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2021-06-24Merge branch 'for-next/kasan' into for-next/coreWill Deacon6-2/+107
Optimise out-of-line KASAN checking when using software tagging. * for-next/kasan: kasan: arm64: support specialized outlined tag mismatch checks
2021-06-24Merge branch 'for-next/insn' into for-next/coreWill Deacon17-265/+358
Refactoring of our instruction decoding routines and addition of some missing encodings. * for-next/insn: arm64: insn: avoid circular include dependency arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h> arm64: insn: decouple patching from insn code arm64: insn: Add load/store decoding helpers arm64: insn: Add some opcodes to instruction decoder arm64: insn: Add barrier encodings arm64: insn: Add SVE instruction class arm64: Move instruction encoder/decoder under lib/ arm64: Move aarch32 condition check functions arm64: Move patching utilities out of instruction encoding/decoding
2021-06-24Merge branch 'for-next/entry' into for-next/coreWill Deacon11-438/+417
The never-ending entry.S refactoring continues, putting us in a much better place wrt compiler instrumentation whilst moving more of the code into C. * for-next/entry: arm64: idle: don't instrument idle code with KCOV arm64: entry: don't instrument entry code with KCOV arm64: entry: make NMI entry/exit functions static arm64: entry: split SDEI entry arm64: entry: split bad stack entry arm64: entry: fold el1_inv() into el1h_64_sync_handler() arm64: entry: handle all vectors with C arm64: entry: template the entry asm functions arm64: entry: improve bad_mode() arm64: entry: move bad_mode() to entry-common.c arm64: entry: consolidate EL1 exception returns arm64: entry: organise entry vectors consistently arm64: entry: organise entry handlers consistently arm64: entry: convert IRQ+FIQ handlers to C arm64: entry: add a call_on_irq_stack helper arm64: entry: move NMI preempt logic to C arm64: entry: move arm64_preempt_schedule_irq to entry-common.c arm64: entry: convert SError handlers to C arm64: entry: unmask IRQ+FIQ after EL0 handling arm64: remove redundant local_daif_mask() in bad_mode()
2021-06-24Merge branch 'for-next/docs' into for-next/coreWill Deacon1-0/+6
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
2021-06-24Merge branch 'for-next/cpuidle' into for-next/coreWill Deacon5-35/+67
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
2021-06-24Merge branch 'for-next/cpufeature' into for-next/coreWill Deacon8-98/+288
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
2021-06-24Merge branch 'for-next/cortex-strings' into for-next/coreWill Deacon10-967/+915
Update our kernel string routines to the latest Cortex Strings implementation. * for-next/cortex-strings: arm64: update string routine copyrights and URLs arm64: Rewrite __arch_clear_user() arm64: Better optimised memchr() arm64: Import latest memcpy()/memmove() implementation arm64: Add assembly annotations for weak-PI-alias madness arm64: Import latest version of Cortex Strings' strncmp arm64: Import updated version of Cortex Strings' strlen arm64: Import latest version of Cortex Strings' strcmp arm64: Import latest version of Cortex Strings' memcmp
2021-06-24Merge branch 'for-next/caches' into for-next/coreWill Deacon27-218/+276
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`
2021-06-24Merge branch 'for-next/build' into for-next/coreWill Deacon2-2/+3
Tweak linker flags so that GDB can understand vmlinux when using RELR relocations. * for-next/build: Makefile: fix GDB warning with CONFIG_RELR
2021-06-24Merge branch 'for-next/boot' into for-next/coreWill Deacon9-58/+51
Boot path cleanups to enable early initialisation of per-cpu operations needed by KCSAN. * for-next/boot: arm64: scs: Drop unused 'tmp' argument to scs_{load, save} asm macros arm64: smp: initialize cpu offset earlier arm64: smp: unify task and sp setup arm64: smp: remove stack from secondary_data arm64: smp: remove pointless secondary_data maintenance arm64: assembler: add set_this_cpu_offset
2021-06-24Merge branch 'for-next/stacktrace' into for-next/coreWill Deacon10-51/+70
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
2021-06-22arm64: Restrict undef hook for cpufeature registersRaphael Gault1-2/+2
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>
2021-06-21arm64: insn: avoid circular include dependencyMark Rutland3-5/+11
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: 3e00e39d9dad ("arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>") Signed-off-by: Will Deacon <will@kernel.org>
2021-06-17arm64: suspend: Use cpuidle context helpers in cpu_suspend()Marc Zyngier1-1/+11
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>
2021-06-17PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter()Marc Zyngier1-2/+7
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>
2021-06-17arm64: Convert cpu_do_idle() to using cpuidle context helpersMarc Zyngier1-32/+9
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>
2021-06-17arm64: Add cpuidle context save/restore helpersMarc Zyngier2-0/+40
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>
2021-06-11arm64: Kill 32-bit applications scheduled on 64-bit-only CPUsWill Deacon2-1/+44
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>
2021-06-11KVM: arm64: Kill 32-bit vCPUs on systems with mismatched EL0 supportWill Deacon1-1/+10
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>
2021-06-11arm64: Allow mismatched 32-bit EL0 supportWill Deacon3-15/+110
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>
2021-06-11arm64: cpuinfo: Split AArch32 registers out into a separate structWill Deacon3-81/+92
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>
2021-06-11arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>Mark Rutland7-3/+9
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>
2021-06-11arm64: insn: decouple patching from insn codeMark Rutland8-11/+15
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>
2021-06-08Makefile: fix GDB warning with CONFIG_RELRNick Desaulniers2-2/+3
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>
2021-06-07arm64: idle: don't instrument idle code with KCOVMark Rutland3-58/+71
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>
2021-06-07arm64: entry: don't instrument entry code with KCOVMark Rutland1-0/+5
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>
2021-06-07arm64: entry: make NMI entry/exit functions staticMark Rutland2-4/+2
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>
2021-06-07arm64: entry: split SDEI entryMark Rutland3-45/+43
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>
2021-06-07arm64: entry: split bad stack entryMark Rutland3-5/+16
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>
2021-06-07arm64: entry: fold el1_inv() into el1h_64_sync_handler()Mark Rutland1-10/+1
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>
2021-06-07arm64: entry: handle all vectors with CMark Rutland4-138/+93
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>
2021-06-07arm64: entry: template the entry asm functionsMark Rutland1-86/+27
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>
2021-06-07arm64: entry: improve bad_mode()Mark Rutland1-15/+16
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>
2021-06-07arm64: entry: move bad_mode() to entry-common.cMark Rutland2-25/+27
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>
2021-06-07arm64: entry: consolidate EL1 exception returnsMark Rutland1-4/+8
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>
2021-06-07arm64: entry: organise entry vectors consistentlyMark Rutland1-21/+21
In subsequent patches we'll rename the entry handlers based on their original EL, register width, and exception class. To do so, we need to make all 3 mandatory arguments to the `kernel_ventry` macro, and distinguish EL1h from EL1t. In preparation for this, let's make the current set of arguments mandatory, and move the `regsize` column before the branch label suffix, making the vectors easier to read column-wise. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> 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/20210607094624.34689-10-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: organise entry handlers consistentlyMark Rutland1-42/+36
In entry.S we have two comments which distinguish EL0 and EL1 exception handlers, but the code isn't actually laid out to match, and there are a few other inconsistencies that would be good to clear up. This patch organizes the entry handers consistently: * The handlers are laid out in order of the vectors, to make them easier to navigate. * The inconsistently-applied alignment is removed * The handlers are consistently marked with SYM_CODE_START_LOCAL() rather than SYM_CODE_START_LOCAL_NOALIGN(), giving them the same default alignment as other assembly code snippets. 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/20210607094624.34689-9-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: convert IRQ+FIQ handlers to CMark Rutland5-108/+110
For various reasons we'd like to convert the bulk of arm64's exception triage logic to C. As a step towards that, this patch converts the EL1 and EL0 IRQ+FIQ triage logic to C. Separate C functions are added for the native and compat cases so that in subsequent patches we can handle native/compat differences in C. Since the triage functions can now call arm64_apply_bp_hardening() directly, the do_el0_irq_bp_hardening() wrapper function is removed. Since the user_exit_irqoff macro is now unused, it is removed. The user_enter_irqoff macro is still used by the ret_to_user code, and cannot be removed at this time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210607094624.34689-8-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: add a call_on_irq_stack helperMark Rutland2-0/+38
When handling IRQ/FIQ exceptions the entry assembly may transition from a task's stack to a CPU's IRQ stack (and IRQ shadow call stack). In subsequent patches we want to migrate the IRQ/FIQ triage logic to C, and as we want to perform some actions on the task stack (e.g. EL1 preemption), we need to switch stacks within the C handler. So that we can do so, this patch adds a helper to call a function on a CPU's IRQ stack (and shadow stack as appropriate). Subsequent patches will make use of the new helper function. 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/20210607094624.34689-7-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: move NMI preempt logic to CMark Rutland2-11/+10
Currently portions of our preempt logic are written in C while other parts are written in assembly. Let's clean this up a little bit by moving the NMI preempt checks to C. For now, the preempt count (and need_resched) checking is left in assembly, and will be converted with the body of the IRQ handler in subsequent patches. Other than the increased lockdep coverage 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/20210607094624.34689-6-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: move arm64_preempt_schedule_irq to entry-common.cMark Rutland2-17/+20
Subsequent patches will pull more of the IRQ entry handling into C. To keep this in one place, let's move arm64_preempt_schedule_irq() into entry-common.c along with the other entry management functions. We no longer need to include <linux/lockdep.h> in process.c, so the include directive is removed. There should be no functional change as a result of this patch. Reviewed-by Joey Gouly <joey.gouly@arm.com> 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/20210607094624.34689-5-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: convert SError handlers to CMark Rutland4-16/+42
For various reasons we'd like to convert the bulk of arm64's exception triage logic to C. As a step towards that, this patch converts the EL1 and EL0 SError triage logic to C. Separate C functions are added for the native and compat cases so that in subsequent patches we can handle native/compat differences in C. 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/20210607094624.34689-4-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: entry: unmask IRQ+FIQ after EL0 handlingMark Rutland2-2/+2
For non-fatal exceptions taken from EL0, we expect that at some point during exception handling it is possible to return to a regular process context with all exceptions unmasked (e.g. as we do in do_notify_resume()), and we generally aim to unmask exceptions wherever possible. While handling SError and debug exceptions from EL0, we need to leave some exceptions masked during handling. Handling SError requires us to mask SError (which also requires masking IRQ+FIQ), and handing debug exceptions requires us to mask debug (which also requires masking SError+IRQ+FIQ). Once do_serror() or do_debug_exception() has returned, we no longer need to mask exceptions, and can unmask them all, which is what we did prior to commit: 9034f6251572a474 ("arm64: Do not enable IRQs for ct_user_exit") ... where we had to mask IRQs as for context_tracking_user_exit() expected IRQs to be masked. Since then, we realised that our context tracking wasn't entirely correct, and reworked the entry code to fix this. As of commit: 23529049c6842382 ("arm64: entry: fix non-NMI user<->kernel transitions") ... we replaced the call to context_tracking_user_exit() with a call to user_exit_irqoff() as part of enter_from_user_mode(), which occurs earlier, before we run the body of the handler and unmask exceptions in DAIF. When we return to userspace, we go via ret_to_user(), which masks exceptions in DAIF prior to calling user_enter_irqoff() as part of exit_to_user_mode(). Thus, there's no longer a reason to leave IRQs or FIQs masked at the end of the EL0 debug or error handlers, as neither the user exit context tracking nor the user entry context tracking requires this. Let's bring these into line with other EL0 exception handlers and ensure that IRQ and FIQ are unmasked in DAIF at some point during the handler. 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/20210607094624.34689-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07arm64: remove redundant local_daif_mask() in bad_mode()Mark Rutland1-1/+0
Upon taking an exception, the CPU sets all the DAIF bits. We never clear any of these bits prior to calling bad_mode(), and bad_mode() itself never clears any of these bits, so there's no need to call local_daif_mask(). This patch removes the redundant call. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> 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/20210607094624.34689-2-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-02arm64: update string routine copyrights and URLsMark Rutland5-11/+11
To make future archaeology easier, let's have the string routine comment blocks encode the specific upstream commit ID they were imported from. These are the same commit IDs as listed in the commits importing the code, expanded to 16 characters. Note that the routines have different commit IDs, each reprsenting the latest upstream commit which changed the particular routine. At the same time, let's consistently include 2021 in the copyright dates. 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/20210602151358.35571-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: Rewrite __arch_clear_user()Robin Murphy1-20/+27
Now that we're always using STTR variants rather than abstracting two different addressing modes, the user_ldst macro here is frankly more obfuscating than helpful. Rewrite __arch_clear_user() with regular USER() annotations so that it's clearer what's going on, and take the opportunity to minimise the branchiness in the most common paths, while also allowing the exception fixup to return an accurate result. Apparently some folks examine large reads from /dev/zero closely enough to notice the loop being hot, so align it per the other critical loops (presumably around a typical instruction fetch granularity). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/1cbd78b12c076a8ad4656a345811cfb9425df0b3.1622128527.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: Better optimised memchr()Robin Murphy1-12/+53
Although we implement our own assembly version of memchr(), it turns out to be barely any better than what GCC can generate for the generic C version (and would go wrong if the size_t argument were ever large enough to be interpreted as negative). Unfortunately we can't import the tuned implementation from the Arm optimized-routines library, since that has some Advanced SIMD parts which are not really viable for general kernel library code. What we can do, however, is pep things up with some relatively straightforward word-at-a-time logic for larger calls. Adding some timing to optimized-routines' memchr() test for a simple benchmark, overall this version comes in around half as fast as the SIMD code, but still nearly 4x faster than our existing implementation. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/58471b42f9287e039dafa9e5e7035077152438fd.1622128527.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: Import latest memcpy()/memmove() implementationRobin Murphy3-233/+230
Import the latest implementation of memcpy(), based on the upstream code of string/aarch64/memcpy.S at commit afd6244 from https://github.com/ARM-software/optimized-routines, and subsuming memmove() in the process. Note that for simplicity Arm have chosen to contribute this code to Linux under GPLv2 rather than the original MIT license. Note also that the needs of the usercopy routines vs. regular memcpy() have now diverged so far that we abandon the shared template idea and the damage which that incurred to the tuning of LDP/STP loops. We'll be back to tackle those routines separately in future. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/3c953af43506581b2422f61952261e76949ba711.1622128527.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: Add assembly annotations for weak-PI-alias madnessRobin Murphy1-0/+8
Add yet another set of assembly symbol annotations, this time for the borderline-absurd situation of a function aliasing to a weak symbol which itself also wants a position-independent alias. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/75545b3c4129b20b887474bb58a9cf302bf2132b.1622128527.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: Import latest version of Cortex Strings' strncmpSam Tebbs1-222/+184
Import the latest version of the former Cortex Strings - now Arm Optimized Routines - strncmp function based on the upstream code of string/aarch64/strncmp.S at commit e823e3a from https://github.com/ARM-software/optimized-routines Note that for simplicity Arm have chosen to contribute this code to Linux under GPLv2 rather than the original MIT license. Signed-off-by: Sam Tebbs <sam.tebbs@arm.com> [ rm: update attribution and commit message ] Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/26110bee02ad360596c9a7536af7eaaf6890d0e8.1622128527.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>