linux/arch/arm64/kernel
Mark Rutland d87a8e65b5 arm64: head.S: always initialize PSTATE
As with SCTLR_ELx and other control registers, some PSTATE bits are
UNKNOWN out-of-reset, and we may not be able to rely on hardware or
firmware to initialize them to our liking prior to entry to the kernel,
e.g. in the primary/secondary boot paths and return from idle/suspend.

It would be more robust (and easier to reason about) if we consistently
initialized PSTATE to a default value, as we do with control registers.
This will ensure that the kernel is not adversely affected by bits it is
not aware of, e.g. when support for a feature such as PAN/UAO is
disabled.

This patch ensures that PSTATE is consistently initialized at boot time
via an ERET. This is not intended to relax the existing requirements
(e.g. DAIF bits must still be set prior to entering the kernel). For
features detected dynamically (which may require system-wide support),
it is still necessary to subsequently modify PSTATE.

As ERET is not always a Context Synchronization Event, an ISB is placed
before each exception return to ensure updates to control registers have
taken effect. This handles the kernel being entered with SCTLR_ELx.EOS
clear (or any future control bits being in an UNKNOWN state).

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113124937.20574-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02 19:44:03 +00:00
..
probes arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line 2020-11-03 14:03:38 +00:00
vdso arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y 2020-11-09 21:49:34 +00:00
vdso32 arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y 2020-11-09 21:49:34 +00:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acpi_numa.c
acpi_parking_protocol.c
acpi.c arm64: permit ACPI core to map kernel memory used for table overrides 2020-09-30 22:27:51 +01:00
alternative.c arm64: alternatives: Remove READ_ONCE() usage during patch operation 2020-11-09 21:49:34 +00:00
armv8_deprecated.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
asm-offsets.c KVM: arm64: Make struct kvm_regs userspace-only 2020-07-07 09:28:38 +01:00
cacheinfo.c
cpu_errata.c arm64: Add workaround for Arm Cortex-A77 erratum 1508412 2020-10-29 12:56:01 +00:00
cpu_ops.c arm64: Introduce get_cpu_ops() helper function 2020-03-24 17:24:19 +00:00
cpu-reset.h
cpu-reset.S arm64/relocate_kernel: remove redundant code 2020-09-11 19:06:25 +01:00
cpufeature.c arm64: add C wrappers for SET_PSTATE_*() 2020-12-02 19:44:02 +00:00
cpuidle.c arm64: Introduce get_cpu_ops() helper function 2020-03-24 17:24:19 +00:00
cpuinfo.c arm64: avoid -Woverride-init warning 2020-10-28 13:38:36 +00:00
crash_core.c arm64/crash_core: Export TCR_EL1.T1SZ in vmcoreinfo 2020-07-02 17:56:49 +01:00
crash_dump.c
debug-monitors.c arm64: Improve diagnostics when trapping BRK with FAULT_BRK_IMM 2020-09-18 16:35:54 +01:00
efi-entry.S arm64 updates for 5.8 2020-06-01 15:18:27 -07:00
efi-header.S arm64: efi: increase EFI PE/COFF header padding to 64 KB 2020-10-28 14:02:03 +00:00
efi-rt-wrapper.S Merge branch 'for-next/scs' into for-next/core 2020-05-28 18:03:40 +01:00
efi.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
entry-common.c arm64: ptrauth: Introduce Armv8.3 pointer authentication enhancements 2020-09-14 12:07:02 +01:00
entry-fpsimd.S arm64/sve: Implement a helper to load SVE registers from FPSIMD state 2020-09-21 18:06:33 +01:00
entry-ftrace.S arm64: entry-ftrace.S: Update comment to indicate that x18 is live 2020-05-18 17:47:50 +01:00
entry.S arm64: Add workaround for Arm Cortex-A77 erratum 1508412 2020-10-29 12:56:01 +00:00
fpsimd.c arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks 2020-10-15 10:50:09 +01:00
ftrace.c arm64: ftrace: Change CONFIG_FTRACE_WITH_REGS to CONFIG_DYNAMIC_FTRACE_WITH_REGS 2020-06-08 15:44:59 +01:00
head.S arm64: head.S: always initialize PSTATE 2020-12-02 19:44:03 +00:00
hibernate-asm.S arm64: kernel: Convert to modern annotations for assembly functions 2020-05-04 12:46:03 +01:00
hibernate.c Merge branch 'for-next/mte' into for-next/core 2020-10-02 12:16:11 +01:00
hw_breakpoint.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hyp-stub.S arm64: kernel: Convert to modern annotations for assembly functions 2020-05-04 12:46:03 +01:00
image-vars.h KVM/arm64 fixes for 5.10, take #1 2020-10-30 13:25:09 -04:00
image.h arm64: get rid of TEXT_OFFSET 2020-09-07 15:00:52 +01:00
insn.c arm64: kprobe: disable probe of fault prone ptrauth instruction 2020-09-14 12:07:02 +01:00
io.c
irq.c arm64: Remove custom IRQ stat accounting 2020-09-17 16:37:28 +01:00
jump_label.c
kaslr.c arm64: kaslr: Use standard early random function 2020-08-07 09:10:11 -07:00
kexec_image.c arm64: kexec_file: try more regions if loading segments fails 2020-11-05 21:48:05 +00:00
kgdb.c arm64: kgdb: Fix single-step exception handling oops 2020-07-08 22:18:54 +01:00
kuser32.S
machine_kexec_file.c arm64: kexec_file: try more regions if loading segments fails 2020-11-05 21:48:05 +00:00
machine_kexec.c arm64: fix the flush_icache_range arguments in machine_kexec 2020-05-11 12:02:14 +01:00
Makefile Merge branch 'for-next/mte' into for-next/core 2020-10-02 12:16:11 +01:00
module-plts.c arm64/module: set trampoline section flags regardless of CONFIG_DYNAMIC_FTRACE 2020-09-02 08:35:33 +01:00
module.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mte.c arm64: mte: Enable swap of tagged pages 2020-09-04 12:46:07 +01:00
paravirt.c arm64: paravirt: Initialize steal time when cpu is online 2020-09-17 18:12:18 +01:00
pci.c PCI: Constify struct pci_ecam_ops 2020-05-01 16:28:59 +01:00
perf_callchain.c arm64: stacktrace: Make stack walk callback consistent with generic code 2020-09-18 14:24:16 +01:00
perf_event.c arm64: perf: Defer irq_work to IPI_IRQ_WORK 2020-09-28 19:00:17 +01:00
perf_regs.c arm64: fix some spelling mistakes in the comments by codespell 2020-09-07 14:18:50 +01:00
pointer_auth.c arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks 2020-10-15 10:50:09 +01:00
process.c arm64: ensure ERET from kthread is illegal 2020-12-02 19:44:02 +00:00
proton-pack.c arm64: add C wrappers for SET_PSTATE_*() 2020-12-02 19:44:02 +00:00
psci.c arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill() 2019-10-25 16:29:11 +01:00
ptrace.c arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset 2020-09-04 12:46:07 +01:00
reloc_test_core.c
reloc_test_syms.S arm64: kernel: Convert to modern annotations for assembly functions 2020-05-04 12:46:03 +01:00
relocate_kernel.S arm64/relocate_kernel: remove redundant code 2020-09-11 19:06:25 +01:00
return_address.c arm64: stacktrace: Make stack walk callback consistent with generic code 2020-09-18 14:24:16 +01:00
scs.c scs: Move DEFINE_SCS macro into core code 2020-05-18 17:47:48 +01:00
sdei.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
setup.c memblock: use separate iterators for memory and reserved regions 2020-10-13 18:38:35 -07:00
signal32.c arm64: compat: Always use sigpage for sigreturn trampoline 2020-06-23 14:56:24 +01:00
signal.c tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume() 2020-10-17 15:04:36 -06:00
sigreturn32.S
sleep.S arm64: head.S: rename el2_setup -> init_kernel_el 2020-12-02 19:44:03 +00:00
smccc-call.S arm64/kernel: Remove needless Call Frame Information annotations 2020-09-01 09:50:36 +02:00
smp_spin_table.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
smp.c arm64/smp: Move rcu_cpu_starting() earlier 2020-10-30 08:13:18 +00:00
stacktrace.c arm64: Move console stack display code to stacktrace.c 2020-09-21 19:43:03 +01:00
suspend.c Merge branch 'for-next/mte' into for-next/core 2020-10-02 12:16:11 +01:00
sys32.c
sys_compat.c arm64: Silence clang warning on mismatched value/register sizes 2019-10-28 09:13:21 +00:00
sys.c
syscall.c arm64: mte: Handle synchronous and asynchronous tag check faults 2020-09-04 12:46:06 +01:00
time.c arm64: time: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-02-12 17:26:38 +00:00
topology.c Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
trace-events-emulation.h
traps.c Merge branches 'for-next/acpi', 'for-next/boot', 'for-next/bpf', 'for-next/cpuinfo', 'for-next/fpsimd', 'for-next/misc', 'for-next/mm', 'for-next/pci', 'for-next/perf', 'for-next/ptrauth', 'for-next/sdei', 'for-next/selftests', 'for-next/stacktrace', 'for-next/svm', 'for-next/topology', 'for-next/tpyos' and 'for-next/vdso' into for-next/core 2020-10-02 12:01:41 +01:00
vdso.c arm64: vdso: Fix unusual formatting in *setup_additional_pages() 2020-09-01 13:37:57 +01:00
vmlinux.lds.S arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y 2020-11-09 21:49:34 +00:00