority of the exception triage logic has been converted
to C, the entry assembly functions all have a uniform structure.
Let's generate them all with an assembly macro to reduce the amount of
code and to ensure they all remain in sync if we make changes in future.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-14-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Our use of bad_mode() has a few rough edges:
* AArch64 doesn't use the term "mode", and refers to "Execution
states", "Exception levels", and "Selected stack pointer".
* We log the exception type (SYNC/IRQ/FIQ/SError), but not the actual
"mode" (though this can be decoded from the SPSR value).
* We use bad_mode() as a second-level handler for unexpected synchronous
exceptions, where the "mode" is legitimate, but the specific exception
is not.
* We dump the ESR value, but call this "code", and so it's not clear to
all readers that this is the ESR.
... and all of this can be somewhat opaque to those who aren't extremely
familiar with the code.
Let's make this a bit clearer by having bad_mode() log "Unhandled
${TYPE} exception" rather than "Bad mode in ${TYPE} handler", using
"ESR" rather than "code", and having the final panic() log "Unhandled
exception" rather than "Bad mode".
In future we'd like to log the specific architectural vector rather than
just the type of exception, so we also split the core of bad_mode() out
into a helper called __panic_unhandled(), which takes the vector as a
string argument.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-13-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In subsequent patches we'll rework the way bad_mode() is called by
exception entry code. In preparation for this, let's move bad_mode()
itself into entry-common.c.
Let's also mark it as noinstr (e.g. to prevent it being kprobed), and
let's also make the `handler` array a local variable, as this is only
use by bad_mode(), and will be removed entirely in a subsequent patch.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-12-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Following the example of ret_to_user, let's consolidate all the EL1
return paths with a ret_to_kernel helper, rather than each entry point
having its own copy of the return code.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-11-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
